List of vacuum tubes

This is a list of vacuum tubes or thermionic valves, and low-pressure gas-filled tubes, or discharge tubes. Before the advent of semiconductor devices, thousands of tube types were used in consumer electronics – most of them to amplify AF, IF and RF signals in TV sets and AM/FM radios; some are still in production today for valve audio amplifiers – but many industrial, military or otherwise professional tubes were also produced, many of these highly specialized; only a few types of those are still used today, mainly in high-power RF/microwave (VLF, LF/LW, MF/MW, HF/SW, VHF, UHF, SHF, EHF, THF) applications.

Heater or filament ratings

Vacuum tubes fall into three mainly non-interchangeable categories regarding their heater or filament voltage/current,^[1] though some tubes' heaters run at both a standardized voltage and current, e.g., 6.3 V at 300 mA or 13 V at 200 mA, making them suitable for either series or parallel operation.

1. Battery types, ubiquitous before the 1930s but since then only for mobile/portable equipment with a low-power filament operated usually from 1 to 2 V; all filaments in a design are rated at the same voltage and are connected in parallel. Early sets had the heaters connected to the battery via a variable filament resistor (rheostat), later via an automatic ballast tube, to compensate for the decreasing battery voltage.
   Battery types are usually directly heated to save heating power (therefore requiring a DC current), except if the (due to the voltage gradient along the filament) poorly defined cathode potential impedes the function of the device, as is the case e.g. with AM detector diodes with filament voltages of 1.9 V or more; in such cases, indirect heaters were employed and marketed as equipotential or unipotential cathode at the time.
   • 1.25 V for one NiCd cell (examples)
   • 1.4 V for one Leclanché cell, later for one dry cell (examples)
   • 1.7 to 1.9 V for one lead-acid cell with a variable filament resistor (German: Heizregler – examples)
   • 2 V for one lead-acid cell^{[2]:12ff[3]:8[4]:5} (examples)
   • 4 V for two lead-acid cells, a 1910s UK standard which e.g. the Fleming valves, the British R, and the French TM tubes ran on.^[1] Major manufacturers kept a directly heated 4VDC product line throughout the 1930s^{[2]:14[3]:9[4]:8f.} (examples)
   • 5 V originally for a three-cell lead-acid battery with a rheostat (examples); later became a standard for indirectly AC-heated full-wave rectifiers (examples)
   • 6.3 V, indirectly heated, for four dry cells or for three lead-acid cells for use in 6-Volts car radios^[5] (examples)
   • 12.6 V, indirectly heated, for six lead-acid cells for 12-Volts car radios (examples)
2. Types for AC-only equipment with a mains transformer; all tube heaters are rated at the same voltage and fed in parallel from a transformer secondary winding; In the US, a 2.5 V_RMS standard was conceived in 1929; elsewhere, nominal heater voltages from 1920's lead-acid/"battery eliminator" era (multiples of 2 or 2.1V) were kept, 4V_RMS in the UK,^[1] but eventually the 6.3V and 12.6V car radio standards prevailed everywhere. Most are indirectly heated.
   • However, most RF power tubes are directly heated, so for the abovementioned reason, the heater voltage must be much smaller than the signal voltage on the grid and is therefore in the 1.1 to 25 V range, drawing up to hundreds of Amperes from a suitable heater transformer; some high-power RF tubes (such as RCA 893, 898 and Philips TAW12/35G, TBL15/125) have a 3-phase heater to reduce hum.
3. Types for equipment designed to run on either AC or DC mains power (ac/dc) with no mains transformer; they are always indirectly heated and all heaters are connected in series across the mains power supply, possibly with an additional barretter or power resistor chosen so that the sum of the heater and ballast voltages equals the mains voltage. All tubes must be rated at the same heater current such as 50, 100, 150, 200, 300, 450 or 600 mA, depending on mains voltage and device tube count, and have a comparable warm-up time.
   • A notable precursor was 1920's European 180mADC standard used in municipalities with a then-still commonplace DC mains system, which ruled out not only mains transformers, but also polarized (electrolytic) capacitors, as the sets had to tolerate accidental reverse-polarity feeding, making it notoriously difficult to filter out dynamo or rectifier howl.^[6] Compatible product lines include the Mullard x20 series,^[2]:19 the Mullard–Philips B-series, the Philips B20xx series,^[3]:7 the Telefunken REN(S)18xx series,^[7] some Loewe WG3x "integrated circuit" tubes, the Tungsram x18 series,^[4]:10 and the Valvo x18 series. Most of these tubes had 20- or 21-Volts heaters; suitable barretters were available.^[8]

The currents drawn by parallel-connected types, and the voltages across series-connected types, vary widely according to the tube's heating power requirements. Otherwise identical tubes were manufactured in several variants with different heater characteristics,^[9] but usually the same heater power, e.g. 6.3 V/300 mA and 12.6 V/150 mA; some tubes feature a center-tapped filament/heater, allowing for two voltage/current options by series or parallel wiring of their two heater sections. See, for example, the RCA Receiving Tube Manuals.

In half-indirectly heated tubes the cathode and one side of the filament share the same pin.

Tube bases and envelopes

Drawings below; relevant standards include:

• IEC 60067: "Dimensions of electronic tubes and valves" (1966; also published as BS 448-1:1981)^[10]
• JEDEC

Bases

• 

  H3A European 3-pin

• 

  A4A European 4-pin

• 

  O5A European 5-pin

• 

  B6H "Hexode" European (continental) 6-pin

• 

  C7H European (continental) 7-pin

• 

  M7A British 7-pin

• 

  B9H British 9-pin

• 

  U4A/UX4 American 4-pin

• 

  U6A/UX6 American 6-pin

• 

  P8A Transcontinental side-contact 8-pin

• 

  V5A Transcontinental side-contact 5-pin

• 

  Y8A German steel tube 8-pin

• 

  K8A [International] Octal ("IO"; IEC 67-I-5a) 8-pin

• 

  B8G Loctal (IEC 67-I-9a) 8-pin

• 

  B9G Loctal/Enneal (IEC 67-I-6a) 9-pin

• 

  B8A Rimlock (IEC 67-I-11a) 8-pin

• 

  B9D Magnoval/Neonoval (IEC 67-I-36a, JEDEC E9-23 - not B9E Novar) 9-pin

• 

  B9A Noval (IEC 67-I-12a, JEDEC E9-1) 9-pin

• 

  B7G Miniature 7-pin ("Small-button" or "Heptal"; IEC 67-I-10a, JEDEC E7-1)

• 

  B7A Septar (IEC 67-I-20a, JEDEC E7-2) 7-pin

• 

  B10B Decal (IEC 67-I-41a, JEDEC E10-61) 10-pin

• 

  B12A Duodecal (IEC 67-I-17a) 12-pin

• 

  B12C Duodecar (IEC 67-I-34a for T9 env. resp. 67-I-35a for T12 env., JEDEC E12-70 resp. E12-74 – Compactron) 12-pin

• 

  U4J Jumbo (IEC 67-I-23, JEDEC A4-29) 4-pin

• 

  B4D Superjumbo (IEC 67-I-28a, JEDEC A4-81) 4-pin

Media related to Vacuum tube bases at Wikimedia Commons

Envelopes

• 

  ST – Shouldered tube, this one with a top cap

• 

  GT – Glass tubular

• 

  All-glass miniature tube (mostly Heptal, Noval, Duodecar base)

• 

  Subminiature all-glass pigtailed (fly-leads in place of pins), low-frequency Pencil tubes

• 

  Acorn tube

• 

  Nuvistor

• 

  Steel tube^(de)

Numbering systems

North American systems

RMA system (1942)

The system assigned numbers with the base form "1A21", and is therefore also referred to as the "1A21 system".^[11]

First digit Filament/heater power rating:

• 1 – No filament/heater; cold cathode or solid state device
• 2 – Up to 10 W
• 3 – 10...20 W
• 4 – 20...50 W
• 5 – 50...100 W
• 6 – 100...200 W
• 7 – 200...500 W
• 8 – 500W...1 kW
• 9 – More than 1 kW

Next character: Function:

• A – Single element (ballast tube/barretter)
• B – Two-element device such as:

• Diode
• TR (Transmit/receive) cell, a cold-cathode water vapor discharge tube for use in radar systems, short-circuits the receiver input to protect it while the transmitter operates
• ATR (Anti-transmit/receive) cell, a cold-cathode water vapor discharge tube for use in radar systems, decouples the transmitter from the antenna while not operating, to prevent it from wasting received energy
• Spark gap

• C – Triode
• D – Tetrode
• E – Pentode or beam power tetrode
• F – Hexode
• G – Heptode
• H – Octode
• J – Magnetically controlled types, usually incorporating a resonator (essentially, magnetrons)
• K – Electrostatically controlled types, including a resonator (klystrons and inductive output tubes)
• L – Vacuum capacitors
• N – Crystal rectifiers (This designation lived on as the "N" in the EIA/JEDEC EIA-370 solid state device numbers standard, like 2N2222)
• P – Photosensitive types (phototubes, photomultipliers, camera tubes, image converters)
• Q – Resonant vacuum cavities
• R – Ignitrons and mercury arc rectifiers
• S – Vacuum switches
• T – Storage, radial beam, and deflection control tubes (no known examples assigned)
• V – Flashtubes
• W – Traveling-wave tube
• X – X-ray tube
• Y – Thermionic converter

The last 2 digits were sequentially assigned, beginning with 21 to avoid possible confusion with receiving tubes or CRT phosphor designations. Multiple section tubes (like the 3E29 or 8D21) are assigned a letter corresponding to ONE set of electrodes.

Examples:

• 1B23 – 20 kW, 400 to 1500 MHz Gas-filled, cold-cathode Transmit/Receive Tube (TR cell)
• 1B41 – Gas-filled, cold-cathode 9.5 kV, 450 A spark gap
• 1B45 – Gas-filled, cold-cathode 14 kV, 450 A spark gap
• 1B49 – Gas-filled, cold-cathode 12 kV, 450 A spark gap
• 1C21 – Gas-filled, 25 mA_avg, 100 mA_peak, triode thyratron
• 1D21 – Strobotron Gas-filled, 50 mA_avg, 5 A_peak, luminiscent tetrode thyratron for use as a stroboscope lamp
• 1N23 – Silicon point contact diode used in early radar mixers
• 1N34 – Germanium point contact diode, still in production^[12]
• 1P21 – 9-stage Photomultiplier, spectral S4 response, 11-pin base
• 1P25 – Infrared image converter used in World War II night vision "sniperscopes"
• 1P29 – Gas-filled phototube, spectral S3 response, 4-pin base
• 1P39 – Vacuum Phototube, spectral S4 response, 4-pin base
• 1S22 – 10 kV, 20 A Vacuum SPDT switch
• 2C21 – Dual transmitting triode, indirectly heated, 7-pin base plus a single top cap for one of the grids
• 2C22 – Transmitting triode, indirectly heated, Octal base plus dual top cap for grid and anode
• 2C36 – Rocket-type disk-seal UHF triode with an internal feedback circuit between cathode and anode, for use as UHF oscillator up to 1.75 GHz
• 2C37 – Rocket triode for use as SHF oscillator up to 3.3 GHz
• 2C39A – Oil can-type disk-seal UHF power triode with glass spacers up to 3 GHz, P_anode = 100 W

• 2C39B – 2C39A with ceramic spacers

• 2C40 – Lighthouse-type disk-seal UHF power triode for continuous operation, P_anode = 6.5 W at 3370 MHz
• 2C41 – Oil can UHF power triode for pulsed operation, 2200 W_peak at 3 GHz
• 2C42 – Lighthouse UHF power triode for pulsed operation, 1750 W_peak at 1050 MHz; improved 446
• 2C43 – Lighthouse UHF power triode, indirectly heated, up to 3.37 GHz, 6-pin base
• 2C46 – Lighthouse UHF power triode
• 2C51 – Dual shielded triode, indirectly heated, Noval base
• 2D21/EN91 (PL21, PL2D21, CV797) – 100 mA_avg, 500 mA_peak, 10 A_surge, Gas-filled, indirectly heated tetrode thyratron, negative starter voltage, miniature 7-pin base, for relay and grid-controlled rectifier service, used in jukeboxes and computer equipment
• 2E22 – 53 W Power pentode, 5-pin base with anode on top cap
• 2E26 – Popular amateur 5.3 W VHF beam power tetrode up to 175 MHz, Octal base
• 2E30 – 10 W Directly heated beam power tetrode with deflection screens available on separate pin, miniature 7-pin base
• 2E31 – Subminiature, directly heated, fully shielded sharp-cutoff RF/IF pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 2E32 – Similar to 2E31, all-glass elliptical cross-section body and flat 5-pin base with short pigtails
• 2E35 – 6 mW Subminiature directly heated power pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 2E36 – Similar to 2E35, all-glass elliptical cross-section body, flat 5-pin base, short pigtails
• 2E41 – Diode, pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 2E42 – Similar to 2E41, all-glass elliptical cross-section body, flat 5-pin base, short pigtails
• 2F21 – Indirectly heated hexode monoscope, Indian Head test pattern, 6-pin base with dual top caps for grid4 and anode
• 2G21 – Directly heated triode/heptode mixer, all-glass elliptical cross-section body, flat 7-pin base, short pigtails
• 2G41 – Triode/heptode mixer, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 2G42 – Similar to type 2G41, all-glass elliptical cross-section body, flat 5-pin base, short pigtails
• 2H21 – Phasitron, a magnetically controlled beam deflection phase modulator tube^[13] similar to the 5593, used in early FM broadcast transmitters^[14][15][16]
• 2J30 to 2J34 – 300 kW S-band Magnetrons
• 2J55 and 2J56 – 40 kW X-band Magnetrons for use as pulsed oscillator
• 2K25 – 25 mW 8.5 to 9.66 GHz Reflex Klystron
• 2K50 – 15 mW 23.5 to 24.5 GHz Reflex Klystron
• 2P23 – Early Image Orthicon video camera tube
• 3B28 – Xenon half-wave rectifier; ruggedized replacement for mercury-vapor type 866
• 3C22 – Disk-seal UHF power triode, P_anode = 125 W with forced-air cooling, 1.4 GHz
• 3C23 – 1.5 A_avg, 6 A_peak, Mercury-vapor triode thyratron, 4-pin base with anode top cap
• 3C45 – 45 mA_avg, 1.5 A_RMS, 35 A_peak, Half-indirectly heated hydrogen triode thyratron, 4-pin base with anode top cap
• 3D21 – Indirectly heated beam power tetrode, Octal base with anode top cap
• 3D22 – Gas-filled, 800 mA_avg, 8 A_peak, tetrode thyratron, 7-pin base
• 3E29 – Dual beam power tetrode used in radar equipment, Septar 7-pin base with dual anode top cap; a pulse rated variant of the earlier 829B
• 4B32 – 10 kV, 1.25 A_avg, 5 A_peak Xenon half-wave rectifier
• 4D21 (6155, Eimac 4-125A) – 125 W Glass VHF beam power tetrode
• 4E27 – 125 W Glass radial-beam power pentode
• 4J31 to 4J35 – 1 MW S-band Magnetrons
• 5B24 – Full-wave, mercury-vapor Tungar bulb, a low-voltage rectifier for charging 60-cell lead-acid batteries at 6 A; 2.5 V, 24 A heater^[17]
• 5C22 – Half-indirectly heated, hydrogen triode thyratron for radar modulators
• 5D22 (6156, Eimac 4-250A) – 250 W, 110 MHz Glass beam power tetrode
• 5J26 – 500 kW, 1.22 to 1.35 GHz S-band Magnetrons
• 6C21 – Triode radar modulator for "hard tube" pulsers
• 7C23 – 120 kW Power triode for high voltage pulse operation
• 8D21 – Internally water-cooled dual tetrode used in early VHF TV transmitters
• 9C21 – 100 kW Water-cooled power triode, directly heated, 4-pin base with dual top caps for grid and anode

RETMA receiving tubes system (1953)

RETMA is the acronym for the Radio Electronic Television Manufacturers Association formed in 1953, originally the RMA, later RTMA, then EIA (Electronic Industries Association, since 1997 Electronic Industries Alliance) – however the standard itself had already been in use for a long time before 1953; for example, the 6L6 was introduced in July 1936.

• The first character group is always a number, consisting of one to three numerals, and represents the heater voltage rounded to the nearest whole number; 0 indicates a cold-cathode tube. Tubes with a center-tapped filament/heater are designated the higher voltage option. Exceptions include 2.0 Volt filament tubes (such as 1C7-G and 1F4) and series heater tubes where the rounding was less exact (such as the 5.9-Volt 5X9 and the 46-Volt 50Y7GT).^[11]
• These numerals are followed by one or two letters assigned to the devices in some sort of semi-chronological order of development and introduction to the marketplace. Combinations like AB, AC, AD, AE... were used, avoiding same-letter repetitions, after the single letters were exhausted. Wherever possible, the 12V equivalent of a 6V tube had the same letters, just 12 instead of 6.
• and then another single numeral that represents the number of active elements in the tube (including any internal shield plus the heater in indirectly heated tubes – electrodes connected together internally count as one). For example, a 1 means a ballast tube/resistor or a barretter, a 7 could mean a heptode (pentagrid converter) such as the 12SA7-GT, or a pentode with two diodes such as the 7E7, or with one diode and a shield pin such as the 12SF7, or triode with two diodes and a shield pin such as the 6SR7, or a twin-input triode such as the 6AE7-GT, or a dual triode such as the 6SN7-GT. Exceptions include the 35L6-GT (with 5 elements, but named for consistency with the 6L6/6L6-G where pin 1 may or may not be connected to a shield, making the sixth element).
• Sometimes a string of up to three Roman letters can be suffixed to the overall number; these generally distinguish various revisions and improvements to the original model or different bulb shapes; the use is somewhat arbitrary:

• A, B, C – Improved backward compatible versions
• E – Export version
• G – Glass bulb, ST-12 to ST-16 size
• GT – Glass bulb, T-9 size (actually 'Glass Tubular')
• GT/G – Glass bulb, T-9 size interchangeable with G and GT types
• L – Loctal
• LM – Loctal-metal
• LT – Locking base
• M – Metal envelope
• MG – Metal-glass
• ML – Metal-Loctal
• S – Metal particles spray-shielded envelope
• W – Ruggedised, or military grade
• WA, WB – Improved, backward compatible military/industrial variants
• X – Low loss ceramic base for RF use
• Y – Low loss mica-filled phenolic resin ("Micanol")^[18] base for RF use

• Lastly, manufacturers may decide to combine two type numbers into a single name, which their one device can replace, such as: 6DX8/ECL84 (6DX8 and ECL84 being identical devices under different naming schemes) or 6BC5/6CE5 (sufficiently identical devices within the RETMA naming system) and even 3A3/3B2, or 6AC5-GT/6AC5-G (where the single type number, 6AC5-GT/6AC5-G, supersedes both the 6AC5-G and the 6AC5-GT).

Ballast tubes/resistors and barretters were designated the following subset:

• <Voltage>A1 to <Voltage>Z1 – No filament tap, no jumper
• <Voltage>A2 – Filament tap for two pilot lights
• <Voltage>B2 – Filament tap for one pilot light
• 1D2, 1E2 – With a jumper to unpower the device when the ballast is pulled from its socket

Often, but not always, vacuum tube designations that differed only in their initial numerals would be identical except for heater characteristics. Exceptions include: the 12BR7 and 9BR7 are unrelated to the 6BR7; the 4BL8/XCF80 is the 4.6 Volt/600 mA series heater version of the 6BL8/ECF80, but the 450mA series heater version is the 6LN8/LCF80 rather than 6BL8. The change of letters was required as the nominal heater voltage for both types is '6' because the 6LN8 is 6.0 volts as opposed to the 6BL8 which is 6.3 volts.

For examples see below

Monochrome CRTs:

• The first number gives the screen diagonal or diameter in inches (instead of the heater voltage)
• One or two sequentially-assigned letters
• The last number is preceded by a P and specifies the phosphor used

Examples:

• 1EP1 (P1 green, medium-persistence), 1EP2 (P2 yellow-green, long-persistence), 1EP11 (P11 blue, short-persistence) – 1" (2.5 cm) CRT for use in oscilloscopes, electrostatic deflection
• 2AP1, 2BP1 – 2" (5.1 cm) CRT for use in oscilloscopes, electrostatic deflection
• 3ABP1, 3ABP2, 3ABP7 (blue/yellow, short/long), 3ABP11 – Dual-beam 3" (7.6 cm) CRT for use in oscilloscopes, electrostatic deflections
• 4AP10 – 4" (10 cm) Skiatron, a CRT where the conventional light-emitting phosphor layer is replaced with a scotophor such as potassium chloride, which has the property that when a crystal is struck by an electron beam, it would change from translucent white to a dark magenta, and when flooded with high-intensity infrared, or by electro-thermal heating, would change back to translucent white. It therefore needs backlighting or external illumination like today's electronic paper^[19][20]
• 4DP1, 4DP2, 4DP7, 4DP11 – Dual-beam 4" CRT for use in oscilloscopes, electrostatic deflections
• 5BP1 (1802-P1) – 5" (13 cm) CRT for use in pre-World War II oscilloscopes, electrostatic deflection, P1 green, medium-persistence^[21]
• 5BP3 (1802-P3) – Pre-World War II, 5" CRT, electrostatic deflection, P3 yellow, medium-persistence^[21]
• 5BP4 (1802-P4) – 5" CRT used in pre-World War II television receivers, such as the RCA TRK-5 and in early radars such as the SCR-268 and SCR-270,^[22] electrostatic deflection, P4 white, medium-persistence^[21]
• 5BP11A – 5" CRT, electrostatic deflection, P11 blue, short-persistence^[23]
• 5CEP11 (blue, short); 10VP15, 5AKP15, 5DKP15, 5ZP15 (blue-green, extremely short); 5BNP16, 5CEP16, 5DKP16, 5ZP16 (violet/near-ultraviolet, very short); 5AKP24, 5AUP24, 5DKP24, 5ZP24 (green, short) – CRT-type flying-spot scanners for use in a telecine
• 6DP1, 6DP2, 6DP7, 6DP11, 6DP14 (purple/orange, medium/long), 6DP19 (orange, long), 6DP25 (orange, very long) – Triple-beam 6" (15 cm) CRT for use in oscilloscopes, electrostatic deflections
• 7JP1 – 7" (18 cm) CRT for use in early postwar oscilloscopes, electrostatic deflection, P1 green, medium-persistence^[24]
• 7JP4 – 7" CRT common in early postwar TV receivers, electrostatic deflection, P4 white, medium-persistence^[24]
• 7JP7 – 5½" (14 cm usable screen diameter) CRT for use in early postwar radar displays, electrostatic deflection, P7 blue-white, long-persistence^[24]
• 8CP1, 8CP2, 8CP4, 8CP5 (blue, very short), 8CP7, 8CP11 – 8" (20 cm) CRT for use in oscilloscopes, electrostatic deflection
• 30BP4 – 30" (76 cm) CRT used in 1950s premium television receivers, 90° magnetic deflection, P4 white, medium-persistence

EIA professional tubes system

A four-digit system was maintained by the EIA for special industrial, military and professional vacuum and gas-filled tubes, and all sorts of other devices requiring to be sealed off against the external atmosphere.

Some manufacturers preceded the EIA number with a manufacturer's code:

• CK, RK – Raytheon Company  
• ECG – Philips/Sylvania  
• F – ITT/Federal Telephone and Radio
• GL – General Electric Corp. (not British General Electric Company)  
• ML – Machlett Laboratories, Inc.
• NL – Eimac/National Electronics, Inc. (Geneva, Illinois, USA)
• NU – National Union Electric Corp. (Orange, New Jersey, USA)
• PL – Philips N.V.  
• SV – Svetlana:

• formerly only ПАО «Светлана» (PJSC "Svetlana"), St. Petersburg, Russia
• now also a brand of New Sensor Corp., Long Island City, New York, USA, manufacturing in Сара́тов (Saratov), Russia

• SY – Standard Telephones and Cables Australia branch, Sydney plant (not Sylvania Inc.)
• WL – Westinghouse Electric Corp.  

For examples see below

Eimac high power RF tubes system

Eitel/McCullough and other manufacturers of high-power RF tubes use the following code since 1945:^[25]

• An initial digit denoting the number of electrodes, or cavitiy resonators:

• 1K – Reflex Klystron
• 2 – Diode
• 2K – 2-cavity Klystron
• 3 – Triode
• 3K – 3-cavity Klystron
• 4 – Tetrode
• 4K – 4-cavity Klystron
• 5 – Pentode
• 5K – 5-cavity Klystron
• 6K – 6-cavity Klystron
• 7K – 7-cavity Klystron

• Up to 2 letters denoting the construction type and the cooling method:

• R or a hyphen ("-") – Glass envelope, radiation cooling
• C – Ceramic/metal envelope
• P – Primarily for pulse applications
• L – External anode, liquid convection cooling
• M – Multiphase-cooled (water/vapor), or has a modulating anode (Klystrons only)
• N – External anode, natural convection air cooling
• S – External anode, conduction cooling
• V – Vapor-cooled (anode is immersed in boiling water, and the steam is collected, condensed and recycled)
• W – Water-cooled (water is pumped through an outer metal jacket thermically connected to the anode)
• X – Forced-air cooled (air is blown through cooling fins thermally connected to the anode)

• A number to indicate the maximum anode dissipation in watts. This can be exceeded for a short time, as long as the average is not exceeded over the anode's thermal time constant (typically 0.1 sec). In Class-C applications, the amplifier output power delivered to the load may be higher than the device dissipation. As of 1 May 1961, Klystron maximum collector dissipation is given in kilowatts for brevity
• One or more manufacturer-proprietary letters denoting the construction variant:

—Klystrons only:

• P – 225 to 390 MHz
• L – 390 to 1550 MHz

• LA – UHF low (analog TV broadcast <600 MHz)
• LF, LK, LQ, LR – UHF high (analog TV broadcast >600 MHz)
• LT, LX – L band

• S – 1.55 to 3.9 GHz

• SH, SI, SJ – S band

• C – 3.9 to 6.2 GHz

• CA, CH – C band, coaxial output
• CB, CG, CK, CL, CS – C band, waveguide output

• X – 6.2 to 10.9 GHz

• XA – X band, coaxial output
• XD, XF, XG, XK, XN, XS – X band, waveguide output

• K – 10.9 to 36 GHz
• Q – 36 to 46 GHz
• V – 46 to 56 GHz

• An optional digit denoting the gain group:

• 1 – ≤10
• 2 – 11...20
• 3 – 21...30
• 4 – 31...50
• 5 – 51...100
• 6 – 101...200
• 7 – 201...500
• 8 – 501...1000

• Optionally a slash "/" followed by the RMA or EIA equivalent.

Examples:

• 2-50A – 30 kV, 75 mA Half-wave rectifier
• 2-2000A – 75 kV, 750 mA Half-wave rectifier
• 2X3000F – 25 kV, 3 A Forced-air cooled, half-wave rectifier
• 3-200A3 = 592 – 150 MHz, 200 W Glass power triode with anode top cap
• 3-400Z/8163 – 110 MHz, 400 W Glass power triode with anode top cap
• 3-1000Z/8164 – 110 MHz, 1 kW Glass power triode with anode top cap
• 3CPN10A5/7815 (contact-cooled), 3CPX100A5/7815R (forced-air cooled) – 3 GHz, 10 W_avg, 2 kW_peak Ceramic/metal UHF pulse power triode
• 3CW5000A1/8240, 3CW5000F1/8241 (with flexible leads for grid and filament) – 5 kW Ceramic/metal power triode, water-cooled
• 3CW5000A3/8242 (up to 75 MHz), 3CW5000F3/8243 (with flexible leads for grid and filament, up to 30 MHz) – 5 kW Ceramic/metal power triode; water-cooled versions of 3CX2500A3 and 3CX2500F3
• 3CW50000C/8350 – 30 MHz, 50 kW Ceramic/metal power triode, water-cooled
• 3CX100A5/7289 (6.0 V heater), 3CX100F5/8250 (26.5 V heater) – 3 GHz, 100 W Oil can-type ceramic/metal disk-seal UHF power triode, forced-air cooled, often used by radio amateurs for 23cm-band microwave amplifiers; 2C39A with different heaters
• 3CX1000A7/8283 – 220 MHz, 1 kW Ceramic/metal power triode
• 3CX1500A7/8877 – 110 MHz, 1.5 kW Ceramic/metal power triode, forced-air cooled
• 3CX2500A3/8161, 3CX2500F3/8251 – 2.5 kW Ceramic/metal triode; forced-air cooled versions of 3CW5000A3 and 3CW5000F3
• 3CX3000A1/8238, 3CX3000F1/8239 (with flexible leads for grid and filament) – 3 kW Ceramic/metal AF power triode
• 3CX10000A1/8158 – 10 kW Ceramic/metal AF power triode
• 3CX10000A3/8159 – 140 MHz, 10 kW Ceramic/metal power triode for use as self-excited high-power oscillator in induction heating equipment
• 3CX10000A7/8160 = Siemens RS2015CL – 110 MHz, 10 kW Ceramic/metal power triode
• 4-65A/8165 – 150 MHz, 65 W Glass beam power tetrode, 5-pin Septar base with anode top cap
• 4-125A/6155 (4D21) – 120 MHz, 125 W Glass beam power tetrode
• 4-250A/6156/5D22 – 110 MHz, 250 W Glass beam power tetrode
• 4-400A/8438, 4-400C/6775 – 110 MHz, 400 W Glass radial-beam power tetrode
• 4-1000A/8166 – 110 MHz, 1 kW Glass beam power tetrode popular in broadcast and amateur transmitters
• 4CM300000G – 50 MHz, 300 kW Ceramic/metal power tetrode, water/vapor cooled, for use in broadcast transmitters
• 4CPX250K/8590 – 500 MHz, 250 W_avg, 17.5 kW_peak Ceramic/metal radial-beam grid-pulsed power tetrode
• 4CW2000A/8244 – 110 MHz, 2 kW Ceramic/metal radial-beam power tetrode; water-cooled version of 4CX1000A/8168
• 4CX250B/7203 = QEL2/275 (6.0 V heater), 4CX250F/7204 = QEL2/275H (26.5 V heater), 4CX250FG/8621 (26.5 V heater) – 500 MHz, 250 W Ceramic/metal power tetrode, forced-air cooled, favored by radio amateurs as a final amplifier
• 4CX250BC/8957 – Long-life, tighter specs version of 4CX250B
• 4CX250K/8245 (6.0 V heater), 4CX250M/8246 (26.5 V heater) – 500 MHz, 250 W Ceramic/metal radial-beam power tetrode
• 4CX300A/8167 – 500 MHz, 300 W Ceramic/metal power tetrode
• 4CX300Y/8561 – 110 MHz, 300 W Ceramic/metal power tetrode
• 4CX350A/8321 = YL1340 (6.0 V heater), 4CX350F/8322 = YL1341 (26.5 V heater) – 350 W Ceramic/metal radial-beam AF power tetrode
• 4CX350FJ/8904 – Improved 4CX350F/8322
• 4CX600J/8809, 4CX600JA/8921 (larger anode cooler) – 600 W Ceramic/metal radial-beam AF power tetrode
• 4CX1000A/8168 (110 MHz), 4CX1000K/8352 (with a solid screen ring for UHF use) – 1 kW Ceramic/metal radial-beam power tetrode; forced-air cooled version of 4CW2000A/8244
• 4CX3000A/8169 – 150 MHz, 3 kW Ceramic/metal radial-beam power tetrode
• 4CX5000A/8170 = Siemens RS2014CL, 4CX5000R/8170W (shock/vibration resistant) – 110 MHz, 5 kW Ceramic/metal radial-beam power tetrode
• 4CX5000J/8909 – 100 MHz, 5 kW Ceramic/metal radial-beam power tetrode
• 4CX10000D/8171 – 110 MHz, 10 kW Ceramic/metal radial-beam power tetrode; 4CX5000A/8170 with a larger cooler
• 4CX12000A/8989 – 220 MHz, 12 kW Ceramic/metal radial-beam power tetrode
• 4CX15000A/8281 – 110 MHz, 15 kW Ceramic/metal radial-beam power tetrode
• 4CX15000J/8910 – 100 MHz, 15 kW Ceramic/metal radial-beam power tetrode
• 4CX20000A/8990 – 110 MHz, 20 kW Ceramic/metal radial-beam power tetrode
• 4CX35000A, 4CX35000C/8349 (longer screen/anode insulator for Class-C screen grid or anode modulation) – 110 MHz, 35 kW Ceramic/metal power tetrode, forced-air cooled, used in numerous 50-kW broadcast transmitters, often in a Doherty configuration as in the Continental Electronics 317C series
• 5-125B/4E27A – 75 MHz, 125 W Glass power pentode
• 5-500A – 500 W Glass radial-beam power pentode
• 5CX1500A – 110 MHz, 1.5 kW Ceramic/metal radial-beam power pentode, forced-air cooled
• 5CX3000A – 150 MHz, 4.0 kW Ceramic/metal radial-beam power pentode, forced-air cooled
• 5K50CB – Ethylene glycol-cooled, 4.4 to 5.0 GHz, 10 kW electromagnet-focused linear-beam, 5-cavity Klystron for use in C-band troposcatter systems
• 5K70SH – Forced-air and water-cooled, 2450 MHz, 30 kW, electromagnet-focused linear-beam, 5-cavity Klystron for use in industrial heating applications
• 5KM300SI – Forced-air and water-cooled, 2.1 to 2.4 GHz, 100 kW, electromagnet-focused linear-beam, 5-cavity Klystron for use in Unified S-band ground transmitters of spacecraft communications systems
• 6K50000LQ – Forced-air and water-cooled, 720 to 980 MHz, 10 kW, permanent magnet-focused linear-beam, 6-cavity Klystron
• 7KP50SV – 3.43 to 3.57 GHz, 11 kW_avg, 3 MW_peak, 7-cavity pulsed Klystron^[26]:9

Eimac also maintained an internal prototype numbering system consisting of the letter X followed by 3 or 4 digits, such as "X-2159".

Media related to Eimac vacuum tubes at Wikimedia Commons

West European systems

Mullard–Philips system

This system is very descriptive of what type of device (triode, diode, pentode etc.) it is applied to, as well as the heater/filament type and the base type (Octal, Noval, etc.).^[11][27] Adhering manufacturers include AEG (de), Amperex (us), CdL (1921, French Mazda brand), CIFTE (fr, Mazda-Belvu brand), EdiSwan (uk, British Mazda brand), La RadioTechnique Compelec (fr, Coprim, Miniwatt-Dario and RTC brands), Lorenz (de), MBLE^(fr, nl) (be, Adzam and Ultron brands), Mullard (uk), Philips (nl, Miniwatt brand), RCA (us), RFT^(de, sv) (de), Siemens (de), Telefunken (de), Tesla (cz), Toshiba (ja), Tungsram (hu), Unitra (pl, Dolam, Polam and Telam brands) and Valvo^(de, it) (de).

Standard tubes

This part dates back to the joint valve code key (German: Röhren-Gemeinschaftsschlüssel) negotiated between Philips and Telefunken in 1933–34. Like the North American system the first symbol describes the heater voltage, in this case a Roman letter rather than a number. Further Roman letters, up to three, describe the device followed by one to four numerals assigned in a semi-chronological order of type development within number ranges assigned to different base types.^[28]

If two devices share the same type designation other than the first letter (e.g. ECL82, PCL82, UCL82) they will usually be identical except for heater specifications; however there are exceptions, particularly with output types (for example, both the PL84 and UL84 differ significantly from the EL84 in certain major characteristics, although they have the same pinout and similar power rating). However, device numbers do not reveal any similarity between different type families; e.g. the triode section of an ECL82 is not related to either triode of an ECC82, whereas the triode section of an ECL86 does happen to be similar to those of an ECC83.

Pro Electron maintained a subset of the M-P system after their establishment in 1966, with only the first letters E, P for the heater, only the second letters A, B, C, D, E, F, H, K, L, M, Y, Z for the type, and issuing only three-digit numbers starting with 1, 2, 3, 5, 8, 9 for the base.^[29]

Note: Marconi preceded the M-P designation with the letter M (as in MEBC3 for EBC3), Tungsram with the letter T, Ultron (MBLE)^(fr, nl) with the letter U and VATEA Rádiótechnikai és Villamossági Rt.-t. (VATEA Radio Technology and Electric Co. Ltd., Budapest, Hungary) with the letter V

• First letter: heater/filament type

Heater ratings for series-string, AC/DC tubes are given in milliamperes; heater ratings for parallel-string tubes are given in volts. Tubes with a center-tapped filament/heater are designated the lower voltage option

• A – 4 V heater for 2-cell lead-acid batteries and for AC mains transformers
• B – 180 mA DC series heater
• C – 200 mA AC/DC series heater
• D – 1.4 V DC filament for Leclanché cells, later low-voltage/low-power filament/heater:

• 0.625 V DC directly heated for NiCd battery, series-heated two-tube designs such as hearing aids. If either filament breaks, further draining of all batteries stops^[30]
• Wide range 0.9 V to 1.55 V DC directly heated for dry cells
• 1.25 V DC directly heated for NiCd batteries
• 1.25 V or 1.4 V AC from a separate heater winding on CRT horizontal-output transformers, in half-indirectly heated EHT rectifiers

• E – 6.3 V parallel heater; for 3-cell lead-acid vehicle crank batteries (mobile equipment) and for AC mains or horizontal-output transformers
• F – 12.6 V DC parallel heater for 6-cell lead-acid vehicle crank batteries
• G – Various heaters between 2.5 and 5.0 V AC (except 4 V) from a separate heater winding on a mains or horizontal-output transformer for the anode voltage rectifier
• H – 150 mA AC/DC series heater

• In 1938, Philips tried to define this letter as "4 V battery", as opposed to A for "4 V AC"^[3]:2

• I – 20 V heater
• K – 2.0 V filament for 1-cell lead-acid batteries, later for AC transformers
• L – 450 mA AC/DC series heater; was shifted here from Y
• M – 1.9 V, directly heated
• N – 12.6 V, indirectly heated
• O – No heater, i.e. semiconductors

• Gas-filled cold-cathode tubes were shifted to Z before their mass production started
• Philips sold a family of 150mA series heater tubes under this letter in South America

• P – 300 mA AC/DC series heater
• Q – 2.4 V, indirectly heated
• R – Not assigned to avoid any confusion with the older Telefunken "R" system
• S – 1.9 V, indirectly heated
• T – Custom heater
• U – 100 mA AC/DC series heater
• V – 50 mA AC/DC series heater
• X – 600 mA AC/DC series heater
• Y – 450 mA AC/DC series heater, shifted to L to avoid conflicts with the professional tubes system
• Z – Cold-cathode tube; was shifted here from O after the advent of semiconductors

• Second and subsequent letters: System type

—Heated tubes (all heater/filament letters except O and Z):

• <none> or R – Resistive element (ballast tube/barretter)
• A – Small signal diode
• B – Dual small signal diode
• C – Small signal triode
• D – Power triode
• E – Small signal tetrode
• F – Small signal pentode
• H – Mixer hexode, special purpose heptode
• K – Mixer heptode or octode
• L – Power pentode or beam power tetrode
• M – Optical tuning/level indicator
• N – Gas-filled thyratron
• P – Secondary emission tube – mostly used as third letter
• Q – Nonode
• S – Special tube (German: Sonderröhre)
• T – Beam deflection tube, or misc.
• W – Gas-filled half-wave rectifier
• X – Gas-filled full-wave rectifier
• Y – Vacuum half-wave rectifier (power diode)
• Z – Vacuum full-wave rectifier (dual power diode with common cathode)

E.g. ECCnn is a 6.3 V dual triode; EABCnn has a single detector diode, a common cathode pair of diodes, and a triode.

—Heater/filament letter O (very early semiconductors):^[31]

• A – Diode

• AP – Photodiode
• AZ – Zener diode

• C – Transistor

• CP – Phototransistor

• D – Power transistor
• RP – Photoresistor
• Y – Power diode

For examples see below under O. This part lived on in the later Pro Electron semiconductor designation system (also the tube letters F "pentode" becoming "RF transistor", and L "power pentode" becoming "RF power transistor")

—Heater/filament letter Z (Cold-cathode tubes):^[32]

• A – Arc discharge tube
• B – Binary counter or switching tube
• C – Common cathode Counter Dekatron that makes only carry/borrow cathodes separately available for cascading
• E – Electrometer tube
• G – Gating tube
• M – Optical indicator
• S – Separate cathode Counter/Selector Dekatron that makes all cathodes available on individual pins for displaying, divide-by-n counter/timer/prescalers, etc.
• T – Relay triode, a low-power triode thyratron, one starter electrode, may need illumination for proper operation if not radioactively primed
• U – Low-power tetrode thyratron, may mean:

• Trigger tetrode, one starter electrode and a primer (keep-alive) electrode for ion availability to keep the ignition voltage constant, for analog RC timers, voltage triggers, etc.
• Relay tetrode, two starter electrodes to make counters bidirectional or resettable

• W – Trigger pentode, two starter electrodes and a primer electrode
• X – Shielded Trigger pentode, two starter electrodes, a primer electrode and a conductive coating of the glass envelope inside connected to a separate pin

For examples see below under Z

• Following digits: Model number

—Heater/filament letters M, N, O, Q, and S: Sequentially assigned number

—All other heater/filament letters: Base type

—Signal tubes:

• Even number: 'High slope' (low/medium/high-µ or sharp-cutoff) tube
• Odd number: Variable mutual conductance (Vari-µ or remote-cutoff) tube

—Power pentodes and triode/power pentode combinations:

• Even number: Linear tube for use in distortion-critical circuits such as Class-A, AB or B, SSB or audio power amplifiers
• Odd number: Less linear tube for use in more distortion-tolerant circuits such as video or Class-C RF amplifiers

• 1–9 – Various pinch-type construction and other European pre-Octal designs:

Note: A G or GT suffix denotes an export version with a K8A Octal base (EBF2G, ECH3G, ECH4G, EK2G, EL3G, KF3G, KK3G, KL4G)

• P8A Side-contact 8
• V5A Side-contact 5 (AB2, CB1, CB2, EB1, EB2, KB2, UY2, VY2)
• A4A European 4-pin (AX1)
• O5A European 5-pin (AB1, AF2, AN1, BB1, BL2, KL1)
• C7H European 7-pin (ACH1, AK1, BCH1, DCH1, KF1, KF2)
• K8A Octal mostly for South American markets (OBC3, OBF2, OCH4, OH4, OF1, OF5, OF9, OM5, PBC3, PBF2, PF9, PH4, PM5, UBC1, UBF2, UBL1, UCH4, UF8, UF9, UL1, UM4, UY1)
• Acorn tube (DxC, DxF, E1C, ExF)
• B4B 4-pin subminiature hearing aid base (EY1)
• B12A Duodecal 12-pin (E1T)

• 10–19 – Various bases:

• Y8A Steel tube 8-pin
• Acorn tube (D1xF, E13F)

• 20–29 – Various bases:

• B8G 8-pin Loctal
• K8A Octal (DAC21, DBC21, DCH21, DF21, DF22, DK21, DL21, DLL21, DM21)
• P8A Side-contact 8 (FDD20)

• 30–39 – K8A Octal
• 40–49 – B8A Rimlock

• 41w – Battery-heated bowl tube^[33] (German: Pressnapfröhre)

• 50–59 – Miscellaneous:

• X3A Lighthouse-type disk-seal tube with a K8A Octal base (EC56, EC57)
• X4A Rocket-type disk-seal tube (EC55)
• Other disk-seal, coaxial tubes (EA52, EA53)
• B8G 8-pin Loctal (DFF50, DFF51, EF51, EF52)
• B9G 9-pin Loctal (EC52, EC54, EE50, EF50, EF54, EF55, EFF50, EFF51)
• K8A Octal (DAH50)
• B9D Magnoval (E55L)
• B26A Trochotron base (ET51)
• A4A European 4-pin (AX50, AZ50)
• 2+1-pin subminiature (DA50)
• B3G 3-pin subminiature (EA50, EC53)
• B4B 4-pin subminiature hearing aid base (DC51, DD51, DF51, DL51, KC50, KC51, KD50, KE50)
• P8A Side-contact 8 (AC50, CF50, CF51, EC50, EL50, EL51, EL53, EL54)
• Y10A Steel tube 10-pin (UEL51)
• BA15d Noise diode base (K5xA)
• Wire leads (DY51, EY51, KY50, ORP5x, Z50T)

• 60–69 – Low-frequency Pencil tubes – subminiature, all-glass inline-pigtailed tubes (DCF60, DF6x, DL6x, ORP6x)

—Before the 1950s:

• 60 – M7A British 7-pin base (AL60)
• 60–64 – B9G 9-pin Loctal (EFP60, EL6x, EW60)

• 70–79 – Low-frequency Pencil tubes with circular pins or pigtails (DC70, DF7x, DL7x, DM7x, DY70, EA76, EC7x, ECC70, EF7x, EL71, EN70, EY70, Z7xU, Z70W)

—Before the 1950s:

• 70–79 – B8G 8-pin Loctal (Lorenz EBL/UBL71, ECH/UCH71, EEL/UEL71, EM71, EM72, PY71, UL71)

• 80–89 – B9A Noval
• 90–99 – B7G Miniature 7-pin
• 100–109 – Various bases:

• O5A European 5-pin (AC101, AC104, AD101)
• P8A Side-contact 8 (AH100)
• B7G Miniature 7-pin (DA101, DFF101, DLL10x)
• P5A, P7A German PTT bases (AC100, AC102, AD100, AD102)
• S8B Wehrmacht base (AF100)

• 110–119 – Various bases:

• Y8A Steel tube 8-pin (EA111, EF111, EF112, EL112, ES/US111)
• B8A Rimlock (ECL113, ED111)

• 130–139 – K8A Octal (EL/PL136, E130L)
• 150–159 – Miscellaneous:

• X3A Lighthouse-type disk-seal tube with a K8A Octal base (EC157, EC158)
• Y10A Steel tube 10-pin (EL151, EL156, EZ150)
• B10V 10-pin glass with one big pin (EL152, EL153, FL152)

• 160–169 – Inline wire-ended low-frequency Pencil tubes (DF16x, DL16x, DM160)

—Before the 1950s:

• 162 – Y8A Steel tube 8-pin (EC162)

• 170–179 – RFT Gnome tubes:^[34]

• G8G 8-pin versions derived from B8G Loctal never got past prototyping because the evacuation tip inside the narrow spigot broke off too easily
• B11G 11-pin all-glass version with one offset pin (EAA/UAA171, EBF/UBF171, ECH/UCH171, EEL/UEL171, EF/UF17x, EL/UL17x, EM/UM171)

• 180–189 – B9A Noval (ECC/PCC/XCC/YCC18x, E18xCC, EF/LF/XF/YF18x, E18xF, EL18x, EY189)
• 190–199 – B7G Miniature 7-pin (DAF191, DF/EF19x, DK192, DL19x)
• 200–209 – B10B Decal; Pro Electron-issued (ECF/LCF/PCF20x, ECH/PCH200, ECL/PCL200, EFL/LFL/PFL200)
• 230–239 – K8A Octal (ECC230, E23xL)
• 270–279 – B11G RFT 11-pin all glass Gnome tube with one offset pin
• 280–289 – B9A Noval (E28xCC, E28xF)
• 300–399 – K8A Octal (EC360, EL/PL3xx, Z30xC, Z300T)
• 400–499 – B8A Rimlock (EF410, EL401)
• 500–529 – B9D Magnoval; Pro Electron-issued (ED/PD5xx, EL/LL/PL/XL5xx, EY/GY/PY50x)
• 560–599 – Miscellaneous:

• Dekatron bases (Z5xxC, Z5xxS)
• Nixie bases (Z5xxM, Z5xx0M)
• Noise diode bases (GA/KA56x)
• Lighthouse-type disk-seal tube (EC560)
• Oil can-type disk-seal tube (EC562)

• 600–699 – Inline wire-ended low-frequency Pencil tubes (DF6xx, DL6xx, Z66xW)
• 700–799 – Circular wire-ended low-frequency Pencil tubes (DC76x, DF703, EC760, EF7xx, Z70xU, Z700W)
• 800–899 – B9A Noval; Pro Electron-issued (EAF801, EC860, ECC8xx, PCE800, ECF/LCF/PCF/XCF8xx, ECL/PCL8xx, ECLL800, EF/IF8xx, E810F, EH860, AL/EL/IL/PL8xx, EM8x0, EMM80x, DY/EY/GY/PY80x, Z86xA, Z80xU, Z8xxW, Z86xX)
• 900–999 – B7G Miniature 7-pin; Pro Electron-issued (DAF961, DD960, DF9xx, DK962, DL9xx, DY900, EAA901, EC/LC/PC90x, ECC96x, EH900, EZ900, Z960A, Z900T)

—Special quality:

• 1000– Round wire-ended (EC10x0)
• 2000– B10B Decal (ECC2000)
• 3000– K8A Octal (EL3010) or P8A Side-contact 8 (EY3000)
• 5000– B9D Magnoval (EF5000, EL50x0)
• 8000– B9A Noval (EC80x0, ECC8100, ECF8070, ECH8000, ED8000, EF8010, EL8000)
• 9000– B7G Miniature 7-pin base

For examples see below

Special quality tubes

SQ tubes (also French: "Securité - Qualité") for professional/industrial/computer/telecommunications use featured some modifications including:

• Long-life design
• Gold-plated base pins
• Narrowly twisted pair filament inside the nickel cathode sleeve to reduce hum pickup from the AC heater supply
• Silicon-free filament to avoid cathode interface/poisoning after prolonged periods in cut-off (required in digital circuitry)
• Improved oxide insulation between the heater and cathode sleeve so the cathode could be elevated to a higher voltage above the heater supply (note that a cathode positive to the heater was less detrimental to the oxide insulation between heater and cathode than the reverse, helping to prevent pyrometallurgical electrolytic reactions where the oxide touches the nickel cathode, that could form conductive aluminium tungstate and which could ultimately develop into a heater/cathode short-circuit)
• Dual getters to maintain a better vacuum
• More rigid electrode supports to reduce microphonics and improve vibration and shock resistance
• Mica spacers without sharp protrusions which could flake off and become loose inside the bulb, possibly lodging between the grids and thus changing the characteristics of the device
• Constricted bulb section to firmly hold specially shaped flakeless mica spacers in place (E80F, E88CC, E90CC)

—SQ numbering before c.1960: System type letter and base type number swapped;^[35] most were modified versions of standard types (ECC82 → E82CC, ECC88 → E88CC), but some were not pin-compatible (EF80 → E80F). A few SQ tubes did not have a standard equivalent (E55L, E90CC, E91H). For examples see below, starting at DC

—SQ numbering after c.1960: 4-digit numbers listed above;^[27] for examples see below, starting at EC

Professional tubes

In use since at least 1961, this system was maintained by Pro Electron after their establishment in 1966.^[29]

Both letters together indicate the type:

• X – High vacuum electro-optical devices

• XA – Phototube
• XG – Miscellaneous
• XM – Character generating cathode ray tube
• XP – Photomultiplier
• XQ – Camera tube
• XR – Monoscope
• XS – Cathode ray charge storage tube
• XT – Memory display tube
• XV – Infrared detector
• XW – Infrared imaging device
• XX – Image intensifier or image converter

• Y – Vacuum tubes

• YA – Diode
• YD – Transmitting or industrial, single or dual triode
• YG – Electrometer tube, vacuum gauge
• YH – Traveling-wave tube
• YJ – Magnetron
• YK – Klystron
• YL – Transmitting or industrial, single or dual tetrode or pentode
• YN – Backward-wave oscillator
• YP – Electron multiplier
• YR – Crossed-field amplifier
• YT – Pulse modulator tube
• YY – High vacuum rectifier

• Z – Gas-filled tubes not employing photosensitive materials

• ZA – Cold-cathode indicator tube
• ZB – Microwave switching tube (TR/ATR cells, etc.)
• ZC – Trigger tube
• ZD – Surge arrester
• ZE – Glow modulator tube, a linear light source for rotating-drum FAX receivers, film soundtrack recording, etc.
• ZF – Flashtube
• ZL – Gas laser
• ZM – Cold-cathode character display tube or counter display tube
• ZP – Radiation counter tube (Geiger-Müller counter tube or proportional counter tube)
• ZQ – Mixed analogue and digital display
• ZR – Plasma display panel
• ZS – Bar graph
• ZT – Thyratron
• ZX – Ignitron
• ZY – Mercury-vapor rectifier
• ZZ – Voltage stabilizer or corona discharge tube

Then follows a 4-digit sequentially assigned number.

Optional suffixes for camera tubes:

Version letter:

• B – Blue
• G – Green
• L – Luminance
• R – Red
• T – Reticule
• X – Medical X-ray

Letter for variants derived by selection:

• D – High resolution
• M – Blemish standard

For examples see below

Transmitting tubes

The first letter (or letter pair, in the case of a dual-system device) indicates the general type:

• B – Backward-wave amplifier
• D – Rectifier, including grid-controlled types
• J – Magnetron
• K – Klystron
• L – Traveling-wave tube
• M – Triode (AF amplifier or modulator)
• P – Pentode
• Q – Tetrode
• R – Rectifier
• T – Triode (AF, RF, oscillator)
• X – Large thyratron (including all hydrogen thyratrons and high-current types)

The following letter indicates the filament or cathode type, or the fill gas or other construction detail. The coding for vacuum devices differs between Philips (and other Continental European manufacturers) on the one hand and its Mullard subsidiary on the other.

—Philips vacuum devices:

• A

• Backward-wave amplifier or Traveling-wave tube: Output power <1W; signal device for use as intermediate amplifier or low-noise receiver front end
• Other tubes: Directly heated tungsten filament

• B

• Backward-wave amplifier or Traveling-wave tube: Output power ≥1W; power device for use in transmitters
• Other tubes: Directly heated thoriated tungsten filament

• C – Directly heated oxide-coated filament
• D – Disk-seal construction
• E – Indirectly heated oxide-coated cathode

—Mullard vacuum devices:

• N – External magnet required (magnetrons)
• P – Packaged construction (magnetrons)
• S – Reflex Klystron
• T – Multiple resonator (klystrons)
• V – Indirectly heated oxide-coated cathode
• X – Directly heated tungsten filament
• Y – Directly heated thoriated tungsten filament
• Z – Directly heated oxide-coated filament

—Gas-filled devices:

• G – Mercury-vapor filling, directly heated oxide-coated filament
• H – Hydrogen filling
• R – Inert-gas filling
• X – Xenon filling

The next letter indicates the cooling method or other significant characteristic:

• H – Helix or other integral cooler
• L – Forced-air cooling
• Q – Shield-grid (tetrode) thyratron (thyratrons only)
• S – Silica envelope, to allow for a glowing anode
• T – Tunable microwave device
• W – Water cooling

The following group of digits indicate:

• Microwave tubes: Frequency in GHz
• Rectifying tubes: DC output voltage in V or kV in a three-phase half-wave configuration
• Thyratrons: Peak inverse voltage in kV
• Transmitting tubes: Maximum anode voltage in kV

Then a delimiter:

• / (slash) – Philips device (used throughout this list)
• - (dash) – Mullard device

The following group of digits indicate the power:

• Backward-wave amplifier or Traveling-wave tube: Output power

• 2nd letter: A – in mW
• 2nd letter: B – in W

• Klystrons: Output power
• Magnetrons: Pulse output power in kW
• Continuously transmitting tubes: Maximum anode dissipation in W or kW in Class-C amplifier telegraphy
• Pulsed transmitting tubes: Maximum peak anode current in A (number preceded by "P")
• Rectifiers: Maximum average anode current in mA
• Thyratrons: Maximum average anode current:

• Less than 3 digits: in mA
• 3 or more digits:

• 1st digit: =0 – in mA
• 1st digit: >0 – in A

An optional following letter indicates the base or connection method:

• B – Cables
• E – Medium 7-pin base
• ED – E27 Edison screw lamp base
• EG – E40 Goliath Edison screw lamp base
• F – Medium 8-pin base
• G – Medium 4-pin base
• GB – Jumbo 4-pin base
• GS – Super jumbo 4-pin base
• N – Medium 5-pin base
• P – Side-contact base

For examples see below

Phototubes and photomultipliers

The first digit indicates the tube base:

• 2 – Loctal 8-pin base
• 3 – Octal 8-pin base
• 5 – Special base
• 8 – Noval base
• 9 – Miniature 7-pin base

The second digit is a sequentially assigned number.

The following letter indicates the photocathode type:

• A – S11, Caesium-activated antimony cathode. Used for reflective-mode photocathodes. Response range from UV to visible, peak sensitivity 420 nm. Widely used
• C – S1, Caesium-on-oxidated-silver cathode. Transmission-mode, sensitive from 300...1200 nm, peak at 800 nm. High dark current; used mainly in near-IR, with the photocathode cooled
• D – Bialkali potassium-antimony-caesium cathode, spectral response from UV to red

• DU – "D" with a Silica window for UV detection

• SBU – Solar-blind caesium-telluride cathode, spectral response from Vacuum UV to UV-B, peak sensitivity 235 nm (UV-C), Silica window
• T – S20, Trialkali sodium-potassium-antimony-caesium cathode, wide spectral response from UV to near-IR; special cathode processing can extend range to 930 nm, then referred to as S25. Used in broadband spectrophotometers

• TU – "T" with a Silica window for UV detection

• U – S13, "A" with a Silica window for UV detection, peak sensitivity 400 nm

The following letter indicates the filling:

• G – Gas-filled
• V – High-vacuum

A following letter P indicates a photomultiplier.

Examples:

• 20AV – Vacuum phototube, blue sensitive, B8G Loctal base
• 20CG – Gas-filled phototube, Red/IR sensitive, B8G Loctal base
• 20CV – Vacuum phototube, Red/IR sensitive, B8G Loctal base
• 57CV – Photometric cell, Red/IR sensitive, British 4-pin base
• 58CG – Gas-filled phototube, Red/IR sensitive, all-glass pigtailed
• 58CV – Vacuum phototube, Red/IR sensitive, all-glass pigtailed
• 90AG – Gas-filled phototube, daylight/blue sensitive, miniature 7-pin base
• 90AV – Vacuum phototube, blue sensitive, miniature 7-pin base
• 90CG – Gas-filled phototube, Red/IR sensitive, miniature 7-pin base
• 90CV – Vacuum phototube, Red/IR sensitive, miniature 7-pin base
• 92AG – Gas-filled phototube, blue sensitive, miniature 7-pin base
• 92AV – Vacuum phototube, blue sensitive, miniature 7-pin base
• 61SV/7634 – PbS infrared (300...3500 nm) photoresistor, 2-pin all-glass pigtailed
• 50AVP – 11-stage photomultiplier for scintillation counters, Duodecal base
• 51UVP – 11-stage photomultiplier, Duodecal base
• 52AVP = XP1180 – 10-stage photomultiplier, 13-pin base
• 53AVP, 153AVP – 10-stage photomultiplier, Diheptal 14-pin base
• 53UVP – 11-stage photomultiplier, Diheptal 14-pin base
• 54AVP – 11-stage photomultiplier, Diheptal 14-pin base
• 55AVP – 15-stage photomultiplier, Bidecal 20-pin base
• 56AVP – 14-stage photomultiplier, Bidecal 20-pin base
• 56DVP, 56DUVP – 12-stage photomultiplier, Bidecal 20-pin base
• 56SBUVP – 14-stage photomultiplier, Bidecal 20-pin base
• 56TVP, 56TUVP – 12-stage photomultiplier, Bidecal 20-pin base
• 56UVP – 14-stage photomultiplier, Duodecal base
• 57AVP – 11-stage photomultiplier, Bidecal 20-pin base
• 58AVP – 14-stage photomultiplier, Bidecal 20-pin base
• 150AVP – 10-stage photomultiplier, Bidecal 20-pin base
• 150CVP – 10-stage photomultiplier, Bidecal 20-pin base

Voltage stabilizers

The first number indicates the burning voltage

The following letter indicates the current range:

• A – max. 10 mA
• B – max. 22 mA
• C – max. 40 mA
• D – max. 100 mA
• E – max. 200 mA

The following digit is a sequentially assigned number.

An optional, following letter indicates the base:

• E – Edison screw lamp base
• K – Octal base
• P – Side-contact base

Examples:

• 70B1 – Voltage reference tube, all-glass pigtailed
• 75B1 – Voltage reference tube, miniature 7-pin base
• 75C1 – Voltage reference tube, miniature 7-pin base
• 83A1 = 7980 – Voltage reference tube, miniature 7-pin base
• 85A1 = 0E3 – Voltage reference tube, B8G Loctal base
• 85A2 = 0G3 – Voltage reference tube, miniature 7-pin base
• 90C1 – Voltage reference tube, miniature 7-pin base
• 95A1 – Voltage reference tube, miniature 7-pin base
• 100E1 – Voltage reference tube, A4A European 4-pin base
• 108C1 = 0B2 – Voltage reference tube, miniature 7-pin base
• 150A1 – Voltage reference tube, P8A side-contact 8 base
• 150B2 = 6354 – Voltage reference tube, miniature 7-pin base
• 150B3 – Voltage reference tube, miniature 7-pin base
• 150C1 – Voltage reference tube, P8A side-contact 8 base
• 150C2 = 0A2 – Voltage reference tube, miniature 7-pin base
• 150C4 – Voltage reference tube, miniature 7-pin base

Compagnie des Lampes (1888, "Métal") system

The first (1888) incarnation of La Compagnie des Lampes produced the TM tube since 1915 and defined one of the first French systems;^[11][36] not to be confused with Compagnie des Lampes (1921, "French Mazda", see below). This system was also used by the British ETA^[37]

First letter: Heater or filament voltage

• A – 1 V
• B – 2 V
• D – 4 V
• E – 5 V
• F – 6 V
• G – 7 V

Second letter: Heater or filament current

• W – ≥200 mA
• X – 150 mA
• Y – 100...140 mA
• Z – 50 mA

Next number: Gain

Next number: Internal resistance in kΩ

Examples:

• BW604 – Métal secteur indirectly AC-heated AF power triode^[38]
• BW1010 – Métal secteur indirectly AC-heated AF triode^[39]

Cossor system

• An optional number: Heater voltage^[11]

• 4, 40–49, 400–499 – 4 V, Mostly indirect, heater

Note: Some tubes in the low 40s and 400s have a 40 V indirect heater

• 13 – 13 V Indirect heater
• 200–299 – 2 V heater
• 600–699 – 6 V Indirect heater
• 800–899 – 7.5 V Indirect heater

• Letter(s): System type

A preceding letter M indicates a 4-volts AC, indirectly heated ("Mains Operated") tube

• B – Dual power triode
• BU – Full-wave rectifier
• DD – Dual diode
• DDT, DHA – Dual diode-triode
• DET – Detector
• DG – Tetrode
• DP – Power triode
• HF, HL, LH – Signal triode
• HPT – Power pentode
• LF – AF triode
• P – Power triode or pentode
• PA – Power triode
• PG, PGA – Heptode pentagrid converter
• PPA – Power pentode
• PT – Power pentode
• RC – Triode
• SG – Sharp-cutoff tetrode
• SPA, SPT – Sharp-cutoff RF pentode
• SU, SUA – Half-wave rectifier
• VPA, VPT – Variable-mu (remote-cutoff) RF pentode
• VS, VSG – Variable-mu tetrode
• XP – Power triode

• An optional number if none preceded the letters

Examples:^[40]

• 4XP – 4 volts, directly heated power triode
• 41MDG – 4 volts tetrode
• 41MP – 4 volts, indirectly heated, power triode
• 41MPG – 4 volts, indirectly heated, heptode pentagrid
• 41MXP – 4 volts, indirectly heated, power triode
• 210DET – 2 volts, directly heated, detector triode
• 210HF – 2 volts, directly heated, triode
• 210HL – 2 volts, directly heated, triode
• 210LF – 2 volts, directly heated, triode
• 210PG – 2 volts, directly heated, variable-mu heptode pentagrid
• 210RC – 2 volts, directly heated, very high impedance triode
• 210SPT – 2 volts, directly heated, sharp-cutoff RF pentode
• 210VPT – 2 volts, directly heated, shielded variable-mu RF pentode
• 215P – 2 volts, directly heated AF power triode
• 220B – 2 volts, directly heated dual power triode
• 220PA – 2 volts, directly heated power triode
• 220PT – 2 volts, directly heated power triode
• 230XP – 2 volts, directly heated power triode
• 240B – 2 volts, directly heated dual AF power triode
• 402P – 40 volts, indirectly heated power triode, 7-pin base
• 410HF – Triode
• 610RC – 6 volts, directly heated signal triode
• 660SU – 6 volts, directly heated 1 kV, 150 mA half-wave rectifier
• 825BU – 7.5 volts, directly heated 500 V, 120 mA full-wave rectifier
• DDT – 4 volts, indirectly heated dual diode + triode
• DP – 16 volts, indirectly heated power triode
• PT41 – 4 volts, directly heated power pentode
• SU25 – 25 kV, 1 mA EHT rectifier
• SU2150 (CV1120) – 8 kV, 2 mA EHT rectifier for use in CRT power supplies

EdiSwan ("British Mazda") systems

EdiSwan (British Mazda) is not to be confused with other licensees of General Electric's Mazda brand: GE's own subsidiary British Thomson-Houston Cie des Lampes (1921, French Mazda, see below) Cie Industrielle Française des Tubes Electroniques – CIFTE (Mazda-Belvu – originating from Societé Radio Belvu; see below)[41] Manufacture Belge des Lampes Électriques,(fr, nl) producing: Light bulbs since 1911 under the Belgian Mazda brand Electronic tubes since 1924 under the Adzam ("Mazda" spelled backwards) brand[42] Mazda-CIPEL, batteries (Cie Industrielle des Piles Électriques) Mazda-Westinghouse, light bulbs Mazda-Toshiba, light bulbs, coexisted with the Japanese automaker in its early years

Note: EdiSwan also used the Mullard–Philips scheme.

Signal tubes

First number: Heater or filament rating^[11]

• 0 – Misc. higher voltages
• 1 – 1.4 V
• 6 – 6.3 V
• 10 – 100 mA
• 20 – 200 mA
• 30 – 300 mA

Following letter or letter sequence: Type

• C – Triode/pentode, triode/hexode or triode/heptode mixer
• D – Signal diode(s)
• F – Tetrode or pentode
• FD – Tetrode or pentode and diode(s)
• FL – Tetrode or pentode, and triode
• K – Small gas triode or tetrode thyratron
• L – Single or dual triode, including oscillator triode
• LD – Triode and diode(s)
• M – Optical tuning/level indicator
• P – Power tetrode or pentode
• PL – Power tetrode or pentode, and signal triode

Final number: Sequentially assigned number

Power rectifiers

Letter(s): Type

• U – High-vacuum half-wave rectifier
• UU – High-vacuum full-wave rectifier

Number: Sequentially assigned number

Examples:

Note: "AC/"-series receiver tubes are listed under other letter tubes - AC/

• 6C10 (6CU7/ECH42) – Triode/hexode mixer, Rimlock base
• 6F22 = 6BK8/6CF8/EF86 (6267) – Low-noise AF pentode, Noval base
• 6F33 – Shielded pentode, miniature 7-pin base
• 6FL2 = ECF812 – Triode + low-power beam tetrode, Noval base; 30FL2 (=PCF812) with a different heater
• 6L12 (6AQ8/ECC85) – Dual triode, Noval base
• 6L19 – Dual triode, 8-pin base
• 6M2 (6CD7/EM34) – Dual-sensitivity tuning indicator, 8-pin Octal base
• 6P9 = 6BM5 – Power pentode, miniature 7-pin base
• 6P15 (6BQ5/EL84) – Power pentode, Noval base
• 10M2 = UM35 (UM4) – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator
• 10PL12 (50BM8/UCL82) – Triode + power pentode, Noval base
• 30C17 = PCF87 – Triode + remote-cutoff pentode for use as VHF mixer in TV receivers
• 30FL2 = PCF812 – Triode + low-power beam tetrode, Noval base; 6FL2 (=ECF812) with a different heater
• 30PL13 = PCL800 – Triode + power pentode
• 30PL14 = PCL88 – Triode + power pentode
• U26 = 2J2/KY80 – CRT EHT rectifier, Noval base
• U381 (38A3/UY85) – Half-wave rectifier, Noval base
• UU9 (6BT4/EZ40) – Full-wave rectifier, Rimlock base

EEV system

This system consists of one or more letters followed by a sequentially assigned number^[43]

• A – High vacuum rectifier
• AFX – Rare gas filled triode thyratron
• AH – Mercury-vapor rectifier
• AX – Xenon filled rectifier
• B – Radiation-cooled triode
• BD – Mercury-vapor rectifier
• BK – Ignitron
• BM – Magnetron
• BR – Forced-air cooled triode
• BS – TR (Transmit/receive) cell, TB cell, Solid-state microwave device
• BT – Mercury-vapor or xenon filled thyratron
• BW – Water-cooled triode
• BY – Vapor-cooled triode
• C – Radiation-cooled tetrode
• CR – Forced-air cooled tetrode
• CW – Water-cooled tetrode
• CX – Hydrogen tetrode thyratron
• E – Storage tube
• FX – Hydrogen triode thyratron
• GX – Spark gap
• K – Klystron
• M – Magnetron
• NFT – Nernst filament, a source of mid-infrared radiation
• P – Video camera tube
• QS – Voltage-regulator tube
• QT – Cold-cathode trigger tube
• T – CRT
• U – Vacuum capacitor
• XL – Glow modulator tube, flashtube, gas laser

Examples:

• B142 – 400 W RF power triode up to 50 MHz similar to 833A
• B1109 = 3C24 – 25 W VHF power triode up to 60 MHz
• B1135 = 5867 = CV1350 – VHF power triode up to 100 MHz
• B1152 – 500W RF power triode up to 50 MHz
• QT1257 – Touch button tube, an illuminated capacitance touch switch; a cold-cathode DC relay tube, external (capacitive) starter activated by touching; then the cathode glow is visible. 6-pin Octal base
• XL601, XL602, XL603, XL627, XL628, XL631 and XL632 – Cold-cathode, linear light source (glow modulator tube), gas diode with a blue-violet glow, modulation up to 1 MHz, 8-pin base, for rotating-drum FAX receivers, etc.

ETL computing tubes system

The British Ericsson Telephones Limited (ETL), of Beeston, Nottingham (not to be confused with the Swedish TelefonAB Ericsson), original holder of the now-generic trademark Dekatron, used the following system:

• An initial letter denoting the filling:

• G – Gas-filled
• V – Vacuum

• One letter denoting the type:

• C – Common cathode Counter Dekatron that makes only carry/borrow cathodes separately available for cascading
• D – Diode, voltage reference, etc.
• PE – Trigger pentode, two starter electrodes and a keep-alive (primer) electrode for ion availability
• R – Register (Readout) – Digital indicator
• S – Trochotron or separate cathode Counter/Selector Dekatron that makes all cathodes available on individual pins for displaying, divide-by-n counter/timer/prescalers, etc.
• TE – Trigger tetrode, one starter electrode and a keep-alive electrode
• TR – Trigger triode, one starter electrode only

• A digit group:

• Dekatrons: Stage count
• Digital indicators: Display cathode count
• Diodes, voltage references: Nominal voltage
• Trigger tubes: Ignition voltage

• An optional digit group after a slash: Accessible cathodes count
• One letter denoting the type:

• A to F – British 4-pin, K8A Octal, B12A Duodecal phenolic bases
• G to T – All-glass tubes with B7G Miniature 7-pin, B9A Noval, B13B, B17A, B26A, B27A bases
• W to Z – All-glass tubes with wire ends

• An optional suffix:

• /M – Trochotron with magnetic shielding
• R – Shock and vibration-resistant
• /S – Tested to military specs

Examples:

• GC10/2P – Neon-filled, 1 kHz Miniature decade Counter Dekatron, a gas-filled, bidirecional decade counter tube
• GC10A – Helium-filled, decade Counter Dekatron
• GC10B – Neon-filled, 4 kHz Long life, decade Counter Dekatron

• GC10/4B – 4 kHz Decade Computing Counter Dekatron with carry/borrow cathodes "0" and "9" and intermediate cathodes "3" and "5" wired to separate pins

• GC10D – 20 kHz Decade Counter Dekatron, for single-pulse operation
• GC12/4B – 4 kHz Duodecimal Counter Dekatron with carry/borrow cathodes 11 and 12 and intermediate cathodes 6 and 8 wired to separate pins
• GCA10G – 10 kHz max. Decade Counter Dekatron with routing guides and aux anodes to directly drive Nixie tubes, B27A base without the inner pin ring
• GD2V – 2 kV, 16 J discharge tube, all-glass studded
• GD75P – 75 V Voltage reference, miniature 7-pin base
• GD90M – 90 V Voltage reference, miniature 7-pin base
• GD340X – 345 V/3...200 µA Corona voltage reference, all-glass pigtailed
• GD350X, GD350Y – 350 V/3...200 µA Corona voltage reference, all-glass pigtailed
• GD550W – 550 V, 1.5 J Discharge tube, e.g. for power relaxation oscillators, all-glass pigtailed
• GDT120M – 9 mA Gas-filled cold-cathode DC triode, one starter and a separate glow diode acting as an optical primer, miniature 7-pin base
• GR2G –  + -  Neon-filled digital indicator tube, 18 x 18 mm characters, side-viewing
• GR2H –  + -  Neon-filled digital indicator tube, 20 x 20 mm characters, top-viewing
• GR4G –  ¼ ½ ¾ 1  Neon-filled digital indicator tube, 18 x 30 mm characters, side-viewing
• GR7M –  + - V A Ω % ~  Neon-filled digital indicator tube, 15.5 mm character height, top-viewing
• GR10A – Gas-filled digital indicator tube with a dekatron-type readout
• GR10G –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 16.86 x 30 mm characters, side-viewing
• GR10H –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 12 x 19 mm characters, top-viewing
• GR10J –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 16.86 x 30 mm characters, side-viewing
• GR10K –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 12 x 19 mm characters, top-viewing
• GR10M –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 10 x 15.5 mm characters, top-viewing
• GR10W –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 8.42 x 15 mm characters, side-viewing, all-glass pigtailed
• GR12G –  A B C D E F G H I J K L  Neon-filled digital indicator tube, 16 x 30 mm characters, side-viewing
• GR12H –  E L M N P R S T U V W X  Neon-filled digital indicator tube, 16 x 30 mm characters, side-viewing

Note: More Nixie tubes under standard - ZM and professional - ZM

• GS10C – 4 kHz max. Decade Counter/Selector Dekatron, top-viewing, Duodecal base
• GS10D – Hydrogen-filled, 20 kHz max. Decade Counter/Selector Dekatron, Duodecal base
• GS10H – 4 kHz max. Decade Counter/Selector Dekatron with routing guides, B17A base
• GS12C – 4 kHz max. Duodecimal Counter/Selector Dekatron, with solder lugs
• GS12D – Neon-filled, 4 kHz max. duodecimal Counter/Selector Dekatron, Duodecal base with two additional pigtails for the guide electrodes
• GSA10G – 10 kHz max. Decade Counter/Selector Dekatron with routing guides and aux anodes to directly drive Nixie tubes, B27A base
• GTE120Y – 5 mA Subminiature DC trigger tetrode, one starter and one primer, all-glass pigtailed
• GTE130T – 8 mA_peak DC trigger tetrode, one starter and one primer, close tolerance, low aging, quadrant I operation only, Noval base
• GTE175M – 3.5 mA_avg, 50 mA_peak DC Trigger tetrode, one starter and one primer, miniature 7-pin base, for Dekatron coupling circuits
• GTR120W – 9 mA Subminiature DC trigger triode, 3-pin all-glass pigtailed, for computer applications
• GTR75M – 75 V Voltage reference, miniature 7-pin
• GTR95M/S – 95 V Voltage reference, miniature 7-pin
• GTR150 – Subminiature, primed 150 V voltage reference, all-glass pigtailed
• VS10G – Trochotron, an electron-beam decade counter tube
• VS10G-M – VS10G with a magnetic shield
• VS10H – High-current trochotron
• VS10K – Low-voltage trochotron

Marconi-Osram system

The British GEC-Marconi-Osram (M-OV) designation from the 1920s uses one or two letter(s) followed by a number and sometimes by a second letter identifying different versions of a particular type.^[11]

The letter(s) generally denote the type or use:

Note: A preceding letter M indicates a 4-volts AC, indirectly heated ("Mains Operated") tube

• A – General professional tube
• B – Dual triode
• D – Dual diode
• DA – More than 25 W power triode
• GT – Gas-filled triode
• GU – Gas-filled rectifier
• H – High-impedance signal triode
• KT – Beam power tetrode ("Kinkless Tetrode")
• KTW – Remote-cutoff beam tetrode
• KTZ – Sharp-cutoff beam tetrode
• L – Low-impedance signal triode

• LP – Power triode

• N – Power pentode
• P – Power triode up to 3 W

• PT – Power pentode
• PX – 3...25 W Power triode

• QP – Dual pentode
• S – Tetrode
• SP – Pentode
• U – Rectifier
• VP, VMP – Remote-cutoff pentode
• VS, VMS – Remote-cutoff tetrode
• W – Remote-cutoff pentode
• X – Triode/hexode mixer
• Y – Optical tuning/level indicator
• Z – Sharp-cutoff RF pentode

In most cases, the first digit of the following number is the heater rating:

• 2 – 2 V
• 3 – 13 V or 300 mA
• 4 – 4 V
• 5 – 5 V (Rectifiers)
• 6 – 6 V

Examples:

• A1834 = 6AS7G/ECC230 = CV2523 – Dual power triode (series regulator), Octal base
• B30 – Dual Class-B power triode
• B309 = 12AT7/ECC81 – High-mu dual triode. Commonly used as RF amplifier/mixer in VHF circuits
• B719 = 6AQ8/ECC85 – Dual RF triode, RF amp & mixer in FM receivers, Noval base
• D41 = EdiSwan V914 – Indirectly heated, dual detector diode, British 5-pin base
• D42 – Indirectly heated, single detector diode, British 4-pin base
• DA30 – AF power triode, P_a=30 W
• DA40 – AF power triode, P_a=40 W
• DA41 – AF power triode, P_a=50 W
• DA60 – AF power triode, P_a=60 W
• DA100 – AF power triode, P_a=100 W
• DA250 – AF power triode, P_a=250 W
• GT1 – Mercury vapor-filled, 1 kV, 300 mA_avg, 500 mA_RMS, 1 A_peak thyratron, 4 V/1.3 A heater, O5A European 5-pin base

• GT1A – Argon-filled, 300 V, 200 mA_avg, 300 mA_RMS, 600 mA_peak version of GT1
• GT1C = AN1 – Argon-filled, 500 V, 300 mA_avg, 500 mA_RMS, 1 A_peak version extensively used in the Colossus computer

• GU21 = EnglishElectricValve AH221 = Mullard RG4/1250 – Half-wave mercury-vapor rectifier, E40 Goliath Edison screw lamp base
• H11, H12 – Directly heated miniature AF triodes, 2 V/60 mA filament, for use in hearing aids; cf. KC50, KC51, Mullard DA1
• H63 = 6F5 – High-mu triode, Octal base
• H610 – Directly heated, high-mu AF triode, British 4-pin base
• HA1 (4 V heater), HA2 (6.3 V heater) – Acorn UHF triodes up to 600 MHz
• KT2 – 1 W Beam power tetrode, British 5-pin base, 2 V/200 mA filament
• KT21 – 1.25 W Beam power tetrode, British 5-pin base, 2 V/300 mA filament
• KT32 (25L6, 25L6G, 25L6GT, 25W6GT) – 7.5 W Beam power tetrode, Octal base, 26 V/300 mA heater for use in AC/DC radio receivers with series heater strings
• KT33 (25A6GT) – 5 W Beam power tetrode, Octal base, 26 V/300 mA heater for use in AC/DC radio receivers with series heater strings

• KT33C – KT33 with a center-tapped heater, so it can also be wired for 13 V/600 mA

• KT36 – 10 W Beam power tetrode, Octal base, 26 V/300 mA heater for use in AC/DC radio receivers with series heater strings
• KT41 – 8.6 W Beam power tetrode, British 7-pin base, 4 V/2 A heater
• KT55 – 25 W Beam power tetrode, Octal base, 52 V/300 mA heater for use in AC/DC radio receivers with series heater strings
• KT61 (6M6G, EL33) – 4.3 W Beam power tetrode, Octal base, 6.3 V/950 mA heater
• KT63 (6F6, 6F6G, 6F6GT) – 6 W Beam power tetrode, Octal base, 6.3 V/700 mA heater
• KT66 (6L6GC) – 7.25 W Beam power tetrode, Octal base, 6.3 V/1.27 A heater
• KT67 – 25 W RF beam power tetrode, B9G Loctal 9-pin base, 6.3 V/1.5 A heater
• KT71 (50L6GT) – 5 W Beam power tetrode, Octal base, 48 V/160 mA heater for use in AC/DC radio receivers with series heater strings
• KT77 – 30 W Beam power tetrode, Octal base, 6.3 V/1.4 A heater; drop-in replacement for the 6CA7/EL34 power pentode
• KT81 – KT61 with a B8G Loctal base
• KT88 = 6550A = CV5220 (EdiSwan 12E13, Brimar 7D11) – AF beam power tetrode, two tubes are capable of providing 100 W output, Class-AB₁, Octal base, 6.3 V/1.6 A heater
• KTW21 – Remote-cutoff RF/IF beam tetrode, 4-pin base with control grid on top cap, 2 V/100 mA filament; upgrade to the older W21
• KTW61, KTW62 – Remote-cutoff RF/IF beam tetrode, Octal base with control grid on top cap, 6.3 V/300 mA heater; upgrade to the older W61

• KTW61M – KTW61 with a metal particles spray-shielded envelope

• KTW63 – Remote-cutoff RF/IF beam tetrode, Octal base with control grid on top cap, 6.3 V/300 mA heater; upgrade to the older W63
• KTW73, KTW73M (Spray-shielded) – Remote-cutoff RF/IF beam tetrode, Octal base with control grid on top cap, 6.3 V/160 mA heater
• KTZ41 – Sharp-cutoff RF/IF beam tetrode, British 7-pin base with control grid on top cap, 4 V/1.5 A heater
• KTZ61 – Sharp-cutoff RF/IF beam tetrode, Octal base with control grid on top cap, 6.3 V/300 mA heater
• KTZ63 – Sharp-cutoff RF/IF beam tetrode, Octal base with control grid on top cap, 6.3 V/300 mA heater; upgrade to the older Z63, beam version of 6J7/EF37 with suppressor plates connected to cathode, not to a separate pin
• KTZ73, KTZ73M (Spray-shielded) – Sharp-cutoff RF/IF beam tetrode, Octal base with control grid on top cap, 6.3 V/160 mA heater
• L11, L12 – Directly heated, miniature AF power triodes, 2 V/60 mA filament, for use in hearing aids; cf. KD50, Mullard DA2, DA3
• L63 = 6J5 – Low-mu triode, Octal base
• L610 – Directly heated, low-mu RF triode, British 4-pin base
• MKT4 – 3.2 W Beam power tetrode, indirect 4 V/1 A heater, British 5 or 7-pin base
• MU12 = EdiSwan UU4 (350 V), MU14 = UU5 = Mullard IW4-500 (500 V) – Full-wave rectifier, indirect 4 V/2.5 A heater, British 4-pin base
• MX40 – Heptode pentagrid converter with an indirect 4 V/1 A heater and a British 7-pin base with g4 on top cap; similar to the Mullard FC4 octode
• N77 = 6AM5/EL91, N78 = 6BJ5 – Power pentodes, miniature 7-pin base
• N309 = 15A6/PL83 – CRT cathode drive power pentode
• P425 = Mullard PM254 – Power triode with a 4 V/200 mA battery heater and a British 4-pin base
• P610 – Directly heated AF power triode, British 4-pin base
• P625 – AF power triode
• PX4 – Directly heated AF power triode designed in the 1930s. Capable of providing about 4.5 W of audio
• PX25 – Directly heated AF power triode designed in the 1930s. Capable of providing about 25 W of audio
• QP21 – Directly heated dual AF (push-pull) power pentode, British 7-pin base
• QP240 – Directly heated dual AF (push-pull) power pentode, British 9-pin base
• S12 – Directly heated miniature AF tetrode, 2 V/60 mA filament, for use in hearing aids; cf. KE50, Mullard DAS1
• S610 – Directly heated sharp-cutoff RF tetrode, British 4-pin base
• U52 = 5AS4A/5U4GB – Full-wave rectifier, Octal base
• VS24 – Directly heated remote-cutoff RF tetrode, British 4-pin base
• W727 = 6BA6/EF93 = 5749 – Remote-cutoff RF pentode, miniature 7-pin base
• X41 – Triode/hexode mixer up to 60 MHz, designed as a drop-in replacement for the MX40 pentagrid converter

• X41c – X41 with a ceramic base for better frequency stability in VHF Band I TV tuners

• X61, X61M = 6J8G – British triode/heptode mixer, Octal based
• X63 = 6A8 – Heptode pentagrid converter, Octal based
• X727 = 6BE6/EK90 = 5750 – Pentagrid converter, miniature 7-pin base
• Y61, Y63 = 6U5G = Mullard VI103 – Tuneray optical tuning/level indicator, Octal base; similar to 6G5
• Z77 = 6AM6/EF91 – Sharp-cutoff RF pentode, miniature 7-pin base
• ZA1 (4 V heater), ZA2 (6.3 V heater) – Acorn sharp-cutoff pentodes

Marconi also traded some Mullard-Philips tubes, with a preceding letter M: MAZ1, MAZ41, MDAC21, MDAF40, MDAF41, MDF21, MDK21, MDK40, MDL21, MDL41, MDM21, MEBC3, MEF5, MEF6, MEF9, MUBC41, MUF9, MUF41, MUL41, MUM4

Media related to Marconi vacuum tubes at Wikimedia Commons

Mullard designations before 1934

Older Mullard tubes were mostly designated PM ("Philips-Mullard"), followed by a number containing the filament voltage.

Many later tubes were designated one to three semi-intuitive letters, followed by a number containing the heater voltage. This was phased out after 1934 when Mullard adopted the Mullard–Philips scheme.

Examples:^[2]

• 2D4 – Dual Diode with a 4 V/650 mA heater and a British 5-pin base
• AP4 = 4676 – Acorn UHF Pentode up to 430 MHz, 4 Volts heater
• AT4 = 4675 – Acorn UHF Triode up to 430 MHz, 4 Volts heater
• DA1 (2 V/50 mA filament), DB1 (1.5 V/70 mA filament) – Directly heated miniature AF triodes for use in Deaf Aids; cf. DC51, KC50, KC51, Marconi-Osram H11, H12
• DA2 (2 V/50 mA filament), DA3 (2 V/55 mA filament), DB3 (1.5 V/70 mA filament) – Directly heated, miniature AF power triodes for use in hearing aids; cf. DD51, KD50, Marconi-Osram L11, L12
• DAS1 (2 V/60 mA filament), DBS1 (1.5 V/70 mA filament) – Directly heated miniature AF tetrodes for use in hearing aids; cf. DF51, KE50, Marconi-Osram S12
• FC4 – Octode Frequency Converter with a 4 V/650 mA heater and a British 7-pin base with g4 on top cap; similar to the Marconi-Osram MX40 heptode^[44]
• FC13 – FC4 with a 13 V/200 mA heater and a side-contact 8 base

• FC13C – FC13 with a British 7-pin base

• Pen20 – Power Pentode with a 20 V/180 mA heater and a British 5- or 7-pin base
• PM254 = M-OV P425 – "Super Power" triode with a 4 V/200 mA battery heater and a British 4-pin base
• TDD4 = M-OV MHD4 = EdiSwan AC/HLDD – Triode + dual Diode with a 4 V/550 mA heater and a British 7-pin base
• TH21C – Triode/Hexode mixer with a 21 V/200 mA series heater and a British 7-pin base
• TP4 = EdiSwan AC/TP – Triode + Pentode with a 4 V/1.25 A heater and a British 7-pin base
• VP2 = M-OV VP21 = VP215 – Variable-mu Pentode with a 2 V/180 mA heater and a British 7-pin base

Media related to Mullard vacuum tubes at Wikimedia Commons

Philips system before 1934

The system consisted of one letter followed by 0 or 1 or 3 or 4 digits.^[28][45][11] It was phased out after 1934 when Philips adopted the Mullard–Philips scheme.

1st letter: Heater current

• A – 60...90 mA
• B – 100...190 mA (This designation lived on as the "B" (180 mA) in the Mullard–Philips system)
• C – 200...390 mA (This designation lived on as the "C" (200 mA) in the Mullard–Philips system)
• D – 400...690 mA
• E – 700...1390 mA
• F – 1.4...2 A

For the earliest tubes, this letter was optionally followed by a sequentially assigned, single digit (examples); later tubes were assigned numbers according to the following scheme:

1 or 2 digit(s): Heater voltage

Last 2 digits: Type

• 00–40, 99: Triode amplification factor
• 41–98:

• second-last digit: sequentially assigned, starting at 4
• last digit:

• 1 – Tetrode with a space charge grid (the 2nd grid is the control grid)
• 2 – Tetrode with a screen grid (the 1st grid is the control grid)
• 3 – Power pentode
• 4 – Binode, a diode/triode or diode/tetrode
• 5 – Remote-cutoff RF tetrode
• 6 – Signal pentode
• 7 – Remote-cutoff RF pentode
• 8 – Sharp-cutoff hexode mixer
• 9 – Remote-cutoff hexode mixer

Examples:^[46]

• A106 – Directly heated triode, 1 V, 60 mA filament, amplification factor = 6
• A425 = RE034 = HR406 – RF triode, 4 V, 60 mA filament
• A435 – Directly heated triode, 4 V, 60 mA filament, amplification factor = 35
• A441 – Directly heated tetrode with a space charge grid, 4 V, 60 mA filament
• A442 = RES094 = S406 – Directly heated tetrode with a screen grid, 4 V, 60 mA filament
• B409 = RE134 = L414 – Triode, 4 Volt, 140 mA filament
• B2038 = REN1821 = R2018 = A2118 – Triode, 180 mA heater
• B2043 = RENS1823D = PP2018D = L2318D – Indirectly heated power pentode, 20 V, 180 mA DC series heater
• B2044 = RENS1854 = DS2218 – Indirectly heated diode + tetrode, 20 V, 180 mA DC series heater

• B2044S = REN1826 – Indirectly heated diode + triode, 20 V, 180 mA DC series heater

• B2045 = RENS1819 – Indirectly heated remote-cutoff RF tetrode, 20 V, 180 mA DC series heater
• B2048 = RENS1824 = MH2018 – Hexode mixer, 20 V, 180 mA heater
• B2099 = REN1814 – Indirectly heated triode, 20 V, 180 mA DC series heater, amplification factor = 99
• E443H = RES964 = PP4101 = L496D = RTP4 = P435 – Power pentode, 4 V heater
• E446 = RENS1284 = HP4101 – Indirectly heated RF pentode, 4 V, 1.1 A heater
• E447 = RENS1294 = HP4106 – Indirectly heated remote-cutoff RF pentode, 4 V, 1.1 A heater
• E448 = RENS1224 = MH4100 – Indirectly heated sharp-cutoff hexode mixer, 4 V, 1.2 A heater
• E449 = RENS1234 = FH4105 – Indirectly heated remote-cutoff hexode mixer, 4 V, 1.2 A heater
• F215 – Indirectly heated triode, 2.5 V, 1.5 A heater, amplification factor = 15

Media related to Philips vacuum tubes at Wikimedia Commons

Media related to Philips gas discharge tubes at Wikimedia Commons

STC/Brimar receiving tubes system

"British Manufactured American Radio" (tubes) used all American designations; STC used the following system:

First number: Type^[11]

• 1 – Half-wave rectifier
• 2 – Diode
• 3 – Power triode
• 4 – High-mu triode
• 5 – Sharp-cutoff tetrode
• 6 – Vari-mu tetrode
• 7 – Power or video pentode
• 8 – Sharp-cutoff RF pentode
• 9 – Vari-mu RF pentode
• 10 – Dual diode
• 11 – Triode and dual diode
• 12 – AF Pentode and dual diode
• 13 – Dual high-mu triode
• 14 – Dual Class-B power triode
• 15 – Heptode
• 16 – DC-coupled power triode
• 17 – RF pentode and dual diode
• 18 – Pentode and triode
• 20 – Triode/hexode or triode/heptode mixer

Next letter: Heater rating

• A – 3.6 to 4.4 V Indirectly heated
• B – 2 V Directly heated
• C – Directly heated other than 2 or 4 V
• D – All other heater ratings, indirectly heated other than 4 V

Number: Sequentially assigned number

Examples:

• 1D6 – Indirectly heated, half-wave rectifier, British 5-pin base
• 4D1 – Indirectly heated triode, British 7-pin base
• 7A3 – Indirectly heated power pentode, British 7-pin base
• 8A1 – Indirectly heated RF sharp-cutoff pentode, British 5-pin base with anode top cap
• 9A1 – Indirectly heated RF/IF remote-cutoff pentode, British 5-pin base with anode top cap
• 10D1 – Indirectly heated, common cathode dual diode, British 5-pin base
• 11A2 – Indirectly heated, common cathode dual diode + triode, British 7-pin base
• 13D3 – Indirectly heated, common cathode dual triode, Noval base
• 15A2 – Indirectly heated, heptode pentagrid converter, British 7-pin base
• 20D4 – Indirectly heated, triode/heptode mixer, Noval base

Valvo system before 1934

Valvo^{(de, it)} was a major German electronic components manufacturer from 1924 to 1989; a Philips subsidiary since 1927, Valvo was one of the predecessors of NXP Semiconductors.

The system consisted of one or two letters followed by 3 or 4 digits. It was phased out after 1934 when Valvo adopted the Mullard–Philips scheme.

First letter(s): Type^[47]

• A – Triode
• AN – Binode, a diode/triode or diode/tetrode
• G – Rectifier
• H – RF tube
• L – Power tube
• LK – Power amplifier
• U – Triode with a space charge grid
• W – Triode for resistor-coupled amplifiers
• X – Hexode

Number:

• If the first digit is 4, the tube has a 4 V heater
• Otherwise, the last two digits give the heater current in tens of mA.

A following letter D indicates more than one grid, not counting a space charge grid

Examples:^[46]

• A2118 = B2038 = REN1821 = R2018 – Triode, 180 mA (=18⋅10 mA) heater
• H2018D = B2042 = RENS1820 = S2018 – RF Tetrode, 180 mA heater
• L496D = E443H = RES964 = PP4101 = RTP4 = P435 – Power pentode, 4 V heater
• L2318D = B2043 = RENS1823D = PP2018D – Power pentode, 180 mA heater

Media related to Valvo vacuum tubes at Wikimedia Commons

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East European systems

Lamina transmitter tube system

Polish Lamina^(pl) transmitter tube designations consist of one or two letters, a group of digits and an optional letter and/or two digits preceded by a "/" sign.

The first letter indicates the tube type, two equal letters denoting a dual tube:

• P – Pentode
• Q – Tetrode
• T – Triode

A group of digits represents the maximum anode power dissipation in kW

An optional letter specifies the cooling method:

• <none> – Radiation
• P – Forced-air
• W – Water

The first of the two digits after the "/" sign means:

• 1 – Tube for radio broadcasting and radiocommunication equipment
• 2 – Tube for industrial equipment
• 3 – Tube used in TV broadcasting equipment
• 4 – Tube for radiocommunication equipment with unbalanced modulation
• 5 – Modulator or pulse tube

The second digit after the "/" is sequentially assigned.

Examples:

• Q01 – Power tetrode up to 125 MHz, 0.1 kW (=100 W)
• Q3.5 – Power tetrode up to 220 MHz, 3.5 kW
• QQ-004/11 – Dual beam power tetrode up to 500 MHz, 0.04 kW (=40 W)

• T01 – Power triode up to 200 MHz, 135 W
• T015/21 – Power triode up to 150 MHz, 150 W
• T02 – Power triode up to 60 MHz, 200 W
• T05P/31 – Forced-air cooled power triode up to 1 GHz, 1 kW
• T2/22 – Power triode up to 60 MHz, 3 kW
• T6 – Power triode up to 30 MHz, 6 kW
• T8P/21 – Forced-air cooled power triode up to 120 MHz, 8 kW
• T10P/22 – Power triode up to 30 MHz, 10 kW
• T-25P – Forced-air cooled power triode up to 30 MHz, 25 kW
• T60W/21 – Water-cooled power triode up to 30 MHz, 6 kW

Media related to Lamina vacuum tubes at Wikimedia Commons

Media related to Lamina gas discharge tubes at Wikimedia Commons

RFT transmitter tube system

Rundfunk- und Fernmelde-Technik^{(de, sv)} was the brand of a group of telecommunications manufacturers in the German Democratic Republic. The designation consists of a group of three letters and a group of three or four digits.

The first two letters determine the tube type:

• GR – Rectifier tube
• SR – Transmitter tube
• VR – Amplifier tube

The third letter specifies the cooling method:

• L – Forced-air
• S – Radiation
• V – Vapor (the anode is immersed in evaporating water, and the steam is collected, condensed and recycled)
• W – Water

The first digit (or the first two digits in double tubes) indicates the number of electrodes:

• 2 – Diode
• 3 – Triode
• 4 – Tetrode
• 5 – Pentode

The last two digits are sequentially assigned.

Examples:

• GRS251 – Radiation-cooled 25 kV/300 mA rectifier
• SRL/W314 – Forced-air/water-cooled triode up to 30 MHz, 12 kW
• SRL364 – Forced-air cooled triode up to 175 MHz, 14 kW
• SRL458 – Forced-air cooled tetrode up to 790 MHz, 10 kW
• SRL462 – Forced-air cooled tetrode up to 30 MHz, 25 kW
• SRS301 – Radiation-cooled triode up to 40 MHz, 900 W
• SRS362 – Radiation-cooled triode up to 100 MHz, 1.25 kW
• SRS401 – Radiation-cooled tetrode up to 120 MHz, 1 kW
• SRS464 – Radiation-cooled, vibration-resistant pulse tetrode up to 300 kW
• SRS4451 – Radiation-cooled dual tetrode up to 500 MHz, 60 W
• SRS4452 = QQE03/20 = 6252 – Radiation-cooled dual tetrode up to 600 MHz, 20 W
• SRS4452 – Radiation-cooled dual tetrode up to 600 MHz, 20 W
• SRS4453 – Pulse version of the SRS4451
• SRS501 – Radiation-cooled pentode up to 50 MHz, 100 W
• SRS552N = ГУ-50 – Radiation-cooled pentode up to 120 MHz, 50 W
• SRV355 – Vapor-cooled triode up to 30 MHz, 50 kW
• SRW353 – Water-cooled tetrode up to 220 MHz, 15 kW
• VRS303 – Radiation-cooled AF triode, 1 kW
• VRS328 – Radiation-cooled AF triode, 150 W
• VRS331 – Radiation-cooled AF triode, 450 W

Note: RFT used the Mullard–Philips and RETMA schemes for their low-power tubes.

—Microwave tubes:

• HKR – Reflex Klystron
• HMD – CW Magnetron
• HMI – Pulse Magnetron
• HRO – Backward-wave oscillator
• HSE – TR cell
• HSS – ATR cell
• HT – Triode
• HTG – Triode oscillator
• HWE – Signal traveling-wave tube
• HWL – Power traveling-wave tube

Then a sequentially assigned number, the first one or two digits of which give the frequency in GHz.

Media related to RFT vacuum tubes at Wikimedia Commons

Tesla systems

Signal tubes

Besides the genuine Mullard–Philips system, Tesla also used an M-P/RETMA hybrid scheme:^[11]

First number: Heater voltage, as in the RETMA system

Next letter(s): Type, subset of the Mullard–Philips system

Next digit: Base

• 1 – K8A Octal
• 2 – B8G Loctal
• 3 – B7G Miniature 7-pin
• 4 – B9A Noval
• 5 – Special, mostly 9 out of 10 1.25mm pins on a 25mm-diameter circle
• 6 – B11A Submagnal
• 7 – B12A Duodecal
• 8 – B14A Diheptal
• 9 – Pigtails

Last digit: Sequentially assigned number

Examples:

• 1M90 = DM70/1M3 – Subminiature indicator tube, 1.4 V/25 mA filament, all-glass pigtailed
• 1Y32 – 7-pin miniature CRT EHT rectifier with 1.4 V/265 mA filament

• 1Y32T – 1Y32 with internal X-radiation shielding

• 4L20 – Directly heated RF power pentode, center-tapped 4.2 V/325 mA filament; Soviet 4П1Л (↦4P1L), German RL4,2P6 with Loctal base
• 6B31 – Dual diode up to 700 MHz, 6.3 V/300 mA heater, miniature 7-pin base
• 6BC32 = 6AV6/EBC91 – Dual diode + triode, 6.3 V/300 mA heater, miniature 7-pin base
• 6CC31 = 6J6/ECC91 – Dual VHF triode up to 600 MHz, 6.3 V/450 mA heater, miniature 7-pin base
• 6CC42 = 2C51 = 6Н3П↦6N3P (5670) – VHF dual triode, 6.3 V/350 mA heater, Noval base
• 6F24 – Telecom pentode, 6.3 V/450 mA heater, Loctal base
• 6F36 = 6AH6 = 6Ж5П↦6J5P – Sharp-cutoff IF/video pentode, 6.3 V/450 mA heater, miniature 7-pin base
• 6H31 = 6BE6/EK90 = 6А2П↦6A2P – Heptode mixer, 6.3 V/300 mA heater, miniature 7-pin base
• 6L31 = 6AQ5/EL90 – Power pentode, 6.3 V/450 mA heater, miniature 7-pin base
• 6L41 = 5763 = 6П1П↦6P1P – Beam power tetrode, 6.3 V/750 mA heater, Noval base
• 35Y31 – Half-wave rectifier, 35 V/150 mA series heater; UY1N with miniature 7-pin base

Power tubes

First letter:

• R – Rectifier or RF tube
• U – Gas-filled power rectifier
• Z – Modulator tube

Next letter(s): Type, subset of the Mullard–Philips scheme

Next number: Anode dissipation in W (if radiation-cooled) or kW (otherwise)

The next letter specifies the cooling method:

• <none> – Radiation
• V – Vapor
• X – Forced-air
• Y – Water

Examples:

• RA0007A (Octal base), RA0007B (Noval base) – 600 V, 700 µA Directly heated, thermally-limited (=saturated) emission diode, 1.4 V/3.5 A_max uncoated tungsten filament, usable as a heating current-controlled, variable series resistor in voltage/current stabilizer circuits, or as an RMS heating current-to-DC anode current converter, or as a noise diode; cf. 5845, YA1000
• RA025B – 20 kV, 250 mA Half-wave rectifier with an E40 Goliath Edison screw lamp base and an anode screw top cap
• RA05A – 25 kV, 700 mA Half-wave rectifier with an E40 Goliath Edison screw lamp base and an anode screw top cap
• RA7YB – 25 kV, 7 A Half-wave rectifier
• RA100A – 40 kV, 100 mA Half-wave rectifier with an E40 Goliath Edison screw lamp base and an anode top cap

• RC5B – Bowl-type UHF power triode up to 5 W

• RD27AS – Radiation-cooled power triode up to 25 MHz, 27 W
• RD200B – Radiation-cooled power triode up to 60 MHz, 200 W
• RD300S – Radiation-cooled power triode up to 200 MHz, 300 W
• RD1XB – Water-cooled power triode up to 30 MHz, 1 kW
• RD1.5XA – Air-cooled power triode up to 30 MHz, 1.5 kW
• RD2XF – Air-cooled power triode up to 150 MHz, 2 kW
• RD3XL – Air-cooled power triode up to 30 MHz, 2 kW
• RD5XF – Air-cooled power triode up to 100 MHz, 5 kW
• RD5YA – Water-cooled power triode up to 20 MHz, 5 kW
• RD8XA – Air-cooled power triode up to 3 MHz, 8 kW
• RD12XB – Air-cooled power triode up to 30 MHz, 12 kW
• RD12YB – Water-cooled power triode up to 30 MHz, 12 kW
• RD18YA – Water-cooled power triode up to 30 MHz, 18 kW
• RD20VL – Vapor-cooled power triode up to 100 MHz, 20 kW
• RD20XF – Air-cooled power triode up to 30 MHz, 20 kW
• RD50VL – Vapor-cooled power triode up to 100 MHz, 50 kW
• RD50XA – Air-cooled power triode up to 3 MHz, 50 kW
• RD50YA – Water-cooled power triode up to 10 MHz, 50 kW
• RD75YB – Water-cooled power triode up to 3 MHz, 75 kW
• RD150YA – Water-cooled power triode up to 3 MHz, 150 kW

• RE40AK = KT88
• RE65A – Radiation-cooled beam power tetrode up to 260 MHz, 65 W
• RE125C – Radiation-cooled beam power tetrode up to 235 MHz, 125 W
• RE400C – Radiation-cooled beam power tetrode up to 235 MHz, 400 W
• RE1000F – Radiation-cooled beam power tetrode up to 150 MHz, 1 kW
• RE041XL – Air-cooled beam power tetrode up to 250 MHz, 500 W
• RE0125XL – Air-cooled beam power tetrode up to 500 MHz, 150 W
• RE025XA – Air-cooled beam power tetrode up to 500 MHz, 250 W
• RE1.5XL – Air-cooled beam power tetrode up to 250 MHz, 2 kW
• RE5XL – Air-cooled beam power tetrode up to 250 MHz, 5 kW
• RE20XL – Air-cooled beam power tetrode up to 220 MHz, 20 kW

• REE30A – Radiation-cooled dual beam power tetrode up to 250 MHz, 20 W

• RL15A – Radiation-cooled power pentode up to 60 MHz, 20 W
• RL40A – Radiation-cooled power pentode up to 120 MHz, 40 W
• RL65A – Radiation-cooled power pentode up to 15 MHz, 65 W

• UA025A – 10 kV, 250 mA Argon-filled, half-wave rectifier with an E27 Edison screw lamp base and an anode screw top cap
• UA1A – 8 kV, 1 A Half-wave mercury-vapor rectifier with an E40 Goliath Edison screw lamp base and an anode screw top cap
• UA3A – 11 kV, 3 A Half-wave mercury-vapor rectifier with an E40 Goliath Edison screw lamp base and an anode screw top cap
• UA5A – 11 kV, 5 A Half-wave mercury-vapor rectifier with a 2-pin base and an anode screw top cap

• ZD1000F – Radiation-cooled power triode up to 60 MHz, 1 kW
• ZD1XB – Air-cooled AF power triode up to 1.2 kW
• ZD3XH – Air-cooled power triode up to 60 MHz, 3 kW
• ZD8XA – Air-cooled power triode up to 20 MHz, 8 kW
• ZD12YA – Air-cooled AF power triode up to 20 MHz, 12 kW

• ZE025XS – Air-cooled beam power tetrode up to 400 MHz, 250 W

Media related to Tesla vacuum tubes at Wikimedia Commons

Media related to Tesla gas discharge tubes at Wikimedia Commons

Tungsram receiving tubes system before 1934

The Tungsram system was composed of a maximum of three letters and three or four digits.^[48][47] It was phased out after 1934 when Tungsram adopted the Mullard–Philips scheme, frequently preceding it with the letter T, as in TAD1 for AD1.

Letter: System type:

Note: A preceding letter A indicates an indirectly heated tube

• D – Detector diode
• DD – Dual diode
• DG – Tetrode with a space charge grid (the 2nd grid is the control grid)
• DS – Diode-tetrode
• FH – Remote-cutoff hexode pentagrid converter
• G – Preamplifier triode
• H – Voltage amplifier triode or grid-leak detector
• HP – RF pentode
• HR – RF triode
• L – AF power triode
• MH – Hexode pentagrid converter
• MO – Octode pentagrid converter
• O – Transmitting tube
• P – Power triode
• PP – Power pentode
• PV – Full-wave rectifier
• R – High-Mu triode
• S – Tetrode
• V – Half-wave rectifier
• X – US-licensed tube

Number:

• First digit (or the first two digits): Heater voltage
• Remaining digits: Heater current in tens of mA, but the last digit is sequentially assigned

Examples:^[46]

• AS4100 – Tetrode, 4 V, 1 A (=100⋅10 mA) indirect heater
• FH4105 = E449 = RENS1234 – Indirectly heated remote-cutoff hexode mixer, 4 V, 1.2 A heater
• HP4101 = E446 = RENS1284 – RF pentode, 4 V, 1 A filament
• HP4106 = E447 = RENS1294 – Indirectly heated remote-cutoff RF pentode, 4 V, 1.1 A heater
• HR406 = A425 = RE034 – RF triode, 4 V, 60 mA (=6⋅10 mA) filament
• L414 = B409 = RE134 – Triode, 4 Volt, 140 mA (=14⋅10 mA) filament
• MH2018 = B2048 = RENS1824 – Hexode mixer, 20 V, 180 mA (=18⋅10 mA) heater
• MH4100 = E448 = RENS1224 – Indirectly heated sharp-cutoff hexode mixer, 4 V, 1.2 A heater
• PP2018D = B2043 = RENS1823D = L2318D – Indirectly heated power pentode, 20 V, 180 mA DC series heater
• PP4101 = E443H = RES964 = L496D = RTP4 = P435 – Power pentode, 4 V heater
• PV4200 – Full-wave rectifier, 4 V, 2 A (=200⋅10 mA) filament
• R2018 = B2038 = REN1821 = A2118 – Triode, 180 mA heater
• S406 = A442 = RES094 – Directly heated tetrode with a screen grid, 4 V, 60 mA filament
• S2018 = B2042 = RENS1820 = H2018D – RF Tetrode, 180 mA heater

Media related to Tungsram vacuum tubes at Wikimedia Commons

Russian systems

Vacuum tubes produced in the former Soviet Union and in present-day Russia are designated in Cyrillic. Some confusion has been created in transliterating these designations to Latin.

1929 system

The first system was introduced in 1929. It consisted of one or two letters and a sequentially assigned number with up to 3 digits^[47]

First letter: System type:

• Б ⟼ B – Power oscillator tube or barretter
• В ⟼ V – Rectifier (Russian: Выпрями́тель "Rectifier")
• Г ⟼ G – RF power tube (Russian: Генератор "Generator")
• Ж ⟼ J – Low-power oscillator tube
• M ⟼ M – Modulator
• Н ⟼ N – AF amplifier (Russian: Низкий "Low" [frequency])
• П ⟼ P – Receiver tube (Russian: Приёмная "Reception")
• С ⟼ S – Special tube, such as a pentode or a CRT (Russian: Специальный "special")
• Т ⟼ T – Carrier frequency tube
• У ⟼ U – Amplifier tube (Russian: Усилитель "Amplifier")

Second letter (optional): Type of cathode:

• Б ⟼ B – Barium-coated
• К ⟼ K – Carburized
• О ⟼ O – Oxide-coated
• Т ⟼ T – Thoriated
• Ц ⟼ C – Caesium-coated

Then a hyphen ("-"), followed by a sequentially assigned number

Examples:^[49][50]

• ВО-116, ВО-188, ВО-202 ⟼ VO-116, VO-188, VO-202 – Full-wave rectifiers with an oxide-coated cathode
• СБ-242, СБ-244, СО-241 ⟼ SB-242, SB-244, SO-241 – 2-volts directly heated tube set for budget-priced portable, battery-operated radios
• СО-118, СО-122, СО-124 ⟼ SO-118 (Triode), SO-122 (Power pentode), SO-124 (Tetrode) – 4-volts indirectly heated tube set for premium radios
• CO-148 ⟼ SO-148 – Variable-mu tetrode with an oxide-coated cathode
• СО-242 ⟼ SO-242 – Heptode with an oxide-coated cathode
• УБ-110 ⟼ UB-110 – Triode with a barium-coated cathode
• УО-104, УО-186 ⟼ UO-104, UO-186 – Power triodes
• СБ-154, УБ-107, УБ-110, УБ-132 ⟼ SB-154, UB-107, UB-110, UB-132 – Budget-priced, 4-volts directly heated power triodes

In 1937, the Soviet Union purchased a tube assembly line from RCA (who at the time had difficulties raising funds for their basic operations), including production licenses and initial staff training, and installed it on the Светлана (Svetlana) plant in St. Petersburg, Russia. US-licensed tubes were produced since then under an adapted RETMA scheme.

Examples:^[51]

• 6Ф5 = 6F5 – High-mu triode
• 6Ф6 = 6F6 – Power pentode
• 6Х6 = 6H6 – Dual diode
• 6Ж7 = 6J7/EF37 – Sharp-cutoff pentode
• 6Л6 = 6L6 – Beam power tetrode
• 6Л7 = 6L7 – Pentagrid converter
• 6Н7 = 6N7 – Dual power triode
• 6АЖ5 = 6AJ5 – Low (6.3-80 V) anode voltage, sharp-cutoff pentode

The Chinese 广州曙光无线电厂 (Guangzhou Shuguang Radio Factory) did the reverse, adapting the GOST system (below) to Latin letters for some of their tubes.^[52]

GOST standard tubes system

In the 1950s a 5-element system (Russian: Государственный Стандарт "State standard" ГОСТ↦GOST 5461-59, later 13393-76) was adopted in the (then) Soviet Union for designating receiver vacuum tubes.^[53][54]

The 1st element is a number specifying filament voltage in volts (rounded to the nearest whole number; 06 means 0.625 V)

The 2nd element is a Cyrillic character specifying the type of device:

• А ⟼ A – Pentagrid converter
• Б ⟼ B – Combined diode-pentode
• В ⟼ V – Vacuum tube with secondary emission
• Г ⟼ G – Combined triode-diode
• Д ⟼ D – Diode, including damper diodes
• Е ⟼ Ye – Optical tuning/level indicator
• Ж ⟼ J – Sharp-cutoff pentode
• И ⟼ I – Triode/hexode, triode/heptode or triode/octode mixer
• К ⟼ K – Variable-mu (remote-cutoff) pentode
• Л ⟼ L – Nonode
• Н ⟼ N – Dual triode

• МН ⟼ MN – Mechanotron-type^(ru) mechano-electronic displacement sensor^[55]

• П ⟼ P – Power pentode or beam power tetrode
• Р ⟼ R – Dual pentode or a dual tetrode
• С ⟼ S – Triode
• У ⟼ U – Power triode (was soon deprecated)
• Ф ⟼ F – Combined triode-pentode
• Х ⟼ H or X – Dual diode

• МХ ⟼ MH – Mechanotron-type mechano-electronic displacement sensor
• МДХ ⟼ MDH – Mechanotron-type mechano-electronic pressure sensor
• МУХ ⟼ MUH – Mechanotron-type mechano-electronic rotation sensor

• Ц ⟼ C – Low-power rectifier (kenotron)
• Э ⟼ E – Tetrode

The 3rd element is a sequentially assigned number – a series designator that distinguishes between different devices of the same type.

The 4th element denotes vacuum tube construction (base, envelope):

• <none> – All-metal tube
• Д ⟼ D – Disk-seal tube for UHF operation
• Ж ⟼ J – Acorn tube
• К ⟼ K – Metal-ceramic envelope
• Л ⟼ L – Loctal base
• М ⟼ M – Short envelope with an Octal base
• Н ⟼ N – Nuvistor
• П ⟼ P – Miniature 9-pin (Noval) or 7-pin (Heptal) all-glass envelope (22.5 or 19 mm in diameter)
• Р ⟼ R – Subminiature all-glass envelope with a diameter up to 5 mm
• А ⟼ A – Subminiature all-glass envelope (5 to 8 mm in diameter) with flexible leads
• Б ⟼ B – Subminiature all-glass envelope (8 to 10.2 mm in diameter) with flexible leads
• Г ⟼ G – Glass envelope (10.2 to 22.5 mm in diameter)
• С ⟼ S – Glass envelope (greater than 22.5 mm in diameter), typically with an Octal base

The 5th element is optional. It consists of a hyphen ("-") followed by one or more characters denoting special characteristics; in most cases this means construction differences to the basic version (rather than a selection for those characteristics from the regular-quality production):

—GOST 5461-59:

• Р ⟼ R – Improved quality
• ВР ⟼ VR – Increased reliability
• ДР ⟼ DR – Very long life
• ЕР ⟼ YeR – Long-life

—GOST 13393-76:

• В ⟼ V – Shock/vibration resistant
• Д ⟼ D – Long-life (≥10000 h)
• Е ⟼ Ye – Long-life (≥5000 h)
• И ⟼ I – Pulse power tube
• К ⟼ K – Low-microphonics/low-noise

For examples see below

Professional tubes system

There is another designation system for professional tubes such as transmitter ones.^[56][47]

The 1st element: Function

• БХ, БХВ, БСМ, БСВ ⟼ BH, BHV, BSM, BSV – X-ray tube
• В ⟼ V – Vacuum power rectifier (Russian: Выпрями́тель)

• ВГ ⟼ VG – Gas-discharge or mercury-vapor power rectifier
• ВИ ⟼ VI – Pulse power rectifier

• Д ⟼ D – Gas-discharge lamp
• Г ⟼ G – RF power tube (Russian: Генератор "Generator"), two-lettered with some notable exceptions such as the Г807

• ГД ⟼ GD – Longwave tube (Russian: Длинный "Long")
• ГК ⟼ GK – Shortwave tube (≤30 MHz; Russian: Короткий "Short")
• ГУ ⟼ GU – VHF tube (≤300 MHz; Russian: Ультракоро́ткий "Ultra-short" [wave tube])
• ГС ⟼ GS – Microwave tube (>300 MHz; Russian: Сверхвысокочастотный)
• ГМ ⟼ GM – Modulator tube
• ГИ ⟼ GI – Impulse tube
• ГМИ ⟼ GMI – Pulse modulator tube
• ГП ⟼ GP – Power tube for use in shunt or series-pass voltage regulators
• ГПИ ⟼ GPI – Pulse power tube
• ГГ ⟼ GG – Gas-discharge rectifier
• ГР ⟼ GR – Mercury-vapor rectifier (Russian: Ртуть "Mercury")
• ГШ, ГШП ⟼ GSha, GShaP – Noise diode (Russian: Шум "Noise")

• ЕГ, ОГ ⟼ YeG, OG – Dekatron
• И ⟼ I – Ignitron
• К, КУ, КИУ ⟼ K, KU, KIU – (Reflex-)Klystron
• Л ⟼ L – Beam deflection tube incl. CRTs (Russian: Электронно-лучевые приборы "Electron beam device", "CRT")

Most CRT designations are preceded by a number giving the screen diagonal or diameter in cm (rounded-off to the nearest whole number)

• ЛИ ⟼ LI – Video camera tube or monoscope (Russian: Изобразить "to picture")
• ЛК ⟼ LK – CRT for TV with magnetic deflection (Russian: Кинеско́п, meaning "picture tube", not "Kinescope")
• ЛМ ⟼ LM – Radar CRT, flying-spot scanner, Skiatron, etc. with magnetic deflection
• ЛН ⟼ LN – Storage tube (Russian: Накопить "to stockpile")
• ЛНС ⟼ LNS – Typotron (Russian: Символ; Знакопечатающая запоминающая трубка "Symbol/Character/Glyph"; "Typographic memory tube")
• ЛО ⟼ LO – CRT for oscilloscopes with electrostatic deflection
• ЛФ ⟼ LF – Analog function generator
• ЛП ⟼ LP – Trochotron (Russian: Электронно-лучевой переключатель "Electron beam switch")
• ЛС ⟼ LS – Charactron (Russian: Знакопечатающая трубка "Typographic tube")

• М ⟼ M – Magnetron

• МИ ⟼ MI – Pulse magnetron
• МУ, МИУ ⟼ MU, MIU – Crossed-field amplifier

• Н ⟼ N – Nuvistor
• ОВ, ОВС ⟼ OV, OVS – Backward-wave amplifier (Russian: Ла́мпа обра́тной волны́)
• Р, РБ, РЭ ⟼ R, RB, RE – Spark gap, surge arrester (Russian: Разрядка "discharge")
• СБМ, СБС, СБТ, СИ, СГМ, СТС ⟼ SBM, SBS, SBT, SI, SGM, STS – Geiger–Müller tube
• СГ ⟼ SG – Voltage reference
• СТ ⟼ ST – Barretter
• Т ⟼ T – Thyratron

• ТГ, ТГИ ⟼ TG, TGI – Gas-filled thyratron
• ТР ⟼ TR – Mercury-vapor thyratron
• ТХ, ТХИ, МТХ ⟼ TH, THI, MTH – Gas-filled, cold-cathode thyratron (Russian: Холодный "Cold")

• УВ, УВИ ⟼ UV, UVI – Forward-wave amplifier
• Ф ⟼ F – Phototube

• ФЭК ⟼ FEK – High-speed pulse phototube with a coaxial output connector
• ФЭУ ⟼ FEU – Photomultiplier (Russian: Фотоэлектронный умножитель)

• ЭМ ⟼ EM – Electrometer tube
• ЭПЛ ⟼ EPL – Semiconductor/tube hybrid (Russian: Электронно-полупроводниковая лампа)

Next elements:

• Ignitrons, Rectifier tubes, Thyratrons:

A digit

Then a hyphen ("-"), followed by the anode current in A

Then a slash ("/"), followed by the anode voltage in kV

Then a letter specifying the cooling method:

• <none> – Radiation
• А ⟼ A – Water

• Transmitting tubes:

A hyphen ("-"), followed by a sequentially assigned number

Then a letter specifying the cooling method:

• <none> – Radiation
• А ⟼ A – Water
• Б ⟼ B – Air
• К ⟼ K – Contact
• П ⟼ P – Vapor

• Phototubes and Photomultipliers:

A hyphen ("-"), followed by a sequentially assigned number

Then one or two letters:

• В ⟼ V – Vacuum
• Г ⟼ G – Gas-filled
• С ⟼ S – Caesium-activated antimony cathode
• Ц ⟼ C – Caesium cathode

For examples see below

Japanese systems

Older numbering system 1941–51

A letter: Structure and usage^[57]

• E – Electron ray tube
• K – Kenotron (rectifier)
• U – General-purpose tube

Then a letter: Base and outline

• N – Pigtailed (Acorn tubes, etc.)
• S – Octal glass/metal
• T – ST large 7-pin
• t – ST small 7-pin
• V – 4-pin
• X – S/ST 4-pin
• x – Peanut 4-pin
• Y – S/ST 5-pin
• y – Peanut 5-pin
• Z – S/ST 6-pin U6A

Then a hyphen ("-"), followed by a sequentially assigned number or the designation of the American original

Then an optional hyphen ("-"), followed by a letter: Version

Examples:^[58]

• EZ-6G5 = 6G5 – Variable-mu "Magic Eye"-type tuning indicator
• KX-80-B – Kenotron
• UN-954 = 954 – Acorn sharp-cutoff pentode
• UN-955 = 955 – Acorn triode
• US-6A8 = 6A8 – Pentagrid converter
• US-6L7G = 6L7G – Pentagrid converter
• UX-26-B – Medium-mu RF triode
• UX-167 – Sharp-cutoff RF pentode
• UY-47B – Pentode
• UZ-58-A – Remote-cutoff RF/IF pentode

JIS C 7001 system

JIS C 7001 was published in 1951 and modified in 1965 and 1970^[57]

A number: Heater voltage range, as in the RETMA scheme

• 1 – 1 V ≤ U_f < 2 V
• 2 – 2 V ≤ U_f < 2.5 V
• 3 – 2.5 V ≤ U_f < 4 V
• 4 – 4 V ≤ U_f < 5 V
• 5 – 5 V ≤ U_f < 6 V
• 6 – 6 V ≤ U_f < 7 V

etc.

Then a letter: Base and Outline

• A – Special base
• B – Other
• C – Duodecar (Compactron)
• D – Subminiature button base
• E – Subminiature flat base
• F – European 4-pin ST
• G – Octal base glass tubular (GT)
• H – Magnoval/Neonoval
• K – Ceramic
• L – Lock-In (Loctal)
• M – Miniature (7-pin)
• N – Nuvistor
• Q – Acorn tube
• R – Noval (9-pin miniature) or Magnoval/Neonoval (9T9)
• S – Octal (US)
• T – Large 7-pin ST
• W – 7-pin ST
• X – 4-pin ST
• Y – 5-pin ST
• Z – 6-pin ST

Then a hyphen ("-"), followed by a letter: Structure and usage

• A – Power triode
• B – Beam power tetrode
• C – Pentagrid converter
• D – Diode
• E – Optical tuning/level indicator
• G – Gas-filled rectifier
• H – High-mu triode (μ>30)
• K – Kenotron (rectifier)

• Even number after K: Full-wave rectifier
• Odd number after K: Half-wave rectifier

• L – Low-mu triode (μ<30)
• P – Power tetrode or pentode
• R – Sharp-cutoff tetrode or pentode
• S – Tetrode with a space charge grid (the 2nd grid is the control grid)
• T – Gas-filled, grid-controlled
• V – Variable-mu (remote-cutoff) tetrode and pentode
• X – Other

Then a sequentially assigned number

Then an optional letter: Version

Examples:^[58]

• 2N-H12 – Nuvistor
• 2X-L2A – Low-mu triode
• 6C-A10 – Power triode
• 6G-A4 – Power triode
• 6G-B8 – Beam power tetrode
• 6G-E12A – 2-channel "Magic Eye"-type tuning indicator, rectangular target
• 6H-B26 – Beam power tetrode
• 6M-DE1 – Diode + "Magic Eye"-type tuning indicator, miniature 7-pin base B7G
• 6M-E4 – "Magic Finger"-type tuning indicator, miniature 7-pin base B7G
• 6M-E5 = 6ME5 – "Magic Eye"-type tuning indicator, miniature 7-pin base B7G
• 6M-E10 – "Magic Eye"-type tuning indicator, miniature 7-pin base B7G
• 6N-H10 – Nuvistor
• 6R-A8 – Power triode
• 6R-B10 – Beam power tetrode
• 6R-B11 – Beam power tetrode

Military naming systems

British CV and M8000s naming systems

This system prefixes a three- or four-digit number with the letters "CV", meaning "civilian valve" i.e. common to all three armed services. It was introduced during the Second World War to rationalise the previous nomenclatures maintained separately by the War Office/Ministry of Supply, Admiralty and Air Ministry/Ministry of Aircraft Production on behalf of the three armed services (e.g. "ACR~", "AR~", "AT~", etc. for CRTs, receiving and transmitting valves used in army equipments, "NC~", "NR~" and "NT~" similarly for navy equipments and "VCR~", "VR~" and "VT~" etc. for air force equipments), in which three separate designations could in principle apply to the same valve (which often had at least one prototype commercial designation as well). These numbers generally have identical equivalents in both the North American, RETMA, and West European, Mullard–Philips, systems but they bear no resemblance to the assigned "CV" number.

Examples:

• CV1988 = 6SN7GT = ECC32 (not a direct equivalent as heater current is different and bulb is larger)
• CV2729 = E80F – An SQ version of EF80 but with revised pin-out and a base screen substituted for the RF screen

The "CV4000" numbers identify special-quality valves though SQ valves CV numbered before that rule came in retain their original CV number:

• CV4007 = E91AA – SQ version of 6AL5
• CV4010 = E95F – SQ version of 6AK5 or EF95
• CV4014 = M8083

The "M8" in the part number denotes that it was developed by the military:

• M8083 – Sharp-cutoff pentode, miniature 7-pin base (SQ version of EF91 = 6AM6 = Z77)
• M8162 = 6060 – High-mu dual triode, for use as RF amplifier/mixer in VHF circuits, Noval base (SQ versions of ECC81 = 12AT7 = B309)

The principle behind the CV numbering scheme was also adopted by the US Joint Army-Navy JAN numbering scheme which was later considerably expanded into the US Federal and then NATO Stock Number system used by all NATO countries. This part-identification system ensures that every particular spare part (not merely thermionic valves) receives a unique stock number across the whole of NATO irrespective of the source, and hence is not held inefficiently as separate stores. In the case of CV valves, the stock number is always of the format 5960-99-000-XXXX where XXXX is the CV number (with a leading 0 if the CV number only has 3 digits).

U.S. naming systems

One system prefixes a three-digit number with the letters "VT", presumably meaning "Vacuum Tube". Other systems prefix the number with the letters "JHS" or "JAN". The numbers following these prefixes can be "special" four-digit numbers, or domestic two- or three-digit numbers or simply the domestic North American "RETMA" numbering system. Like the British military system, these have many direct equivalents in the civilian types.

Confusingly, the British also had two entirely different "VT" nomenclatures, one used by the Royal Air Force (see the preceding section) and the other used by the General Post Office, responsible for post and telecommunications at the time, where it may have stood for "valve, telephone"; none of these schemes corresponded in any way with each other.

Examples:

• "VT" numbering systems

• North American VT90 = 6H6
• British (RAF) VT90 – VHF Transmitting triode
• British (GPO) VT90 = ML4 = CV1732 – Power triode
• VT104 – RF pentode
• VT105 – RF triode

Other systems

The oldest numbering systems date back to the early 1920s, such as a two-digit numbering system (examples), starting with the UV-201A, which was abbreviated as "type '01A", and extended almost continuously up into the 1980s.

Since the 1930s, several proprietary systems exist. These tend to be used for devices for professional equipment.

Some systems were used by only one manufacturer (examples), who sometimes derived a letter prefix from the behavior of devices considered to be exceptional:

• Mazda/EdiSwan sold their first tubes for 4-volts AC mains transformer (as opposed to home storage battery) heating with the prefix AC/ (examples)
• The first beam tetrodes manufactured in the UK in the late 1930s by M-OV, carried a "KT" prefix meaning Kinkless Tetrode (examples)

Other systems grew into informal standards adopted by many manufacturers:

• 700s – Mainly Western Electric
• 800s – Mainly RCA

• Low 800s – Mainly transmitter output types
• High 800s – Mainly (gas-filled) rectifiers and thyratrons

• 900s – Mainly RCA

• Low 900s – Mainly phototubes and photomultipliers
• High 900s – Mainly Acorn tubes

• 1600s – Mainly RCA
• 9000s – Mainly RCA VHF/UHF tubes

Use was not rigorously systematic; optional letter prefixes are mostly manufacturer's codes:

• C – RCA/Cunningham
• CK, QK, RK – Raytheon Company  
• ECG – Philips/Sylvania  
• EM – Eitel McCullough (Eimac)
• F – ITT/Federal Telephone and Radio
• GE, GL – General Electric Corp. (not British General Electric Company)  
• HK – Heintz & Kaufman, Ltd. (San Francisco, California, USA)
• HY – CBS/Hytron (Salem, Massachusetts, USA)
• KU – ITT/Kuthe Laboratories (Newark, New Jersey, USA)
• ML – Machlett Laboratories, Inc.
• NL – Eimac/National Electronics, Inc. (Geneva, Illinois, USA)
• NU – National Union Electric Corp. (Orange, New Jersey, USA)
• PL – Philips N.V.  
• RCA – RCA/Radiotron  
• SV – Светлана (Svetlana)
• SY – Standard Telephones and Cables Australia branch, Sydney plant (not Sylvania Inc.)
• TH – Compagnie Française Thomson-Houston
• WE – Western Electric Company
• WL – Westinghouse Electric Corp.  
• XD – Central Electronic Manufacturers (Denville, New Jersey, USA)

List of American RETMA tubes

Note: Typecode explained above

_{LoVT ⟶ List of American RETMA tubes ⟶}

0 prefix - Gas-filled cold-cathode tubes

First character is numeric zero, not letter O.

_{LoVT ⟶ List of American RETMA tubes ⟶ 0 prefix - Gas-filled cold-cathode tubes ⟶}

Voltage stabilisers and references

Notes:

• Used in a similar way to a Zener diode, at higher voltages
• 7-pin miniature-based regulators: Letter order (A-B-C) indicates decreasing voltage; cathode on pins 2, 4, 7; anode on pins 1, 5
• Octal-based regulators: Letter order (A-B-C) indicates increasing voltage; cathode on pin 2; anode on pin 5; jumper between pins 3 and 7 to unpower the device when the regulator is pulled from its socket

• 0A2 = 150C2 – 150 volt regulator, miniature 7-pin base
• 0A3 = VR75 – 75 volt regulator, Octal base
• 0B2 = 108C1 (6627) – 105 volt regulator, miniature 7-pin base
• 0B3 = VR90 – 90 volt regulator, Octal base
• 0C2 – 75 volt regulator, miniature 7-pin base
• 0C3 = VR105 – 105 volt regulator, Octal base
• 0D3 = VR150 – 150 volt regulator, Octal base
• 0E3 = 85A1 – 85 volt regulator, 3-pin base
• 0G3 = 85A2 – 85 volt regulator, miniature 7-pin base

_{LoVT ⟶ List of American RETMA tubes ⟶ 0 prefix - Gas-filled cold-cathode tubes ⟶}

Trigger tubes

• 0A4G (Z300T) – 25 mA_avg, 100 mA_peak Gas triode designed for use as a ripple control receiver; with the cathode tied to the midpoint of a series-resonance LC circuit across live mains, it would activate a relay in its anode circuit while f_res is present
• 0A5 – 1 kV, 10 A_peak Gas triode with a keep-alive (primer) electrode and a shield grid, designed for relay drive and general switching service

_{LoVT ⟶ List of American RETMA tubes ⟶ 0 prefix - Gas-filled cold-cathode tubes ⟶}

Rectifiers

• 0Y4 – 40 ≤ I ≤ 75 mA Half-wave gas rectifier with a starter anode, 5-pin Octal base
• 0Z3 – 30 ≤ I ≤ 75 mA Full-wave gas rectifier, 5-pin base. Used in vibrator power supplies in early automobile radio receivers
• 0Z4 – 30 ≤ I ≤ 90 mA Argon-filled, full-wave gas rectifier, 5-pin Octal base. Widely used in vibrator power supplies in early automobile radio receivers

_{LoVT ⟶ List of American RETMA tubes ⟶}

1 prefix - 1 volt filament/heater tubes

_{LoVT ⟶ List of American RETMA tubes ⟶ 1 prefix - 1 volt filament/heater tubes ⟶}

1.25 volt DC filament subminiature tubes

The following tubes were used in post-World War II walkie-talkies and pocket-sized portable radios. All have 1.25 volt DC filaments and directly heated cathodes. Some specify which end of the filament is to be powered by the positive side of the filament power supply (usually a battery). All have glass bodies that measure from 0.285 to 0.400 inches (7.2 to 10.2 millimetres) wide, and from 1.25 to 2.00 inches (32 to 51 millimetres) in overall length

• 1AC5 – Power pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 1AD4/DF62 – Sharp-cutoff pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 1AD5 – Sharp-cutoff pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• 1AE5 – Heptode mixer, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 1AG4 – Power pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 1AG5 – Diode + pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 1AH4 – RF pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 1AJ5 – Diode + sharp-cutoff pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 1AK4 – Sharp-cutoff pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 1AK5 – Diode + sharp-cutoff pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails
• 1C8 – Heptode pentagrid converter, all-glass round cross-section body and circular 8-pin/pigtails base
• 1D3 – Low-mu UHF triode, all-glass round cross-section body, circular 8-pin/pigtails base
• 1E8 – Heptode pentagrid converter, all-glass round cross-section body, circular 8-pin/pigtails base
• 1Q6 – Diode + pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• 1S6 – Diode + pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• 1T6 – Diode + pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• 1V5 – Power pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• 1V6/DCF60 – Oscillator/mixer triode/pentode, all-glass elliptical cross-section body, flat 7-pin base, long pigtails
• 1W5 – Sharp-cutoff pentode, all-glass round cross-section body, circular 8-pin/pigtails base

More of these tubes are listed as equivalents under M-P D - 1.4 V filament/heater

_{LoVT ⟶ List of American RETMA tubes ⟶ 1 prefix - 1 volt filament/heater tubes ⟶}

1.4 volt DC filament/heater tubes

• 1A3/DA90 – Indirectly heated FM discriminator diode, miniature 7-pin base, 1.4 V/150 mA heater. Used as a detector in some portable AM/FM receivers
• 1A7GT/DK32 – Heptode pentagrid converter, re-engineered version of types 1A6 and 1D7-G, designed for use in Three-way portable (AC/DC/Dry-cell battery) radios introduced in 1938. Has 1.4 V/50 mA filament
• 1B7GT – Heptode pentagrid converter, re-engineered version of types 1C6 and 1C7-G, designed for use in dry-cell battery radios with shortwave bands. Has 1.4 V/100 mA filament
• 1G6G – Dual power triode. "GT" version also available
• 1L6 – Heptode pentagrid converter for battery radios with 50 mA filament
• 1LA6 (Loctal) and later 1L6 (Miniature 7-pin) – Battery heptode pentagrid converter for Zenith Trans-Oceanic shortwave radio, 50 mA filament
• 1LB6 – Heptode pentagrid converter for battery-operated radios
• 1LC6 – 1LA6 with higher conversion transconductance
• 1R5/DK91 – Heptode pentagrid converter, anode voltage in the 45...90 volt range
• 1S4/DL91 – Power pentode Class-A amplifier, anode voltage in the 45...90 volt range
• 1S5/DAF91 – Diode + sharp-cutoff pentode Class-A amplifier, used as detector and first AF stage in battery radio receivers. Anode voltage in the 67...90 volt range, 50 mA filament

• 1S5-SF = 1S5T = 1AR5 – 1S5/DAF91 with a 25 mA filament

• 1T4/DF91 – Remote-cutoff RF pentode Class-A amplifier, used as RF and IF amplifier in battery radio receivers (B7G base)
• 1U4/DF904/5910 – Sharp-cutoff RF pentode Class-A amplifier, used as RF and IF amplifier in battery radio receivers; similar characteristics to 6BA6/EF93 (B7G base)
• 1U6 – 1L6 with a 1.4 V/25 mA filament

More of these tubes are listed as equivalents under M-P D - 1.4 V filament/heater

_{LoVT ⟶ List of American RETMA tubes ⟶ 1 prefix - 1 volt filament/heater tubes ⟶}

2 volt DC filament tubes

These tubes were made for home storage battery receivers manufactured during the early to mid-1930s; all have 2.0 volt DC filaments despite the 1-prefix, intended to distinguish them from the 2.5 volt AC heated tubes listed below

• 1A4P – Remote-cutoff pentode, U4A American 4-pin base
• 1A4T – Remote-cutoff tetrode, U4A American 4-pin base
• 1A6 – Heptode pentagrid converter, U6A American 6-pin base, up to only 10 MHz due to low heater power (2 V/60 mA) and consequent low emission in the oscillator section; also occasionally used as a grid-leak detector
• 1B4P – Sharp-cutoff pentode, U4A American 4-pin base
• 1B4T – Sharp-cutoff tetrode, U4A American 4-pin base
• 1B5 – Dual detector diode + medium-mu triode, U6A American 6-pin base, usually numbered 1B5/25S
• 1C5/DL35 – Power pentode, Octal base; similar to 3Q5 except for filament
• 1C6 – Heptode pentagrid converter; 1A6 with double the heater power and double the frequency range
• 1C7G – 1C6 with an Octal base
• 1D5GP – 1A4P with an Octal base
• 1D5GT – 1A4T with an Octal base (Note: This is a shouldered "G" Octal, not a cylindrical "GT" Octal)
• 1D7G – 1A6 with an Octal base
• 1E5GP – 1B4P with an Octal base
• 1E5GT – 1B4T with an Octal base (Note: This is a shouldered "G" Octal, not a cylindrical "GT" Octal)
• 1E7G – Dual power pentode, Octal base, for use as a driver when parallel-connected, or as a push-pull output. "GT" version also available
• 1F4 – Power pentode, U5A American 5-pin base
• 1F5G – 1F4 with an Octal base
• 1F6 – Dual diode + sharp-cutoff pentode, U6A American 6-pin base
• 1F7G – 1F6 with an Octal base
• 1G5G – Power pentode, Octal base
• 1H4G – Medium-mu triode, can be used as a power triode; 30 (upgraded version of type 01-A) with an Octal base. "GT" version also available
• 1H6G – 1B5/25S with an Octal base. "GT" version also available
• 1J5G (950) – AF power pentode, Octal base
• 1J6G – Dual power triode; 19 with an Octal base. "GT" version also available

_{LoVT ⟶ List of American RETMA tubes ⟶ 1 prefix - 1 volt filament/heater tubes ⟶}

One-volt ballast tubes

Used to adapt the above 2 volt DC filament tubes to 2-cell dry batteries

• 1D1 – 240 mA filament
• 1D2, 1G1 – 420 mA filament
• 1A1 – 490 mA filament
• 1R1, 1Y1 – 540 mA filament
• 1K1 – 550 mA filament
• 1T1, 1V1 – 560 mA filament
• 1J1 – 620 mA filament
• 1E2, 1S1, 1W1 – 660 mA filament
• 1F1 – 720 mA filament
• 1U1 – 740 mA filament
• 1C1 – 745 mA filament
• 1Z1 – 900 mA filament

_{LoVT ⟶ List of American RETMA tubes ⟶ 1 prefix - 1 volt filament/heater tubes ⟶}

CRT anode rectifiers

• 1AD2 – Compactron CRT EHT rectifier with 1.25 V/200 mA filament

• 1AD2A – 1AD2 retrofitted with an internal X-radiation shielding, introduced after the 1967 General Electric X-radiation scandal^[59]

• 1AJ2 – Compactron CRT EHT rectifier with 1.25 V/200 mA filament
• 1AY2 – Duopin 2-pin base CRT EHT rectifier. Has similar electrical characteristics as 1B3GT/DY30
• 1B3GT/1G3GT/DY30 – CRT EHT rectifier with 1.25 V filament common in monochrome TV receivers of the 1950s and early 1960s. Peak inverse voltage of 30 kV. Anode current 2 mA average, 17 mA peak, Octal base. Derived from the earlier industrial type 8016
• 1BC2 – Noval CRT EHT rectifier with 1.25 V/200 mA filament

• 1BC2A, 1BC2B – 1BC2 with internal X-radiation shielding

• 1BG2/DY51 – Subminiature half-indirectly heated 15 kV portable-TV CRT EHT rectifier, 1.4 V/575 mA filament internally connected to cathode, all-glass, filament pigtails on one end, anode pigtail on the other
• 1BQ2/DY802 – Half-indirectly heated 20 kV CRT EHT rectifier, Noval base, silicone-coated envelope to avoid flush-over in high-humidity and low atmospheric-pressure conditions, 1.4 V/600 mA filament internally connected to cathode
• 1BY2 – Compactron CRT EHT rectifier with 1.25 V/200 mA filament

• 1BY2A – 1BY2 with internal X-radiation shielding

• 1H2 – Noval CRT EHT rectifier with 1.4 V/550 mA filament
• 1J3GT/1K3GT – Octal CRT EHT rectifier. Same characteristics as 1B3GT/DY30. Has filament-plate shorting protection
• 1S2/DY86 – Half-indirectly heated 18 kV CRT EHT rectifier, Noval base, 1.4 V/550 mA filament internally connected to cathode; 6S2/EY86 or GY86 with a different heater

• 1S2A/DY87 – 6S2A/EY87 with a different heater; 1S2/DY86 with a silicone-coated envelope

• 1T2 = Brimar R16 – Subminiature, directly heated CRT EHT rectifier with 1.4 V/140 mA filament; filament pigtails on one end, anode pigtail on the other
• 1V2 – CRT EHT rectifier with 0.625 V/300 mA filament (B7G base)
• 1X2 – Noval CRT EHT rectifier with 1.25 V/200 mA filament

• 1X2A, 1X2B. 1X2C – 1X2 with internal X-radiation shielding

• 1Y2 – 4-pin CRT EHT rectifier with 1.5 V/290 mA filament. 50 kV max PIV, 10 mA peak, 2 mA average. Usable up to 1 MHz
• 1Z1 – Octal CRT EHT rectifier with 0.7 V/180 mA filament
• 1Z2 – Noval CRT EHT rectifier with 1.25 V/265 mA filament

_{LoVT ⟶ List of American RETMA tubes ⟶}

2 volt heater/filament tubes

Some 6-prefix tubes were also available as 2-prefix, for television receivers with series heater strings (see below)

_{LoVT ⟶ List of American RETMA tubes ⟶ 2 volt heater/filament tubes ⟶}

2.5 volt AC heater tubes

—Tubes used in AC-powered radio receivers of the early 1930s:

• 2A3 – Directly heated power triode, used for AF output stages in 1930s–1940s audio amplifiers and radios
• 2A5 – Power pentode; 42 or 6F6 with a different heater
• 2A6 – Dual diode + high-mu triode; 75 with a different heater
• 2A7 – Heptode pentagrid converter; 6A7, 6A8 or 12A8 with a different heater
• 2B7 – Dual diode + remote-cutoff pentode; 6B7 with a different heater
• 2E5 – Top-view, "Magic Eye"-type tuning indicator; 2G5 with with a sharp-cutoff driver triode; 6E5 with a different heater
• 2G5 – Top-view, "Magic Eye"-type tuning indicator; 2E5 with with a remote-cutoff driver triode; 6G5/6U5 with a different heater

—Thyratrons:

• 2A4 – Directly heated triode thyratron, 2.5 V/2.5 A heater, Octal 7-pin base
• 2B4 = 885 – Indirectly heated triode thyratron used in DuMont oscilloscopes as a sweep generator; 6Q5-G = 884 with a 2.5 V/2.5 A heater and a 5-pin base
• 2C4 – Indirectly heated triode thyratron for use in portable equipment, 2.5 V/650 mA heater, 7-pin miniature base

_{LoVT ⟶ List of American RETMA tubes ⟶ 2 volt heater/filament tubes ⟶}

CRT anode rectifiers

• 2X2 = 879 – CRT EHT rectifier; similar to 1B3 and 1S2/DY86 except for heater ratings

• 2X2A – 2X2, shock resistant up to 250 g

More of these tubes are listed as equivalents under M-P K - 2.0 V heater

_{LoVT ⟶ List of American RETMA tubes ⟶}

3 volt heater/filament tubes

Many 6-prefix tubes were also available as 3-prefix with a 3.15 V heater with twice the heater current, for television receivers with series heater strings

_{LoVT ⟶ List of American RETMA tubes ⟶ 3 volt heater/filament tubes ⟶}

2.8 volt DC filament tubes

These tubes are directly heated with a center-tapped filament, so they can be switched to 1.4 V, for use in Three-way portable (AC or DC mains, or batteries) radio receivers

• 3A4/DL93 – 1.2 W RF/AF power pentode, miniature 7-pin base
• 3A5/DCC90 – Dual RF power triode, miniature 7-pin base
• 3A8GT – Diode + triode + pentode with internal shield connected to filament center-tap, Octal base
• 3B4/DL98 – 1.25 W RF power pentode up to 100 MHz, miniature 7-pin base
• 3B5GT – AF beam power pentode, Octal base
• 3B7 – 1.4 W Dual VHF power triode up to 125 MHz, Loctal base
• 3C4/DL96 – 440 mW AF power pentode, miniature 7-pin base
• 3E5 – 200 mW AF beam power pentode, miniature 7-pin base
• 3E6 – Sharp-cutoff pentode with internal shield connected to filament center-tap, Loctal base
• 3LF4 – 330 mW AF beam power pentode, Loctal base
• 3Q4/DL95 – 270 mW AF power pentode, miniature 7-pin base
• 3S4/DL92 – 270 mW AF power pentode, miniature 7-pin base, 2.8 V/50 mA (series) or 1.4 V/100 mA (parallel) filament

• 3S4-SF = 3S4T = 3W4 – 3S4/DL92 with a 2.8 V/25 mA (series) or 1.4 V/50 mA (parallel) filament

• 3V4/DL94 – 1.3 W AF power pentode, miniature 7-pin base

More of these tubes are listed as equivalents under M-P D - 1.4 V filament/heater

_{LoVT ⟶ List of American RETMA tubes ⟶ 3 volt heater/filament tubes ⟶}

CRT anode rectifiers

• 3A3/3B2/3AW3 – CRT EHT rectifier for color TV, Octal base, 3.15 V/220 mA heater

• 3A3A – 3A3 with increased anode current capability
• 3A3C – 3A3A retrofitted with an internal X-radiation shielding, introduced after the 1967 General Electric X-radiation scandal^[59]

• 3AT2 – CRT EHT rectifier for color TV, compactron base, 3.15 V/220 mA heater

• 3AT2B – 3AT2 with internal X-radiation shielding

• 3AW2 – CRT EHT rectifier for color TV, compactron base, 3.15 V/350 mA heater

• 3AW2A – 3AW2 with internal X-radiation shielding

• 3BL2 – CRT EHT rectifier for color TV, compactron base, 3.3 V/285 mA heater

• 3BL2A – 3BL2 with internal X-radiation shielding

• 3BM2 – CRT EHT rectifier for color TV, compactron base, 3 V/300 mA heater

• 3BM2A – 3BM2 with internal X-radiation shielding

• 3BN2 – CRT EHT rectifier for color TV, compactron base, 3.15 V/300 mA heater

• 3BN2A – 3BN2 with internal X-radiation shielding

• 3BS2 – CRT EHT rectifier for color TV, compactron base, 3.15 V/480 mA quickstart heater

• 3BS2A, 3BS2B – 3BS2 with internal X-radiation shielding

• 3BT2 – CRT EHT rectifier for color TV, compactron base, 3.15 V/480 mA quickstart heater

• 3BT2A – 3BT2 with internal X-radiation shielding

Note: All subsequent CRT EHT rectifiers were designed after the 1967 GE scandal and had internal X-radiation shielding right from the start

• 3BW2 – CRT EHT rectifier for color TV, compactron base, 3.15 V/480 mA quickstart heater; has a diffusion-bonded cathode, which prevents anode-to-cathode arcing caused by emissive particles being pulled from the cathode coating by the high electrostatic field
• 3CA3 – CRT EHT rectifier for color TV, Octal base; 3.6 V/225 mA heater
• 3CN3 – CRT EHT rectifier with a diffusion-bonded cathode for color TV, Octal base; 3.15 V/480 mA quickstart heater
• 3CU3 – CRT EHT rectifier for color TV, Octal base; 3.15 V/280 mA heater
• 3CZ3 – CRT EHT rectifier for color TV, Octal base; 3.15 V/480 mA quickstart heater

More of these tubes are listed as equivalents under M-P G - Miscellaneous

_{LoVT ⟶ List of American RETMA tubes ⟶}

4 volt heater/filament tubes

Some 6-prefix tubes were also available as 4-prefix with a 4.2 V heater with 1.5 times the heater current, for television receivers with series heater strings (see below)

4 volt DC filament tubes

• 4A6G – Dual power triode, Octal base, directly heated with a center-tapped 4.0 V filament, so it can also be wired for 2 V

Ballast tubes

• 4A1 – 300 mA filament

_{LoVT ⟶ List of American RETMA tubes ⟶}

5 volt heater/filament tubes

Some 6-prefix tubes were also available as 5-prefix, for television receivers with series heater strings (see below)

5 volt DC filament tubes

• 5A6 – RF beam power pentode up to 100 MHz, Noval base, directly heated with a center-tapped 5.0 V filament, so it can also be wired for 2.5 V

Rectifiers

• 5AR4/GZ34 – Full-wave rectifier
• 5AS4 – Full-wave rectifier
• 5R4 – Full-wave rectifier
• 5U4 – Full-wave rectifier
• 5V4/GZ32 – Full-wave rectifier
• 5Y3 – Full-wave rectifier; 80 with an Octal base

More of these tubes are listed as equivalents under M-P G - 5.0 V heater

_{LoVT ⟶ List of American RETMA tubes ⟶}

6 volt heater tubes

Note: 6-prefix tubes with center-tapped heaters are listed under 300 mA series heater tubes

• 6A6 – Dual power triode, U7B 7-pin base, used as a Class-A audio driver or a Class-B audio output; 6.3 volt heater version of type 53 which had a 2.5 volt heater. Octal version: 6N7
• 6A7 (U7A 7-pin base) and 6A8 (K8A Octal base; PH4, M-OV X63) – Heptode pentagrid converter with control grid (grid 4) on top cap; based on type 2A7, which had a 2.5 volt heater; Loctal version: type 7B8
• 6AB4/EC92 – High-mu triode, miniature 7-pin base; 6C4/EC90 pinout except pin 5 unconnected
• 6AB5/6N5 – Top-view, "Magic Eye"-type tuning indicator with with a sharp-cutoff driver triode
• 6AC5-G – High-mu power triode
• 6AC7 = 1852 – TV sharp-cutoff RF pentode, often encountered in a black metal envelope (not to be confused with the 6CA7/EL34)
• 6AC10 – Compactron High-mu triple triode for use as NTSC chroma signal demodulator matrix in analog color TV receivers, 12-pin base
• 6AD6-G and 6AF6-G – Top-view, driverless "Magic Eye"-type tuning indicators. Both have two "pie wedge" shadow indicators, one each on opposite sides of a single circular indicator target. Both shadows may be used in tandem or may be driven by two different signal sources. Type 6AE6-G is specifically made to drive each indicator with different signals. May also be driven by separate pentodes with different characteristics. E.g., a sharp-cutoff pentode like a 6J7 – which would be hyper-sensitive to any signal change – would drive one shadow, while a remote-cutoff pentode like a 6K7 – which would only react to stronger signals – would drive the other shadow. Both tubes have Octal bases. Type 6AD6-G, with a target voltage rated from 100 to 150 volt, is designed for AC/DC radios. Type 6AF6-G, with a target voltage rated at 250 volt, is designed for larger AC radios
• 6AE6-G – A driver triode specially designed for "Magic Eye" tuning indicator types 6AD6-G and 6AF6-G. Has a common heater and indirectly heated cathode, two internally connected triode grids – one with sharp-cutoff characteristics, one with remote-cutoff characteristics – and two anodes, one for each grid. The sharp-cutoff grid reacts to any signal change, while the remote-cutoff grid reacts only to stronger signal changes
• 6AE7-GT – Dual triode with a common, single anode, for use as a power triode driver
• 6AF4/EC94 – UHF Medium-mu oscillator triode, commonly found in TV tuners and converters
• 6AF11 – Compactron High-mu dual triode + sharp-cutoff pentode
• 6AG11 – Compactron High-mu dual triode + dual diode
• 6AH5-G – Beam power tetrode for early TV use. Same as type 6L6-G, but with scrambled pinout. Used in some Philco receivers
• 6AJ5 – Low (6.3-80 V) anode voltage, sharp-cutoff pentode
• 6AK5/EF95 = 6Ж1П (↦6J1P) (5654, CV4010, 408A) – VHF/RF/IF Sharp-cutoff pentode, miniature 7-pin base, used in old Radiosonde weather balloon transmitters, receiver front ends and contemporary audio equipment
• 6AK6 – Power pentode; 6G6-G with a miniature 7-pin base. Unusual low-power consumption output tube with 150 mA heater
• 6AK8/EABC80 – Triple diode + high-mu triode. Diodes have identical characteristics – two have cathodes connected to the triode's cathode, one has a separate cathode. Used as a combination AM detector/AVC rectifier/FM ratio detector/AF amplifier in AM/FM radios manufactured outside of North America. Triode amplification factor: 70; 6T8 with a longer glass envelope
• 6AK9 – Compactron 1x high-mu + 1x medium-mu dual triode + beam power pentode, 12-pin base
• 6AK10 – Compactron High-mu triple triode for use as NTSC chroma signal demodulator matrix in analog color TV receivers, 12-pin base
• 6AL3/EY88 – TV "Damper/Efficiency" diode
• 6AL5/EAA91 = M-OV D77 – Dual diode with separate cathodes, for use as detector. Often used in vacuum tube volt meters (VTVMs); 6H6 with a miniature 7-pin base; 12AL5/HAA91, UAA91 or 3AL5/XAA91 with a different heater
• 6AL6-G – Beam power tetrode for early TV use. Same as type 6L6-G, but with scrambled pinout and anode connected to top cap
• 6AL7-GT – Top-view, driverless, triple (independently controllable) bar graph-type tuning/level indicator used in many early AM/FM Hi-Fi radios
• 6AM6/EF91 = M-OV Z77 (M8083) – Sharp-cutoff RF pentode used in receiver front ends and test gear such as VTVMs and TV broadcast modulation monitors
• 6AN7/ECH80 – Triode/remote-cutoff hexode mixer; 6CU7/ECH42 with a Noval base
• 6AN8 – Triode + pentode used in CRT vertical deflection timebase circuits, electrically fairly similar to ECL80 but with a different pinout
• 6AQ5/EL90 – Beam power pentode, miniature 7-pin similar of type 6V6
• 6AQ8/ECC85 – Dual RF/VHF triode with separate cathodes and an internal shield between the two sections, designed for use as oscillator and mixer in FM receivers. The heater to cathode insulation is inadequate for use in cascode operation; similar to 6BK7, 6BQ7, 6BZ7
• 6AR8, 6JH8, 6ME8 – Beam deflection tubes for use as NTSC chroma signal demodulators in analog color TV receivers
• 6AS6 – Pentode with a fine-pitched suppressor grid which could serve as a second control grid. Used in radar phantastron circuits
• 6AS7/ECC230 (6080) – Dual low-mu triode, low impedance, mostly used for voltage regulation circuits
• 6AS11 – Compactron 1x high-mu + 1x medium-mu dual triode + sharp-cutoff pentode, 12-pin base
• 6AT6/EBC90 – Dual diode + high-mu triode; 6Q7 with a miniature 7-pin base. Triode amplification factor: 70
• 6AU4 – TV "Damper/Efficiency" diode
• 6AU6/EF94, 6AU6A – Sharp-cutoff pentode
• 6AV6/EBC91 – Dual diode + high-mu triode. Triode amplification factor: 100. (Triode section similar in characteristics to one half of a 12AX7); miniature 7-pin version of type 75
• 6AV11 – Compactron Medium-mu triple triode, 12-pin base
• 6AX4 – TV "Damper/Efficiency" diode
• 6AX5 – Full-wave rectifier. Octal base. Similar in structure to type 6X5, but with higher voltage and current ratings which are comparable to those of types 5Y3 and 80
• 6B6-G – Dual diode + high-mu triode, grid on top cap; Octal version of type 75, later 6SQ7 (with under-chassis connection for triode grid). Miniature 7-pin version: 6AV6/EBC91
• 6B7 (UX7 base) and 6B8 (EBF32, Octal base) – Dual diode + semiremote-cutoff pentode with control grid on top cap. Based on type 2B7 which had a 2.5 volt heater. The diode anodes are most commonly used as (second) detectors and AVC rectification in superheterodyne receivers. Because their control grids have both sharp-cutoff and remote-cutoff characteristics, these types were used as IF amplifiers with AVC bias to the control grid, and as AF amplifiers. These types were also used in reflex receivers. In a typical 2B7/6B7/6B8 reflex circuit, the IF signal from the converter is injected into the pentode and is amplified. The diodes then act as detectors, separating the AF signal from the RF signal. The AF signal is then re-injected into the pentode, amplified, and sent to the audio output tube^[60]
• 6BA6/EF93 = M-OV W727 (5790) – Semiremote-cutoff RF pentode (Often encountered in car radios)
• 6BD11 – Compactron 1x high-mu + 1x medium-mu dual triode + sharp-cutoff pentode, 12-pin base
• 6BE6/EK90 = M-OV X727 (5750) – Heptode pentagrid converter (Often encountered in car radios)
• 6BF6 – Dual diode + medium-mu triode; 6R7 with a miniature 7-pin base
• 6BF8 – Sextuple diode with a common cathode
• 6BG6 – Beam power pentode, anode on top cap, used in early TV magnetic-deflection horizontal-output stage
• 6BH11 – Compactron Medium-mu dual triode + sharp-cutoff pentode
• 6BK4 – High voltage beam power triode, U_a=27 kV, I_a=1.5 mA, P_a=25 W, U_h-c=-200 V; used as shunt regulator in color TV receivers and in measurement equipment such as high voltage meters

• 6BK4A – 6BK4 with P_a=30 W
• 6BK4B – 6BK4A with P_a=40 W, U_h-c=-450 V
• 6BK4C/6EL4A – 6BK4B retrofitted with an internal X-radiation shielding, introduced after the 1967 General Electric X-radiation scandal^[59]

• 6BK7 – Dual RF/VHF triode with separate cathodes and an internal shield between the two sections; similar to 6BQ7, 6BZ7, 6AQ8/ECC85
• 6BK8/6CF8/EF86 = M-OV/GEC Z729 – AF Pentode used in microphone preamplifiers and audiophile equipment
• 6BK11 – Compactron 2x High-mu + 1x medium-mu triple triode preamplifier, 12-pin base; used in some guitar amps made by Ampeg
• 6BL6 (5836) – Sutton tube, a reflex klystron used as a 250 mW CW microwave source, 1.6 to 6.5 GHz depending upon an external cavity. 4-pin peewee base with cavity contact rings and top cap
• 6BL8/ECF80 – General-purpose triode + pentode used in TV, audio and test gear
• 6BM6 (5837) – Sutton tube used as a 150 mW CW microwave source, 550 MHz to 3.8 GHz depending upon an external cavity. 4-pin peewee base with cavity contact rings and top cap
• 6BM8/ECL82 – Triode + pentode used as the driver and output stages in audio amplifiers, audio output and vertical deflection output stages in TV receivers and has even been seen in an electronic nerve stimulator
• 6BN6/6KS6 – Gated-beam discriminator pentode, used in radar, dual channel oscilloscopes and FM quadrature detectors; cf. 6DT6, Nonode
• 6BQ5/EL84 = M-OV N709 – 5.7 Watts AF power pentode, Noval base
• 6BQ6-GT – Beam power pentode, used as a horizontal deflection output tube in monochrome TV receivers of the 1950s. Most commonly used in receivers with diagonal screen sizes less than 19 inches (48 cm). (However, may be found in some larger models) Larger receivers often used similar type 6DQ6. Later versions of this tube branded as 6BQ6-GTB/6CU6
• 6BQ7 – Dual RF/VHF triode with separate cathodes and an internal shield between the two sections, which can be used independently or in a cascode stage; similar to 6BK7, 6BZ7, 6AQ8/ECC85

• 6BQ7A/ECC180 – Improved 6BQ7 capable of operation at UHF frequencies

• 6BU8 – Split-anode pentode for use as TV sync separator
• 6BX6/EF80 – Sharp-cutoff RF/IF/Video pentode, Noval base
• 6BY6 – Similar to type 6CS6/EH90, but with higher transconductance; 3BY6 with a different heater
• 6BY7/EF85 = M-OV W719 – Remote-cutoff RF pentode (TV IF)
• 6BZ6 – Sharp-cutoff RF pentode used in video IF circuits of the 1960s
• 6BZ7 – Dual RF/VHF triode with separate cathodes and an internal shield between the two sections; similar to 6BK7, 6BQ7, 6AQ8/ECC85
• 6C4/EC90 – 3.6 W small-power VHF triode up to 150 MHz; single 12AU7/ECC82 system
• 6C6 – Sharp-cutoff RF pentode. Most common commercial uses were as a tuned RF amplifier, a detector, and an AF amplifier. Also used in test equipment. Has UX6 base with top cap. Based on type 57, which had a 2.5 volt heater. Similar to types 1603, 77 and Octal types 6J7 and 6SJ7
• 6C10 – Compactron High-mu triple triode, 12-pin base – not related to the Mazda/EdiSwan 6C10 triode-hexode
• 6CA4/EZ81 – Full-wave rectifier
• 6CA7/EL34 – AF power pentode
• 6CA11 – Compactron High-mu dual triode + sharp-cutoff pentode
• 6CB6/EF190 – Remote-cutoff RF pentode used in video IF circuits of the 1950s and early 1960s
• 6CG7 – Dual triode, used in TV and some audio amplifiers including modern solid-state designs often as a cathode follower; similar to 6SN7
• 6CJ6/EL81 – CRT horizontal deflection output pentode
• 6CL6 – Power pentode
• 6CM5/EL36 – AF or CRT horizontal deflection output beam power tetrode
• 6CW4 – Nuvistor High-mu VHF triode, 6.3 V/135 mA heater, most common one in consumer electronics
• 6CZ5 (6973) – Beam power pentode for use as vertical deflection or audio amplifier
• 6D4 – 25 mA_avg, 100 mA_peak Indirectly heated, argon triode thyratron, negative starter voltage, miniature 7-pin base; found an additional use as a 0 to 10 MHz noise source, when operated as a diode (starter tied to cathode) in a transverse 375 G (37.5 mT) magnetic field. Sufficiently filtered for "flatness" ("white noise") in a band of interest, such noise was used for testing radio receivers, servo systems and occasionally in analog computing as a random value source
• 6D6 – Remote-cutoff RF pentode. Most common commercial uses were as an IF amplifier or as a superheterodyne mixer, aka 1st detector. Also used in test equipment. Has UX6 base with top cap. Based on type 58, which had a 2.5 volt heater; similar to type 78. Octal version: 6U7-G
• 6D8-G – Heptode pentagrid converter, Octal base with top cap, 150 mA heater, used in pre-war 6-volt farm radios; similar to type 6A8
• 6D10 – High-mu triple triode for use as oscillator, mixer, amplifier or AGC tube, 12-pin base
• 6DA6/EF89 – RF Pentode used in AM/FM radios manufactured outside North America
• 6DJ8/ECC88 = 6Н23П (↦6N23P) = Shuguang 6N11 (↤6Н11) – Dual RF/AF triode (often used in TV broadcast equipment, test gear, oscilloscopes and audiophile gear) similar to 6ES8/ECC189, 6922/E88CC
• 6DQ6 – Beam power pentode, used as a horizontal deflection output tube in monochrome TV receivers of the 1950s. Most often found in receivers with diagonal screen measurements larger than 17 inches (43 cm). Smaller receivers often used similar type 6BQ6-GT. Also used as audio output tubes in Standel guitar amplifiers. Later versions branded as 6DQ6-B/6GW6
• 6DR8/EBF83 – Common cathode dual diode + low (6.3-50 V) anode voltage pentode for use as IF amplifier, detector and AGC diode in vehicle equipment, Noval base
• 6DS4 – Nuvistor High-mu VHF triode used in TV tuners immediately prior to the introduction of solid state tuning circuits. (RCA TVs equipped with a 6DS4 tuner bore the trademark "Nu-Vista Vision"); successor of the 6CW4
• 6DS8/ECH83 – Low (6.3-25 V) anode voltage, triode/heptode mixer, for use in vehicle equipment
• 6DT6 – Quadrature detector pentode used in TV audio circuits of the 1950s and early 1960s; cf. 6BN6, nonode
• 6DV4 – Medium-mu Nuvistor triode for UHF oscillators; some versions had a gold-plated envelope
• 6DX8/ECL84 – Triode + pentode
• 6E5 – Top-view, "Magic Eye"-type tuning indicator, UX6 base; 6G5/6U5 with a sharp-cutoff driver triode; 2E5 with a different heater
• 6EM5 – CRT vertical deflection output pentode
• 6ES6/EF97 (remote-cutoff), 6ET6/EF98 (sharp-cutoff) – Low (6.3-50 V) anode voltage RF pentodes, used in car radios
• 6ES8/ECC189 – Dual triode used as cascode RF amplifier in TV tuners and VHF receiver front ends, also used as general-purpose dual triode in test gear; similar to 6DJ8/ECC88
• 6EZ8 – High-mu triple triode, Noval base
• 6F4 – Acorn UHF triode up to 1.2 GHz, for use as an oscillator
• 6F5 – High-mu triode, equal to triode section of type 6Q7
• 6F6, M-OV KT63 – Power pentode, moderate power output rating – 9 watts max. (Single-ended Class-A circuit); 11 watts max. (Push-pull Class-A circuit); 19 watts max. (push-pull Class-AB₂ circuit). Available in metal (numbered "6F6"), shouldered glass ("6F6-G"), and cylindrical glass ("6F6-GT"). Sometimes used as a transformer-coupled audio driver for types 6L6-GC and 807 when those tubes were used in Class-AB₂ or Class-B amplifiers. Also used as a Class-C oscillator/amplifier in transmitters; Octal base version of type 42
• 6F7 – Remote-cutoff pentode + medium-mu triode. Has UX7 base with the pentode control grid on top cap. Most common uses were as superheterodyne mixer ("first detector") and local oscillator, or as a combination IF amplifier (pentode) and (second) detector or AF amplifier (triode); Octal version: 6P7-G
• 6FA7 – Diode + sharp-cutoff dual-anode tetrode for use as frequency divider or complex-wave generator, 6.3 V/300 mA heater, Noval base
• 6FH8 – Medium-mu triode + three-anode sharp-cutoff tetrode for use in TV receivers and complex wave generators
• 6FS5, 6GU5 – Sharp-cutoff, Shadow-Grid beam pentodes with a beam-forming extra grid between control and screen grids, intended to reduce screen current and hence anode/screen grid distribution noise (technically a hexode), 7-pin miniature base; cf. DAH50, EF8, EF38
• 6G5/6U5 – Top-view, "Magic Eye"-type tuning indicator, UX6 base; 6E5 with a remote-cutoff driver triode; 2G5 with a different heater

• 6G5G/6U5G – 6G5/6U5 with an Octal base

• 6G6-G – Power pentode. Octal base. Low power output – 1.1 watt max. output. Has 150 mA heater. Used in pre-war 6-volt farm radios; miniature 7-pin version: 6AK6
• 6G8-G – Dual diode + sharp-cutoff pentode (Used as Detector and first AF stage in Australian 1940s radios)
• 6GK5 – Miniature 7-pin VHF triode (Used as VHF local oscillator in some TV turret tuners)
• 6GM5 – 19 W Beam power pentode; 7591 or 7868 with a Noval base
• 6GS8 – Dual-anode pentode for TV receiver sync separation or AGC service
• 6GV8/ECL85 – Triode + power pentode for use as CRT vertical deflection output
• 6GW8/ECL86 – AF Triode + power pentode for use as audio or CRT vertical deflection output
• 6GY8 – High-mu triple triode for use as oscillator, mixer, RF amplifier or AGC tube, Noval base
• 6H5 – Top-view, "Magic Eye"-type tuning indicator, UX6 base; 6G5/6U5 with an extra grid tied to the cathode and a fixed 90° shadow oppopsite the controllable one
• 6H6 (EB34, M-OV D63, RFT HF/OSW3109) – Dual diode, Octal base. Most commonly found as a "stubby" metal envelope tube. Glass versions 6H6-G and 6H6-GT are also found
• 6HS8 – Dual-anode pentode for TV receiver sync separation service or as a two-channel VCA
• 6J5 (M-OV L63) – Medium-mu triode
• 6J5WGT – Heater cathode type, medium-mu triode; 12J5WGT with a different heater
• 6J6/ECC91 – Dual VHF triode with common cathode up to 600 MHz, miniature 7-pin base
• 6J7/EF37 – Sharp-cutoff pentode, control grid on top cap. Most common commercial uses were as a tuned RF amplifier, a (second) detector, or an AF amplifier; Octal version of type 77, later 6SJ7 (control grid connection on pin 4)
• 6J8-G – Triode/heptode mixer
• 6JU8A – 9 mA, Four-diode bridge rectifier
• 6K6-G – Power pentode, low-to-moderate power output rating: 0.35 to 4.5 watts (single-ended Class-A circuit), 10.5 watts max. (push-pull Class-A circuit); Octal version of type 41
• 6K7/EF39 – Remote-cutoff RF pentode, control grid on top cap. Most common commercial uses were as an IF amplifier or as a superheterodyne mixer, aka 1st detector. Also used in test equipment; Octal version of type 78, later 6SK7 (control grid connection on pin 4)
• 6K8 – American triode/hexode mixer, 1938; 12K8 with a different heater
• 6K11 – Compactron 2x High-mu + 1x medium-mu triple triode, 12-pin base
• 6KM8 – Diode + three-anode sharp-cutoff tetrode for use in musical instruments, frequency dividers and complex wave generators
• 6L4 – Acorn UHF triode for use as an oscillator
• 6L5-G – Medium-mu triode (Similar to type 6J5-G, available only in ST shape)
• 6L6 (EL37) – Beam power tetrode

There are several variations. Except for types 6L6-GC and 6L6-GX, all have the same maximum output ratings:

• 11.5 watts (single-ended Class-A circuit)
• 14.5 watts (push-pull Class-A circuit)
• 34 watts (push-pull Class-AB₁ circuit)
• 60 watts (push-pull Class-AB₂ circuit)

6L6 (metal envelope) and 6L6-G (shouldered glass envelope) were used in pre-World War II radios and Public Address amplifiers

6L6 and 25L6 were introduced in 1935 as the first beam power tetrodes. Both types were branded with the L6 ending to signify their (then) uniqueness among audio output tubes. However, this is the only similarity between the two tubes (Type 6W6-GT is the 6.3 volt heater version of types 12L6-GT, 25L6-GT and 50L6-GT)

• 6L6GA – Post-war version of type 6L6-G, in smaller ST-14 shape with Shouldered Tubular (ST) shaped bulb, revision A
• 6L6GB – Post-war improved version in a cylindrical glass envelope. Similar to type 5881

• 6L6GTB – 6L6 with Tubular, (T), shaped bulb, revision B, (higher power rating, as it happens. The 6L6GTB can always replace the 6L6, 6L6G, and 6L6GT, but a 6L6GTB running at maximum rating should not be replaced with another subtype)
• 6L6-WGB – "Industrial" version of type 6L6GB

• 6L6GC – Final and highest-powered audio version of the tube. Max. outputs:

• 17.5 watts (single-ended Class-A circuit)
• 32 watts (push-pull Class-A circuit)
• 55 watts (push-pull Class-AB₁ circuit)
• 60 watts (push-pull Class-AB₂ circuit)

• 6L6-GX – Class-C oscillator/amplifier used in transmitters. Max. output 30 watts. (All versions may be used as a Class-C oscillator/amplifier, but this version is specifically designed for this purpose, has a special ceramic base)

• 6L7 – Heptode pentagrid converter often used in console radios of the late 1930s. Similar in structure to heptodes 6SA7 and 6BE6, except that a separate oscillator – usually type 6C5 – is required, as grid 1 is the RF input, remote-cutoff control grid and grid 3 is the oscillator input grid. (In types 6SA7 and 6BE6, grid 1 is the internal oscillator grid, grid 3 is the control grid) Because of low conversion transconductance, radios using type 6L7 typically have either a tuned RF pre-amplifier stage, or at least two stages of IF amplification. (A few models have both)
• 6LF6 – Beam power tetrode with a duodecar Compactron base and anode cap, for CRT horizontal deflection amplifiers
• 6M5/EL80 – AF power pentode (Used as Class-A or C output stages of 1950s Australian radiograms) similar to 6BQ5
• 6M11 – Compactron Dual triode + pentode
• 6MD8 – Medium-mu triple triode for use as NTSC chroma signal demodulator matrix in analog color TV receivers, B9E Novar 9-pin base
• 6ME5 – Top-view, "Magic Eye"-type tuning indicator, miniature 7-pin base B7G
• 6MK8 – Dual-anode pentode for TV receiver sync separation service or as a two-channel VCA
• 6MJ8 – Medium-mu triple triode for use as NTSC chroma signal demodulator matrix in analog color TV receivers, 12-pin base
• 6MN8 – High-mu triple triode for use as NTSC chroma signal demodulator matrix in analog color TV receivers, 12-pin base
• 6N3/EY82 – Half-wave rectifier
• 6N5 – See 6AB5/6N5
• 6N6 – Triple-Twin AF signal + 4-Watts power triode, internally connected as a cathode follower like today's Darlington transistors
• 6N7, 6N7-G, 6N7-GT – Dual power triode, used as Class-A audio driver or as Class-B power output, max. output (Class-B): 10 watts; 6A6 with an Octal base
• 6N8/EBF80 – Remote-cutoff pentode + dual diode for use as detector plus RF or AF amplifier in radios
• 6P5-G/GT – Medium-mu triode, often used as driver for type 6AC5-G; Octal version of type 76
• 6P7-G – Rarely seen Octal version of type 6F7
• 6Q5-G = 884 – Triode gas thyratron used in DuMont oscilloscopes as a sweep generator; 2B4 = 885 with a 6.3 V/600 mA heater and an Octal base
• 6Q11 – Medium-mu triple triode, 12-pin base, for use as a sync clipper and gated AGC amplifier in TV receivers
• 6R3/EY81 – TV "Damper/Efficiency" diode
• 6R7, 6R7-G, 6R7-GT – Dual diode + medium-mu triode, Octal base with top cap, amplification factor: 16; miniature 7-pin version: 6BF6
• 6S7-G – Remote-cutoff RF pentode, Octal base with top cap, 150 mA heater, used in pre-war 6-volt farm radios; similar to type 6K7
• 6S8-GT – Triple diode + high-mu triode. Octal tube with triode grid on top cap. Has three identical diodes – two diodes share a cathode with the triode, one has a separate cathode. Used as a combined AM detector/AVC rectifier/FM ratio detector/AF amplifier in AM/FM radios. Typically, all sections of this tube are arranged around a single heater
• 6SA7 – First heptode pentagrid converter, Octal base; miniature 7-pin version: 6BE6
• 6SB7Y (Octal base), 6BA7 and 12BA7 (Noval base) – VHF heptode pentagrids, 1946
• 6SC7 – Common-cathode dual high-mu triode
• 6SK7 – Remote-cutoff pentode used in IF stages of North American radios; miniature 7-pin version: 6BD6
• 6SL7/ECC35 – Dual triode, used in TV and general electronics
• 6SN7/ECC32 (M-OV B65, Brimar 13D2, CV1986, 6042?) – Medium-mu dual triode, each section is equivalent to a 6J5, used in audio amplifiers, Hammond organs, television, and extensively in World War II radar; Noval version: 12AU7
• 6SS7 – Remote-cutoff pentode; 6SK7 with a 150 mA heater, found in some AA6 radios as both the RF amplifier and first IF. This is the only RETMA tube to have a same-letter repetition
• 6T5 – Top-view, "Magic Eye"-type tuning indicator with a remote-cutoff driver triode, UX6 base; 6G5/6U5 with a ring-shaped indicating area that varies its inner diameter with the signal strength
• 6T7-G – Dual diode + high-mu triode, Octal base with top cap, 150 mA heater, used in pre-war farm radios; similar to type 6Q7
• 6T8 – Triple diode + high-mu triode. Has three identical diodes – two have cathodes connected to the triode's cathode, one has a separate cathode. Triode amplification factor: 70. Used as an AM detector/AVC rectifier/FM ratio detector/AF amplifier in North American AM/FM radios; 6AK8/EABC80 with a shorter glass envelope
• 6U5 – See 6G5/6U5
• 6U7-G – Remote-cutoff RF pentode. Most common commercial uses were as an IF amplifier or as a superheterodyne mixer, aka 1st detector. Also used in test equipment; 6D6 with an Octal base. Most direct substitute: 6K7. Similar to types 58, 78 and 6SK7
• 6U8/ECF82 – Triode + pentode, Noval base. Audio preamplifier
• 6U10 – 1x High-mu + 2x medium-mu triple triode, 12-pin base
• 6V4/EZ80 – 90 mA Full-wave rectifier, indirectly heated, Noval base
• 6V6 – Beam power tetrode, used in single-ended Class-A audio output stages of radios and sometimes seen in Class-B audio amplifiers (see also: 5V6 and 12V6). Electrically similar to 6AQ5/EL90

• 6V6G – 6V6 with Shouldered Tubular (ST) shaped bulb
• 6V6GT – 6V6 with Tubular, (T), shaped bulb

• 6V7-G – Dual diode + medium-mu triode, amplification factor: 8.3; Octal version of type 85, similar to type 6R7
• 6W6-GT – Beam power pentode, used most often as a vertical deflection output tube in monochrome TV receivers of the 1950s. Can also used as an audio output tube; 12L6-GT or 25L6-GT or 50L6-GT with a 6.3 volt heater
• 6X4/EZ90 (Miniature 7-pin base) and 6X5/EZ35 (Octal base) – Full-wave rectifiers with indirectly heated common cathode, based on type 84/6Z4
• 6Z10 – Compactron quadrature detector pentode + power pentode, used in TV audio circuits of the 1950s and early 1960s; cf. 6BN6, 6DT6, nonode

More of these tubes are listed as equivalents under M-P E - 6.3 V heater

_{LoVT ⟶ List of American RETMA tubes ⟶}

7 prefix - Loctal tubes

These tubes all have 6.3 V heaters despite the 7-prefix, intended to indicate a Loctal base

Actual 7V heater tubes are listed below as series heater tubes

• 7A4 – Medium-mu triode; Loctal version of type 6J5, often numbered 7A4/XXL
• 7A5 – Beam power pentode; Loctal version of type 6U6GT
• 7A6 – Dual detector diode; similar to type 6H6
• 7A7 – Remote-cutoff pentode; Loctal version of type 6SK7
• 7A8 – The only octode pentagrid converter produced in America by Sylvania, 1939. Used mostly in Philco radios
• 7AB7 – Sharp-cutoff pentode
• 7AD7 – Power pentode
• 7AF7 – Dual medium-mu triode
• 7AG7 – Sharp-cutoff pentode
• 7AH7 – Remote-cutoff pentode
• 7AJ7 – Sharp-cutoff pentode
• 7AK7 – Sharp-cutoff, dual-control pentode for computer service. Perhaps the first active device specifically designed for computer use
• 7B4 – High-mu triode; Loctal version of types 6F5 and 6SF5
• 7B5 – Power pentode; Loctal version of types 6K6 and 41
• 7B6 – High-mu triode + dual detector diodes; Loctal version of type 75, similar to types 6AV6/EBC91 and 6SQ7
• 7B7 – Remote-cutoff pentode
• 7B8 – Heptode pentagrid converter; Loctal version of types 6A7 and 6A8
• 7C4 – High frequency diode
• 7C5 – Beam power pentode; Loctal version of type 6V6
• 7C6 – High-mu triode + dual detector diode
• 7C7 – Sharp-cutoff pentode
• 7E5 – Medium-mu RF triode
• 7E6 – Medium-mu triode + dual detector diode; Loctal version of types 6R7 and 6SR7; miniature 7-pin version: 6BF6
• 7E7 – Semiremote-cutoff pentode + dual detector diode; similar to types 6B7 and 6B8
• 7F7 – High-mu dual triode; Loctal version of type 6SL7-GT
• 7F8 – Medium-mu VHF triode, used as FM RF amplifier and converter
• 7G7 – Sharp-cutoff pentode
• 7G8 – Sharp-cutoff dual tetrode
• 7H7 – Semiremote-cutoff pentode
• 7J7 – Triode/heptode mixer; similar to type 6J8-G
• 7K7 – High-mu triode + dual detector diode; similar to types 6AT6/EBC90 and 6Q7
• 7L7 – Sharp-cutoff pentode
• 7N7 – Dual medium-mu triode; Loctal version of type 6SN7-GT
• 7Q7 – Heptode pentagrid converter; similar to type 6SA7
• 7R7 – Remote-cutoff pentode + dual detector diode
• 7S7 – Triode/heptode mixer
• 7T7 – Sharp-cutoff pentode
• 7V7 – Sharp-cutoff pentode
• 7W7 – Sharp-cutoff pentode

Note: Types 7V7 and 7W7 are electronically identical except for base connections of pins 4, 5 and 7. On type 7V7, the suppressor grid (grid 3) is connected to pin 4, an internal shield is connected to pin 5, and the cathode is connected to pin 7. On type 7W7, the suppressor grid and internal shield are connected to pin 5, and the cathode is connected to pins 4 and 7. All other pin connections are the same. If interchanging these tube types is necessary, confirm that pins 4 and 7 are connected at the socket. Pin 5 is usually connected to the chassis.

• 7X6 – Separate cathode dual rectifier for use as a voltage doubler
• 7X7 – High-mu triode + dual detector diodes on separate cathodes, used as FM discriminator and AF amplifier, often numbered 7X7/XXFM
• 7Y4 – Full-wave rectifier
• 7Z4 – Full-wave rectifier

_{LoVT ⟶ List of American RETMA tubes ⟶}

12 volt heater tubes

_{LoVT ⟶ List of American RETMA tubes ⟶ 12 volt heater tubes ⟶}

For fixed/mobile equipment

Many of these tubes have a 150 mA heater and so were popular in AA5 radio receivers; some have 300, 450 or 600 mA heaters for use in TV receivers

• 12A7 – Power pentode + rectifier diode. Pentode section is similar to type 38. Diode has a low power rating – 120 V/30 mA – that limits the number of tubes that can be tied to its B+ circuit. Used in one-tube portable phonographs and a few two- and three-tube radios. Forerunner of such types as 32L7-GT, 70L7-GT and 117L7-GT. UX7 base with top cap. Not related to types 2A7 and 6A7
• 12AB5 – Beam power tetrode^[61]
• 12AC10 – Compactron High-mu triple triode for use as NTSC chroma signal demodulator matrix in analog color TV receivers, 12-pin base
• 12AE10 – Compactron Beam power tetrode + sharp-cutoff pentode^[61]
• 12AL5/HAA91 – Dual diode with separate cathodes, miniature 7-pin base; 6AL5/EAA91, UAA91 or 3AL5/XAA91 with a different heater
• 12AT6/HBC90 – Dual diode + triode (Commonly replaced by 12AV6/HBC91 in consumer radios)
• 12AV6/HBC91 – Dual diode + high-mu triode; 6AV6/EBC91 with a different heater
• 12BA6/HF93 – Remote-cutoff pentode; 6BA6/EF93 with a different heater
• 12BE6/HK90 – Heptode pentagrid converter; 6BE6/EK90 with a different heater
• 12DT6 – Sharp-cutoff pentode
• 12FQ8 – Common cathode, dual split-anode triode for use in musical instruments, frequency dividers and complex wave generators^[62]
• 12GA6 – Similar to type 12FA6, but with lower conversion transconductance
• 12J5WGT – Heater cathode type, medium-mu triode; 6J5WGT with a different heater
• 12MD8 – Medium-mu triple triode for use as NTSC chroma signal demodulator matrix in analog color TV receivers, B9E Novar 9-pin base
• 12MN8 – High-mu triple triode for use as NTSC chroma signal demodulator matrix in analog color TV receivers, 12-pin base
• 12SA7 – Heptode pentagrid converter; 12BE6/HK90 with an Octal base
• 12SK7 – Remote-cutoff pentode; 12BA6/HF93 with an Octal base
• 12SQ7 – Dual diode + triode; 12AV6/HBC91 with an Octal base
• 12U5G – Tuning indicator; 6U5G with a different heater
• 12Z3 – Half-wave rectifier, UX4 base

—with a center-tapped heater, used in:

• 12A4 – High-perveance triode for use as vertical deflection amplifier, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base
• 12A5 – Power pentode, UX7 base, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater. Mostly used in pre-war car radios
• 12AD7 – Dual high-mu triode, center-tapped 12.6 V/225 mA resp. 6.3 V/450 mA heater, Noval base
• 12AT7/ECC81, M-OV B309 (6060, M8162) – High-mu dual triode with a center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater. Commonly used as RF amplifier/mixer in VHF circuits^[61]
• 12AU7/ECC82, M-OV B329 (6067, M8136) – Medium-mu dual triode with a center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater.^[61] Two 6C4/EC90s in one envelope;^[63] however, it is only specified as an audio frequency device. Commonly used in audio applications and TV receivers
• 12AV7 (5965) – Medium-mu dual triode with a center-tapped 12.6 V/225 mA resp. 6.3 V/450 mA heater. Principally designed for VHF amplifier/mixer operation^[64]
• 12AX7/ECC83, M-OV B327 (6057, M8137) – High-mu dual triode with a center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater. Very similar to triode section of 6AV6/EBC91. Commonly used in high-gain audio stages^[61]
• 12AY7 – Dual triode with a center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater. Medium gain but low noise, intended for low-level/preamplifier use^[61]
• 12AZ7 – Medium-mu dual triode with a center-tapped 12.6 V/225 mA resp. 6.3 V/450 mA heater, Noval base, for use as AF Amplifier, or combined oscillator and mixer^[65][61]
• 12B4A – Power triode with a center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base^[61]
• 12BH7 – Medium-mu dual power triode with a center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater^[66][61]
• 12BV7, 12BY7/EL180, 12DQ7 – CRT cathode drive power pentodes with a center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater^[67]
• 12BZ7 – Dual high-mu triode for use as sync separator and amplifier, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base
• 12DF5 – Separate cathode dual rectifier, center-tapped 12.6 V/450 mA resp. 6.3 V/900 mA heater, Noval base
• 12DF7 – Dual triode, low-microphonics version of 12AX7, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater, Noval base
• 12DM7 – Dual high-mu triode, low hum, center-tapped 12.6 V/130 mA resp. 6.3 V/260 mA heater, Noval base
• 12DQ7 – CRT cathode drive beam power pentode, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base
• 12DT7 – Dual high-mu AF triode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater, Noval base
• 12DW7/ECC832 (7247) – Dual dissimilar AF triode with a center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater; one half 12AX7-type triode, other half 12AU7-type triode
• 12GN7/12HG7 – Sharp-cutoff pentode for use as video amplifier, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base
• 12H4 – Triode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater, 7-pin Miniature base
• 12HL7 – Sharp-cutoff pentode for use as video amplifier, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base
• 12U7 – Dual medium-mu triode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater, Noval base

_{LoVT ⟶ List of American RETMA tubes ⟶ 12 volt heater tubes ⟶}

For mobile equipment

• 12AC6 – Low (12.6-30 V) anode voltage remote-cutoff pentode, 12.6 V/150 mA heater, 7-pin miniature base
• 12AD6 – Low (10.0-15.9 V) anode voltage sharp-cutoff heptode pentagrid converter
• 12AE7 – Low (12.6-16 V) anode voltage dissimilar (medium-mu + low-mu) triodes, 12.6 V/450 mA heater, Noval base
• 12AG6 – Low (12.6-16 V) anode voltage heptode pentagrid converter, 12.6 V/150 mA heater, 7-pin miniature base
• 12AL8 – Low (12.6-30 V) anode voltage medium-mu triode + power tetrode with a space charge grid, 12.6 V/550 mA heater, Noval base
• 12CX6 – Low (12.6-33 V) anode voltage sharp-cutoff pentode, 12.6 V/150 mA heater, 7-pin miniature base
• 12DE8 – Diode + low (12.6-30 V) anode voltage, remote-cutoff pentode, 12.6 V/200 mA heater, Noval base
• 12DK7 – Dual diode + low (12.6-30 V) anode voltage power tetrode, 12.6 V/500 mA heater, Noval base
• 12DL8 – Dual diode + low (12.6-30 V) anode voltage power tetrode with a space charge grid, 12.6 V/550 mA heater, Noval base
• 12DS7 – Dual diode + low (12.6-16 V) anode voltage power tetrode, 12.6 V/400 mA heater, Noval base
• 12DU7 – Dual diode + low (12.6-16 V) anode voltage power tetrode, 12.6 V/250 mA heater, Noval base
• 12DV7 – Dual diode + low (12.6-16 V) anode voltage triode, 12.6 V/150 mA heater, Noval base
• 12DV8 – Dual diode + low (12.6-16 V) anode voltage power tetrode with a space charge grid, 12.6 V/375 mA heater, Noval base
• 12DW8 – Diode + low (12.6-16 V) anode voltage, dissimilar dual triode, 12.6 V/450 mA heater, Noval base
• 12DY8 – Low (12.6-16 V) anode voltage medium-mu triode + remote-cutoff pentode, 12.6 V/350 mA heater, Noval base
• 12DZ6 – Low (12.6-16 V) anode voltage RF pentode, 12.6 V/190 mA heater, 7-pin miniature base
• 12EA6 – Low (12.6-16 V) anode voltage IF pentode, 12.6 V/175 mA heater, 7-pin miniature base
• 12EC8 – Low (12.6-16 V) anode voltage medium-mu triode + semiremote-cutoff pentode, 12.6 V/225 mA heater, Noval base
• 12EG6 – Low (12.6-30 V) anode voltage heptode pentagrid converter, both grids 1 and 3 are sharp-cutoff, 12.6 V/150 mA heater, 7-pin miniature base
• 12EL6 – Dual diode + low (12.6-30 V) anode voltage, high-mu triode, 12.6 V/150 mA heater, 7-pin miniature base
• 12EM6 – Diode + low (12.6-30 V) anode voltage power tetrode, 12.6 V/500 mA heater, Noval base
• 12FA6 – Low (12.6-30 V) anode voltage heptode pentagrid converter, 12.6 V/150 mA heater, 7-pin miniature base; car radio version of 12BE6/HK90
• 12FM6 – Dual diode + low (12.6-30 V) anode voltage, medium-mu triode, 12.6 V/150 mA heater, 7-pin miniature base
• 12FR8 – Diode + low (12.6-16 V) anode voltage triode + pentode for use as IF/AF amplifier and detector, 12.6 V/320 mA heater, Noval base
• 12FT6 – Dual diode + low (12.6-30 V) anode voltage triode for use as detector and AF Amplifier, 12.6 V/150 mA heater, 7-pin miniature base
• 12FX8 – Low (12.6-16 V) anode voltage triode/heptode mixer, 12.6 V/270mA heater, Noval base
• 12GA6 – Low (12.6-16 V) anode voltage heptode pentagrid converter, 12.6 V/150 mA heater, 7-pin miniature base
• 12J8 – Dual diode + low (12.6-30 V) anode voltage power tetrode, 12.6 V/325 mA heater, Noval base
• 12K5 – Low (12.6-30 V) anode voltage power tetrode with a space charge grid, 12.6 V/400 mA heater, 7-pin miniature base; cf. 13П1С, Shuguang 13P1P
• 12SW7 – Dual diode + low (26.5-250 V) anode voltage triode, 12.6 V/150 mA heater, Octal base
• 12SX7GT – Low (26.5-300 V) anode voltage dual triode, 12.6 V/300 mA heater, Octal base
• 12SY7 – Low (26.5-300 V) anode voltage pentagrid converter, 12.6 V/150 mA heater, Octal base

_{LoVT ⟶ List of American RETMA tubes ⟶}

14 prefix - Loctal tubes

These tubes all have 12.6 V heaters despite the 14-prefix, intended to indicate a Loctal base. Most draw 150 mA for use in AA5 radio receivers

Actual 14V heater tubes are listed below as series heater tubes

• 14A4 – Medium-mu triode; Loctal version of type 12J5
• 14A5 – Beam power pentode
• 14A7 – Remote-cutoff pentode, often numbered 14A7/12B7
• 14AF7 – Dual medium-mu triodes, often numbered 14AF7/XXD
• 14B6 – High-mu triode + dual detector diode; similar to types 12AV6/HBC91 and 12SQ7
• 14B8 – Heptode pentagrid converter; Loctal version of type 12A8
• 14C5 – Beam power pentode; Loctal version of type 12V6-GT
• 14C7 – Sharp-cutoff pentode
• 14E6 – Medium-mu triode + dual detector diode; Loctal version of 12SR7
• 14E7 – Semiremote-cutoff pentode + dual detector diode; similar to type 12C8
• 14F7 – High-mu dual triode; Loctal version of type 12SL7-GT
• 14F8 – Medium-mu high frequency triode, used as FM RF amplifier and converter
• 14H7 – Semiremote-cutoff pentode
• 14J7 – Triode/heptode mixer
• 14N7 – Dual medium-mu triode; Loctal version of type 12SN7-GT
• 14Q7 – Heptode pentagrid converter; similar to type 12SA7
• 14R7 – Remote-cutoff pentode + dual detector diode
• 14S7 – Triode/heptode mixer
• 14W7 – Sharp-cutoff pentode
• 14X7 – High-mu triode + dual detector diodes on separate cathodes, used as FM discriminator and AF amplifier
• 14Y4 – Full-wave rectifier

_{LoVT ⟶ List of American RETMA tubes ⟶}

25 volt series heater tubes

For AA5 radio receivers with 150 mA series heater strings

• 25F5 – Beam power pentode; 50C5 with half the heater power, allowing for push-pull output stages with the heater spec of a single 50C5

For AA5 radio receivers with 300 mA series heater strings

• 25A6 – Power pentode, Octal version of type 43
• 25C5 – Beam power pentode; 50C5 with a different heater
• 25L6 – Beam power pentode; 12L6 or 50L6 with a different heater; besides AA5, also popular for high-speed gating, or as a relay or keypunch solenoid driver, in early computers such as the UNIVAC I, where the heater ran off the equipment's 24-volts supply bus. As the 25L6GT developed cathode interface/poisoning after prolonged periods in cut-off, the EIA-type 6046 was derived from it, which didn't suffer from this problem
• 25Z5 – Separate cathode dual rectifier for use as a voltage doubler
• 25Z6 – 25Z5 with an Octal base

_{LoVT ⟶ List of American RETMA tubes ⟶}

35 volt series heater tubes

For AA5 radio receivers with 150 mA series heater strings

• 35A5 – Beam power tetrode, Loctal base; similar to 35L6
• 35B5 – Beam power tetrode
• 35C5 – 35B5 with a revised pinout to address concerns that high peak voltage between 4 (heater) and 5 (anode) would promote socket breakdown^[68]
• 35DZ8 – High-mu triode + power pentode, used for audio; similar to 35HB8
• 35HB8 – Triode + beam power tetrode, used primarily as both the audio preamplifier and output
• 35L6-GT – Beam power pentode similar to, but not electronically identical to, types 12L6-GT, 25L6-GT and 50L6-GT
• 35W4 – Half-wave rectifier
• 35Y4 – Half-wave rectifier with a heater tap for a pilot light, Loctal base; similar to 35Z5
• 35Z3 – Half-wave rectifier, Loctal base; similar to 35Z4
• 35Z4-GT – Half-wave rectifier
• 35Z5-GT – 35Z4-GT with a heater tap for a pilot light

_{LoVT ⟶ List of American RETMA tubes ⟶}

50 volt series heater tubes

For AA5 radio receivers with 150 mA series heater strings

• 50A5 – Beam power tetrode, Loctal base; similar to 50L6
• 50B5 – Beam power tetrode, 35B5 with a 50 volt heater
• 50C5 – 50B5 with a revised pinout to address concerns that high peak voltage between 4 (heater) and 5 (anode) would promote socket breakdown^[68]
• 50DC4 – Half-wave rectifier, 35W4 with a 50 volt heater
• 50EH5 – Beam power tetrode, some radios that use this tube do not have an audio amplifier section; similar to 50C5 but with higher gain
• 50HK6 – Power pentode with a heater tap for a pilot light
• 50L6 – Beam power tetrode, 12L6 or 25L6 with a 50 volt heater
• 50X6 – Separate cathode dual rectifier for use as a voltage doubler, Loctal base

_{LoVT ⟶ List of American RETMA tubes ⟶}

117 volt heater tubes

These tubes operate with their heaters connected directly to the 117 volt (now 120 volt) electrical mains of North America. They are indirectly heated and were used in one-tube phonographs and Three-way portable (AC or DC mains, or batteries) radio receivers

_{LoVT ⟶ List of American RETMA tubes ⟶ 117 volt heater tubes ⟶}

Rectifier and beam power pentode

• 117L7GT = 117M7GT – Half-wave rectifier + beam power pentode
• 117N7GT – Half-wave rectifier + beam power pentode
• 117P7GT – Half-wave rectifier + beam power pentode

_{LoVT ⟶ List of American RETMA tubes ⟶ 117 volt heater tubes ⟶}

Rectifiers

• 117Z3 – Half-wave rectifier; 117Z4GT with a miniature 7-pin base
• 117Z4GT – Half-wave rectifier
• 117Z6GT – Separate cathode dual rectifier for use as a voltage doubler; some versions have a center-tapped heater that can also be wired for 150 mA/58.5 V

_{LoVT ⟶ List of American RETMA tubes ⟶}

100 mA series heater tubes

Used in radio receivers with series heater strings

• 18FX6 – Heptode pentagrid converter; 6BE6/EK90 or 12BE6/HK90 with a different heater
• 18FY6 – Dual diode + triode; 6AV6/EBC91 or 12AV6/HBC91 with a different heater
• 34GD5 – Beam power tetrode; 35C5 or 50C5 with a different heater
• 36AM3 – Half-wave rectifier; 35W4 with a different heater
• 60FX5 – AF power pentode; 12FX5 or 19FX5 with a different heater

More of these tubes are listed as equivalents under M-P U - 100 mA heater

_{LoVT ⟶ List of American RETMA tubes ⟶}

150 mA series heater tubes

Used in AA5 radios, and semi-transistorized TV receivers with series heater strings

• 14GT8/7724, 14JG8 – Dual diode, high-mu triode for use as FM detector and AF amplifier
• 17EW8/HCC85 – Dual triode for use as VHF oscillator/mixer up to 200 MHz, Noval base; 6AQ8/ECC85, 9AQ8/PCC85 or UCC85 with a different heater
• 19T8/HABC80 – High-mu triode + triple diode (two on common cathode with triode, one with independent cathode), Noval base, used as an AF amplifier, AM detector and FM ratio detector in series-heated post-war AM/FM radios; 5T8, 6T8, 6AK8/EABC80, 9AK8/PABC80 or 27AK8/UABC80 with a different heater
• 40B2 – 20 to 60 V Barretter, Octal base, to stabilize against mains voltage fluctuations
• 50JY6 – Horizontal deflection beam power pentode
• 56R9 – Compactron AF triode + beam power pentode, separate heaters for triode (14 V) and pentode (42 V) for flexibility with the series string order
• 70A7, 70L7 – Half-wave rectifier + beam power pentode

More of these tubes are listed as equivalents under M-P H - 150 mA heater

_{LoVT ⟶ List of American RETMA tubes ⟶}

300 mA series heater tubes

Most are series heater versions of respective 6-prefix tubes; used in TV receivers with series heater strings

• 4HK5 – VHF frame-grid, variable-mu triode; 2HK5, 3HK5 or 6HK5 with a different heater
• 6AU7 – AF, Medium-mu dual triode; 12AU7/ECC82 with a different, but also center-tapped heater that can be wired for 300 mA/6.3 V or 600 mA/3.15 V
• 6AX7 – AF, High-mu dual triode; 12AX7/ECC83 with a different, but also center-tapped heater that can be wired for 300 mA/6.3 V or 600 mA/3.15 V
• 6CN7 – Dual common cathode diode + triode for use as horizontal phase detector and reactance tube in TV receivers; 8CN7 with a different, but also center-tapped heater that can be wired for 300 mA/6.3 V or 600 mA/3.15 V
• 7AU7/XCC82 – 6AU7 Dual triode with a 300 mA/7.0 V resp. 600 mA/3.5 V heater
• 42A1 (141 Ω), 49A1 (162 Ω), 55A1 (183 Ω), 80A1 (266 Ω), 86A1 (287 Ω), 92A1 (308 Ω) – Straight ballast resistors, Octal base, for use in areas with a stable power grid
• 42A2, 49A2, 55A2, 80A2, 86A2, 92A2 – Straight ballast resistors with tap for 2 pilot lights
• 42B2, 49B2, 55B2, 80B2, 86B2, 92B2 – Straight ballast resistors with tap for 1 pilot light
• 50A2 (with tap for 2 pilot lights), 50B2 (with tap for 1 pilot light) – 50 V Barretter, 4-pin base, to stabilize against mains voltage fluctuations
• 58HE7 – Compactron High-perveance damper diode + horizontal deflection beam power pentode; 6HE7, 12HE7 or 38HE7 with a different heater

More of these tubes are listed as equivalents under M-P P - 300 mA heater

_{LoVT ⟶ List of American RETMA tubes ⟶}

450 mA series heater tubes

Most are series heater versions of respective 6-prefix tubes; used in TV receivers with series heater strings

• 2CW4 – Nuvistor High-mu VHF triode, 6CW4 with a 2.1 volt/450 mA heater
• 2EN5 – Dual diode
• 4CB6 – Sharp-cutoff pentode
• 7KY6 – Sharp-cutoff frame-grid pentode with a 7.3 V/450 mA heater for use as video output tube in TV receivers, Noval base^[69]
• 8AC10 – Compactron High-mu triple triode for use as NTSC chroma signal demodulator matrix in analog color TV receivers, 12-pin base
• 8B10 – Compactron Dual triode + dual diode
• 8CN7 – Dual common cathode diode + triode for use as horizontal phase detector and reactance tube in TV receivers; 6CN7 with a different, but also center-tapped heater that can be wired for 225 mA/8.4 V or 450 mA/4.2 V
• 8FQ7/8CG7 – Dual triode; 6CG7 with an 8.4 V/450 mA heater
• 11DS5 – Beam power tetrode; 50B5 or 35B5 with an 11.2 V/450 mA heater
• 38HE7, 38HK7 – Compactron High-perveance damper diode + horizontal deflection beam power pentode
• 42KN6 – Compactron Horizontal deflection beam power pentode; 6KN6 with a different heater

More of these tubes are listed as equivalents under M-P L - 450 mA heater

_{LoVT ⟶ List of American RETMA tubes ⟶}

600 mA series heater tubes

Most are series heater versions of respective 6-prefix tubes; used in color TV receivers with series heater strings

• 2AF4 – UHF Medium-mu oscillator triode; 6AF4/EC94 with a different heater
• 2BN4 – VHF triode
• 2CY5 – VHF sharp-cutoff tetrode
• 2EA5 – VHF sharp-cutoff tetrode
• 2EG4 – Nuvistor High-mu VHF triode, 1.7 volt/600 mA heater
• 2ER5/XC95 – Variable-mu VHF triode; 4ER5/PC95 or 6ER5/EC95 with a different heater
• 2ES5 – VHF triode
• 2EV5 – VHF sharp-cutoff tetrode
• 2FH5 – VHF triode
• 2FQ5 – VHF semiremote-cutoff triode
• 2FV6 – VHF sharp-cutoff tetrode
• 2FY5/XC97 – Frame-grid VHF triode; 4FY5/PC97 or 6FY5/EC97 with a different heater
• 5J6 – Dual VHF triode; 6J6/ECC91 with a 4.7 V/600 mA controlled warm-up heater^[70]
• 5T8 – High-mu triode + triple diode (two on common cathode with triode, one with independent cathode), Noval base, used as an AF amplifier, AM detector and FM ratio detector in series-heated post-war AM/FM radios; 6T8, 6AK8/EABC80, 9AK8/PABC80, 19T8/HABC80 or 27AK8/UABC80 with a different heater
• 10DE7 – Dual triode (dissimilar triode sections) for use as vertical deflection oscillator and amplifier; 6DE7 or 13DE7 with a different heater
• 30KD6 – Compactron Horizontal deflection beam power pentode; 6KD6 or 36KD6/40KD6 with a different heater

More of these tubes are listed as equivalents under M-P X - 600 mA heater

_{LoVT ⟶ List of American RETMA tubes ⟶}

Other tubes

• 13CW4 – Nuvistor High-mu VHF triode (13.5 V/60 mA heater version of the 6CW4) for use as a low-noise front end in standalone, semi-transistorized antenna boosters; later also used as a preamplifier in Neumann condenser microphones U-47 and U-48 after the production of the VF14M ceased^[71]
• 20EZ7 – Dual high-mu AF triode, center-tapped 20 V/100 mA resp. 10 V/200 mA heater, Noval base; cf. 407A
• 26A6 – Remote-cutoff pentode with a 12-cell lead-acid battery heater
• 26A7GT – Low (26.5-50 V) anode voltage dual AF beam power pentode designed for both heater and anode to run directly off the standard avionics 28-volts DC bus, for use as a push–pull audio amplifier; cf. 13П1С, Shuguang 13P1P
• 26BK6, 26C6 – Dual diode + triode with a 12-cell lead-acid battery heater
• 26D6 – Heptode pentagrid with a 12-cell lead-acid battery heater
• 26E6WG – Avionics AF beam power pentode
• 26Z5W – Avionics dual power diode, separate cathodes
• 28D7W – Low (28-100 V) anode voltage dual AF beam power pentode designed for both heater and anode to run directly off the standard avionics 28-volts DC bus, shock resistant up to 350 g, for use as a push–pull audio amplifier, or as switching element of a self-excited push–pull DC/DC converter to provide up to 725 mW of anode high voltage supply for conventional tubes
• 40A1, 50A1 – Barretters for use as cathode resistors of horizontal-deflection output tubes in early TV receivers to stabilize the picture width against mains voltage fluctuations

List of EIA professional tubes

Note: Most of these are special quality versions of the equivalents given. Some manufacturers preceded the EIA number with a manufacturer's code, as explained above.

_{LoVT ⟶ List of EIA professional tubes ⟶}

4000s

• 4042 – Ceramic/metal pencil-type disk-seal UHF power triode for pulsed operation up to 425 W
• 4062A – Ceramic/metal pencil-type disk-seal SHF power triode up to 4 GHz, mu = 100, P_anode = 10 W
• 4065 – Directly heated electrometer triode, grid current ≤125 fA, 4-pin all-glass pigtail, for probe amplifiers
• 4205 – Directly heated power triode, 4-pin bayonet base with offset pin
• 4270A = STC 3C/350E – Directly heated power triode, 3-pin base
• 4275 – Directly heated power triode, 4-pin base
• 4300 – Directly heated power triode, 4-pin base
• 4307A – Directly heated power pentode; remotely similar to the indirectly heated 807 beam power tetrode. Both types have an ST-16 envelope with an anode cap and a U5A American 5-pin base

The SY4307A made by Standard Telephones and Cables Australia is historically notable because a pair of them in parallel Class-C was used as the output stage in a transmitter built in secret by Australian soldiers in Japanese-occupied Portuguese Timor during World War II in 1942. This transmitter, now reconstructed and on display at the Australian War Memorial in Canberra, was called "Winnie the War Winner".^[72]

• 4307AF – 4307A qualified for use in standard aircraft radio

• 4560 – Character generator monoscope for text mode video rendering in early computer monitors, with a square target having letters, digits and symbols stenciled into it in a customer-supplied 8x8 array. An electron beam selects and scans a character, both by appropriate electrostatic deflection, and generates an analog video signal;^[73] cf. CK1414, TH9503
• 4598,^[74] 7539,^[75] 7828,^[76] 8087,^[77] 8098^[78] – Graphechon dual-electron gun scan conversion tubes, analog video transcoders with simultaneous R/W capability for realtime resolution and frame rate transcoding between different analog video standards. This was achieved by a CRT/camera tube combination; the CRT part writes onto a thin, dielectric target; the camera part reads the generated charge pattern at a different scan rate from the back side of this target.^[79] The setup could also be used as a genlock
• 4613 – Directly heated power triode, 4-pin base
• 4614 – Indirectly heated power triode, 5-pin base
• 4641 – Directly heated power triode, 4-pin base
• 4671/E1C (955) – Indirectly heated Acorn triode
• 4672/E1F (954) – Indirectly heated Acorn pentode
• 4674 – Indirectly heated Acorn diode
• 4675 – 4671/E1C with a 4 Volts heater
• 4676 – 4672/E1F with a 4 Volts heater
• 4678 (EM1) – Indirectly heated tuning indicator
• 4683 – Directly heated power triode, side-contact 8 base
• 4695/E2F (956) – Indirectly heated Acorn pentode

_{LoVT ⟶ List of EIA professional tubes ⟶}

5000s

• 5331, 5332, 5514 – Directly heated power triodes, 4-pin base with anode top cap
• 5556 – Directly heated power triode, 4-pin base
• 5593 – Phasitron, a magnetically controlled beam deflection phase modulator tube^[80] similar to the 2H21, used in early FM broadcast transmitters^[14][15][16]
• 5608 – Dual power triode, designed for use with AC anode voltage and critical grid leak requirements
• 5651 – 86-volts, cold-cathode, glow-discharge voltage reference, miniature 7-pin base
• 5654/E95F, CV4010, 408A – VHF/RF/IF Sharp-cutoff pentode, miniature 7-pin base, common in vintage radar IF amplifiers; premium version of 6AK5/EF95/6Ж1П (↦6J1P)
• 5678 – 5 leads subminiature shielded pentode for RF applications
• 5691 – Special Red ruggedized long-life high-mu triode for industrial applications
• 5692 – Special Red ruggedized long-life medium-mu triode for industrial applications
• 5693 – Special Red ruggedized long-life sharp-cutoff pentode for industrial applications
• 5704 – Subminiature diode, all-glass round cross-section body, but flat 4-pin base, long pigtails
• 5727 – 650 V, 100 mA_avg, 500 mA_peak, 10 A_surge Indirectly heated tetrode thyratron, positive starter voltage, miniature 7-pin base
• 5729 – Beam deflection, 30-channel analog multiplexer for telecomms transmitting channel banks, internal electrostatic focusing and deflection to determine through which one out of 30 grids the electron beam passes to the common anode;^[81] cf. 5738, 6090, 6091, 6170, 6324
• 5731 – Narrow-tolerance selected 955 Acorn triode for use in Radiosonde weather balloon transmitters
• 5734 – Mechanotron-type mechano-electronic displacement sensor; a vacuum triode with its anode mounted on a shaft that extends through a thin, flexible metal diaphragm; shaft movement is reflected in anode current; F_res = 12 kHz^[82][83]
• 5738 – Cyclophon, a beam deflection, secondary emission, 25-channel analog multiplexer, internal electrostatic focusing and deflection to determine which one out of 25 individually controllable dynodes receives the electron beam controlled by a common grid;^[84] cf. 5729, 6090, 6091, 6170, 6324
• 5749 – RF pentode, premium version of 6BA6/EF93, M-OV W727
• 5750 – Heptode pentagrid converter, premium version of 6BE6/EK90, M-OV X727
• 5751 – Low-voltage, low-noise avionics dual triode with separate cathodes
• 5814A – Dual triode; industrial/computer-rated version of 12AU7/ECC82 (shock/vibration resistant, no cathode interface/poisoning after prolonged periods in cut-off)
• 5836, 6BL6
  

  Raytheon RK5836
  – Sutton tube, a reflex klystron used as a 250 mW CW microwave source, 1.6 to 6.5 GHz depending upon an external cavity. 4-pin peewee base with cavity contact rings and top cap
• 5837, 6BM6 – Sutton tube used as a 150 mW CW microwave source, 550 MHz to 3.8 GHz depending upon an external cavity. 4-pin peewee base with cavity contact rings and top cap
• 5845 – Directly heated, dual 300 V, 1 mA thermally-limited (=saturated) emission diode, center-tapped 5 V/435 mA_max uncoated tungsten filament, usable as a heating current-controlled, variable series resistor in voltage/current stabilizer circuits, or as an RMS heating current-to-DC anode current converter, or as a noise diode; cf. Tesla RA0007, YA1000
• 5876A – Glass pencil-type disk-seal UHF power triode up to 2 GHz
• 5930 – Ruggedized, directly heated power triode, 4-pin base
• 5962 – 700 V/2...55 µA Corona voltage reference, miniature 7-pin base with anode top cap
• 5963 (Noval base), 5964 (7-pin miniature base, common cathode), 5965 (Noval base) – Dual triode; industrial/computer-rated versions of 12AV7 (high zero-bias anode current, no cathode poisoning after prolonged periods in cut-off)
• 5998, 6336A, 6394, 6520, 6528, 7802 – Dual power triodes, designed for series voltage regulator applications

_{LoVT ⟶ List of EIA professional tubes ⟶}

6000s

• 6047 – Additron, a triple-control grid, split-anode tetrode for use as a single-bit digital full adder^[85] (technically a hexode)
• 6057, M8137 – High-mu dual triode; premium version of 12AX7/ECC83, M-OV B339
• 6059 – Low-microphonics pentode, premium version of 6BR7, 6J7
• 6060, M8162 – High-mu dual triode; premium version of 12AT7/ECC81, M-OV B309
• 6064, M8083 – Sharp-cutoff RF pentode; premium version of 6AM6/EF91 = M-OV Z77
• 6067, M8136 – Medium-mu dual triode; premium version of 12AU7/ECC82, M-OV B329
• 6080 – Very-low impedance dual power triode, designed for series voltage regulator applications, now popular for output transformerless audio amplifiers; premium version of 6AS7/ECC230
• 6082 – Ruggedized, indirectly heated power triode, Octal base
• 6090 – Cyclophon, a beam deflection, 18-channel analog demultiplexer for telecomms receiving channel banks, internal electrostatic focusing and deflection to determine which one out of 18 anodes receives the electron beam controlled by a common grid;^[86] cf. 5729, 5738, 6091, 6170, 6324
• 6091 – Beam deflection, 25-channel analog multiplexer for telecomms transmitting channel banks, internal electrostatic focusing and deflection to determine through which one out of 25 grids the electron beam passes to the common anode;^[87] cf. 5729, 5738, 6090, 6170, 6324
• 6146 – 60 MHz, 120 W AF/RF/VHF beam power pentode

• 6146B, 8298A – Improved version of 6146, 6146A and 8298

• 6170 and 6324 – Beam deflection, 25-channel analog multiplexer for telecomms transmitting channel banks, external focusing and deflection by a multiphase, rotating magnetic field to determine through which one out of 25 grids the electron beam passes to the common anode;^[88] cf. 5729, 5738, 6090, 6091
• 6173 – Pencil-type disk-seal UHF diode up to 3.3 GHz
• 6196 – Directly heated dual, compensating electrometer tetrode with space charge grids for use in the 2 branches of a differential-in, differential-out bridge circuit^[89]
• 6218/E80T (CV5724) – Modulated, single-anode beam deflection tube for pulse generation up to 375 MHz; shock resistant up to 500 g^{[90][91][92][93]}
• 6263 – Pencil-type disk-seal UHF power triode up to 500 MHz, P_anode = 8 W
• 6351 – Secondary emission pentode for wide band RF amplifiers
• 6353 – 19.3 kV/25...1000 µA Corona voltage reference, miniature 7-pin base with anode top cap
• 6361 – Convectron, an inclinometer tube that senses tilt from the vertical by means of different gas convections around a heating wire in a glass envelope, of two 6361s aligned in a 90° V-shaped position to each other and the heating wires connected in a bridge circuit
• 6386 – Dual variable-mu triode for use as VHF cascode amplifiers or in audio compressors
• 6391 – Subminiature low-microphonics pentode, 8-pin all-glass pigtailed
• 6441 – 650 V, 100 mA_avg, 300 mA_surge Tacitron, a grid turn-off hydrogen thyratron with a grid that forms a shield around both the cathode and anode and separates the two by a wire mesh, so the arc discharge can be extinguished by a negative grid that surrounds the positive anode with a field of opposing polarity and inhibits conduction, taking over part of the anode current during deionisation – similar to today's GTOs; Octal base;^[94] cf. EC860, 20TC4, 30TC1
• 6462 – Magnetic pickup tube, a 1-axis beam deflection magnetometer with approx. 1 G (100 μT) resolution; an electron beam is electrostatically centered between two anodes while no magnetic field is present; the magnetic field to be detected will then deflect the beam more towards one of the anodes, resulting in an imbalance between the two anode currents^[95]
• 6498 – Memotron, a storage tube^[96]
• 6499 – Radechon, an early form of digital computer memory^[97]
• 6550 – 20 W AF beam power tetrode with a 35 watt anode, for high fidelity amplifiers

• 6550A – Improved 6550 with a 42 watt anode

• 6571 – Williams-type computer memory tube^[98]
• 6577 – Typotron, a charactron for text mode video rendering in early computer monitors^[99]
• 6694, 6957, 7412, 7536, 7633/ORP11, 8100, 8142, 8143, 8217, 8318, 8345, 8346, 8347, 8474, 8475, 8476, 8477, 8478, 8582 – CdS photoresistors (LDR)
• 6700 – 200 ns Decade counter Magnetron Beam Switching Tube, 6.3 V, 300 mA heater^[100]
• 6701 – Low-voltage 500 ns decade counter Magnetron Beam Switching Tube, 6.3 V, 300 mA heater^[101]
• 6702 (200 to 400 MHz), 6713 (0.15 to 30 MHz) – Beam-X Switch modified for use as a noise source by removing all but the last two spade and grid pairs, thus introducing asymmetries of the already undulated electric field inside, using the principle of random noise generation in a magnetron-like device operated near cutoff, 6.3 V heater
• 6703 – 500 ns Decade counter Magnetron Beam Switching Tube, 6.3 V, 300 mA heater
• 6704 – 100 ns Decade counter Magnetron Beam Switching Tube with internal spade load resistors, 6.3 V, 300 mA heater
• 6710, 6711, 6712 (High current), 6714 (Low-voltage) – 2 MHz Decade counter Beam-X Switch, 6.3 V heater
• 6762 – Wamoscope ("Wave modulated oscilloscope"), a TWT/CRT combination used to directly visualize an incoming microwave signal by electron velocity-sorting^[102]
• 6835, 7570, 7571 – Single-electron gun recording storage tube, an analog video frame freezer tube. This was achieved by a CRT that writes the video image onto a thin, dielectric target and subsequently can read the generated charge pattern up to 30000 times from that target, producing a video signal containing a static shot that resembles a still photograph^{[103][104][105]}
• 6846 – Gas-filled, three-cathode, glow-transfer 1-bit binary counter or switching tube, miniature 7-pin base^[106]
• 6877, 7233 – Power triodes, designed for series voltage regulator applications
• 6900 – Dual power triode for pulse applications in missiles, avionics and industrial systems; Noval base
• 6922/E88CC – Dual triode used as cascode RF amplifier, industrial version of 6DJ8/ECC88
• 6973 (6CZ5) – Beam power pentode popular in some makes of 1960s era guitar amplifiers, though rarely implemented in modern times

_{LoVT ⟶ List of EIA professional tubes ⟶}

7000s

• 7025 – Low-hum and noise version of 12AX7

• 7025A – Low-microphonics version of 7025

• 7027 – AF power pentode, improved 6L6 with a 25 watt anode and different pinout

• 7027A – Improved 7027 with a 35 watt anode

• 7077 – Miniature ceramic/metal disk-seal planar UHF triode
• 7105 – 6080 with a 12.6 volts heater
• 7189/6BQ5/EL84 – AF power pentode

• 7189A – Improved 7189

• 7199 – AF triode + AF pentode, Noval base. Similar to 6U8
• 7229,^[107] 7230,^[108] 7231,^[109] 7232,^[110] 7439, 7440, 7441, 7595, 7596, 7597, 7598, 7599, 7600, 7602 – Krytrons, cold-cathode gas-filled trigger tubes with a primer electrode for use as a very high-speed, high-surge current switch^[111] – second source to EG&G
• 7236 – Dual power triode for use as long-life power amplifier in computer applications
• 7241, 7242 – Triple-grid/cathode power triodes, designed for hi-rel series voltage regulator applications
• 7266 – Miniature ceramic/metal disk-seal planar UHF diode
• 7289 – 3 GHz, 40 W UHF planar power triode
• 7296 – Miniature ceramic/metal disk-seal planar VHF triode for use on PCBs
• 7308/E188CC – Premium version of 6922
• 7323, 7400 (top-viewing), 7401, 7979 – Small neon-filled cold-cathode thyratrons for use as a latching indicator, all-glass pigtaled; cf. 395A, МТХ-90
• 7360 – Beam deflection tube, used as balanced modulator/mixer up to 100 MHz^{[112][113][114]}
• 7414 – Time Totalizer, a metal-vapor coulometer, a cold-cathode gas-discharge tube where metal is constantly sputtered off the cathode and deposited on a collector element whose resistance therefore decreases with elapsed time^[115]
• 7416 – Constant firing diode, a gas-filled cold-cathode switching diode with a very stable breakdown voltage over age and temperature, for use as a trigger in RC timing crcuits; miniature 7-pin base
• 7430 – Flat-envelope version of the 6AK5/EF95 sharp-cutoff pentode for use on PCBs in Radiosonde weather balloon transmitters
• 7462 – Miniature ceramic/metal disk-seal planar UHF triode; PCB version of 7077
• 7486 – Miniature ceramic/metal disk-seal planar UHF triode
• 7548 – Secondary emission hexode for pulse generator and pulse amplifier applications
• 7551 (12-15V heater for mobile equipment), 7558 (6.3V heater for fixed equipment) – 175 MHz, 10 W Noval-base beam power pentode used for telephony, RF amplification, and more rarely AF amplification
• 7554 – Ceramic/metal Pencil-type disk-seal SHF power triode up to 5 GHz
• 7572, 7575, 7702 – Dual-electron gun recording storage tube, a realtime analog video frame freezer tube with simultaneous R/W, and storing capability. This was achieved by a CRT/camera tube combination; the CRT part writes the video signal onto a thin, dielectric target, which can hold the generated charge pattern for many hours; the camera part reads the charge pattern from the back side of this target, producing a video signal containing a static shot that resembles a still photograph^{[116][117][118]}
• 7586 – First Nuvistor available on the market, medium-mu triode
• 7587 – Nuvistor Sharp-cutoff tetrode
• 7588 – Miniature ceramic/metal disk-seal planar UHF triode for use on PCBs
• 7591 – 19 W Beam power pentode; 6GM5 or 7868 with a 7-pin Octal base. Found in many guitar amps made by Gibson and Ampeg
• 7610 – Electron bombarded semiconductor tube for high-speed, 8-bit A/D conversion; a beam deflection tube where the analog signal to be digitized deflects a sheet beam across an array of 8 long semiconductor diodes that is covered by a metal layer with windows patterned to encode the Gray code. The 8 diodes are reverse-biased and when hit through a window by the electron beam, generate currents that digitally represent the analog signal;^[119] cf. ЭПЛ-1
• 7625 – Miniature ceramic/metal disk-seal planar AF triode for use on PCBs
• 7688, 7690 (Medium-mu), 7689 (high-mu) – Triple triodes
• 7699 – Dual tetrode for wide band push-pull amplifiers
• 7720 – Miniature ceramic/metal disk-seal planar UHF triode for use on PCBs
• 7733 – CRT cathode drive power pentode, premium version of 12BY7/EL180
• 7762 – Shock-proof avionics AF beam power pentode
• 7763 – Beam deflection tube, used as IF amplifier/limiter where a constant phase shift over a wide range of input signal amplitudes is required^[120]
• 7768 – Miniature ceramic/metal disk-seal planar SHF triode up to 4 GHz
• 7846 – CdSe infrared (500...900 nm) photoresistor, 2-pin all-glass pigtailed
• 7868 – 19 W Beam power pentode; 6GM5 or 7591 with a B9E Novar base. Found in many of the once popular Challenger series PA amps made by Bogen Communications, also found in some guitar amplifiers made by Ampeg
• 7895 – Improved 7586 Nuvistor with higher mu

_{LoVT ⟶ List of EIA professional tubes ⟶}

8000s

• 8011 – Micropup-type UHF power triode up to 600 MHz
• 8032A (6883B, 8552 – 13.5V heater), 8298A (6146B – 6.3V heater) – 60 MHz, 120 W AF/RF/VHF beam power pentode
• 8056 – Nuvistor triode for low supply voltage
• 8058 – Nuvistor triode with grid on envelope and an anode cap, for grounded-grid UHF circuits
• 8069 – 8 kV/23...1000 µA Corona voltage reference, cathode cylinder and anode top cap
• 8081 – Miniature ceramic/metal disk-seal planar AF triode for use on PCBs
• 8082 – Miniature ceramic/metal disk-seal planar UHF triode for use on PCBs
• 8083 – Miniature ceramic/metal disk-seal planar UHF triode for use on PCBs
• 8089 – 1.6 kV/20...800 µA Corona voltage reference, 2-pin all-glass pigtailed
• 8090 – 3.5 kV/50...1000 µA Corona voltage reference, 9-pin with anode top cap
• 8091 – 4 kV/50...1000 µA Corona voltage reference, 9-pin with anode top cap
• 8122 – Forced-air cooled, 300 W@470 MHz beam power tetrode
• 8203 – Nuvistor power triode up to 250 MHz
• 8256 – 3.5 kV/35...1900 µA Corona voltage reference, 2-pin all-glass pigtailed
• 8257 – 1.2 kV/15...750 µA Corona voltage reference, 2-pin all-glass pigtailed
• 8380 – Nuvistor power tetrode for use in sonobuoys, up to 80 MHz
• 8382 – Nuvistor power triode for use in sonobuoys, up to 175 MHz
• 8393 – Nuvistor medium-mu triode, used in Tektronix oscilloscopes, 12.6 Volt heater
• 8414 – Low (26.5 V) anode voltage, sharp-cutoff, VHF/RF/IF, frame-grid pentode designed for both heater and anode to run directly off the standard avionics 28-volts DC bus, all-glas pigtails, up to 80,000 ft (24 km) altitude; cf. 28D7W
• 8428 (2.4 kilowatts), 8455 (4 kilowatts) – High pulse power, grid-controlled electron multiplier tubes with a flanged metal envelope and an SO-239 UHF output connector
• 8441 – Nuvistor high-mu triode for use in sonobuoys
• 8456 – Nuvistor medium-mu triode for use in sonobuoys
• 8461 – 80 kV, 200 kW Water-cooled power triode with three 15 V/200 A (each) filaments for 3-phase operation in series regulator, or hard-tube modulator applications, considerable X-radiation
• 8469 – 400 V/5...400 µA Corona voltage reference, 2-pin all-glass pigtailed
• 8506 – Miniature ceramic/metal disk-seal planar UHF triode
• 8514 – 1 kV/10...800 µA Corona voltage reference, 7-pin with anode top cap
• 8515 – 1.6 kV/20...950 µA Corona voltage reference, 7-pin with anode top cap
• 8525, 8526, 8527 – Nuvistor medium-mu dual triodes
• 8549 – 70 kV, 500 kW Water-cooled power triode with a 7.6 V/1.9 kA filament, considerable X-radiation, can deliver 10-ms pulses of 60 MW at 6% duty factor
• 8569 (ИВ-29↦IV-29) – Vacuum fluorescent display, single pixel, top-view, for use as flip-flop status indicator in transistorized computers. All-glass pigtailed, 700 mV/35 mA filament; cf. 6977/DM160
• 8627 – Nuvistor power triode up to 1.2 GHz
• 8628 – Nuvistor high-mu AF triode for use in valve microphones and piezoelectric pickup preamplifiers up to 200 kHz
• 8808 – Nuvistor high-mu triode up to 1.2 GHz
• 8873 – 500 MHz, 200 W anode dissipation power triode
• 8874 – 500 MHz, 400 W anode dissipation power triode
• 8875 – 500 MHz, 300 W anode dissipation power triode
• 8877 = Eimac 3CX1500A7 – Ceramic, forced-air cooled, 1.5 kW power triode
• 8974 (Eimac X-2159) – 30 MHz, 1.5 MW Water-cooled tetrode used for very high-power broadcast and industrial service, two-section 18.5 V/650 A (each) filament

List of European Mullard–Philips tubes

Note: Typecode explained above. The part behind a slash ("/") is the RMA/RETMA/EIA equivalent.

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

A - 4 V heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

AAB

• AAB1 – Triple diode with common cathode, side-contact 8 base; EAB1 or PAB1 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

AB

• AB1 – Dual common cathode signal diode, 650 mA heater, European 5-pin base with one anode on top cap
• AB2 – AB1 with a side-contact 5 base; CB2 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

ABC

• ABC1 – Dual diode + triode, side-contact 8 base with triode grid on top cap; CBC1 with a 4 V/650 mA heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

ABF

• ABF1 – Common cathode dual diode + remote-cutoff RF/IF/AF pentode, side-contact 8 base with control grid on top cap

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

ABL

• ABL1 – Dual diode + 9-watts power pentode, side-contact 8 base with control grid on top cap; EBL1 with a 4 V/2.4 A heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

AC

• AC2 – Triode for use as AF amplifier or as oscillator together with an AH1 mixer, side-contact 8 base with triode grid on top cap; EC2 with a 4 V/650 mA heater
• AC50/4686 – 3 mA_avg, 300 mA_peak, Argon-filled triode thyratron, side-contact 8 base with grid on top cap, for relaxation oscillators up to 50 kHz; 4 V/600 mA heater
• AC100 – Triode for use as AF amplifier or as oscillator together with an AH100 mixer; AC2 with a P5A German PTT 5-pin base
• AC101 – Triode for use as AF amplifier or as oscillator together with an AH100 mixer; AC2 with an O5A European 5-pin base
• AC102 – Triode, P7A German PTT 7-pin base with 2 unused pins
• AC104 – Triode, O5A European 5-pin base^[121]
• AC701 – Subminiature AF triode, 4-pin all-glass pigtailed with grid on top wire, for condenser microphone preamplifiers
• AC761 – Subminiature AF triode, 4-pin all-glass pigtailed with grid on top wire, for microphone preamplifiers

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

ACH

• ACH1 – Triode/remote-cutoff hexode mixer, European 7-pin base with hexode control grid 1 on top cap; BCH1 with a 4 V/1 A heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

A D

• AD1 – Directly heated, 4.2 W power triode, side-contact 8 base, 4 V/950 mA filament
• AD100 – 1.7 W Power triode, P7A German PTT 7-pin base with 2 unused pins
• AD101 – 1.7 W Power triode, O5A European 5-pin base
• AD102 – 5.5 W Power triode, P7A German PTT 7-pin base with 2 unused pins

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

AF

• AF2 – Remote-cutoff pentode, 4 V/1.1 A heater, European 5-pin base with anode on top cap
• AF3 – Remote-cutoff pentode, side-contact 8 base with control grid on top cap; CF3 with a 4 V/650 mA heater
• AF7 – Sharp-cutoff pentode, side-contact 8 base with control grid on top cap; CF7, EF7 or VF7 with a 4 V/650 mA heater
• AF100 – Wide band, sharp-cutoff pentode

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

AH

• AH1 – Remote-cutoff hexode for use as mixer or RF gain control, side-contact 8 base with grid 1 on top cap; CH1 with a 4 V/650 mA heater
• AH100 – Remote-cutoff hexode for use as mixer or RF gain control, side-contact 8 base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

AK

• AK1 – Remote-cutoff octode pentagrid converter, European 7-pin base with grid 4 on top cap, 4 V/650 mA heater
• AK2 – Remote-cutoff octode pentagrid converter, side-contact 8 base with grid 4 on top cap; CK1 with a 4 V/650 mA heater, similar to EK2

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

AL

• AL1 – 3.1 W AF power pentode, side-contact 8 base, 4 V/1.1 A heater
• AL2 – 3.8 W AF power pentode, side-contact 8 base with control grid on top cap, 4 V/1 A heater
• AL3 – AF power pentode, side-contact 8 base
• AL4 – AF power pentode, side-contact 8 base; EL3N with a 4 V/1.75 A heater
• AL5 – AF power pentode, side-contact 8 base; EL5 with a 4 V/2 A heater
• AL60 – Power pentode, M7A British 7-pin base with anode on top cap^[122]
• AL860 – Directly heated, 3 W RF/AF power pentode, Noval base; center-tapped, 4.8 V/280 mA (series) or 2.4 V/560 mA (parallel) filament

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

AM

• AM1 – Top-view, "Magic Cross"-type tuning indicator, side-contact 8 base; EM1 with a 4 V/300 mA heater
• AM2/4677 – Top-view, "Magic Eye"-type tuning indicator, side-contact 8 base; CM2 or EM2 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

AN

• AN1 = M-OV GT1C – -1300 to +650 V_a, 300 mA_avg, 2 A_peak, 15 A_surge, Gas-filled triode thyratron with negative control characteristic, 4 V/1.45 A heater, O5A European 5-pin base, for industrial control applications

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

AX

• AX1/4652 – 500 V_PIV, 125 mA Gas-filled, full-wave rectifier, European 4-pin base

Note: This particular 4652 is a Philips-proprietary designation and not an EIA number

• AX50 – 500 V_PIV, 275 mA Gas-filled, full-wave rectifier, European 4-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ A - 4 V heater ⟶}

AZ

• AZ1 – 100 mA Full-wave rectifier, side-contact 8 base
• AZ2 – 160 mA Full-wave rectifier, side-contact 8 base
• AZ3 – 120 mA Full-wave rectifier, side-contact 8 base
• AZ4 – 200 mA Full-wave rectifier, side-contact 8 base
• AZ11 – Full-wave rectifier, AZ1 with Y8A steel tube base
• AZ12 – Full-wave rectifier, AZ4 with Y8A steel tube base
• AZ21 – 120 mA Full-wave rectifier, B8G Loctal base
• AZ31 – Full-wave rectifier, AZ1 with 5-pin Octal base
• AZ32 – Full-wave rectifier, AZ2 with 5-pin Octal base
• AZ33 – 120 mA Full-wave rectifier, 4-pin Octal base
• AZ41 – 70 mA Full-wave rectifier, Rimlock base
• AZ50 – 300 mA Full-wave rectifier, European 4-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

B - 180 mA heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ B - 180 mA heater ⟶}

BB

• BB1 – Shielded common cathode dual diode, CB2 with a 16 V heater and a European 5-pin base with one anode on top cap^[123][124]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ B - 180 mA heater ⟶}

BCH

• BCH1 – Triode/remote-cutoff hexode mixer; ACH1 with a 24 V heater^[123][124]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ B - 180 mA heater ⟶}

BL

• BL2 – Power pentode, CL2 with a 30 V heater and a European 5-pin base with the control grid on top cap^[123][124]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

C - 200 mA heater

Note: Many "C" tubes had 13V/200mA heaters, so apart from 1930s European AC/DC radios, these were also used in 12-Volts car radios^[3]:6

Barretters with a side-contact 8 base

The six free pins were used as jumpers to switch the anode supply circuit between 110V and 220V mains

• C1 – 80 to 200 V filament for 220V mains
• C2 – 35 to 100 V filament for 110V mains
• C3 – 100 to 200 V filament with a surge-limiting Urdox (UO₂) power thermistor
• C8 – 80 to 200 V filament
• C9 – 35 to 100 V filament
• C10 – 35 to 100 V filament
• C12 – 80 to 200 V filament

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ C - 200 mA heater ⟶}

CB

• CB1 – Common cathode dual diode, side-contact 5 base, 13 V heater
• CB2 – Common cathode dual diode, side-contact 5 base; AB2 with a 13 V heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ C - 200 mA heater ⟶}

CBC

• CBC1 – Common cathode dual diode + triode, side-contact 8 base with triode grid on top cap; ABC1 with a 13 V heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ C - 200 mA heater ⟶}

CBL

• CBL1 – Common cathode dual diode + power pentode, side-contact 8 base with control grid on top cap, 44 V heater
• CBL6 – Common cathode dual diode + power pentode, side-contact 8 base with control grid on top cap, 44 V heater
• CBL31 – Common cathode dual diode + power pentode; CBL1 with an Octal base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ C - 200 mA heater ⟶}

CC

• CC2 – Triode for use as AF amplifier or as oscillator together with an CH1 mixer, side-contact 8 base with triode grid on top cap; AC2 with a 13 V heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ C - 200 mA heater ⟶}

CCH

• CCH1 – Triode/remote-cutoff hexode mixer, side-contact 8 base with hexode control grid 1 on top cap, 20 V heater
• CCH2 – Triode/remote-cutoff hexode mixer, side-contact 8 base with hexode control grid 1 on top cap, 29 V heater
• CCH35 – Triode/remote-cutoff hexode mixer; ECH3 with an Octal base and a 7 V heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ C - 200 mA heater ⟶}

CF

• CF1 – Sharp-cutoff pentode, side-contact 8 base with control grid on top cap, 13 V heater
• CF2 – Remote-cutoff pentode, side-contact 8 base with control grid on top cap, 13 V heater
• CF3 – Remote-cutoff pentode, side-contact 8 base with control grid on top cap; AF3 with a 13 V heater
• CF7 – Sharp-cutoff pentode, side-contact 8 base with control grid on top cap; AF7, EF7 or VF7 with a 13 V heater
• CF50 – Microphone preamplifier sharp-cutoff pentode, side-contact 8 base with control grid on top cap, 30 V heater
• CF51 – Microphone preamplifier sharp-cutoff pentode, side-contact 8 base with control grid on top cap

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ C - 200 mA heater ⟶}

CH

• CH1 – Remote-cutoff hexode mixer, side-contact 8 base with grid 1 on top cap; AH1 with a 13 V heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ C - 200 mA heater ⟶}

CK

• CK1 – Remote-cutoff octode pentagrid converter, side-contact 8 base; AK2 with a 13 V heater
• CK3 – Remote-cutoff beam octode pentagrid converter, side-contact 8 base; EK3 with a 19 V heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ C - 200 mA heater ⟶}

CL

• CL1 – 5 Watts power pentode for anode voltages above 200 V, side-contact 8 base with control grid on top cap, 13 V heater
• CL2 – 8 Watts power pentode for anode voltages below 200 V; BL2 with a 24 V heater and a side-contact 8 base with control grid on top cap
• CL4 – 9 Watts power pentode, side-contact 8 base with control grid on top cap, 33 V heater
• CL6 – 5 Watts power pentode, side-contact 8 base with control grid on top cap, 35 V heater
• CL33 – AF power pentode, CL4 with an Octal base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ C - 200 mA heater ⟶}

CM

• CM2 – Top-view, "Magic Eye"-type tuning indicator, side-contact 8 base; AM2 with a 6.3 V/200 mA heater, therefore marketed as C/EM2

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ C - 200 mA heater ⟶}

CY

• CY1 – 250 V, 80 mA Half-wave rectifier, side-contact 8 base, 20 V heater
• CY2 – Separate cathode dual^[125] 250 V, 60 mA rectifier, side-contact 8 base, 30 V heater, for use as half-wave rectifier or as voltage doubler
• CY31 – CY1 with an Octal base
• CY32 – CY2 with an Octal base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

D - 1.4 V filament/heater

Note: D-type tubes except some rectifiers are directly heated

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DA

• DA50 – Subminiature diode, 3-pin all-glass
• DA90/1A3 – Indirectly heated FM discriminator diode, miniature 7-pin base, 1.4 V/150 mA heater
• DA101 – Diode, miniature 7-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DAC

• DAC1 – AM detector diode + AF triode, side-contact 8 base with control grid on top cap, 1.4 V/50 mA filament^[126]
• DAC21 – AM detector diode + AF triode, Octal base, 1.4 V/25 mA filament
• DAC22 – AM detector diode + AF triode, B8G Loctal base
• DAC25 – AM detector diode + AF triode, B8G Loctal base
• DAC31 – AM detector diode + AF triode, Octal base
• DAC32/1H5GT – AM detector diode + AF triode, Octal base, 1.4 V/50 mA filament
• DAC41w – AM detector diode + AF triode^[33]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DAF

• DAF1 – AM detector diode + AF pentode^[127]
• DAF11 – AM detector diode + AF pentode, wide-range 0.9-1.5 V/50 mA filament, Y8A steel tube base with 1 unused pin
• DAF26/1LD5 – AM detector diode + AF pentode, B8G Loctal base
• DAF40 – AM detector diode + remote-cutoff RF/IF pentode, Rimlock base, 1.4 V/25 mA filament
• DAF41 – AM detector diode + AF pentode, Rimlock base, 1.4 V/25 mA filament
• DAF70 – Subminiature AM detector diode + AF pentode, all-glass round cross-section body, circular 8-pin/pigtails base, 1.25 V/25 mA filament
• DAF91/1S5 – AM detector diode + AF pentode, miniature 7-pin base, 1.4 V/50 mA filament
• DAF92/1U5 – AM detector diode + AF pentode, miniature 7-pin base
• DAF96/1AH5 – AM detector diode + AF pentode, miniature 7-pin base, 1.4 V/25 mA filament
• DAF191 – AM detector diode + AF pentode, miniature 7-pin base, 1.4 V/50 mA filament
• DAF961 – AM detector diode + AF pentode, miniature 7-pin base, 1.2 V/60 mA filament

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DAH

• DAH50 – Diode + low (15-25 V) anode voltage pentode with extra beam-forming rods and a space charge grid between cathode and control grid (technically a heptode), Octal base with control grid on top cap; center-tapped, 2.8 V/25 mA (series) or 1.4 V/50 mA (parallel) filament; cf. 6FS5, 6GU5, EF8, EF38

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DBC

• DBC21 – Dual diode + triode, Octal base, 1.4 V/50 mA filament
• DBC31 – Dual diode + triode, Octal base^[128]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DC

• DC11 – AF driver triode for DDD11, wide-range 0.9-1.5 V/25 mA filament, Y8A steel tube base with 3 unused pins
• DC25 – AF driver triode, B8G Loctal base, for DDD25
• DC41w – Driver triode^[33]
• DC51 – Directly heated miniature AF triode, 1.5 V/70 mA filament, for use in hearing aids;^[129] cf. KC50, KC51, Mullard DB1
• DC70/6375 – Subminiature UHF triode for walkie-talkies, all-glass round cross-section body, circular 8-pin/pigtails base, 1.25 V/200 mA filament
• DC80/1E3/5882 – Triode for use as VHF amplifier or self-oscillating mixer in FM receivers, Noval base
• DC90 – Triode for use as VHF amplifier or self-oscillating mixer, miniature 7-pin base, 1.4 V/50 mA filament
• DC96 – Triode for use as VHF amplifier or self-oscillating mixer, miniature 7-pin base, 1.4 V/25 mA filament^[124]
• DC703 – Subminiature UHF triode, all-glass round cross-section body, circular 5-pin/pigtails base
• DC760 – Subminiature electrometer inverted triode for probes, all-glass round cross-section body, circular 8-pin/pigtails base
• DC761 – Subminiature UHF triode, all-glass round cross-section body, circular 8-pin/pigtails base
• DC762 – Subminiature electrometer inverted triode for probes, 100 fA grid current, all-glass round cross-section body, circular 8-pin/pigtails base

—Special quality:

• D1C (957) – Acorn UHF triode
• D2C (958) – Acorn UHF triode

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DCC

• DCC90/3A5 – Dual triode, RF amplifier or oscillator, miniature 7-pin base; center-tapped, 2.8 V/110 mA (series) or 1.4 V/220 mA (parallel) filament

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DCF

• DCF60/1V6 – Oscillator/mixer triode/pentode, all-glass flat 7-pin pigtailed, 1.25 V/40 mA filament

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DCH

• DCH1 – Triode/hexode mixer, European 7-pin base^[130]
• DCH11 – Triode/remote-cutoff hexode mixer, Y8A steel tube base, wide-range 0.9-1.5 V/75 mA filament
• DCH21 – Triode/remote-cutoff hexode mixer, Octal base
• DCH22 – Triode/remote-cutoff hexode mixer, B8G Loctal base
• DCH25 – Triode/remote-cutoff hexode mixer, B8G Loctal base
• DCH31 – Triode/remote-cutoff hexode mixer, Octal base^[131]
• DCH41w – Triode/remote-cutoff hexode mixer^[33]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DD

• DD51 – Directly heated, miniature AF power triode, 1.5 V/70 mA filament, for use in hearing aids; cf. KD50, Mullard DB3
• DD960 – VHF power triode, miniature 7-pin base; center-tapped, 2.4 V/100 mA (series) or 1.2 V/200 mA (parallel) filament

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DDD

• DDD11 – Dual AF power triode, wide-range 0.9-1.5 V/100 mA filament, Y8A steel tube base with 1 unused pin – preferred driver is DC11
• DDD25 – Dual AF power triode, B8G Loctal base – preferred driver is DC25
• DDD41w – Dual power triode^[33]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DF

• DF1 – RF/IF pentode, side-contact 8 base with control grid on top cap^[132]
• DF11 – Remote-cutoff RF/IF pentode, wide-range 0.9-1.5 V/100 mA filament, Y8A steel tube base with 2 unused pins
• DF21 – Sharp-cutoff RF/IF/AF pentode, Octal base, 1.4 V/25 mA filament
• DF22 – Remote-cutoff RF/IF pentode, Octal base, 1.4 V/50 mA filament
• DF23 – Remote-cutoff RF/IF pentode, B8G Loctal base
• DF25 – Remote-cutoff RF/IF pentode, B8G Loctal base
• DF26 – Sharp-cutoff RF/IF pentode, B8G Loctal base
• DF31 – Sharp-cutoff RF/IF/AF pentode, Octal base^[133]
• DF32 – Sharp-cutoff RF/IF/AF pentode, Octal base^[133]
• DF33/1N5GT – Remote-cutoff RF/IF pentode, Octal base, 1.4 V/50 mA filament^[133]
• DF41w – Remote-cutoff RF/IF pentode^[33]
• DF51 – Miniature, 1.5 V/70 mA half-indirectly heated, sharp-cutoff RF/IF pentode;^[134] cf. KE50
• DF60/5678 – Subminiature sharp-cutoff RF/IF/AF pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, 1.25 V/50 mA filament
• DF61 – Subminiature sharp-cutoff RF or mixer pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, 1.25 V/25 mA filament
• DF62/1AD4 – Subminiature sharp-cutoff RF pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, 1.25 V/100 mA filament, for use as RF/IF stage
• DF63 – Subminiature remote-cutoff RF pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, 1.25 V/25 mA filament, for use as RF/IF stage
• DF64 – Subminiature AF pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, 0.625 V/10 mA filament, for use in hearing aids
• DF65 – Subminiature AF pentode, all-glass round cross-section body, circular 5-pin/pigtails base, 0.625 V/13.3 mA filament, for use in hearing aids
• DF66 – Subminiature AF pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, 0.625 V/15 mA filament, for use in hearing aids
• DF67/6008 – DF65 with round cross-section body, but flat 5-pin base
• DF70 – Subminiature AF pentode, all-glass round cross-section body, circular 8-pin/pigtails base, 0.625 V/25 mA filament, for use in hearing aids
• DF72 – Subminiature sharp-cutoff RF pentode, all-glass round cross-section body, circular 8-pin/pigtails base, for use as RF/IF stage
• DF73 – Subminiature remote-cutoff RF pentode, all-glass round cross-section body, circular 8-pin/pigtails base, for use as RF/IF stage
• DF91/1T4 – Remote-cutoff RF/IF pentode, miniature 7-pin base, 1.4 V/50 mA filament
• DF92/1L4 – Sharp-cutoff RF/IF pentode, miniature 7-pin base, 1.4 V/50 mA filament
• DF96/1AJ4 – Remote-cutoff RF/mixer pentode, miniature 7-pin base, 1.4 V/25 mA filament
• DF97/1AN5 – Remote-cutoff RF/IF pentode, miniature 7-pin base, 1.4 V/25 mA filament
• DF161 – Subminiature AF pentode, all-glass pigtailed, for use in hearing aids
• DF167 – Subminiature AF pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, 0.625 V/13.3 mA filament, for use in hearing aids
• DF191 – RF pentode, miniature 7-pin base, 1.4 V/50 mA filament
• DF650 = Raytheon CK538DX – Subminiature AF pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, for use in hearing aids^[135]
• DF651 = Raytheon CK549DX – Subminiature AF pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, for use in hearing aids
• DF668 – Subminiature RF pentode, all-glass elliptical cross-section body, flat 5-pin base, 1.25 V/100 mA filament; similar to 1AD4
• DF669 – Subminiature RF/IF pentode, all-glass elliptical cross-section body, flat 5-pin base, 1.25 V/50 mA filament; similar to 5678
• DF703 (5886) – Subminiature electrometer pentode, envelope has a moisture-repellent coating, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, 1.25 V/10 mA filament, for probe amplifiers
• DF904/1U4/5910 – Sharp-cutoff SW/VHF pentode, miniature 7-pin base
• DF906 – Sharp-cutoff SW/VHF pentode, miniature 7-pin base
• DF961 – Sharp-cutoff SW/VHF pentode, miniature 7-pin base, 1.2 V/60 mA filament

—Special quality:

• D1F – D11F with a hand grip
• D2F – D12F with a hand grip
• D3F (959) – Acorn VHF pentode
• D11F – Acorn remote-cutoff RF/IF/AF pentode for portable transceivers, 1.4 V/100 mA filament
• D12F – Acorn RF/IF/AF pentode for portable transceivers, 1.4 V/240 mA filament

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DFF

• DFF50 – Dual pentode, B8G Loctal base^[136]
• DFF51 – Dual pentode, B8G Loctal base^[136]
• DFF101 – Dual pentode, miniature 7-pin base^[136]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DK

• DK1 – Octode pentagrid converter, side-contact 8 base with grid 4 on top cap^[137]
• DK21 – Remote-cutoff octode beam pentagrid converter, Octal base, 1.4 V/50 mA filament
• DK22 – Octode pentagrid converter, B8G Loctal base^[138]
• DK25 – Remote-cutoff octode pentagrid converter, B8G Loctal base
• DK31 – Remote-cutoff octode pentagrid converter, Octal base^[138]
• DK32/1A7GT – Remote-cutoff heptode pentagrid converter, Octal base with grid 4 on top cap, 1.4 V/50 mA filament
• DK40 – Remote-cutoff octode pentagrid converter, Rimlock base, 1.4 V/50 mA filament
• DK91/1R5 – Remote-cutoff heptode pentagrid converter, miniature 7-pin base, 1.4 V/50 mA filament
• DK92/1AC6 – Heptode pentagrid converter, miniature 7-pin base, 1.4 V/50 mA filament
• DK96/1AB6 – Heptode pentagrid converter, miniature 7-pin base, 1.4 V/25 mA filament
• DK192 – Heptode pentagrid converter, miniature 7-pin base, 1.4 V/50 mA filament
• DK962 – Heptode pentagrid converter, miniature 7-pin base, 1.2 V/60 mA filament

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DL

• DL2 – Power pentode, side-contact 8 base^[139]
• DL11 – 350 mW AF power pentode, wide-range 0.9-1.5 V/50 mA filament, Y8A steel tube base with 2 unused pins
• DL21 – 700 mW AF power pentode, Octal base, 1.4 V/50 mA filament
• DL22 – Power pentode, B8G Loctal base^[140]
• DL25 – Power pentode, B8G Loctal base
• DL26 – Power pentode, B8G Loctal base
• DL29/3D6 – 1.4 W VHF beam power pentode up to 50 MHz with a center-tapped, 2.8/1.4 V filament, B8G Loctal base
• DL31/1A5 – Power pentode, Octal base^[140]
• DL33/3Q5GT – 400 mW AF power pentode, Octal base; center-tapped, 2.8 V/50 mA (series) or 1.4 V/100 mA (parallel) filament
• DL35/1C5GT – 400 mW Power pentode, Octal base, 1.4 V/100 mA filament
• DL36/1Q5GT – Power pentode, Octal base^[139]
• DL41 – 600 mW Power pentode, Rimlock base; center-tapped, 2.8 V/50 mA (series) or 1.4 V/100 mA (parallel) filament

• DL41w – Bowl Power pentode^[33]

• DL51 – Miniature, 1.5 V/130 mA half-indirectly heated power pentode
• DL64 – Subminiature AF power pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, for use in hearing aids, U_A = 15 V, U_Amax = 45 V, 1.25 V/10 mA filament
• DL65 – Subminiature AF power pentode, all-glass round cross-section body, circular 5-pin/long pigtails base, U_A = 22.5 V, U_Amax = 45 V, 1.25 V/13 mA filament, for use in hearing aids; DL67/6007 with a different pinout
• DL66 – Subminiature AF power pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, for use in hearing aids, U_A = 22.5 V, U_Amax = 45 V, 1.25 V/15 mA filament
• DL67/6007 – DL65 with round cross-section body, but flat 5-pin base
• DL68 – Subminiature AF power pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, for use in hearing aids, U_A = 22.5 V, U_Amax = 45 V, 1.25 V/25 mA filament
• DL69 – Subminiature power pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, U_A = 90 V, 1.25 V/25 mA filament
• DL70 – Subminiature VHF power pentode up to 200 MHz, all-glass round cross-section body, circular 8-pin/pigtails base, for use in walkie-talkies, U_A = 150 V, 1.25 V/110 mA filament
• DL71 – Subminiature AF power pentode, all-glass round cross-section body, circular 8-pin/pigtails base, for use in hearing aids, U_A = 22.5 V, U_Amax = 45 V, 1.25 V/25 mA filament
• DL72 – Subminiature AF power pentode, all-glass round cross-section body, circular 8-pin/pigtails base, for use in hearing aids, U_Amax = 45 V, 1.25 V/25 mA filament
• DL73 (CV2299) – Subminiature VHF power pentode up to 200 MHz, all-glass round cross-section body, circular 8-pin/pigtails base, for use in walkie-talkies, U_A = 150 V, 1.25 V/200 mA filament
• DL75 – Subminiature AF power pentode, all-glass round cross-section body, circular 8-pin/pigtails base^[141]
• DL91/1S4 – Power pentode, miniature 7-pin base
• DL92/3S4 – 270 mW AF power pentode with a center-tapped, 2.8 V/50 mA (series) or 1.4 V/100 mA (parallel) filament, miniature 7-pin base
• DL93/3A4 – 1.2 W RF/AF power pentode with a center-tapped, 2.8 V/100 mA (series) or 1.4 V/200 mA (parallel) filament, miniature 7-pin base
• DL94/3V4 – 1.3 W AF power pentode with a center-tapped, 2.8 V/50 mA (series) or 1.4 V/100 mA (parallel) filament, miniature 7-pin base
• DL95/3Q4 – 270 mW AF power pentode with a center-tapped, 2.8 V/50 mA (series) or 1.4 V/100 mA (parallel) filament, miniature 7-pin base
• DL96/3C4 – 440 mW AF power pentode with a center-tapped, 2.8 V/25 mA (series) or 1.4 V/50 mA (parallel) filament, miniature 7-pin base
• DL97/3Y4 – Power pentode with a center-tapped filament, miniature 7-pin base^[142]
• DL98/3B4 – 1.25 W RF power pentode with a center-tapped, 2.5 V/165 mA (series) or 1.25 V/330 mA (parallel) filament, up to 100 MHz, miniature 7-pin base
• DL161 – Subminiature AF power pentode, all-glass pigtailed, for use in hearing aids
• DL167 – 1.8 mW Subminiature AF power pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, 1.25 V/13.3 mA filament, for use in hearing aids
• DL192 – 150 mW AF power pentode with a center-tapped, 2.8 V/50 mA (series) or 1.4 V/100 mA (parallel) filament, miniature 7-pin base
• DL193 – 650 mW AF power pentode with a center-tapped, 1.4 V/200 mA filament, miniature 7-pin base
• DL620 – 110 mW Subminiature power pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, U_Amax = 90 V, 1.25 V/50 mA filament
• DL650 = Raytheon CK532DX – 45 mW Subminiature power pentode, all-glass elliptical cross-section body, flat 5-pin base, long pigtails, U_Amax = 30 V, 1.25 V/15 mA filament
• DL651 = Raytheon CK546DX – DL650 with a 1.25 V/10 mA filament
• DL761 (6397) – Subminiature RF power pentode, all-glass pigtailed
• DL907 – SW/VHF power pentode, miniature 7-pin base
• DL962 – 150 mW AF power pentode with a center-tapped, 2.4 V/60 mA (series) or 1.2 V/120 mA (parallel) filament, miniature 7-pin base
• DL963 – RF/AF power pentode with a center-tapped, 2.4 V/100 mA (series) or 1.2 V/200 mA (parallel) filament, miniature 7-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DLL

• DLL21 (Octal base), DLL25 (B8G Loctal base) – 1.5 W AF Dual power pentode, center-tapped, 2.8 V/100 mA (series) or 1.4 V/200 mA (parallel) filament
• DLL31 – DLL21 with a different pinout
• DLL101 – Dual power pentode, miniature 7-pin base
• DLL102 – Dual power pentode, miniature 7-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DM

• DM21 – Top-view, "Magic Eye"-type tuning indicator, Octal base, 1.4 V/25 mA filament
• DM70/1M3 – Side-view, subminiature band-and-dot-type tuning/level indicator, all-glass pigtailed
• DM71/1N3 – Side-view, subminiature band-and-dot-type tuning/level indicator, all-glass pigtailed
• DM160/6977 (ИВ-15↦IV-15) – First vacuum fluorescent display, single segment, side-view, for use as flip-flop status indicator in transistorized computers. All-glass pigtailed, 1 V/30 mA filament; cf. 8569

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ D - 1.4 V filament/heater ⟶}

DY

• DY30/1B3GT – 30 kV CRT EHT rectifier, Octal base with anode on top cap
• DY51/1BG2 – Half-indirectly heated 15 kV portable-TV CRT EHT rectifier, filament internally connected to cathode, all-glass, filament pigtails on one end, anode pigtail on the other
• DY70 – 10 kV CRT EHT rectifier, 3-pin all-glass pigtailed, anode on top wire
• DY80/1X2A – 23 kV CRT EHT rectifier, Noval base
• DY86/1S2 – Half-indirectly heated 18 kV CRT EHT rectifier, Noval base, filament internally connected to cathode; EY86/6S2 or GY86 with a different heater
• DY87/1S2A – EY87/6S2A with a different heater; DY86/1S2 with a silicone-coated envelope to avoid flush-over in high-humidity and low atmospheric-pressure conditions
• DY802/1BQ2 – Half-indirectly heated 20 kV CRT EHT rectifier, Noval base, silicone-coated envelope, filament internally connected to cathode; EY802 or GY802 with a different heater
• DY900 – Half-indirectly heated 16 kV CRT EHT rectifier, miniature 7-pin base, filament internally connected to cathode

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

E - 6.3 V heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EA

• EA40 – 7 kV, 25 mA Diode, 4-pin Rimlock base
• EA50/2B35 – Diode for TV detectors, 3+1-pin all-glass subminiature with anode on top pin
• EA52/6923 – Instrumentation rectifier diode up to 1 GHz, Rocket-type disk-seal tube
• EA53 – Co-axial instrumentation rectifier diode up to 1 GHz, Rocket-type disk-seal tube
• EA76 (6489) – Diode, all-glass round cross-section body, circular 5-pin/pigtails base
• EA111 – Diode for time bases, Y8A steel tube base
• EA766 (5704) – Diode, all-glass round cross-section body, circular 5-pin/pigtails base
• EA960 – 100 V_PIV VHF Diode, miniature 7-pin base
• EA961 – 2 kV_PIV VHF Diode, miniature 7-pin base
• EA962 – 100 V_PIV VHF Diode with extremely small distance between cathode and anode for extended frequency range, miniature 7-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EAA

• EAA11 – Dual diode, Y8A steel tube base
• EAA91/6AL5 – Dual diode with separate cathodes, miniature 7-pin base; HAA91/12AL5, UAA91 or XAA91/3AL5 with a different heater; EB91 with a shorter envelope
• EAA171 – Dual diode, separate cathodes and separate heaters, gnome tube; UAA171 with a different heater
• EAA766 – Virtual dual diode for use in homing beacons
• EAA901S/5726 – Dual RF diode, miniature 7-pin base

—Special quality:

• E91AA – Dual diode, miniature 7-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EAB

• EAB1 – Triple diode with common cathode, side-contact 8 base; AAB1 or PAB1 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EABC

• EABC80/6AK8 = M-OV DH719 (6T8, 6T8A) – High-mu triode + triple low-voltage diode (two on common cathode with triode, one with independent cathode), Noval base, used as an AF amplifier, AM detector and FM ratio detector in post-war European AM/FM radios; 5T8, HABC80/19T8, PABC80/9AK8 or UABC80/27AK8 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EAC

• EAC91 – Diode/triode UHF mixer, miniature 7-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EAF

• EAF21 – Diode + remote-cutoff RF/IF/AF pentode, B8G Loctal base; UAF21 with a different heater
• EAF41 – Diode + remote-cutoff RF/IF/AF pentode, Rimlock base; UAF41 with a different heater
• EAF42/6CT7 – Diode + remote-cutoff RF/IF/AF pentode, Rimlock base
• EAF801 – Diode + remote-cutoff RF/IF pentode, Noval base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EAM

• EAM86/6GX8 – Diode + side-view, horizontal band-type tuning/level indicator, Noval base; the diode is to rectify the audio signal when indicating a recording level or a modulation depth

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EB

• EB1 – Common cathode dual diode, side-contact 5 base
• EB2 – Common cathode dual diode, side-contact 5 base^[123]
• EB4 – Separate cathodes dual diode; EB11 or EB34 with a side-contact 8 base
• EB11 – Separate cathodes dual diode with separate cathodes; EB4 or EB34 with a Y8A steel tube base
• EB34 – Separate cathodes dual diode with separate cathodes; EB4 or EB11 with an Octal base
• EB40 – Common cathode dual diode, Rimlock base
• EB41 – Separate cathodes dual diode, Rimlock base; UB41 with a different heater
• EB91 – Separate cathodes dual diode with separate cathodes, miniature 7-pin base, for FM ratio detectors; EAA91/6AL5 with a longer envelope

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EBC

• EBC1 – Dual diode + AF triode, side-contact 8 base with triode grid on top cap; ABC1 with a different heater
• EBC3 – Dual diode + AF triode, side-contact 8 base with triode grid on top cap
• EBC11 – Dual diode + AF triode, Y8A steel tube base
• EBC33/6Q7 – Dual diode + AF triode; EBC3 with an Octal base
• EBC41/6CV7 – Shielded dual diode + AF triode; UBC41 with a different heater; EBC81/6BD7A with a Rimlock base
• EBC80/6BD7 – Shielded dual diode + AF triode, Noval base
• EBC81/6BD7A – Shielded dual diode + AF triode; UBC81 with a different heater; EBC41 with a Noval base
• EBC90/6AT6 – High-mu AF triode + common cathode dual diode, miniature 7-pin base; HBC90/12AT6 with a different heater
• EBC91/6AV6 – High-mu AF triode + common cathode dual diode, for use in FM ratio detectors, miniature 7-pin base; HBC91/12AV6 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EBF

• EBF1 (6B7) – Common cathode dual diode + remote-cutoff RF/IF/AF pentode, side-contact 8 base with control grid on top cap^[143]
• EBF2 – Common cathode dual diode + remote-cutoff RF/IF/AF pentode; EBF11 or EBF35 with a side-contact 8 base
• EBF11 – Common cathode dual diode + remote-cutoff RF/IF/AF pentode; EBF2 and EBF35 with a Y8A steel tube base; VBF11 with a different heater
• EBF15 – Common cathode dual diode + remote-cutoff RF/IF/AF pentode, Y8A steel tube base; UBF15 with a different heater
• EBF21 – Common cathode dual diode + remote-cutoff RF/IF/AF pentode, B8G Loctal base^[144]
• EBF32 (6B8) – Common cathode dual diode + remote-cutoff RF/IF pentode, Octal base with g1 on top cap
• EBF35 – Common cathode dual diode + remote-cutoff RF/IF pentode; EBF2 or EBF11 with an Octal base with g1 on top cap
• EBF80/6N8 = WD709 – Common cathode dual diode + remote-cutoff pentode, Noval base
• EBF81/6AD8 – Common cathode dual diode + remote-cutoff pentode, Noval base
• EBF83/6DR8 – Common cathode dual diode + low (6.3-50 V) anode voltage sharp-cutoff pentode for use as IF amplifier, detector and AGC diode in vehicle equipment, Noval base
• EBF89/6DC8/7125 – Common cathode dual diode + semiremote-cutoff RF/IF pentode, Noval base
• EBF171 – Dual diode + remote-cutoff RF/IF/AF pentode; the first gnome tube, a modified and repackaged EBF11; UBF171 with a different heater
• EBF175 – Common cathode dual diode + remote-cutoff RF/IF/AF pentode,^[145] prototype only

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EBL

• EBL1 – Dual diode + 9-watts power pentode; EBL21 or EBL31 with a side-contact 8 base, ABL1 with a different heater
• EBL21 = EBL71 – Dual diode + power pentode; EBL1 or EBL31 with a B8G Loctal base
• EBL31 – Dual diode + power pentode; EBL1 or EBL21 with an Octal base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EC

• EC2 – Triode for use as AF amplifier or as oscillator, side-contact 8 base; AC2 with a different heater
• EC21 – Triode, B8G Loctal base^[146]
• EC31 – Triode, Octal base^[147]
• EC40 – VHF Triode up to 500 MHz; EC80 with a B8A Rimlock base
• EC41 – UHF oscillator triode; EC81 with a B8A Rimlock base
• EC50 – Helium-filled triode thyratron for use as a horizontal sweep, sawtooth waveform generator in oscilloscopes, side-contact 8 base with anode on top cap
• EC52 – RF triode for use as an oscillator, B9G Loctal 9-pin base
• EC53 – VHF triode for use as an oscillator up to 600 MHz, 3-pin base with grid and anode on top pins
• EC54 – Triode, B9G Loctal 9-pin base^[148]
• EC55/5861 = La Radiotechnique R243 – 3 GHz, 10 W Rocket-type disk-seal UHF triode
• EC56 – 4 GHz Lighthouse-type disk-seal microwave triode
• EC57 (EC157) – Lighthouse-type disk-seal microwave triode
• EC70/6K4/6778 – Subminiature UHF triode for use as an oscillator in the 500 MHz range, all-glass round cross-section body, circular 8-pin/pigtails base
• EC71/5718 – Subminiature UHF triode up tp 1 GHz, for use as an oscillator in the 500 MHz range, all-glass round cross-section body, circular 8-pin/pigtails base
• EC80/6Q4 – VHF Triode up to 500 MHz, Noval base
• EC81/6R4 – UHF oscillator triode, Noval base
• EC84/6AJ4 – High-mu triode, Noval base
• EC86/6CM4 – UHF triode, Noval base; PC86/4CM4 with a different heater
• EC88/6DL4 – UHF triode, Noval base; PC88/4DL4 with a different heater. This and the EC86 were often encountered in UHF TV tuners, the latter as a self oscillating mixer
• EC90/6C4 (6100) – 3.6 W Small-power VHF triode up to 150 MHz, miniature 7-pin base; single ECC82/12AU7 system
• EC91/6AQ4 – VHF triode up to 250 MHz, miniature 7-pin base
• EC92/6AB4 – VHF triode for FM receiver front ends, miniature 7-pin base, single ECC81/12AT7 system; UC92/9AB4 with a different heater
• EC93/6BS4 – UHF Medium-mu oscillator triode, miniature 7-pin base^[149]
• EC94/6AF4 – UHF Medium-mu oscillator triode, miniature 7-pin base
• EC95/6ER5 – Variable-mu VHF triode, miniature 7-pin base; PC95/4ER5 or XC95/2ER5 with a different heater
• EC97/6FY5 – Frame-grid VHF triode, miniature 7-pin base; PC97/4FY5 or XC97/2FY5 with a different heater
• EC98 – UHF triode, miniature 7-pin base
• EC157/8108 – 4 GHz, 12.5 W Lighthouse-type disk-seal microwave triode
• EC158 – Low-voltage, 4 GHz, 30 W Lighthouse-type disk-seal microwave triode
• EC162 – RF power triode, Y8A steel tube base
• EC360 – Triode, center-tapped heater, Octal base
• EC560 (2C40) – Lighthouse-type disk-seal microwave triode
• EC562 (2C39B) – Oil can-type disk-seal microwave triode
• EC760 (EC71/5718) – Subminiature VHF oscillator/mixer triode up to 500 MHz, all-glass round cross-section body, circular 7-pin/pigtails base
• EC860 – 20 mA_avg, 500 mA_pk Helium-filled grid-turn-off triode thyratron e.g. for relaxation oscillators up to 150 kHz, Noval base; cf. 6441, 20TC4, 30TC1
• EC866 – Low-noise UHF triode, Noval base
• EC900/6HA5 – VHF triode, miniature 7-pin base; LC900/3HA5 or PC900/4HA5 with a different heater
• EC903 – RF/IF Triode, miniature 7-pin base^[150]

—Special quality:

• EC1000/8254 – Triode for use as amplifier in probes, 8-pin all-glass pigtailed with grid on top wire
• EC1030 – Indirectly heated UHF triode, hot-standby (no cathode current) resistant, all-glass round cross-section body with 8 circular, tinned, 38 mm long wires
• EC1031 – EC1030 with 5.5 mm long, gold-plated pins for insertion into a special socket
• EC8010/8556 – UHF triode for use as amplifier or oscillator up to 1 GHz, Noval base
• EC8020 – UHF triode, Noval base
• E1C/4671 (955) – Acorn UHF triode
• E20C – RF triode for wide band cascode circuits, B8G Loctal base^[124]
• E86C (EC806S) – UHF triode up to 800 MHz, Noval base with gold-plated pins
• E88C/8255 – UHF triode for grounded-grid amplifiers, up to 1 GHz, Noval base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

ECC

• ECC31 – Common cathodes dual AF power triode, Octal base^[151]
• ECC32/6SN7 – Separate cathodes dual AF triode, Octal base
• ECC33 – Separate cathodes, high-mu dual triode for use as a flip-flop, Octal base
• ECC34 – Separate cathodes, dual triode for use as a CRT vertical deflection power multivibrator, Octal base
• ECC35/6SL7 – Separate cathodes, high-mu AF dual triode, Octal base
• ECC40 – Separate cathodes, AF dual triode, Rimlock base
• ECC70/6021 – Separate cathodes, subminiature VHF medium-mu dual triode, all-glass round cross-section body, circular 8-pin/pigtails base
• ECC81/12AT7
  

  ECC83/12AX7
  (6060, M8162, B309) – High-mu dual triode with a center-tapped heater, for use as RF amplifier/mixer in VHF circuits, Noval base
• ECC82/12AU7 (6067, M8136, B329) – Medium-mu dual triode with a center-tapped heater for use as AF amplifier, Noval base; XCC82/7AU7 with a different heater. Two EC90/6C4s in one envelope;^[63] however, it is only specified as an audio frequency device
• ECC83/12AX7 (6057, M8137, B339) – High-mu dual triode with a center-tapped heater for use as a high-gain AF amplifier, Noval base
• ECC84/6CW7 – Dual VHF triode for grounded-grid/cascode amplifiers in TV tuners; section 1 cathode is connected to two adjacent pins and the screen between the two sections is internally connected to the section 2 grid; Noval base; PCC84/7AN7 or UCC84 with a different heater
• ECC85/6AQ8 – Dual triode for use as VHF oscillator/mixer up to 200 MHz, Noval base; HCC85/17EW8, PCC85/9AQ8 or UCC85 with a different heater
• ECC86/6GM8 – Dual low (6.3-25 V) anode voltage triode, Noval base, for use in VHF tuners in vehicle equipment
• ECC87/6085 – Renamed to E80CC/6085
• ECC88/6DJ8 – Dual triode used as cascode RF amplifier in TV tuners and VHF receiver front ends, or as general-purpose instrumentation dual triode, Noval base; PCC88/7DJ8 with a different heater
• ECC89/6FC7 – Dual triode used as cascode RF amplifier in TV tuners and VHF receiver front ends, or as general-purpose instrumentation dual triode, Noval base

Notes:

• All ECC8x have separate cathodes
• ECC81, 82 & 83 have the individual triode heaters internally series-connected, with the midpoint on a separate pin, so they could be run on both 6.3 V and 12.6 V (hence RETMA lists them as 12V types), which was useful in dual-system (6V and 12V) car radios
• All other ECC8x have no heater midpoint tap; ECC85, 86 & 88 have the freed-up pin being used for an internal screen between the sections

• ECC91/6J6 – Common cathode dual VHF triode up to 600 MHz, miniature 7-pin base
• ECC92 – Common cathode dual triode for use as a flip-flop in computers, miniature 7-pin base
• ECC99 – Separate cathodes dual RF triode, Noval^[125] base
• ECC171 – Separate cathodes and separate heaters dual triode, 11-pin gnome tube with internal shield, prototype only; UCC171 with a different heater
• ECC180/6BQ7A – Separate cathodes, dual VHF triode for cascode amplifiers, Noval base
• ECC186/7316 – Separate cathodes, dual triode for use in digital computers, no cathode interface/poisoning after prolonged periods in cut-off, Noval base
• ECC189/6ES8 – Separate cathodes, dual variable-mu VHF triode for cascode amplifiers, Noval base; PCC189/7ES8, XCC189/4ES8 or YCC189/5ES8 with a different heater
• ECC230/6AS7G (6080) – Separate cathodes, dual low-mu power^[125] triode for use as series regulator in DC power supplies, servo applications, or as a horizontal booster triode in TV monitors, Octal base
• ECC801S/6201 – Separate cathodes, dual RF triode, Noval base
• ECC802S/6189 – Separate cathodes, dual AF triode, Noval base
• ECC803S/6057 – Separate cathodes, dual low-microphonics AF triode, Noval base
• ECC804/6GA8 – Separate cathodes, dual triode, Noval base^[152]
• ECC807S – Separate cathodes, dual AF triode for high-gain preamplifiers, Noval base
• ECC808/6KX8 – Separate cathodes, dual AF triode for use as record head output tube in tape recorders, Noval base
• ECC812 – Separate cathodes, dual shielded triode for color TV chrominance outputs in SECAM TV receivers, Noval base
• ECC813 (6463) – Separate cathodes, dual triode for computer circuits, heaters internally series-connected, with the midpoint on a separate pin, Noval base
• ECC832/12DW7/7247 – Dual dissimilar AF triode, a combination of one ECC83/12AX7 system for use as a high-gain amplifier and one ECC82/12AU7 system for use as a phase inverter or cathode follower, Noval base
• ECC865 – Long-life version of the ECC85
• ECC960, ECC962 – Common cathode, dual triodes for use as a flip-flop in computers, miniature 7-pin base

—Special quality:

• ECC2000 – VHF separate cathodes, dual triode with neutralization screen, Decal base, for use in cascode amplifiers up to 300 MHz
• ECC8100 – VHF separate cathodes, dual triode with neutralization screen ("Neutrode") connected to the heater, for use in cascode amplifiers, Noval base
• E80CC/6085 – Separate cathodes, dual triode for use as DC or AF amplifier, Noval base
• E81CC/6201 – Separate cathodes, dual triode for AF and RF amplifiers, mixers up to 300 MHz, oscillators, impulse circuits; Noval base; withstands zero cathode current for extended periods of time
• E82CC/6189 – Separate cathodes, dual triode, shock/vibration resistant, no cathode interface/poisoning after prolonged periods in cut-off, Noval base, for use as amplifier or multivibrator; premium version of ECC82/12AU7
• E83CC/6681 – Separate cathodes, low-microphonics dual triode, Noval base
• E88CC/6922 – Separate cathodes, dual triode, Noval base with gold-plated pins
• E90CC/5920 – Common cathode, dual triode for use as a flip-flop in computers, no cathode poisoning after prolonged periods in cut-off, miniature 7-pin base
• E92CC – Common cathode, dual triode for use as a flip-flop in computers, no cathode poisoning after prolonged periods in cut-off, miniature 7-pin base
• E180CC/7062 – Separate cathodes, dual triode for use as a flip-flop in computers, no cathode poisoning after prolonged periods in cut-off, Noval base
• E181CC/7118 – Separate cathodes, dual triode for use in digital computers, no cathode poisoning after prolonged periods in cut-off, Noval base
• E182CC/7119 – Separate cathodes, dual triode for use as a flip-flop in computers, no cathode poisoning after prolonged periods in cut-off, Noval base
• E188CC/7308 – Separate cathodes, dual triode for use as RF/IF/AF amplifier, Noval base
• E283CC – Separate cathodes, dual triode for use as AF or instrumentation amplifier, Noval base
• E288CC/8223 – Separate cathodes, dual triode for use in IF, RF and cascode amplifiers, Noval base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

ECF

• ECF1 – AF Triode + remote-cutoff IF pentode, side-contact 8 base with pentode control grid on top cap
• ECF12 – Triode + sharp-cutoff pentode for use as RF amplifier and superregenerative FM detector, Y8A steel tube base; UCF12 with a different heater
• ECF80/6BL8 – VHF oscillator/mixer triode/pentode, Noval base; LCF80/6LN8, PCF80/9A8, UCF80 or XCF80/4BL8 with a different heater
• ECF82/6U8 – VHF oscillator/mixer triode/pentode, Noval base; PCF82/9U8A or XCF82/5U8 with a different heater
• ECF83 – Low-microphonics VHF oscillator/mixer triode/remote-cutoff pentode, Noval base, for vehicle equipment
• ECF86/6HG8 – VHF oscillator/mixer triode/pentode, Noval base; LCF86/5HG8, PCF86/7HG8, 8HG8 or XCF86/4HG8 with a different heater
• ECF174 – Triode + pentode, gnome tube, prototype only; UCF174 with a different heater
• ECF200/6X9 – Triode + sharp-cutoff pentode for use as IF amplifier in TV receivers, Decal base; PCF200/8X9 with a different heater
• ECF201/6U9 – Triode + remote-cutoff pentode for use as IF amplifier and sync sep in TV receivers, Decal base; LCF201/5U9 or PCF201/8U9 with a different heater
• ECF202/6AJ9 – Triode + sharp-cutoff pentode for use as SECAM chroma signal demodulators in analog color TV receivers, Decal base
• ECF801/6GJ7 – Triode + remote-cutoff pentode for use as VHF mixer in TV receivers, Noval base; LCF801/5GJ7, PCF801/8GJ7 or XCF801/4GJ7 with a different heater
• ECF802/6JW8 – Triode + sharp-cutoff pentode for use as reactance and sinewave oscillator in TV receivers, Noval base; LCF802/6LX8, PCF802/9JW8 or 5JW8 with a different heater
• ECF803 – ECF801/6GJ7 with separate cathodes
• ECF804 – Triode + sharp-cutoff pentode for use as wide band amplifier, Noval base; PCF804 with a different heater
• ECF805/6GV7 – Triode + remote-cutoff pentode for use as VHF mixer in TV receivers, Noval base; PCF805/7GV7 with a different heater
• ECF812 = EdiSwan 6FL2 – Triode + low-power semiremote-cutoff beam tetrode, Noval base;^[153] PCF812 (=30FL2) with a different heater

—Special quality:

• ECF8070 – Triode + pentode
• E80CF/7643 – Triode + pentode

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

ECH

• ECH2 – Triode/remote-cutoff heptode mixer, side-contact 8 base^[154]
• ECH3 – Triode/remote-cutoff hexode mixer, ECH33 with a side-contact 8 base
• ECH4 – Triode/remote-cutoff heptode mixer, ECH21 with a side-contact 8 base
• ECH11 – Triode/remote-cutoff hexode mixer, Y8A steel tube base; VCH11 with a different heater
• ECH21 = ECH71 (M-OV X143) – Triode/remote-cutoff heptode mixer; ECH4 with a B8G Loctal base
• ECH33 – Triode/remote-cutoff hexode mixer; ECH3 with an Octal base
• ECH35 (M-OV X147) – Triode/remote-cutoff hexode mixer, Octal base
• ECH41 – Triode/remote-cutoff hexode mixer, Rimlock base
• ECH42/6CU7 – Triode/remote-cutoff hexode mixer; ECH80/6AN7 with a Rimlock base; UCH42 with a different heater
• ECH43 – Triode/remote-cutoff hexode mixer, Rimlock base, low-microphonics version of ECH42; UCH43 with a different heater
• ECH80/6AN7 – Triode/remote-cutoff hexode mixer;^[124] ECH42/6CU7 with a Noval base
• ECH81/6AJ8 = M-OV X719 – Triode/remote-cutoff heptode mixer, Noval base; XCH81/3AJ8 with a different heater
• ECH83/6DS8 – Low (6.3-25 V) anode voltage, triode/sharp-cutoff heptode mixer, Noval base, for use in vehicle equipment
• ECH84/6JX8 – Triode/sharp-cutoff heptode mixer, Noval base
• ECH171 – Triode/remote-cutoff heptode mixer, gnome tube; UCH171 with a different heater
• ECH200/6V9 – Triode/sharp-cutoff heptode, Decal base, for TV sync sep; PCH200 with a different heater

—Special quality:

• ECH8000 – Triode/remote-cutoff heptode mixer, Noval base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

ECL

• ECL11 – AF Triode + AF power tetrode, Y8A steel tube base
• ECL80/6AB8 – Triode + power pentode, Noval base
• ECL81 – Triode + power pentode; PCL81 with a different heater
• ECL82/6BM8 – AF Triode + AF power pentode; PCL82/16A8, UCL82/50BM8 or XCL82/8B8 with a different heater
• ECL83 – AF Triode + AF power pentode; PCL83 with a different heater
• ECL84/6DX8 – TV sync sep triode + CRT cathode drive power pentode; LCL84/10DX8, PCL84/15DQ8 or XCL84/8DX8 with a different heater
• ECL85/6GV8 – Triode + power pentode used in TV receivers for vertical timebase, generally as a multivibrator, with the pentode section doubling as one half of the multivibrator and the power output device; LCL85/10GV8, PCL85/18GV8 or XCL85/9GV8 with a different heater
• ECL86/6GW8 – AF Triode + AF power pentode, used for audio amplification in European TV receivers; PCL86/14GW8 with a different heater
• ECL113 – Triode + AF power pentode, Rimlock base
• ECL200 – Triode + CRT drive power pentode, Decal base; PCL200 with a different heater
• ECL802 – Triode + Power pentode for use as vertical oscillator and output tube in TV receivers, Noval base
• ECL805 – Triode + Power pentode with separate cathodes; PCL805 with a different heater, Noval base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

ECLL

• ECLL800 – Triode + dual screened power pentode, for 9.2 W (Class-B) or 8.5 W (Class-AB) AF push-pull power amplifiers. The triode shares its control grid with the 1st pentode and acts as a phase inverter for the 2nd pentode; both pentodes share screen and suppressor grids;^[155] Noval base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

ED

• ED111 – 6 W VHF power triode up to 85 MHz, Rimlock base
• ED500/6ED4 – PD500/9ED4 with a different heater, Magnoval base; considerable X-radiation despite the envelope being fabricated from lead glass
• ED501 – 27 kV Color CRT EHT shunt stabilizer triode, Magnoval base

—Special quality:

• ED8000 – Power triode for use in series-pass voltage regulators, Noval base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EDD

• EDD11 – Dual power triode, Y8A steel tube base
• EDD171 – Dual high-mu power triode, gnome tube, prototype only

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EE

• EE1/4696 (EEP1) – Single-ended secondary emission amplifier for use as a wide band amplifier and phase inverter, side-contact 8 base with control grid on top cap
• EE50 – Single-ended secondary emission amplifier, B9G Loctal 9-pin base, for use in TV receivers

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EEL

• EEL71 – AF Tetrode + AF power pentode, B8G 8-pin Loctal base, for use as audion detector, AF preamplifier, AF power amplifier
• EEL171 – Remote-cutoff tetrode + 4-Watt power pentode, gnome tube; UEL171 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EEP

• EEP1 See EE1/4696

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EF

• EF1 – Sharp-cutoff RF/IF pentode, side-contact 8 base with control grid on top cap^[123]
• EF2 – Remote-cutoff RF/IF pentode, side-contact 8 base with control grid on top cap^[123]
• EF3 – Remote-cutoff RF/IF pentode, side-contact 8 base with control grid on top cap^[123]
• EF5 – Remote-cutoff pentode, side-contact 8 base with control grid on top cap
• EF6 – Sharp-cutoff AF pentode; EF36 with a side-contact 8 base with control grid on top cap
• EF7 – RF/IF Pentode, side-contact 8 base with control grid on top cap;^[123] AF7, CF7 or VF7 with a 6.3 V heater
• EF8 – Selektode, a remote-cutoff pentode with a beam-forming extra grid between control and screen grids, intended to reduce screen current and hence anode/screen grid distribution noise (technically a hexode), EF38 with a side-contact 8 base with control grid on top cap; cf. DAH50, 6FS5, 6GU5
• EF9 – Remote-cutoff RF/IF/AF pentode; EF22/7B7, EF39/6K7 or EF41/6CJ5 with a side-contact 8 base with control grid on top cap
• EF11 – Remote-cutoff pentode, Y8A steel tube base
• EF12 – Sharp-cutoff pentode, Y8A steel tube base

• EF12K – Low-microphonics version of the EF12

• EF13 – Remote-cutoff pentode, Y8A steel tube base
• EF14 – Sharp-cutoff pentode, Y8A steel tube base; UF14 and VF14 with a different heater
• EF15 – Remote-cutoff pentode, Y8A steel tube base; UF15 with a different heater
• EF21 – Remote-cutoff pentode, both 8- or 9-pin Loctal base^[156]
• EF22/7B7 – Remote-cutoff RF/IF/AF pentode; EF9, EF39/6K7 and EF41/6CJ5 with a B8G Loctal base
• EF27 – Sharp-cutoff AF pentode, B8G Loctal base
• EF36 – Sharp-cutoff pentode for use as a tuned RF amplifier, a (second) detector, or an AF amplifier; EF6 with an Octal base with control grid on top cap
• EF37/6J7 – EF36 with low hum and microphonics
• EF38 – EF8 with an Octal base^[124]
• EF39/6K7 – Remote-cutoff RF pentode for use as an IF amplifier or as a superheterodyne mixer (1st detector), also used in test equipment; EF4, EF22/7B7 or EF41/6CJ5 with an Octal base with control grid on top cap
• EF40 – Sharp-cutoff AF pentode, Rimlock base
• EF41/6CJ5 (Cossor 62VP) – Remote-cutoff RF/IF pentode; EF4, EF22/7B7 or EF39/6K7 with a Rimlock base
• EF42 – Sharp-cutoff RF pentode; EF52 with a Rimlock base
• EF43 – Remote-cutoff RF pentode, Rimlock base
• EF50, EF53 – Remote-cutoff pentode for use in the IF stages of 1940s TV and radar receivers, B9G Loctal 9-pin base
• EF51 – Remote-cutoff pentode, B8G Loctal base
• EF52 – Sharp-cutoff RF pentode; EF42 with a B8G Loctal base
• EF54 – Sharp-cutoff RF pentode, B9G Loctal 9-pin base
• EF55 – Sharp-cutoff RF/video pentode, B9G Loctal 9-pin base
• EF70 – Subminiature sharp-cutoff pentode, suppressor grid available on separate pigtail and internally connected to a separate diode to prevent positive grid voltage, for use as a NAND gate in coincidence circuits; all-glass round cross-section body, circular 8-pin/pigtails base
• EF71/5899 – Subminiature remote-cutoff pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• EF72 – Subminiature sharp-cutoff RF pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• EF73 – Subminiature sharp-cutoff pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• EF74 – Subminiature, low-microphonics pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• EF80/6BX6 = M-OV Z152 – Sharp-cutoff RF/IF/Video pentode, Noval base; XF80/3BX6, 12BX6 or UF80/19BX6 with a different heater
• EF81/6BH5 – Remote-cutoff RF/IF/Video pentode, Noval base
• EF83 – Remote-cutoff AF pentode, Noval base
• EF85/6BY7 = M-OV W719 – Remote-cutoff wideband RF pentode, Noval base; HF85 or XF85 with a different heater
• EF86/6BK8/6CF8 = M-OV/GEC Z729 (6267) – Sharp-cutoff AF pentode, also for use in Transitron circuits in TV receivers, Noval base; PF86 or UF86 with a different heater
• EF89/6DA6 – Remote-cutoff RF pentode, Noval base
• EF91/6AM6 = M-OV Z77 = 8D3 (6064, M8083) – Sharp-cutoff pentode, miniature 7-pin base
• EF92/6CQ6 (M8161) – Remote-cutoff RF pentode, miniature 7-pin base
• EF93/6BA6 = M-OV W727 – Remote-cutoff RF pentode, miniature 7-pin base; HF93/12BA6 with a different heater
• EF94/6AU6 – Sharp-cutoff RF/IF/AF pentode, miniature 7-pin base; HF94/12AU6 or XF94/3AU6 with a different heater
• EF95/6AK5 = 6Ж1П (↦6J1P) (5654, CV4010, 408A) – VHF/RF/IF Sharp-cutoff pentode, miniature 7-pin base
• EF96/6AG5 = 6Ж3П (↦6J3P) – Sharp-cutoff RF pentode, miniature 7-pin base
• EF97/6ES6 – Low (6.3-50 V) anode voltage, remote-cutoff RF/IF pentode, for use in vehicle equipment, miniature 7-pin base
• EF98/6ET6 – Low (6.3-50 V) anode voltage, sharp-cutoff pentode, for use as oscillator or IF/AF amplifier in vehicle equipment, miniature 7-pin base
• EF111 – Remote-cutoff pentode, Y8A steel tube base
• EF112 – Sharp-cutoff pentode, Y8A steel tube base
• EF172 – RF/IF/AF Pentode, gnome tube; UF172 with a different heater
• EF174 – Pentode, gnome tube; UF174 with a different heater
• EF175 – Remote-cutoff RF/IF pentode, gnome tube; UF175 with a different heater
• EF176 – VHF Pentode, gnome tube, prototype only; UF176 with a different heater
• EF177 – VHF Pentode, gnome tube, prototype only; UF177 with a different heater
• EF183/6EH7 – Frame-grid, remote-cutoff IF pentode for use in TV receivers; LF183/YF183/4EH7 or XF183/3EH7 with a different heater^[157]
• EF184/6EJ7 – Frame-grid, sharp-cutoff IF pentode for use in TV receivers; LF184/YF184/4EJ7 or XF184/3EJ7 with a different heater^[158]
• EF190/6CB6 – Remote-cutoff RF pentode for use in video IF circuits
• EF410 – RF/IF Pentode, Rimlock B8A base
• EF730/5636 – Subminiature dual-control, sharp-cutoff RF/IF pentode for use as a gated or gain-controlled amplifier, all-glass round cross-section body, circular 8-pin/pigtails base; similar to 5784
• EF731 – Subminiature remote-cutoff RF pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• EF732 – Subminiature sharp-cutoff RF pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• EF734 – Subminiature sharp-cutoff RF pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• EF762 – Subminiature sharp-cutoff RF/IF pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• EF800 – Long-life sharp-cutoff RF/IF pentode
• EF802 – Long-life sharp-cutoff RF/IF pentode
• EF804 – Sharp-cutoff, low-hum, low-microphonics AF pentode
• EF804S – Ruggedized, long-life version of EF804
• EF805S – Long-life remote-cutoff RF/IF pentode
• EF806S/6267 – Ruggedized, long-life AF pentode
• EF812 – RF/IF Pentode^[159]
• EF814 – RF/IF Pentode^[160]
• EF816 – Dual-anode pentode for TV receiver sync separation service
• EF860 – Long-life sharp-cutoff RF pentode for use as preamplifier in telecomms wide-area receivers; IF860 with a 300 mA heater
• EF861 – Wideband pentode
• EF866 – AF pentode
• EF905 = E95F/6AK5W/5654

—Special quality:

• EF5000 – Secondary emission wide band pentode, Magnoval base^[125]
• EF8010 – Remote-cutoff RF/IF pentode
• E1F/4672 (954) – Acorn UHF pentode
• E2F/4695 (956) – Acorn UHF pentode
• E3F – E13F with a hand grip
• E13F – Acorn remote-cutoff RF/IF/AF signal/power pentode for portable transceivers
• E80F/6084 – AF or electrometer pentode, gold-plated pins
• E83F/6689 – Long-life, wide band pentode for use in telephone equipment, gold-plated pins
• E90F/6BH6/7693 – RF Pentode
• E95F/6AK5W/5654 – VHF/RF/IF Sharp-cutoff pentode, miniature 7-pin base
• E99F/6BJ6/7694 – Remote-cutoff RF pentode
• E180F/6688 – Wide band pentode, wideband amplifier for professional equipment
• E186F/7737 – Wide band pentode, wideband amplifier
• E280F/7722 – Wide band pentode, wideband amplifier
• E282F – Pentode, wideband amplifier up to 250 MHz
• E810F/7788 – Wide band pentode, gold-plated pins

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EFF

• EFF50 – Dual VHF pentode, B9G Loctal 9-pin base^[161]
• EFF51 – Dual VHF pentode up to 500 MHz, B9G Loctal 9-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EFL

• EFL200/6Y9 – Sync sep pentode + CRT cathode drive power pentode, Decal base; LFL200/11Y9 or PFL200/16Y9 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EFM

• EFM1 – Variable-mu AF pentode + top-view, "Magic Eye"-type tuning indicator, side-contact 8 base; beam control rods internally tied to the floating screen grid on a weak pullup resistor so its DC voltage mirrors the gain-control voltage fed to the control grid together with the audio signal to be amplified
• EFM11 – Variable-mu AF pentode + top-view, "Magic Eye"-type tuning indicator, Y8A steel tube base; beam control rods internally tied to the floating screen grid

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EFP

• EFP60 – Secondary emission wide band pentode for TV amplifiers, B9G Loctal 9-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EH

• EH1 – Remote-cutoff hexode pentagrid converter, side-contact 8 base with control grid 1 on top cap, separate oscillator^[123]
• EH2 – Remote-cutoff heptode pentagrid converter, side-contact 8 base with grid 4 on top cap, separate oscillator
• EH81 – Heptode
• EH90/6CS6 – Dual-control heptode for use in TV receivers
• EH171 – Sharp-cutoff heptode, gnome tube, prototype only
• EH860 – Heptode
• EH900S/5915 – Dual-control switching heptode, designed for high speed digital computers, no cathode interface/poisoning after prolonged periods in cut-off

—Special quality:

• E81H – Heptode
• E91H/6687 – Dual-control heptode with a passivated third grid to reduce secondary emission, for use as a NAND gate in a coincidence circuit

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EK

• EK1 – Octode pentagrid converter, side-contact 8 base with grid 4 on top cap^[123]
• EK2 – Remote-cutoff octode pentagrid converter; EK32 with a side-contact 8 base with grid 4 on top cap, similar to AK2
• EK3 – Remote-cutoff beam octode pentagrid converter, side-contact 8 base with grid 4 on top cap; similar to AK2; CK3 with a different heater
• EK32 – Octode pentagrid converter; EK2 with an Octal base
• EK90/6BE6 – Heptode pentagrid converter; HK90/12BE6 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EL

• EL1 – Power pentode, side-contact 8 base with control grid on top cap^[123]
• EL2 – Power pentode; EL32 with a side-contact 8 base with control grid on top cap
• EL3, EL3N – Power pentode; EL11 or EL33 with a side-contact 8 base

• EL3G (6V6) – EL3 with an Octal base

• EL5 – Power pentode; AL5 with a different heater; EL35 with a side-contact 8 base
• EL6 – Power pentode; EL12 with a side-contact 8 base
• EL8 – Power pentode; EL13 with a side-contact 8 base
• EL11 – Power pentode; EL3 or EL33 with a Y8A steel tube base
• EL12 – Power pentode; EL6 with a Y8A steel tube base
• EL13 – Power pentode; EL8 with a Y8A steel tube base
• EL20 – Power pentode, B8G Loctal base^[162]
• EL21 – Power pentode, B8G Loctal base;^[163] related to UL21/UL71; not related to EL71/5902
• EL22 – Power pentode, B8G Loctal base^[162]
• EL30 – Power pentode, Octal base^[164]
• EL31 – Power pentode, Octal base, very similar to EL38/6CN6
• EL32 – Power pentode; EL2 with an Octal base
• EL33 (6AG6G, 6M6G) – Power pentode; EL3 or EL11 with an Octal base
• EL34/6CA7 – Power pentode, Octal base
• EL35 – Power pentode; EL5 with an Octal base
• EL36/6CM5 – AF or CRT horizontal deflection output power pentode; EL12 with an Octal base; XL36/13CM5 with a different heater
• EL37 (6L6) – Power pentode, Octal base
• EL38/6CN6 – Power pentode, Octal base; PL38 with a different heater
• EL39 – Power pentode, Octal base^[165]
• EL41/6CK5 = M-OV N150 – 3.9 W AF power pentode; EL80 with a Rimlock base
• EL42 = M-OV N151 – Power pentode; EL85 with a Rimlock base
• EL43 – Power pentode, Rimlock base^[166]
• EL44 – Power pentode, Rimlock base; UL44 with a different heater
• EL50/4654 – 80 W Power pentode, side-contact 8 base with anode on top cap
• EL51 – 140 W Power pentode, side-contact 8 base with anode on top cap
• EL53 – Power pentode, side-contact 8 base^[167]
• EL54 – Power pentode, side-contact 8 base^[168]
• EL60 – Power pentode; EL34 with a B9G 9-pin Loctal base
• EL61 – Power pentode, B9G 9-pin Loctal base
• EL70 – Subminiature power pentode, round cross-section body, circular 8-pin/pigtails base
• EL71/5902 – Subminiature 4 W AF power pentode, all-glass round cross-section body, circular 8-pin/pigtails base
• EL80/6M5 – 3.9 W AF power pentode; EL41 with a Noval base
• EL81/6CJ6 – CRT horizontal deflection or stabilized power supply series regulator pentode^[169]
• EL82/6DY5 – CRT vertical deflection or AF power pentode
• EL83/6CK6 – CRT cathode drive power pentode
• EL84/6BQ5 = M-OV N709 – 6 W AF power pentode
• EL85/6BN5 – 6 W RF/AF power pentode up to 120 MHz, for use in mobile equipment; EL42 with a Noval base
• EL86/6CW5 – 5.3 W AF or CRT vertical deflection output power pentode; LL86/10CW5, PL84/15CW5^[170][171] or XL86/8CW5 with a different heater
• EL90/6AQ5 = M-OV N727 (6005) – 4.5 W AF power pentode
• EL91/6AM5 (M8082) – 4 W AF power pentode
• EL95/6DL5 – 3 W AF power pentode
• EL112 – Radiation-cooled power pentode for 85W SW/VHF service, or for AF amplifiers; EL152 or EL401 with a Y8A steel tube base
• EL136/6FV5 – Horizontal-output power pentode for 110° deflection color TV, Octal base
• EL151 – 60-Watts AF power pentode, Y10A steel tube 10-pin base
• EL152 – Radiation-cooled power pentode for 85W SW/VHF service, or for AF amplifiers; EL112 or EL401 with a B10V glass 10-pin base with one big pin for the anode; FL152 with a different heater
• EL153 – Radiation-cooled power pentode for 70W SW/VHF service, B10V glass 10-pin base with one big pin for the anode
• EL156 – 50-Watts AF power pentode, Y10A steel tube 10-pin base
• EL171 – 4-Watts Power pentode, gnome tube; UL171 with a different heater
• EL172 – 8-Watts Power pentode, gnome tube
• EL173 – Power pentode, gnome tube, prototype only for TV receivers
• EL180/12BY7 – CRT cathode drive power pentode
• EL183 – CRT cathode drive power pentode
• EL300/6FN5 – CRT horizontal deflection power pentode, Octal base; PL300/35FN5 with a different heater
• EL360 – Power pentode for use in radar PPI scanning, series regulators and pulse modulators, Octal base
• EL401 – Radiation-cooled power pentode for 85W SW/VHF service, or for AF amplifiers; EL112 or EL152 with a B8G Loctal base
• EL500/6GB5 – CRT horizontal deflection output beam power pentode, Magnoval base; LL500/18GB5, PL500/27GB5 or XL500/13GB5 with a different heater
• EL502 – CRT horizontal deflection output power pentode, Magnoval base
• EL503/8278 – AF power pentode, Magnoval base
• EL504 – CRT horizontal deflection output power pentode, Magnoval base; PL504 with a different heater
• EL505/6KG6 – CRT horizontal deflection output power pentode for color TV, Magnoval base; PL505/40KG6 with a different heater
• EL508/6KW6 – CRT vertical deflection output power pentode for color TV, Magnoval base; PL508/17KW6 with a different heater
• EL509/6KG6A – EL505/6KG6 with an increased max. anode dissipation, Magnoval base; PL509/40KG6A with a different heater
• EL511 – CRT horizontal deflection output power pentode, Magnoval base
• EL519 – CRT horizontal deflection output power pentode, Magnoval base; PL519 with a different heater
• EL802/6LD6 – CRT cathode drive power pentode for color TV, Noval base; PL802 with a different heater
• EL803 – Wide band power pentode
• EL804 – Wide band power pentode
• EL805 – CRT vertical deflection output power pentode; PL805 with a different heater
• EL806 – CRT cathode drive power pentode
• EL820 – Power pentode^[172]
• EL821/6CH6 (6132) – CRT cathode drive power pentode for use in high definition television equipment
• EL822 – CRT cathode drive power pentode
• EL844 – 9 W RF power pentode
• EL861 – Long-life sharp-cutoff 1 W RF power pentode for use as output amplifier in telecomms wide-area transmitters; IL861 with a different heater

—Special quality:

• EL3010 – 16.5 W Linear power pentode, Octal base
• EL5000 – AF power pentode, Magnoval base
• EL5070/8608 – Wideband video power pentode, Magnoval base
• EL8000 – Power pentode, Noval base
• E55L/8233 – Wide-band power pentode for use as CRT vertical deflection electrode driver in oscilloscopes, Magnoval base
• E80L/6227
  

  E80L
  – 2.8 W AF power pentode, Noval base with gold-plated pins
• E81L/6686 – Long-life 1 W power pentode for use in telephone equipment, Noval base with gold-plated pins (No relationship to EL81)
• E84L/7320 – 6 W Power pentode for use in AF amplifiers and stabilized power supplies, Noval base
• E130L/7534 – Wide band power pentode, Octal base
• E235L/7751 – Wide band power pentode, Octal base
• E236L – Wide band power pentode, Octal base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

ELL

• ELL1 – Dual power pentode, side-contact 8 base
• ELL80/6HU8 – Dual AF power pentode, Noval base; PLL80/12HU8 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EM

• EM1 (4678) – Top-view, "Magic Eye"-type tuning indicator, side-contact 8 base
• EM2 – Top-view, "Magic Eye"-type tuning indicator, side-contact 8 base; AM2 with a 6.3 V/200 mA heater, therefore marketed as C/EM2
• EM3 – Top-view, "Magic Eye"-type tuning indicator, side-contact 8 base^[173]
• EM4 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator; EM34 with a side-contact 8 base
• EM5 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator, EM11 or EM35 with a side-contact 8 base
• EM11 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator; EM5 or EM35 with a Y8A steel tube base
• EM31 – Top-view, "Magic Eye"-type tuning indicator, Octal base^[174]
• EM34/6CD7 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator; EM4 with an Octal base
• EM35 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator; EM5 or EM11 with an Octal base

Note: Telefunken EM35s appear to have a different pin-out than examples from other manufacturers^[175]

• EM71 – Top-view, fan-type tuning indicator with an unusual offset cathode,^[176] B8G 8-pin Loctal base; HM71 with a different heater
• EM72 – EM71 with two segments of the fluorescent screen uncoated with phosphor, intended for indicating low and peak levels but not average level, useless for tuning but intended for recording level indication
• EM80/6BR5 – Side-view, fan-type tuning indicator for AM receivers, Noval B9A base
• EM81/6DA5 – EM80/6BR5 with 25% greater sensitivity
• EM83 – Side-view, "Magic Balance" band-type dual-channel tuning/level indicator, two DC amplifier triodes and one electron gun for two separate screen anodes, Noval B9A base, mainly for stereo use in tape recorders
• EM84/6DH7/6FG6 – Side-view, band-type tuning/level indicator, Noval B9A base

• EM84a – Improved EM84 with twice the sensitivity^[177]

• EM85 – Side-view, fan-type tuning indicator; HM85 or UM85 with a different heater

• EM85E – Band-type drop-in replacement for EM85^[178]

• EM87/6HU6 (CV10407) – Side-view, band-type tuning/level indicator, Noval B9A base
• EM171 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator, gnome tube;^[179] UM171 with a different heater
• EM800 – Side-view, bar graph-type tuning/level indicator, Noval B9A base
• EM840 – Side-view, band-type tuning/level indicator, Noval B9A base

—Special quality:

• E82M – Side-view, rectangle-type dual-channel level indicator, two DC amplifier triodes control separate deflection rods before a 17mmx20mm screen anode, Noval B9A base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EMM

• EMM801 – Side-view, dual, band-type indicator with brightness control, for voltage comparison, Noval B9A base
• EMM803 – Side-view, dual, band-type tuning indicator for FM-stereo receivers (field strength, 19kHz pilot present), Noval B9A base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EN

• EN31 – 10 mA_avg, 750 mA_peak, Helium-filled, indirectly heated triode thyratron for high-frequency timebases and control equipment, Octal base with anode cap
• EN32/6574 – 300 mA_avg, 2 A_peak, 10 A_surge, Gas-filled, indirectly heated tetrode thyratron with negative control characteristic; for industrial control applications, Octal base
• EN70 – 20 mA_avg, 100 mA_peak, Subminiature, gas-filled, indirectly heated tetrode thyratron with negative control characteristic, all-glass round cross-section body, circular 8-pin/pigtails base
• EN91/2D21 (PL21, PL2D21, CV797) – 100 mA_avg, 500 mA_peak, 10 A_surge, Gas-filled, indirectly heated tetrode thyratron, negative starter voltage, miniature 7-pin base, for relay and grid-controlled rectifier service
• EN92 (5696) – 25 mA_avg, 100 mA_peak, 2 A_surge, Gas-filled, indirectly heated tetrode thyratron, negative starter voltage, miniature 7-pin base, for industrial control

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EQ

• EQ40 – Nonode for FM quadrature detection, Rimlock base
• EQ80/6BE7 – Nonode for FM quadrature detection or as phase detector in TV flywheel sync circuits^[180]
• EQ171 – Nonode, gnome tube, prototype only; UQ171 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

ES

• ES111 – TV sync oscillator (German: Kipp-Pentode), a special power relaxation oscillator pentode, an attempt to cut costs on TV receiver production; one ES111 each were needed for vertical and horizontal deflection; the output power for the deflection yoke was extracted not from the anode, but from the screen grid, the sync pulses were applied to the suppressor grid via a separate pin. The anode acted only as a small-signal amplified/gated-sync output which was added to the feedback from an auxiliary winding on the deflection yoke, and fed to the control grid. As there was no vertical deflection output transformer, a secondary, magnetically decoupled vertical deflection yoke received a variable, smoothed-out part of the screen grid current to compensate for its DC component in the primary vertical deflection yoke; it was variable to adjust the vertical picture position on the CRT screen. The screen grid delivered enough power even for an EHT winding on the horizontal deflection output transformer and for the 6.3V/0.2A heater of an RFG5 16-kV EHT rectifier.^{[181][182][183][184]} Y8A steel tube base with 2 unused pins, screen grid on top cap; compare US111

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

ET

• ET51 – Trochotron, an electron-beam decade counter tube

—Special quality:

• E1T/6370 – Trochotron with side-viewing, fluorescent-screen readout, Duodecal (12-pin) base
• E80T/6218 (CV5724) – Modulated, single-anode beam deflection tube for pulse generation up to 375 MHz, Noval base; shock resistant up to 500 g^{[91][90][92][93]}

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EW

• EW60 – 700 V_PIV, 400 mA, Gas-filled, half-wave rectifier, 9-pin Loctal base with 2 unused pins^[124]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EY

• EY1 – CRT EHT rectifier; EY51 with a B4B 4-pin subminiature hearing aid base with anode on top cap
• EY51/6X2 – CRT EHT rectifier, pigtailed version of EY1
• EY70 – 850 V half-wave rectifier, all-glass round cross-section body, circular 8-pin/pigtails base
• EY80/6U3 – CRT horizontal deflection output booster diode, Noval base; PY80 with a different heater
• EY81/6R3 – CRT horizontal deflection output booster diode
• EY82/6N3 – Half-wave rectifier; PY82/19Y3 with a different heater
• EY83 – CRT horizontal deflection output booster diode; PY83 with a different heater
• EY84/6374 – Half-wave rectifier for operation at high altitudes
• EY86/6S2 – CRT EHT rectifier, anode on top cap; DY86/1S2 or GY86 with a different heater
• EY87/6S2A – DY87/1S2A with a different heater; EY86 with a silicone-coated envelope to avoid flush-over in high-humidity and low atmospheric-pressure conditions
• EY88/6AL3 – CRT horizontal deflection output booster diode; LY88/20AQ3, PY88/30AE3 or XY88/16AQ3 with a different heater
• EY91 – Half-wave rectifier, miniature 7-pin base
• EY189/6AL3 – Half-wave rectifier, Noval base
• EY500A/6EC4A – PY500A with a different heater
• EY802 – CRT EHT rectifier, silicone-coated envelope, Noval base with anode on top cap; DY802/1BQ2 or GY802 with a different heater

—Special quality:

• EY3000 – 800 V, 750 mA Half-wave rectifier, side-contact 8 base with anode on top cap

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EYY

• EYY13 – Dual power diode, separate cathodes, Y8A steel tube base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ E - 6.3 V heater ⟶}

EZ

• EZ1 – 250 V, 50 mA Full-wave rectifier for 6V car radios, side-contact 8 base; FZ1 with a different heater
• EZ2 – Full-wave rectifier, side-contact 8 base
• EZ3 – Full-wave rectifier, side-contact 8 base
• EZ4 – Full-wave rectifier, side-contact 8 base
• EZ11 – Full-wave rectifier for vehicle equipment, Y8A steel tube base
• EZ12 – Full-wave rectifier, Y8A steel tube base
• EZ22 – Full-wave rectifier, B8G Loctal base
• EZ30/6CF4 – Full-wave rectifier, Octal base
• EZ35/6X5 – Full-wave rectifier, Octal base
• EZ40/6BT4 – Full-wave rectifier, Rimlock base; GZ40 with a different heater
• EZ41 – Full-wave rectifier, Rimlock base
• EZ80/6V4 – Full-wave rectifier, Noval base
• EZ81/6CA4 – Full-wave rectifier
• EZ90/6X4 – Full-wave rectifier, miniature 7-pin base; HZ90/12X4 with a different heater
• EZ91/6AV4 – Full-wave rectifier, miniature 7-pin base
• EZ150 – Full-wave rectifier, separate cathodes, Y10A steel tube 10-pin base
• EZ900/6063 – Full-wave rectifier, miniature 7-pin base^[185]

—Special quality:

• E90Z/6063 – Full-wave rectifier, miniature 7-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

F - 12.6 V heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ F - 12.6 V heater ⟶}

FDD

• FDD20 – Common cathode dual power triode, 12.6 V/350 mA heater, side-contact 8 base - available with two different pinouts;^[186] similar to 53, 6A6, 6N7G

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ F - 12.6 V heater ⟶}

FL

• FL152 – EL152 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ F - 12.6 V heater ⟶}

FZ

• FZ1 – 250 V, 50 mA Full-wave rectifier for 12V car radios, side-contact 8 base; EZ1 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

G - 5.0 V heater or misc.

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ G - 5.0 V heater or misc. ⟶}

GA

• GA560 – Directly heated, thermally-limited (=saturated) emission, vacuum noise diode, 2.5 to 3,5 V/1.9 to 2.2 A uncoated, thorium-free tungsten filament, all-glass, 3-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ G - 5.0 V heater or misc. ⟶}

GY

• GY11 – Half-wave rectifier, 2.5 V/5 A heater, Y8A steel tube base with anode on top cap
• GY86 – CRT EHT rectifier, Noval base with anode on top cap; DY86/1S2 or EY86/6S2 with a 2.6 V/300 mA heater
• GY501/3BH2 – CRT EHT rectifier for color TV, 3.15 V/400 mA heater, Magnoval base with anode on top cap
• GY802 – CRT EHT rectifier, silicone-coated envelope to avoid flush-over in high-humidity and low atmospheric-pressure conditions, Noval base with anode on top cap; DY802/1BQ2 or EY802 with a 2.6 V/310 mA heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ G - 5.0 V heater or misc. ⟶}

GZ

These tubes all have a 5.0 V heater

• GZ30/5Z4-G – Full-wave rectifier, Octal base
• GZ32/5V4/5AQ4 – Full-wave rectifier, Octal base
• GZ33 – Full-wave rectifier, Octal base
• GZ34/5AR4 – Full-wave rectifier, Octal base
• GZ37 – Full-wave rectifier, Octal base
• GZ40 – Full-wave rectifier, Rimlock base; EZ40 with a different heater
• GZ41 – Full-wave rectifier, Rimlock base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

H - 150 mA heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ H - 150 mA heater ⟶}

HAA

• HAA91/12AL5 – Dual diode with separate cathodes, miniature 7-pin base; EAA91/6AL5, UAA91 or XAA91/3AL5 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ H - 150 mA heater ⟶}

HABC

• HABC80/19T8 – High-mu triode + triple diode (two on common cathode with triode, one with independent cathode), Noval base, used as an AF amplifier, AM detector and FM ratio detector in series-heated post-war AM/FM radios; 5T8, 6T8, EABC80/6AK8, PABC80/9AK8 or UABC80/27AK8 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ H - 150 mA heater ⟶}

HBC

• HBC90/12AT6 – High-mu triode + common cathode dual diode, miniature 7-pin base; EBC90/6AT6 with a different heater
• HBC91/12AV6 – High-mu AF triode + common cathode dual diode, for use in FM ratio detectors, miniature 7-pin base; EBC91/6AV6 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ H - 150 mA heater ⟶}

HCC

• HCC85/17EW8 – Dual triode for use as VHF mixer up to 200 MHz, Noval base; ECC85/6AQ8, PCC85/9AQ8 or UCC85 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ H - 150 mA heater ⟶}

HCH

• HCH81/12AJ7 – Triode/remote-cutoff heptode mixer, Noval base; UCH81/19D8 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ H - 150 mA heater ⟶}

HF

• HF85 – Remote-cutoff wideband RF pentode, Noval base; EF85/6BY7 or XF85 with a different heater
• HF93/12BA6 – Remote-cutoff pentode, miniature 7-pin base; EF93/6BA6 with a different heater
• HF94/12AU6 – Sharp-cutoff RF/IF/AF pentode, miniature 7-pin base; EF94/6AU6 or XF94/3AU6 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ H - 150 mA heater ⟶}

HK

• HK90/12BE6 – Heptode pentagrid converter, miniature 7-pin; EK90/6BE6 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ H - 150 mA heater ⟶}

HL

• HL84 – AF power pentode, Noval base; UL84 with a different heater
• HL90/12AQ5 – AF power pentode, miniature 7-pin; EL90 with a different heater
• HL92/50C5 – AF beam power pentode, miniature 7-pin
• HL94/30A5 – AF power pentode, miniature 7-pin

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ H - 150 mA heater ⟶}

HM

• HM34 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator; EM34 with different heater ratings; UM4 with different base and heater ratings
• HM71 – Top-view, fan-type tuning indicator, B8G Loctal base; EM71 with a different heater
• HM85 – Side-view, fan-type tuning indicator, Noval base; EM85 or UM85 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ H - 150 mA heater ⟶}

HY

• HY90/35W4 – Half-wave rectifier, miniature 7-pin

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ H - 150 mA heater ⟶}

HZ

• HZ90/12X4 – Full-wave rectifier, miniature 7-pin base; EZ90/6X4 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

I - 20 V heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ I - 20 V heater ⟶}

IF

• IF860 – Long-life sharp-cutoff RF pentode for use as preamplifier in telecomms wide-area receivers; EF860 with a 95 mA heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ I - 20 V heater ⟶}

IL

• IL861 – Long-life sharp-cutoff RF power pentode for use as output amplifier in telecomms wide-area transmitters; EL861 with a 120 mA heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

K - 2.0 V heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KA

• KA560 (6357) – Gas-filled, directly heated noise diode for the 10 cm band, waveguide output, BA15d lamp base with anode top cap
• KA561 (6356) – Gas-filled, directly heated noise diode for the 7.5 cm band, waveguide output, BA15d lamp base with anode top cap
• KA562 (6358) – Gas-filled, directly heated noise diode for the 3 cm band, waveguide output, BA15d lamp base with anode top cap
• KA563 (6359) – Gas-filled, directly heated noise diode for the 1.25 cm band, waveguide output, BA15d lamp base with anode top cap
• K50A (6358) – Neon-filled, directly heated noise diode for the 3 cm band, waveguide output, BA15d lamp base with anode top cap
• K51A – Neon-filled, directly heated noise diode for the 10 cm band, waveguide output, BA15d lamp base with anode top cap
• K81A – Directly heated, thermally-limited (=saturated) emission, vacuum VHF noise diode, 2.5 A_max uncoated tungsten filament, Noval base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KB

• KB1 – Directly heated dual diode with common cathode, poor performance as an AM detector lead to the introduction of the KB2; see introduction
• KB2 – Indirectly heated dual diode with common cathode, side-contact 5 base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KBC

• KBC1 – Dual diode + triode, side-contact 8 base with triode grid on top cap
• KBC32 – Dual diode + triode, Octal base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KC

• KC1 – Triode, side-contact 8 base
• KC3 – Triode, side-contact 8 base
• KC4 – Triode, side-contact 8 base
• KC50 – Triode for use in hearing aids, 4-pin base;^[187] cf. Marconi-Osram H11, H12, Mullard DA1
• KC51 – Triode, 4-pin base;^[188] cf. DC51

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KCF

• KCF30 – Triode + remote-cutoff pentode, oscillator/mixer, Octal base with control grid on top cap

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KCH

• KCH1 – Triode/hexode mixer, side-contact 8 base with hexode control grid 1 on top cap

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KD

• KD50 – Power triode for use in hearing aids, 4-pin base;^[189] cf. DD51, Marconi-Osram L11, L12, Mullard DA2, DA3

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KDD

• KDD1 – 1.5 W Dual power triode, side-contact 8 base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KE

• KE50 – Tetrode for use in hearing aids, 4-pin base with anode on top cap;^[190] cf. DF51, Marconi-Osram S12, Mullard DAS1

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KF

• KF1 – RF/IF Pentode, European 7-pin base with anode on top cap
• KF2 – Remote-cutoff RF/IF pentode, European 7-pin base with anode on top cap
• KF3 – Remote-cutoff RF/IF pentode, side-contact 8 base with control grid on top cap
• KF4 – RF/IF Pentode, side-contact 8 base with control grid on top cap
• KF7 – RF/IF Pentode, side-contact 8 base with anode on top cap^[123]
• KF8 – Remote-cutoff RF/IF pentode, side-contact 8 base with anode on top cap^[123]
• KF35 – Remote-cutoff RF pentode, Octal base with control grid on top cap

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KH

• KH1 – Hexode pentagrid converter, side-contact 8 base with grid 1 on top cap

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KK

• KK1 – Octode pentagrid converter, side-contact 8 base with grid 4 on top cap^[191]
• KK2 – Remote-cutoff octode pentagrid converter; KK32 with a side-contact 8 base with grid 4 on top cap
• KK32 – Octode pentagrid converter; KK2 with an Octal base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KL

• KL1 – Power pentode, O5A European 5-pin base
• KL2 – Power pentode, side-contact 8 base
• KL4 – Power pentode, side-contact 8 base
• KL5 – Power pentode, side-contact 8 base
• KL35 – 340 mW Power pentode, Octal base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KLL

• KLL3 – Dual power pentode, side-contact 8 base^[192]
• KLL32 – 1.2W Dual power pentode, Octal base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ K - 2.0 V heater ⟶}

KY

• KY50/2L2 = EdiSwan U25 – CRT EHT rectifier, all-glass pigtailed
• KY80/2J2 = EdiSwan U26 – CRT EHT rectifier, Noval base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

L - 450 mA heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ L - 450 mA heater ⟶}

LC

• LC900/3HA5 – VHF triode; EC900/6HA5 or PC900/4HA5 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ L - 450 mA heater ⟶}

LCF

• LCF80/6LN8 – VHF oscillator/mixer triode/pentode; ECF80/6BL8, PCF80/9A8, UCF80 or XCF80/4BL8 with a different heater^[193]
• LCF86/5HG8 – VHF oscillator/mixer triode/pentode; ECF86/6HG8, PCF86/7HG8, 8HG8 or XCF86/4HG8 with a different heater^[194]
• LCF201/5U9 – Triode + pentode for use as IF amplifier and sync sep in TV receivers, Decal base; ECF201/6U9 or PCF201/8U9 with a different heater^[195]
• LCF801/5GJ7 – Medium-mu triode + sharp-cutoff pentode for use as VHF mixer in TV receivers, Noval base; ECF801/6GJ7, PCF801/8GJ7 or XCF801/4GJ7 with a different heater^[196]
• LCF802/6LX8 – Medium-mu triode + sharp-cutoff pentode for use as reactance and sinewave oscillator in TV receivers, Noval base; ECF802/6JW8, PCF802/9JW8 or 5JW8 with a different heater^[197]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ L - 450 mA heater ⟶}

LCL

• LCL84/10DX8 – High-mu TV sync sep triode + sharp-cutoff CRT cathode drive power pentode; ECL84/6DX8, PCL84/15DQ8 or XCL84/8DX8 with a different heater^[198]
• LCL85/10GV8 – Triode + power pentode used in TV receivers for vertical timebase, generally as a multivibrator, with the pentode section doubling as one half of the multivibrator and the power output device; ECL85/6GV8, PCL85/18GV8 or XCL85/9GV8 with a different heater^[199]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ L - 450 mA heater ⟶}

LF

• LF183/YF183/4EH7 – Frame-grid, remote-cutoff IF pentode for use in TV receivers; EF183/6EH7 or XF183/3EH7 with a different heater^[157][200]
• LF184/YF184/4EJ7 – Frame-grid, sharp-cutoff IF pentode for use in TV receivers; EF184/6EJ7 or XF184/3EJ7 with a different heater^[158][201]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ L - 450 mA heater ⟶}

LFL

• LFL200/11Y9 – Sync sep pentode + CRT cathode drive power pentode, Decal base; EFL200/6Y9 or PFL200/16Y9 with a different heater^[202]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ L - 450 mA heater ⟶}

LL

• LL86/10CW5 – AF or CRT vertical deflection output power pentode; EL86/6CW5, PL84/15CW5^[170][171] or XL86/8CW5 with a different heater
• LL500/18GB5 – CRT horizontal deflection beam power pentode, Magnoval base; EL500/6GB5, PL500/27GB5 or XL500/13GB5 with a different heater^[203]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ L - 450 mA heater ⟶}

LY

• LY88/20AQ3 – CRT horizontal deflection output booster diode; EY88/6AL3, PY88/30AE3 or XY88/16AQ3 with a different heater^[204]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

M - 1.9 V heater

Note: Marconi preceded the M-P designation with the letter M, as in MEBC3 for EBC3

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ M - 1.9 V heater ⟶}

MC

• MC1 = RL2T15 – AF triode for use in audions^{[205][206][207]}

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ M - 1.9 V heater ⟶}

MF

• MF2 = RV2P800 – RF pentode^{[208][206][207]}
• MF6 = RV2P7 – RF pentode^[209]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

N - 12.6 V heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ N - 12.6 V heater ⟶}

ND

• ND4 – 600 MHz, 10 W VHF power triode^[210]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ N - 12.6 V heater ⟶}

NF

• NF2 – Sharp-cutoff RF pentode;^[211][206] AF7 or CF7 with a different heater; also produced by JRC in the then-axis power of Japan^[212]
• NF3 – Remote-cutoff RF pentode;^[213][206] CF2 with a different heater
• NF4 = RV12P4000 – RF pentode^[214][206]
• NF6 = RV12P2000 – RF pentode^[215][207] also produced by JRC in Japan^[212]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

O - No heater

Notes:

• The semiconductors had a different function letter scheme^[31]
• Gas-filled cold-cathode tubes were shifted to Z before their mass production in Europe started, but before that, most producers published RETMA 0-prefix tube data appearantly under this letter: OA2, OA3, OB2, OB3, OC2, OC3, OD3, etc.
• Philips sold a family of 150mA series heater tubes under this letter in South America: OBC3/12SQ7GT, OBF2, OCH4, OH4/12A8GT, OF1/6S7G, OF5/12K7GT, OF9 and OM5, used in combination with RETMA types 35Z5 and 50L6

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ O - No heater ⟶}

OA

• OA5 – 100 V, 150 mA Germanium gold-bonded point-contact diode
• OA85 – 90 V, 50 mA Germanium point-contact diode
• OA127 – 19 V, 40 mA Silicon diode
• OA214 – 700 V, 500 mA Silicon diode
• OA262 – 200 V, 15 A Silicon diode
• OA1154Q – Quad germanium point-contact diode
• OA1182 – 80 V, 150 mA Germanium diode

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ O - No heater ⟶}

OAP

• OAP12 – Germanium photodiode, all-glass pigtailed, black-tinted except top dome, max. sensitivity at λ = 1.55 μm

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ O - No heater ⟶}

OAZ

• OAZ200 – 4.7 V, 420 mW Silicon zener diode
• OAZ292 – 9.1 V, 7 W Silicon zener diode

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ O - No heater ⟶}

OC

• OC2 – Germanium PNP bipolar junction transistor, β > 20
• OC43 – 15 V, 50 mA Germanium PNP transistor, β: 50...200
• OC44 – 15 V, 5 mA Germanium PNP transistor, β: 100
• OC45 – 15 V, 5 mA Germanium PNP transistor, β: 50
• OC46 – 20 V, 100 mA Germanium PNP transistor, β: 20...80
• OC47 – 20 V, 100 mA Germanium PNP transistor, β: 50...200

Note: The German Clevite-Intermetall sold their first lineup of silicon PNP transistors initially under these same type numbers OC43...47; when this became clear, they appended a 0 to their type numbers, henceforth selling this line as OC430...470^[216]

• OC50 – 20 V, 1.5 mA Germanium PNP point-contact transistor, β: 2.1
• OC70 – 30 V, 10 mA Germanium PNP transistor, black-tinted all-glass pigtailed, β: 30
• OC71 – 30 V, 10 mA Germanium PNP transistor, black-tinted all-glass pigtailed, β: 47
• OC141 – 20 V, 400 mA Germanium NPN transistor, β: 150
• OC170 – 20 V, 10 mA Germanium NPN transistor, β: 100
• OC200 – 25 V, 50 mA Silicon NPN transistor, β: 15...60
• OC430 – 10 V, 50 mA Silicon PNP transistor, β: 10...20
• OC440 – 30 V, 50 mA Silicon PNP transistor, β: 10...20
• OC450 – 75 V, 50 mA Silicon PNP transistor, β: >10
• OC460 – 10 V, 50 mA Silicon PNP transistor, β: >20
• OC470 – 30 V, 50 mA Silicon PNP transistor, β: >20
• OC604 – 10 V, 50 mA Germanium PNP AF transistor, black-tinted all-glass pigtailed, β: 45
• OC604spez. – 15 V, 500 mA Germanium PNP AF power transistor, OC604 with improved internal heat transfer and a cooling fin
• OC703 – 80 V, 50 mA Silicon PNP transistor, β: 10...25
• OC800 – 50 V, 10 mA Silicon FET (Clevite-Intermetall), µ: 4.5, g_m: 50 μ℧

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ O - No heater ⟶}

OCP

• OCP70 –
  

  OCP71
  Germanium PNP phototransistor, OC70 without black tint, max. sensitivity at λ = 1.55 μm
• OCP71 – Germanium PNP phototransistor, OC71 without black tint, max. sensitivity at λ = 1.55 μm

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ O - No heater ⟶}

OD

• OD650 – 60 V, 15 A, 45 W Germanium AF PNP power transistor, β: 80
• OD652 – 60 V, 30 A, 45 W Germanium AF PNP power transistor, β: 50
• OD750 – 100 V, 2 A, 150 W Silicon AF NPN power transistor, β: 30
• OD751 – 100 V, 5 A, 150 W Silicon AF NPN power transistor, β: 30

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ O - No heater ⟶}

ORP

• ORP10/7632 – InSb mid-infrared photoresistor, top window, 2-pin pigtailed, max. sensitivity at λ = 6 μm
• ORP11/7633 – CdS photoresistor (LDR), top window, 3-pin base, max. sensitivity at λ = 675 nm
• ORP12/LDR03 – CdS photoresistor, top window, 2-pin pigtailed, max. sensitivity at λ = 675 nm
• ORP13 – InSb mid-infrared photoresistor in a liquid nitrogen dewar, side window via mirror, max. sensitivity at λ = 4.5...5.4 μm
• ORP14/RPY14 – CdS photoresistor, side window, 2-pin gold-plated pigtailed, max. sensitivity at λ = 675 nm
• ORP30 – 350 V_max CdS photoresistor, top window, 4-pin Octal base, max. sensitivity at λ = 675 nm
• ORP31 – 350 V_max CdS photoresistor, top window, 4-pin Octal base
• ORP50 (300 V_max), ORP52 (200 V_max) – CdS photoresistor 45° tilt under dome, 2-pin all-glass pigtailed, max. sensitivity at λ = 675 nm
• ORP60 (top window), ORP61 (side window) – 350 V_max CdS photoresistor, 2-pin all-glass pigtailed, max. sensitivity at λ = 675 nm
• ORP62 (side window), ORP69 (45° tilt) – 350 V_max CdS photoresistor, 2-pin all-glass pigtailed, max. sensitivity at λ = 675 nm
• ORP63 – 75 V_max CdS photoresistor, side window, 2-pin all-glass pigtailed, max. sensitivity at λ = 675 nm
• ORP90, ORP93, ORP94 – 350 V_max CdS photoresistor, side window, miniature 7-pin base, max. sensitivity at λ = 675 nm

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ O - No heater ⟶}

OY

• OY2 – 100 V, 200 mA Germanium half-wave rectifier
• OY114 – 200 V, 1 A Germanium half-wave rectifier
• OY252 – 200 V, 500 mA Silicon half-wave rectifier
• OY5066 – 600 V, 10 A Silicon half-wave rectifier
• OY6047 – 700 V, 1 A Silicon half-wave rectifier

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

P - 300 mA heater

Note: Philips sold a family of 300mA series heater tubes under this letter in South America: PAB1, PBC3/6SQ7GT, PBF2/6B8G, PF9/6K7G, PH4/6A8G and PM5, used in combination with RETMA types 25L6 and 25Z6

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ P - 300 mA heater ⟶}

PAB

• PAB1 – Triple diode with common cathode, side-contact 8 base; AAB1 or EAB1 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ P - 300 mA heater ⟶}

PABC

• PABC80/9AK8 – High-mu triode + triple low-voltage diode (two on common cathode with triode, one with independent cathode), Noval base, used as an AF amplifier, AM detector and FM ratio detector in series-heated post-war European AM/FM radios and TV receivers; EABC80/6AK8, 5T8, 6T8, HABC80/19T8, UABC80/27AK8 or DH719 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ P - 300 mA heater ⟶}

PC

• PC86/4CM4 – UHF Triode; EC86/6CM4 with a different heater
• PC88/4DL4 – UHF Triode; EC88/6DL4 with a different heater
• PC92 – RF Triode
• PC93 – Triode
• PC95/4ER5 – Variable-mu VHF triode; EC95/6ER5 or XC95/2ER5 with a different heater
• PC96 – Triode
• PC97/4FY5 – Frame-grid VHF triode; EC97/6FY5 or XC97/2FY5 with a different heater
• PC900/4HA5 – VHF Triode; EC900/6HA5 or LC900/3HA5 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ P - 300 mA heater ⟶}

PCC

• PCC84/7AN7 – Dual triode for VHF cascode amplifiers, Noval base; ECC84/6CW7 or UCC84 with a different heater
• PCC85/9AQ8 – Dual triode for use as VHF oscillator/mixer up to 200 MHz, Noval base; ECC85/6AQ8, HCC85/17EW8 or UCC85 with a different heater
• PCC88/7DJ8 – Dual triode for use as cascode amplifiers; ECC88/6DJ8 with a different heater
• PCC89/7FC7 – Dual variable-mu triode for use as cascode amplifiers up to 220 MHz
• PCC189/7ES8 – Dual variable-mu VHF triode for cascode amplifiers; ECC189/6ES8, XCC189/4ES8 or YCC189/5ES8 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ P - 300 mA heater ⟶}

PCE

• PCE82 – Triode + CRT cathode drive beam tetrode
• PCE800 = EdiSwan 30FL1 – Triode + low-power semiremote-cutoff beam tetrode, Noval base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ P - 300 mA heater ⟶}

PCF

• PCF80/9A8 – VHF oscillator/mixer triode/pentode; ECF80/6BL8, LCF80/6LN8, UCF80 or XCF80/4BL8 with a different heater
• PCF82/9U8A – ECF82/6U8 or XCF82/5U8 with a different heater
• PCF86/7HG8 – VHF oscillator/mixer triode/pentode; ECF86/6HG8, LCF86/5HG8, 8HG8 or XCF86/4HG8 with a different heater
• PCF87 = EdiSwan 30C17 – Triode + remote-cutoff pentode for use as VHF mixer in TV receivers^[217]
• PCF200/8X9 – Triode + pentode for use as IF amplifier in TV receivers, Decal base; ECF200/6X9 with a different heater
• PCF201/8U9 – Triode + pentode for use as IF amplifier and sync sep in TV receivers, Decal base; ECF201/6U9 or LCF201/5U9 with a different heater
• PCF800 (EdiSwan 30C15) – Triode + pentode for use as VHF mixer in TV receivers
• PCF801/8GJ7 – Triode + remote-cutoff pentode for use as VHF mixer in TV receivers, Noval base; ECF801/6GJ7, LCF801/5GJ7 or XCF801/4GJ7 with a different heater
• PCF802/9JW8 – Triode + pentode for use as reactance and sinewave oscillator in TV receivers, Noval base; ECF802/6JW8, LCF802/6LX8 or 5JW8 with a different heater
• PCF803 – PCF801/8GJ7 with separate cathodes
• PCF805/7GV7 – Triode + remote-cutoff pentode for use as VHF mixer in TV receivers, Noval base; ECF805/6GV7 with a different heater
• PCF806 – Triode + sharp-cutoff, frame-grid pentode for use as VHF mixer in TV receivers
• PCF812 = EdiSwan 30FL2 – Triode + low-power semiremote-cutoff beam tetrode, Noval base;^[153] ECF812 (=6FL2) with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ P - 300 mA heater ⟶}

PCH

• PCH200/9V9 – Triode/heptode, Decal base, for TV sync sep; ECH200/6V9 with a different heater

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PCL

• PCL81 – ECL81 with a different heater
• PCL82/16A8 – AF triode + AF power pentode; ECL82/6BM8; UCL82/50BM8 or XCL82/8B8 with a different heater
• PCL83 – Triode + power pentode; ECL83 with a different heater
• PCL84/15DQ8 – TV sync sep triode + CRT cathode drive power pentode; ECL84/6DX8 or LCL84/10DX8 or XCL84/8DX8 with a different heater
• PCL85/18GV8 – Triode + power pentode used in TV receivers for vertical timebase, generally as a multivibrator, with the pentode section doubling as one half of the multivibrator and the power output device; ECL85/6GV8, LCL85/10GV8 or XCL85/9GV8 with a different heater
• PCL86/14GW8 – AF Triode + AF power pentode, used for audio amplification in European TV receivers; ECL86/6GW8 with a different heater
• PCL88 = EdiSwan 30PL14 – Triode + power pentode^[218]
• PCL200 – Triode + CRT drive power pentode, Decal base; ECL200 with a different heater
• PCL800 = EdiSwan 30PL13 – Triode + power pentode^[219]
• PCL802 – Triode + power pentode
• PCL805 – Triode + power pentode; ECL805 with a different heater

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PD

• PD500/9ED4 – 25 kV Color CRT EHT shunt stabilizer triode, Magnoval base; considerable X-radiation despite the envelope being fabricated from lead glass; may be replaced by the PD510 after rewiring the arc-safety shield pin of the socket; ED500/6ED4 with a different heater
• PD510 – PD500 with a higher PbO content in the glass, improving the X-radiation screening,^[59] and therefore should never be replaced by a PD500 in equipment designed for the PD510^[220]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ P - 300 mA heater ⟶}

PF

• PF83 – Remote-cutoff AF pentode for use as a VCA in remotely controllable TV receivers
• PF86 – Sharp-cutoff AF pentode, also for use in Transitron circuits in TV receivers; EF86/6BK8/6CF8 or UF86 with a different heater

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PFL

• PFL200/16Y9 – Sync sep pentode + CRT cathode drive power pentode, Decal base; EFL200/6Y9 or LFL200/11Y9 with a different heater

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PL

• PL11 – Power pentode, Y8A steel tube base
• PL33 – CRT vertical deflection or AF power pentode, Octal base
• PL36/25E5 – British high voltage high frequency switching pentode valve, Octal base with anode on top cap. Used in TV receivers for horizontal deflection output and/or EHT generation up to c1964. Last consumer electronics use DECCA series DR101, 202, 303, 404, 505, 606 monochrome receivers
• PL38 – CRT horizontal deflection output power pentode, Octal base; EL38/6CN6 with a different heater

• PL38M – PL38 with a metal particles spray-shielded envelope on a separate pin^[221]

• PL81/21A6 – AF or CRT horizontal deflection output power pentode, Noval base

• PL81A – Similar to PL81 but optimised for portable television designs

• PL82/16A5 – AF or CRT vertical deflection output power pentode
• PL83/15A6 = M-OV N309 – CRT cathode drive power pentode
• PL84/15CW5 – AF or CRT vertical deflection output power pentode; EL86/6CW5,^[170] LL86/10CW5 or XL86/8CW5^[171] with a different heater
• PL95 – AF power pentode
• PL136/35FV5 – Color TV 110° horizontal deflection output power pentode, Octal base
• PL300/35FN5 – CRT horizontal deflection power pentode, Octal base; EL300/6FN5 with a different heater
• PL302 – CRT horizontal deflection beam power pentode, Octal base
• PL500/27GB5/28GB5 – CRT horizontal deflection beam power pentode, Magnoval base; EL500/6GB5, LL500/18GB5 or XL500/13GB5 with a different heater
• PL502 – CRT horizontal deflection output power pentode
• PL504 – CRT horizontal deflection output power pentode, replacement for PL500; EL504 with a different heater
• PL505/40KG6 – CRT horizontal deflection output power pentode for color TV; EL505/6KG6 with a different heater
• PL508/17KW6 – CRT vertical deflection output power pentode for color TV; EL508/6KW6 with a different heater
• PL509/40KG6A – PL505/40KG6 with an increased max. anode dissipation; EL509/6KG6A with a different heater
• PL511 – CRT horizontal deflection output power pentode
• PL519 – CRT horizontal deflection output power pentode; EL519 with a different heater
• PL521/29KQ6 – CRT horizontal deflection output power pentode, separate pin for grid 3 to minimize "snivets", Magnoval base; 21KQ6 with a different heater
• PL802 – CRT cathode drive output pentode for color TV, Noval base; EL802/6LD6 with a different heater
• PL805 – CRT vertical deflection output power pentode; EL805 with a different heater
• PL820 – CRT horizontal deflection output power pentode^[221]
• PL841 – AF or CRT vertical deflection output power pentode

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PLL

• PLL80/12HU8 – Dual AF power pentode, Noval base; ELL80/6HU8 with a different heater

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PM

• PM84 – Side-view, band-type tuning/level indicator for use in TV receivers, Noval base; UM84/12FG6 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ P - 300 mA heater ⟶}

PY

• PY31 – Half-wave rectifier, Octal base
• PY32 – Half-wave rectifier, Octal base
• PY33 – Half-wave rectifier, Octal base
• PY71 – Half-wave rectifier, B8G Loctal base
• PY80/19X3 – CRT horizontal deflection output booster diode, Noval base; EY80 with a different heater
• PY81/17Z3 – CRT horizontal deflection output booster diode
• PY82/19Y3 – Half-wave rectifier; EY82/6N3 with a different heater
• PY83 – Half-wave rectifier; EY83 with a different heater
• PY88/30AE3 – CRT horizontal deflection output booster diode; EY88/6AL3, LY88/20AQ3 or XY88/16AQ3 with a different heater
• PY500A/42EC4A – CRT horizontal deflection output booster diode for color TV, Magnoval base; EY500A/6EC4A with a different heater
• PY800 – CRT horizontal deflection output booster diode, Noval base
• PY801 – CRT horizontal deflection output booster diode^[222]

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PZ

• PZ30 – Dual 200 mA rectifier diode, separate cathodes, Octal base, for use as a voltage doubler in TV receivers

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Q - 2.4 V heater

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QC

• QC100 – Low-microphonics triode^[223]

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QZ

• QZ100 – Full-wave rectifier^[224]

Further types such as the QD100, QF100,^[225] QH100, QLL100, QY100 were under development, but didn't get past the prototyping phase^[226]

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S - 1.9 V heater

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SA

• SA100 – Instrumentation rectifier diode up to 3 GHz^[227]
• SA101 – Instrumentation rectifier diode^[228]
• SA102 – Instrumentation rectifier diode^[229]

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SD

• SD1A – Shortwave power triode^{[230][206][207]}
• SD3 – 750 MHz, 3.5 W VHF power triode^[231]

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SF

• SF1A – Sharp-cutoff RF pentode;^[232] NF6 resp. RV12P2000 with a different heater

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T - Custom heater

Note: Tungsram preceded the M-P designation with the letter T, as in TAD1 for AD1

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TY

• TY86F – 7.4 V, 77 mA heater version of the EY86 18-kV CRT EHT rectifier,^[221] for use as a hotfix in early-production Ferguson Radio Corporation TV receivers 306T and 308T^[233] where the horizontal-output transformer produced excessive heater voltage which destroyed the originally fitted EY86's

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U - 100 mA heater

Notes:

• Ultron (MBLE)^(fr, nl) preceded the M-P designation with the letter U, as in UAD1 for AD1
• Philips sold a family of 100mA series heater tubes under this letter in South America: UBC1, UBF2, UBL1, UCH4, UF8, UF9, UL1, UM4 and UY1

Barretters

• U30 – 70 to 122.5 V filament, Octal base, for 110 to 127V mains

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ U - 100 mA heater ⟶}

UAA

• UAA11 – Dual diode with separate cathodes, Y8A steel tube base
• UAA91 – Dual diode with separate cathodes, miniature 7-pin base; EAA91/6AL5, HAA91/12AL5 or XAA91/3AL5 with a different heater
• UAA171 – Dual diode, separate cathodes and separate heaters, gnome tube; EAA171 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ U - 100 mA heater ⟶}

UABC

• UABC80/27AK8 – High-mu triode + triple low-voltage diode (two on common cathode with triode, one with independent cathode), Noval base, used as an AF amplifier, AM detector and FM ratio detector in series-heated post-war European AM/FM radios; EABC80/6AK8, 5T8, 6T8, HABC80/19T8, PABC80/9AK8 and DH719 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ U - 100 mA heater ⟶}

UAF

• UAF21 – Diode + remote-cutoff RF/IF/AF pentode, B8G Loctal base; EAF21 with a different heater
• UAF41 – Diode + remote-cutoff RF/IF/AF pentode, Rimlock base; EAF41 with a different heater
• UAF42/12S7 – Diode + remote-cutoff RF/IF/AF pentode, Rimlock base

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UB

• UB41 – Dual RF diode with separate cathodes, Rimlock base; EB41 with a different heater

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UBC

• UBC41/14L7 – Shielded dual diode + AF triode; EBC41 with a different heater; UBC81 with a Rimlock base
• UBC81 – Shielded dual diode + AF triode; EBC81/6BD7A with a different heater; UBC41 with a Noval base

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UBF

• UBF11 – Dual diode + remote-cutoff pentode, Y8A steel tube base; EBF11 with a different heater
• UBF15 – Dual diode + remote-cutoff pentode, Y8A steel tube base; EBF15 with a different heater
• UBF80/17C8 – Dual diode + remote-cutoff pentode
• UBF89 = EdiSwan 19FL8 – Dual diode + remote-cutoff pentode
• UBF171 – Dual diode + remote-cutoff RF/IF/AF pentode, gnome tube; EBF171 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ U - 100 mA heater ⟶}

UBL

• UBL1 – Dual diode + power pentode, Octal base
• UBL3 – Dual diode + power pentode, side-contact 8 base
• UBL21 = UBL71 – Dual diode + power pentode, B8G Loctal base

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UC

• UC92/9AB4 – VHF triode for FM receiver front ends, single ECC81/12AT7 system; EC92/6AB4 with a different heater

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UCC

• UCC84 – Dual triode for VHF cascode amplifiers, Noval base; ECC84/6CW7 or PCC84/7AN7 with a different heater
• UCC85 – Dual triode for use as VHF oscillator/mixer up to 200 MHz, Noval base; ECC85/6AQ8, HCC85/17EW8 or PCC85/9AQ8 with a different heater
• UCC171 – Separate cathodes and separate heaters dual triode, 11-pin gnome tube with internal shield, prototype only; ECC171 with a different heater

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UCF

• UCF12 – Triode + sharp-cutoff pentode for use as RF amplifier and superregenerative FM detector, Y8A steel tube base; ECF12 with a different heater
• UCF80 – VHF oscillator/mixer triode/pentode; ECF80/6BL8, LCF80/6LN8, PCF80/9A8 or XCF80/4BL8 with a different heater
• UCF174 – Triode + pentode, gnome tube, prototype only; ECF174 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ U - 100 mA heater ⟶}

UCH

• UCH4 – Triode/remote-cutoff heptode mixer; UCH5 or UCH21 with an Octal base
• UCH5 – UCH4 or UCH21 with a side-contact 8 base
• UCH11 – Triode/remote-cutoff hexode mixer, Y8A steel tube base
• UCH21 = UCH71 – UCH4 or UCH5 with a B8G Loctal base
• UCH41 – Triode/remote-cutoff hexode mixer, Rimlock base
• UCH42/14K7 – Triode/remote-cutoff hexode mixer, Rimlock base; ECH42 with a different heater
• UCH43 – Triode/remote-cutoff hexode mixer, Rimlock base, low-microphonics version of UCH42; ECH43 with a different heater
• UCH81/19D8 – Triode/remote-cutoff heptode mixer; HCH81 with a different heater
• UCH171 – Triode/remote-cutoff heptode mixer, gnome tube; ECH171 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ U - 100 mA heater ⟶}

UCL

• UCL11 – Triode + power tetrode, Y8A steel tube base
• UCL81 – Triode + power pentode; PCL81 with a different heater
• UCL82/50BM8 – AF triode + AF power pentode; ECL82/6BM8; PCL82/16A8 or XCL82/8B8 with a different heater
• UCL83 – Triode + power pentode; PCL83 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ U - 100 mA heater ⟶}

UEL

• UEL11 – Tetrode + power tetrode, Y8A steel tube base; VEL11 with a different heater
• UEL51 – Tetrode + power pentode, Y10A steel tube 10-pin base
• UEL71 – Tetrode + power pentode, B8G 8-pin Loctal base; EEL71 with a different heater
• UEL171 – Remote-cutoff tetrode + 4-Watt power pentode, gnome tube; EEL171 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ U - 100 mA heater ⟶}

UF

• UF5 – Remote-cutoff pentode, side-contact 8 base
• UF6 – Pentode, side-contact 8 base
• UF9 – Remote-cutoff pentode, Octal base
• UF11 – Remote-cutoff pentode, Y8A steel tube base
• UF14 – Sharp-cutoff pentode, Y8A steel tube base; EF14 or VF14 with a different heater
• UF15 – Remote-cutoff pentode, Y8A steel tube base; EF15 with a different heater
• UF21 – Remote-cutoff pentode, B8G Loctal base
• UF41/12AC5 – Remote-cutoff RF pentode, Rimlock base; EF41 with a different heater
• UF42 – Wide band pentode, Rimlock base; EF42 with a different heater
• UF43 – Wide band, remote-cutoff pentode, Rimlock base; EF43 with a different heater
• UF80/19BX6 – Sharp-cutoff RF/IF/Video pentode, Noval base; XF80/3BX6, EF80/6BX6 or 12BX6 with a different heater
• UF85/19BY7 – Remote-cutoff RF pentode
• UF86 – EF86/6BK8/6CF8 or PF86 with a different heater
• UF89 – Remote-cutoff IF pentode
• UF172 – RF/IF/AF Pentode, gnome tube; EF172 with a different heater
• UF174 – Pentode, gnome tube; EF174 with a different heater
• UF175 – Remote-cutoff RF/IF pentode, gnome tube; EF175 with a different heater
• UF176 – VHF Pentode, gnome tube, prototype only; EF176 with a different heater
• UF177 – VHF Pentode, gnome tube, prototype only; EF177 with a different heater

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UFM

• UFM11 – Remote-cutoff AF pentode + top-view, "Magic Eye"-type tuning indicator, Y8A steel tube base; EFM11 with a different heater

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UH

• UH171 – Sharp-cutoff heptode, gnome tube, prototype only

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UL

• UL2 – Power pentode, side-contact 8 base
• UL11 – Power pentode, Y8A steel tube base
• UL12 – Power pentode, Y8A steel tube base
• UL21 = UL71 – Power pentode, B8G Loctal base
• UL41/45A5 – AF power pentode, Rimlock base
• UL44 – Power pentode, Rimlock base; EL44 with a different heater
• UL46 – Power pentode, Rimlock base^[234]
• UL84/45B5 – AF power pentode
• UL171 – 4-Watts Power pentode, gnome tube; EL171 with a different heater

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ULL

• ULL80 – Dual AF power pentode; ELL80, PLL80 with a different heater

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UM

• UM4 (10M2) – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator, Octal base; UM34 with a different pinout
• UM11 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator, Y8A steel tube base; EM11 with a different heater
• UM34 – UM4 with a different pinout; HM34 with different heater ratings
• UM35 = EdiSwan 10M2 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator, Octal base
• UM80/19BR5 – Side-view, fan-type tuning indicator for AM receivers
• UM81 – Side-view, fan-type tuning indicator
• UM84/12FG6 – Side-view, band-type tuning/level indicator; PM84 with a different heater
• UM85 – Side-view, fan-type tuning indicator, Noval base; EM85 or HM85 with a different heater
• UM171 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator, gnome tube;^[235] EM171 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ U - 100 mA heater ⟶}

UQ

• UQ80 – Nonode; EQ80/6BE7 with a different heater
• UQ171 – Nonode, gnome tube, prototype only; EQ171 with a different heater

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US

• US111 – TV sync oscillator, a special relaxation oscillator pentode with the suppressor grid on a separate pin to act as a second control grid; Y8A steel tube base with 2 unused pins, screen grid on top cap. See ES111

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UY

• UY1 – Half-wave rectifier, Octal base
• UY2 – Half-wave rectifier, side-contact 5 base
• UY3 – Half-wave rectifier, side-contact 8 base
• UY4 – Half-wave rectifier, side-contact 8 base
• UY11 – Half-wave rectifier, Y8A steel tube base
• UY21 – Half-wave rectifier, B8G Loctal base
• UY31 – Half-wave rectifier, Octal base
• UY41/31A3 – Half-wave rectifier, Rimlock base
• UY42 – Half-wave rectifier, Rimlock base
• UY82/55N3 – Half-wave rectifier
• UY85/38A3 – Half-wave rectifier
• UY89/31AV3 – Half-wave rectifier
• UY92 – Half-wave rectifier

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V - 50 mA heater

Notes:

• Apart from AC/DC radios,^[236] "V" tubes were also used in miniaturized equipment with only one single supply for both anode and heater.^[71]
• VATEA Rádiótechnikai és Villamossági Rt.-t. (VATEA Radio Technology and Electric Co. Ltd., Budapest, Hungary) preceded the M-P designation with the letter V, as in VEL5 for EL5.

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VBF

• VBF11 – Dual diode + pentode, Y8A steel tube base; EBF11 with a 38 V heater^[124]

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VC

• VC1 – Triode, side-contact 8 base with grid on top cap, 55 V^[236] heater^[124]

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VCH

• VCH11 – Triode/hexode mixer, Y8A steel tube base, ECH11 with a 38 V heater^[124]

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VCL

• VCL11 – Triode + power tetrode, 90 V heater, Y8A steel tube base

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VEL

• VEL11 – AF Tetrode + AF beam power tetrode, Y8A steel tube base with E-tetrode grid on top cap, UEL11 with a 90 V heater^[124]

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VF

• VF3 – Pentode, side-contact 8 base; AF3 with a 55 V heater^[124]
• VF7 – Pentode, side-contact 8 base; AF7, CF7 or EF7 with a 55 V heater^[124]
• VF14 – Sharp-cutoff pentode, Y8A steel tube base; EF14 or UF14 with a 55 V heater^[124]

• VF14M – Selected VF14 in production until the end of the 1950s for use as a preamplifier in Neumann condenser microphones U-47 and U-48 where they were run at only half their rated heater power to reduce noise^[71]

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VL

• VL1 – 1.6 W AF Pentode, side-contact 8 base, CL1 with a 55 V^[236] heater^[124]
• VL4 – 4 W AF Pentode, side-contact 8 base, CL4 with a 110 V heater^[124]

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VY

• VY1 – 60 mA Half-wave rectifier, 55 V^[236] heater, side-contact 8 base^[124]
• VY2 – 250 V, 20 mA Half-wave rectifier, 30 V heater, side-contact 5 base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

X - 600 mA heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ X - 600 mA heater ⟶}

XAA

• XAA91/3AL5 – Dual diode with separate cathodes, miniature 7-pin base; EAA91/6AL5, HAA91/12AL5 or UAA91 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ X - 600 mA heater ⟶}

XC

• XC95/2ER5 – Variable-mu VHF triode; EC95/6ER5, PC95/4ER5 with a different heater
• XC97/2FY5 – Frame-grid VHF triode; EC97/6FY5 or PC97/4FY5 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ X - 600 mA heater ⟶}

XCC

• XCC82/7AU7 – Dual triode; ECC82/12AU7 with a different heater
• XCC189/4ES8 – Dual VHF triode for cascode amplifiers; ECC189/6ES8, PCC189/7ES8 or YCC189/5ES8 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ X - 600 mA heater ⟶}

XCF

• XCF80/4BL8 – VHF oscillator/mixer triode/pentode; ECF80/6BL8, PCF80/9A8, LCF80/6LN8 or UCF80 with a different heater
• XCF82/5U8 – Triode + pentode; ECF82/6U8 or PCF82/9U8A with a different heater
• XCF801/4GJ7 – VHF oscillator/mixer triode/pentode, Noval base; ECF801/6GJ7, LCF801/5GJ7 or PCF801/8GJ7 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ X - 600 mA heater ⟶}

XCH

• XCH81/3AJ8 – Triode/heptode mixer; ECH81/6AJ8 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ X - 600 mA heater ⟶}

XCL

• XCL82/8B8 – AF triode + AF power pentode; ECL82/6BM8, PCL82/16A8 or UCL82/50BM8 with a different heater
• XCL84/8DX8 – TV sync sep triode + CRT cathode drive power pentode; ECL84/6DX8, LCL84/10DX8 or PCL84/15DQ8 with a different heater
• XCL85/9GV8 – Triode + power pentode for CRT vertical deflection output; ECL85/6GV8, LCL85/10GV8 or PCL85/18GV8 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ X - 600 mA heater ⟶}

XF

• XF80/3BX6 – Sharp-cutoff RF/IF/Video pentode, Noval base; EF80/6BX6, 12BX6 or UF80/19BX6 with a different heater
• XF85 – Remote-cutoff wideband RF pentode, Noval base; EF85/6BY7 or HF85 with a different heater
• XF94/3AU6 – Sharp-cutoff RF/IF/AF pentode, miniature 7-pin base; EF94/6AU6 or HF94/12AU6 with a different heater
• XF183/3EH7 – Frame-grid, remote-cutoff IF pentode for use in TV receivers; EF183/6EH7 or LF183/YF183/4EH7 with a different heater^[157]
• XF184/3EJ7 – Frame-grid, sharp-cutoff IF pentode for use in TV receivers; EF184/6EJ7 or LF184/YF184/4EJ7 with a different heater^[158]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ X - 600 mA heater ⟶}

XL

• XL36/13CM5 – AF or CRT horizontal deflection output power pentode; EL36/6CM5 with a different heater
• XL84 – Power pentode; EL84 with a different heater
• XL86/8CW5 – AF or CRT vertical deflection output power pentode; EL86/6CW5, LL86/10CW5 or PL84/15CW5^[170][171] with a different heater
• XL500/13GB5 – CRT horizontal deflection beam power pentode, Magnoval base; EL500/6GB5, LL500/18GB5 or PL500/27GB5 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ X - 600 mA heater ⟶}

XY

• XY88/16AQ3 – CRT horizontal deflection output booster diode; EY88/6AL3, LY88/20AQ3 or PY88/30AE3 with a different heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

Y - 450 mA heater

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ Y - 450 mA heater ⟶}

YCC

• YCC189/5ES8 – Dual VHF triode for cascode amplifiers; ECC189/6ES8, PCC189/7ES8 or XCC189/4ES8 with a different heater^[237]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ Y - 450 mA heater ⟶}

YF

• YF183/LF183/4EH7 – Frame-grid, remote-cutoff IF pentode for use in TV receivers; EF183/6EH7 or XF183/3EH7 with a different heater^[157][200]
• YF184/LF184/4EJ7 – Frame-grid, sharp-cutoff IF pentode for use in TV receivers; EF184/6EJ7 or XF184/3EJ7 with a different heater^[158][201]

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶}

Z - Cold-cathode tube

Notes:

• Special-quality cold-cathode "Z" tubes had a different function letter scheme.
• See also the professional tubes under Z

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ Z - Cold-cathode tube ⟶}

ZA

• Z860A – 250 V Arc discharge tube for use as switching element in a high voltage pulse generator such as an electric fence energizer, Noval base
• Z861A – 450 V Arc discharge tube, Noval base
• Z862A – 650 V Arc discharge tube, Noval base
• Z960A – 75 V Cold-cathode surge protector for receiver front ends, miniature 7-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ Z - Cold-cathode tube ⟶}

ZC

• Z302C – Unusual decade Counter Dekatron, a counterclockwise-only decade counter tube with separate odd and even extinguishing electrodes except "0", which is tied to a -300V supply so reaching the terminal count produces a negative spike on the anode voltage which can be used to advance the next counter stage with no intermediate active components
• Z303C – Neon-filled, 4 kHz bidirecional decade Counter Dekatron
• Z563C – Neon-filled 4 kHz bidirecional decade Counter Dekatron
• Z565C – 4 kHz Bidirecional decade Counter Dekatron
• Z573C – Neon-filled 4 kHz bidirecional decade Counter Dekatron with aux anodes for direct control of Nixie tubes

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ Z - Cold-cathode tube ⟶}

ZE

• Z862E – Noble-gas filled, cold-cathode electrometer tube, control current 10 pA, silicone-coated envelope for isolation, guard ring, envelope inside radioactively coated for a constant ignition voltage

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ Z - Cold-cathode tube ⟶}

ZM

• ZM11 – Neon-filled digital indicator tube, 21 mm character height, top-viewing, showing a cross with a central dot and independent arms, for use in industrial control panels
• ZM13 – Neon-filled digital indicator tube, 21 mmCH, top-viewing, showing a vertical line and a circle with a small gap, for use in industrial control panels
• ZM13U – Neon-filled digital indicator tube, 21 mmCH, top-viewing, showing a vertical line and a circle, for use in industrial control panels
• ZM14 – Neon-filled digital indicator tube, 21 mmCH, top-viewing, showing a vertical line, a circle, a triangle and a three-winged star, for use in industrial control panels
• Z510M –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 15.5 mmCH, top-viewing, no decimal point
• Z520M = ZM1020
• Z521M = ZM1021
• Z522M = ZM1040
• Z550M = 8453 = ZM1050
• Z560M – Z5600M with a red contrast filter coating
• Z561M = ZM1021 – Z5610M with a red contrast filter coating
• Z565M – Gas-filled digital indicator tube with a dekatron-type readout; similar to GR10A, Z503M and ZM1050
• Z566M – Z5660M with a red contrast filter coating
• Z567M – Z5670M with a red contrast filter coating
• Z568M – Z5680M with a red contrast filter coating
• Z570M – Z5700M with a red contrast filter coating
• Z571M – Z5710M with a red contrast filter coating
• Z573M – Z5730M with a red contrast filter coating
• Z574M – Z5740M with a red contrast filter coating
• Z580M – Z5800M with a red contrast filter coating
• Z581M – Z5810M with a red contrast filter coating
• Z590M – Z5900M with a red contrast filter coating
• Z870M – Z8700M with a red contrast filter coating
• Z5200M = ZM1022
• Z5220M = ZM1042
• Z5600M –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 15.5 mmCH, top-viewing, no decimal point
• Z5610M –  A V Ω + - ~ % W  Neon-filled digital indicator tube, 15.5 mmCH top-viewing, for use in digital multimeters
• Z5660M –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 30 mmCH, side-viewing, no decimal point
• Z5670M –  + - ~  Neon-filled digital indicator tube, 18/30 mmCH side-viewing
• Z5680M –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 50 mmCH side-viewing, no decimal point
• Z5700M –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 13 mmCH side-viewing, no decimal point
• Z5710M –  + - ~  Neon-filled digital indicator tube, 10.5/13 mmCH side-viewing
• Z5730M –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 13 mmCH side-viewing, right decimal points
• Z5740M –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 13 mmCH side-viewing, left decimal points
• Z5800M –  T G M k m µ n p  Neon-filled digital indicator tube, 13 mmCH side-viewing
• Z5810M –  A F H S V Ω Hz s  Neon-filled digital indicator tube, 13 mmCH side-viewing, for use in digital multimeters
• Z5900M –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 10 mmCH side-viewing, both left and right decimal points
• Z8700M –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 10 mmCH side-viewing, no decimal point, 5 dual cathodes and separate odd/even anode compartments for biquinary multiplexing

Note: More Nixie tubes under professional - ZM and ETL examples

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ Z - Cold-cathode tube ⟶}

ZS

• Z502S – Neon-filled, 4 kHz max. decade Counter/Selector Dekatron
• Z504S = ZM1070 = 8433 – Neon-filled, 5 kHz max. decade Counter/Selector Dekatron
• Z505S = ZM1060 – Argon-filled, 50 kHz max. decade Counter/Selector Dekatron
• Z562S – Neon-filled, 4 kHz max. decade Counter/Selector Dekatron, envelope inside radioactively coated for a constant ignition voltage
• Z564S – 25 kHz max. Decade Counter/Selector Dekatron, envelope inside radioactively coated for a constant ignition voltage
• Z572S – Neon-filled, 5 kHz max. decade Counter/Selector Dekatron, aux anodes to directly drive Nixie tubes, envelope inside radioactively coated for a constant ignition voltage

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ Z - Cold-cathode tube ⟶}

ZT

• Z50T – Subminiature, 6 mA_avg, 24 mA_peak, Gas-filled, cold-cathode trigger triode, 1 starter, 3-pin all-glass pigtailed, for use as switch in bang–bang controllers
• Z300T = PL1267 (0A4G) – 25 mA_avg, 100 mA_peak, Gas-filled, cold-cathode DC trigger triode, one starter, Octal base
• Z900T = 5823 – 25 mA_avg, 100 mA_peak, Gas-filled, cold-cathode AC trigger triode, one starter, miniature 7-pin base

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ Z - Cold-cathode tube ⟶}

ZU

• Z0.7/10U – 700 V, 500 mA_avg, 10 A_peak, Gas-filled, cold-cathode DC arc trigger tetrode, one starter and a primer electrode, positive starter voltage^[125]
• Z0.7/100U – 700 V, 2 A_avg, 100 A_peak, Gas-filled, cold-cathode DC arc trigger tetrode, one starter and a primer electrode, positive starter voltage, for triggering ignitrons^[125]
• Z1/100U – 1 kV, 2 A_avg, 100 A_peak, Gas-filled, cold-cathode DC arc trigger tetrode, one starter and a primer electrode, positive starter voltage, for use in welding machines^[125]
• Z70U = 7710 – Subminiature, 3 mA_avg, 12 mA_peak, Gas-filled, cold-cathode DC trigger tetrode, one starter and a primer electrode, positive starter voltage, 4-pin all-glass pigtailed
• Z71U = 7711 – Subminiature, 7 mA_avg, 12 mA_peak, Gas-filled, cold-cathode DC trigger tetrode, two starters, positive starter voltage, 4-pin all-glass pigtailed, low impedance at audio frequencies for use in a telephone exchange
• Z700U – Subminiature, 4 mA_avg, 16 mA_peak, Gas-filled, cold-cathode DC trigger tetrode, one starter and a primer electrode, positive starter voltage, all-glass pigtailed, for use in Dekatron circuits up to 2...5 kHz
• Z701U – Subminiature, Gas-filled, cold-cathode trigger tetrode, all-glass pigtailed
• Z800U – 2.5 mA_avg, 10 mA_peak, Gas-filled, cold-cathode DC trigger tetrode, one starter and a primer electrode, positive starter voltage, Noval base, for voltage control, sensitive relay circuits and timers
• Z801U – 2.5 mA_avg, 10 mA_peak, Gas-filled, cold-cathode DC trigger tetrode, one starter and a primer electrode, negative starter voltage, Noval base, for use with Geiger-Müller tubes
• Z803U = 6779 (ZC1020) – 25 mA_avg, 100 mA_peak, Gas-filled, cold-cathode DC trigger tetrode, one starter and a primer electrode, positive starter voltage, Noval base, for voltage control, sensitive relay circuits and timers
• Z804U = 7713 – 5 mA_avg, 25 mA_peak, Gas-filled, cold-cathode AC trigger tetrode, one starter and a primer envelope coating, negative starter voltage, Noval base, direct operation from a 200...250VAC mains grid but should be triggered only while U_A > 0
• Z805U = 7714 – 5 mA_avg, 25 mA_peak, Gas-filled, cold-cathode AC trigger tetrode, one starter, two primers and separate cathode and anode shields on individual pins, positive starter voltage, Noval base, direct operation from a 200...250VAC mains grid, for relay drivers, timers, photoelectric controls, etc.

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ Z - Cold-cathode tube ⟶}

ZW

• Z70W = 7709 – 4 mA, Gas-filled, cold-cathode DC trigger pentode, two starters and a primer electrode, positive starter voltage, 5-pin all-glass pigtailed, for use in bidirectional counters
• Z660W (GR43) – 12 mA_avg, 50 mA_peak, Gas-filled, cold-cathode DC trigger pentode, two starters and a primer electrode, positive starter voltage, 5-pin all-glass pigtailed, envelope inside radioactively coated for a constant ignition voltage, for use in bidirectional counters
• Z661W (ZC1010) – 8 mA_avg, 50 mA_peak, Gas-filled, cold-cathode AC trigger pentode, two starters and a primer electrode, positive starter voltage, 5-pin all-glass pigtailed, envelope inside radioactively coated for a constant ignition voltage, for use in bidirectional counters
• Z700W – 4 mA, Gas-filled, cold-cathode DC trigger pentode, two starters and a primer electrode, positive starter voltage, 5-pin all-glass pigtailed, for use in bidirectional counters
• Z806W – Gas-filled, cold-cathode trigger tetrode, one starter and dual primer, Noval base, used in elevator controls
• Z865W – 25 mA_avg, 200 mA_peak Gas-filled, cold-cathode AC/DC trigger tetrode, one starter and a primer electrode, low positive starter voltage for transistorized circuits, Noval base, envelope inside radioactively coated for a constant ignition voltage, for use as a relay driver

_{LoVT ⟶ List of European Mullard–Philips tubes ⟶ Z - Cold-cathode tube ⟶}

ZX

• Z860X – 40 mA_avg, 200 mA_peak, Gas-filled, cold-cathode DC trigger pentode, two starters, a primer electrode and an internal shield, positive starter voltage, Noval base, envelope inside radioactively coated for a constant ignition voltage, for use in counters
• Z861X – 40 mA_avg, 200 mA_peak, Gas-filled, cold-cathode AC trigger pentode, two starters, a primer electrode and an internal shield, positive starter voltage, Noval base, envelope inside radioactively coated for a constant ignition voltage, for use in counters
• Z863X – 40 mA_avg, 200 mA_peak, Gas-filled, cold-cathode DC trigger pentode, two starters, a primer electrode and an internal shield, negative starter voltage, Noval base, envelope inside radioactively coated for a constant ignition voltage, for use in counters

List of Pro Electron professional tubes

Note: Typecode explained above.

_{LoVT ⟶ List of Pro Electron professional tubes ⟶}

X - Electro-optical devices

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ X - Electro-optical devices ⟶}

XA

• XA1003 – Phototube, caesium-on-oxydated-silver cathode, 2-pin all-glass pigtailed

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ X - Electro-optical devices ⟶}

XG

• XG2000 – Image converter for x-ray diagnostics

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ X - Electro-optical devices ⟶}

XL

• XL7900 – Vibrating-capacitor chopper front end for dosimeters, electrometers, pH meters etc., Magnoval base with gold-plated pins^[125]

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ X - Electro-optical devices ⟶}

XM

• XM1000 – Nimo tube, directly heated cathode-ray 1-digit numeric display tube, decimal points on both sides, hence 12 stenciled electron guns, top-viewing, green, 15 mm high Futura Medium font, oval envelope for easy horizontal stacking, 14-pin base

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ X - Electro-optical devices ⟶}

XP

• XP1000 – 10-stage photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, Diheptal (14-pin) base
• XP1001 – 10-stage photomultiplier for gamma ray scintillation spectrometry, Sb-Cs cathode, Ag-Mg-O-Cs dynodes
• XP1002 – 10-stage photomultiplier, blue/green/yellow/orange-sensitive Sb-Na-K-Cs cathode, Ag-Mg-O-Cs dynodes, Diheptal base
• XP1003 – 10-stage photomultiplier with Silica window, UV/blue/green/yellow/orange-sensitive Sb-Na-K-Cs cathode, Ag-Mg-O-Cs dynodes, Diheptal base
• XP1004 – 10-stage photomultiplier with Silica window, UV/blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, Diheptal base
• XP1005 – 10-stage Ag-O-Cs (800±100 nm) photomultiplier, IR/red-sensitive Ag-O-Cs cathode, Ag-Mg-O-Cs dynodes, Diheptal base
• XP1010 – 10-stage photomultiplier for r-ray and gamma ray scintillation spectrometry, selected 150AVP for low noise and resolution, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, Duodecal (12-pin) base
• XP1011 – 10-stage photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, shock and vibration-proof, Duodecal base
• XP1020 – 12-stage photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, 100 Ω coaxial output, Duodecal (20-pin) base
• XP1021 – 12-stage photomultiplier, UV/blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, 50 Ω coaxial output, Duodecal base
• XP1023 – 12-stage photomultiplier with Silica window Sb-Cs cathode, Ag-Mg-O-Cs dynodes, UV/blue-sensitive, 50 Ω coaxial output, Duodecal base
• XP1030 – 10-stage photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, Diheptal (14-pin) base
• XP1031 – 10-stage photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, for gamma ray scintillation spectrometry
• XP1032 – 10-stage photomultiplier with 3 mm Silica window, UV/blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, Diheptal base
• XP1033 – 10-stage photomultiplier with 10 mm Silica window, UV/blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, Diheptal base
• XP1040 – 14-stage photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, concave window, Duodecal base
• XP1110 – Photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes
• XP1111 – Photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, pigtails
• XP1113 – 6-stage Photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes
• XP1114 – 4-stage Photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes
• XP1115 – Photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, pigtails, shock and vibration-proof
• XP1116 – Photomultiplier, red-sensitive Ag-O-Cs cathode, Ag-Mg-O-Cs dynodes, shock and vibration-proof
• XP1117 – 9-stage photomultiplier, blue/green/yellow/orange-sensitive Sb-Na-K-Cs cathode, Ag-Mg-O-Cs dynodes
• XP1118 – Photomultiplier with Silica window, UV/blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes
• XP1120 – 17-stage windowless photomultiplier for x-ray (λ > 200 pm) or UV (λ < 150 nm) photon counting in a high-vacuum environment up to 10⁻⁵ mmHg (1.3 mPa), Nickel cathode, Cu-Be-O dynodes, coaxial outputs, built-in resistor ladder
• XP1121 – 17-stage windowless photomultiplier for ion (> 10 keV) or electron (0.1...10 keV) photon counting in a high-vacuum environment up to 10⁻⁵ mmHg, Cu-Be-O cathode and dynodes, coaxial outputs, built-in resistor ladder
• XP1122 – 17-stage windowless photomultiplier for x-ray (λ > 200 pm) or UV (λ < 150 nm) photon counting in a high-vacuum environment up to 10⁻⁵ mmHg, Nickel cathode, Cu-Be-O dynodes, coaxial outputs, built-in resistor ladder
• XP1123 – 17-stage windowless photomultiplier for ion (> 10 keV) or electron (0.1...10 keV) photon counting in a high-vacuum environment up to 10⁻⁵ mmHg, Cu-Be-O cathode and dynodes, coaxial outputs, built-in resistor ladder
• XP1130 – 17-stage windowless photomultiplier for x-ray (λ > 200 pm) or UV (λ < 150 nm) photon counting in a high-vacuum environment up to 10⁻⁵ mmHg, Nickel cathode, Cu-Be-O dynodes, coaxial outputs, built-in resistor ladder
• XP1131 – 17-stage windowless photomultiplier for ion (> 10 keV) or electron (0.1...10 keV) photon counting in a high-vacuum environment up to 10⁻⁵ mmHg, Cu-Be-O cathode and dynodes, coaxial outputs, built-in resistor ladder
• XP1140 – 6-stage photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, fast, Diheptal base
• XP1141 – 7-stage photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, fast, Diheptal base
• XP1180 = 52AVP – 10-stage photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, fast, Diheptal base
• XP1240 – Photomultiplier

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ X - Electro-optical devices ⟶}

XQ

• XQ1023 – Camera tube
• XQ1029R – Camera tube
• XQ1032 – 1" Vidicon; magnetic focusing and deflection
• XQ1053 – Camera tube
• XQ1072 – 1" Plumbicon
• XQ1073 – XQ1072 with higher resolution and improved low level contrast
• XQ1200 – Vidicon, silicon target
• XQ1270 – ⅔" Vidicon; Overall length 108mm (4¼")
• XQ1272 – Camera tube
• XQ1274 – ⅔" Newvicon, magnetic focussing and deflection, zinc telluride, zinc selenide target
• XQ1275 – Vidicon, silicon target
• XQ1276 – XQ1274 with high sensitivity into the near infrared
• XQ1277 – XQ1275 with high sensitivity into the near infrared
• XQ1278 – XQ1275 with better geometry and uniform signal
• XQ1285 – 1" Vidicon; magnetic focusing and deflection, precision electron gun
• XQ1290 – Camera tube
• XQ1293 – Camera tube
• XQ1300 – Saticon Camera Tube
• XQ1340 – Low-light Vidicon
• XQ1371 – Resistron camera tube
• XQ1380 – XQ1274 with radiation resistant (anti-browning) faceplate
• XQ1381 – ⅔" Newvicon; electrostatioc focusing and magnetic deflection with radiation-resistant (anti-browning) faceplate
• XQ1395 – High-resolution Resistron camera tube
• XQ1410B/G/R – Plumbicon with color filter for color TV broadcast
• XQ1412 – 6/5" Plumbicon; low lag, unity gamma matched to P20 phosphor
• XQ1413B/G/R – Plumbicon with color filter for color TV broadcast
• XQ1415B/G/R – Plumbicon with color filter for color TV broadcast
• XQ1427 – ⅔" Plumbicon; low lag
• XQ1427B/G/R – Plumbicon with color filter for color TV broadcast
• XQ1430B/G/R – Plumbicon with color filter for color TV broadcast
• XQ1435B/G/R – Plumbicon with color filter for color TV broadcast
• XQ1440 – 1" Newvicon, separate mesh, zinc telluride, zinc selenide target
• XQ1500B/G/R – Plumbicon with color filter for color TV broadcast
• XQ1505B/G/R – Plumbicon with color filter for color TV broadcast
• XQ1560 – 1" Saticon
• XQ1565 – 1" Saticon
• XQ1570 – 1" Saticon
• XQ1575 – 1" Saticon
• XQ1585 – 1" Saticon
• XQ1600 – ½" Vidicon; separate mesh, electrostatic focusing and magnetic deflection
• XQ1601 – ½" Newvicon; separate mesh, electrostatic focusing and magnetic deflection
• XQ2070/02B/G/R – Plumbicon with color filter for color TV broadcast
• XQ2070/05B/G/R – Plumbicon with color filter for color TV broadcast
• XQ2075/02B/G/R – Plumbicon with color filter for color TV broadcast
• XQ2075/05B/G/R – Plumbicon with color filter for color TV broadcast
• XQ2172 – 1" Plumbicon; wide dynamic range matched to digital radiography applications
• XQ2182 – 1" Plumbicon; wide dynamic range matched to digital radiography applications
• XQ2427B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3070/02B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3070/05B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3075/02B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3075/05B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3427B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3430B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3435B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3440B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3445B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3457B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3467B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3477B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3487B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3550B/G/R – Plumbicon with color filter for color TV broadcast
• XQ3555B/G/R – Plumbicon with color filter for color TV broadcast
• XQ4187B/G/R – Plumbicon with color filter for color TV broadcast
• XQ4502 – 2" Plumbicon; Highest resolution, low lag
• XQ5002 – 2" Plumbicon; Electrostsatic deflection for improved corner resolution, low output capacitance
• XQ7002 – 1" Plumbicon; Low output capacitance
• XQ8002 – 1" Plumbicon
• XQ9002 – 1" Plumbicon

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ X - Electro-optical devices ⟶}

XR

• XR1000 – Monoscope, test pattern specified by suffix

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ X - Electro-optical devices ⟶}

XX

• XX1000 – 2-stage image intensifier
• XX1010 – Image intensifier
• XX1020 – Image intensifier
• XX1030 – Image intensifier
• XX1050 – Image intensifier
• XX1060 – Image intensifier
• XX1066 – 1. Gen. 3-stage image intensifier
• XX1140 – 1. Gen. 3-stage image intensifier
• XX1190 – 1. Gen. inverter, 1-stage image intensifier
• XX1192 – 1. Gen. inverter, 1-stage image intensifier
• XX1200 – 1. Gen. inverter, 1-stage image intensifier
• XX1211 – 1. Gen. inverter, 3-stage image intensifier
• XX1270 – 1. Gen. inverter, 2-stage image intensifier
• XX1400 – 2. Gen. inverter, 1-stage image intensifier
• XX1430 – 1. Gen. inverter, 1-stage image intensifier
• XX1510 – 1. Gen. 3-stage image intensifier
• XX1610 – 2. Gen. image intensifier
• XX1800 – 2. Gen. proximity focused, 1-stage image intensifier

_{LoVT ⟶ List of Pro Electron professional tubes ⟶}

Y - Vacuum tubes

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Y - Vacuum tubes ⟶}

YA

• YA1000 – 5 kV, 5 mA Directly heated, thermally-limited (=saturated) emission diode, 4.3 V/325 mA_max uncoated tungsten filament, Noval base, for use as an RMS heating current-to-DC anode current converter in AC voltage/current stabilizer circuits;^[238] cf. 5845, Tesla RA0007

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Y - Vacuum tubes ⟶}

YD

• YD1000 – 120 kW, Water-cooled RF power triode
• YD1001 – 120 kW, Air-cooled RF power triode
• YD1012 – 360 kW, Vapor-cooled RF power triode
• YD1130 – 580 W, Air-cooled, linear RF/AF power triode
• YD1252 (RS 2051 V) – 420 kW, Water-cooled, modulator power triode
• YD1300 – 35 W, Air-cooled, UHF power triode
• YD1301 – 50 W, Air-cooled, UHF power triode
• YD1302 – 55 W, Air-cooled, UHF power triode
• YD1332 – 250 W, Air-cooled, UHF power triode
• YD1333 – 100 W, Air-cooled, UHF power triode
• YD1334 – 110 W, Air-cooled, UHF power triode
• YD1335 – 550 W, Air-cooled, UHF power triode
• YD1336 – 220 W, Air-cooled, UHF power triode
• YD1342 – 30 MHz, 530 kW, Water-cooled RF power triode
• YD1352S = 8867 = Amperex DX334 – 5 MHz, 3 kW, Water-cooled Neotron, a gridless field-effect tube where a magnetically-focused electron beam is modulated by varying the voltage of a gate electrode surrounding it. Used as RF power amplifier or oscillator

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Y - Vacuum tubes ⟶}

YG

• YG1000 – Directly heated electrometer tetrode with an oxide cathode and a space charge grid, grid current ≤600 fA, Magnoval base with input grid on top cap

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Y - Vacuum tubes ⟶}

YH

• YH1000 – 1.7 to 2.3 GHz, 16 W Traveling-wave tube for use in L-band point-to-point radio links
• YH1050 – 4.4 to 5.0 GHz, 2 W Traveling-wave tube for use in C-band point-to-point radio links
• YH1110 – 5.8 to 8.5 GHz, 15 W Traveling-wave tube for use in C-band point-to-point radio links
• YH1120 – 5.8 to 8.5 GHz, 10 W Traveling-wave tube for use in C-band point-to-point radio links
• YH1131 – 11.7 to 12.7 GHz, 10 W K_u-band Traveling-wave tube
• YH1150 – 1.7 to 2.3 GHz, 1 kW Traveling-wave tube for use in L-band satellite ground stations/radar/troposcatter
• YH1160 – 3.6 to 4.2 GHz, 14 W Traveling-wave tube for use in S-band point-to-point radio links
• YH1181 – 4.4 to 5.0 GHz, 1 kW Traveling-wave tube for use in C-band satellite ground stations/radar/troposcatter
• YH1190 – 11.7 to 12.7 GHz, 70 W Traveling-wave tube for use in K_u-band satellite ground stations/radar/troposcatter
• YH1200 – 5.8 to 7.5 GHz, 12 W C-band Traveling-wave tube
• YH1210 – 220 W Traveling-wave tube for use in UHF TV transposers between 470 and 860 MHz

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Y - Vacuum tubes ⟶}

YJ

• YJ1000 – Indirectly heated, 2.5 kW magnetron for use as a pulsed X-band oscillator between 9.19 and 9.32 GHz
• YJ1420 – 900 W magnetron for use in domestic microwave ovens between 2.43 and 2.47 GHz
• YJ1462 – Indirectly heated, 28 kW coaxial magnetron for use as a pulsed X-band oscillator at 9.375 GHz

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Y - Vacuum tubes ⟶}

YK

• YK1000 – Water-cooled, 11 kW UHF permanent magnet-focused linear-beam, 4-cavity Klystron for use in TV transmitters between 400 and 620 MHz
• YK1004 – Water-cooled, 11 kW UHF permanent magnet-focused linear-beam, 4-cavity Klystron for use in TV transmitters between 610 and 790 MHz
• YK1005 – Water-cooled, 11 kW UHF permanent magnet-focused linear-beam, 4-cavity Klystron for use in TV transmitters between 470 and 860 MHz
• YK1010 – 67 to 74 GHz, 130 mW V-band Reflex Klystron
• YK1046 – 9.16 to 9.34 GHz, 35 mW X-band Reflex Klystron
• YK107x – 5.9 to 8.1 GHz, 1.2 W C-band Reflex Klystrons, contact-cooled versions of the YK114x
• YK1090 (flying leads), YK1091 (B3A 3-pin base) – 10.5 to 12.2 GHz, 400 mW X-band Reflex Klystrons
• YK1110 – Water-cooled 6 MW_peak, 2998±5 MHz, electromagnet-focused linear-beam, 3-cavity pulsed Klystron for use in linear particle accelerators
• YK114x (KS6/1000x, KS7/1000x) – 5.9 to 8.1 GHz, 1.2 W C-band Reflex Klystrons, forced-air cooled versions of the YK107x
• YK1151 – Forced-air cooled, 25 kW UHF permanent magnet-focused linear-beam, 4-cavity Klystron for use in TV transmitters between 470 and 860 MHz
• YK1190 – Water-cooled 40 kW UHF electromagnet-focused linear-beam, 4-cavity Klystron for use in TV transmitters between 470 and 610 MHz
• YK1191 – Water-cooled 40 kW UHF electromagnet-focused linear-beam, 4-cavity Klystron for use in TV transmitters between 590 and 720 MHz
• YK1192 – Water-cooled 40 kW UHF electromagnet-focused linear-beam, 4-cavity Klystron for use in TV transmitters between 710 and 860 MHz
• YK1200 – Water-cooled 25 MW_peak, 2998±5 MHz, electromagnet-focused linear-beam, 5-cavity pulsed Klystron for use in linear particle accelerators
• YK1220 – Water-cooled 15 kW UHF electromagnet-focused linear-beam, 4-cavity Klystron for use in TV transmitters between 470 and 860 MHz
• YK1223 – YK1220 with a modulating anode
• YK1230 – Water-cooled 25 kW UHF electromagnet-focused linear-beam, 4-cavity Klystron for use in TV transmitters between 470 and 860 MHz
• YK1233 – YK1230 with a modulating anode

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Y - Vacuum tubes ⟶}

YL

• YL1000 = 8463 – 50 MHz, 12 W RF power pentode, B9A Noval base, 1.1 V/880 mA quickstart heater
• YL1020 = 8118 = QQZ03/20
• YL1030 = QQZ06/40
• YL1050 – 1215 MHz, 1.6 kW Forced-air cooled, coaxial, metal-ceramic UHF power tetrode, 3.8 V/20.5 A heater
• YL1060 = 7854 = QQE06/40
• YL1070 = 8117 (Center-tapped 12.6/6.3 V heater), YL1071 = 8116 (center-tapped 26.5/13.25 V heater) – 60 MHz, 100 W Dual linear RF power tetrode, B7A Septar base
• YL1080 = 8348 – 200 MHz, 5 W Dual VHF power tetrode, Noval base, internally neutralized, 1.6 V/2.5 A quickstart heater
• YL1120 = 8429 – 60 MHz, 4 kW Forced-air cooled, coaxial, metal-ceramic, linear RF power tetrode, 16 V/16.5 A heater
• YL1130 = 8408 – 200 MHz, 4 W Dual VHF power pentode, Noval base, internally neutralized, 1.1 V/2.9 A quickstart heater
• YL1150 = 8579 – 60 MHz, 75 W Linear RF beam power tetrode, Septar base, center-tapped 12.6/6.3 V heater
• YL1190 = 8580 – 500 MHz, 8 W Dual UHF power tetrode, B9D Magnoval base, internally neutralized, 1.1 V/4.2 A quickstart heater
• YL1200 = PE1/100
• YL1210 = 8457 – QQE03/12 with a center-tapped 12.6/6.3 V heater
• YL1220 = 8577 – QQE02/5 with a center-tapped 13.5/6.75 V heater
• YL1240 = 8458 – 200 MHz, 10 W Dual VHF power tetrode, B9E Novar base, internally neutralized, center-tapped 13.5/6.75 V heater
• YL1250 = 8505 – 250 MHz, 30 W VHF beam power tetrode, Magnoval base, center-tapped 13.5/6.75 V heater
• YL1270 = 8581 – 500 MHz, 18 W Dual UHF power tetrode, B8G Loctal base, internally neutralized, 1.1 V/4 A quickstart heater
• YL1290 – QE08/200 with a 19 V/1.4 A heater
• YL1310 = 8603 – 75 MHz, 30 W RF beam power tetrode, Magnoval base, 1.2 V/4.2 A quickstart heater
• YL1360 – QQE04/5 with a 13.5 V/280 mA heater
• YL1370 = 6146B (6.3 V/1.125 A heater), YL1371 (12.6 V/562 mA heater), YL1372 (26.5 V/300 mA heater) – 60 MHz, 35 W RF beam power tetrode, K8A Octal base
• YL1570 (RS1084CJ) – 250 MHz, 60 kW Water-cooled, coaxial, metal-ceramic, linear VHF power tetrode, 12.5 V/200 A heater

_{LoVT ⟶ List of Pro Electron professional tubes ⟶}

Z - Gas-filled tubes

Note: See also standard M-P tubes under Z

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Z - Gas-filled tubes ⟶}

ZA

• ZA1000 – Neon-filled, coaxial, tritium-primed (half-life: 12.32 years), sputtered-molybdenum cold-cathode switching diode, meshed cylinder anode, all-glass pigtailed^[239]
• ZA1001 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode with traces of heavy gas (krypton/xenon) for slow de-ionization, e.g. for low-frequency relaxation oscillators; meshed cylinder anode, all-glass pigtailed
• ZA1002 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode, large difference between burning and ignition voltage, meshed cylinder anode, 3-pin all-glass pigtailed
• ZA1003 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode for use as indicator tube in transistorized circuits, meshed cylinder anode, 3-pin all-glass pigtailed
• ZA1004 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode, small difference between burning and ignition voltage, for use as indicator tube in transistorized circuits or as 86.4 V Voltage reference, meshed cylinder anode, 3-pin all-glass pigtailed
• ZA1005 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode for use like a DIAC in thyristor circuits, meshed cylinder anode, 2-pin all-glass pigtailed

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Z - Gas-filled tubes ⟶}

ZC

• ZC1010 (Z661W) – 8 mA_avg, 50 mA_peak, Gas-filled, cold-cathode AC trigger pentode, two starters and a primer electrode, positive starter voltage, 5-pin all-glass pigtailed, envelope inside radioactively coated for a constant ignition voltage, for use in bidirectional counters
• ZC1040 – 25 mA, Gas-filled, cold-cathode AC trigger tetrode, one starter and a primer electrode, positive starter voltage, Noval base
• ZC1050 – 2 mA, Gas-filled, cold-cathode, luminiscent trigger tetrode, one starter and a primer, 300 mlm light output^[240] for use as self-displaying shift register cells in large-format, crawling-text dot-matrix displays;^[241] all-glass pigtailed
• ZC1060 – 20 mA_avg, 5 kA_peak, Gas-filled, cold-cathode, high-current trigger triode for e.g. capacitor discharge circuits. One external (capacitive) starter electrode

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Z - Gas-filled tubes ⟶}

ZM

• ZM1000 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 14 mm character height side-viewing, left decimal point
• ZM1000R – ZM1000 with a red contrast filter coating
• ZM1001 –  + - ~ X Y Z  Neon-filled digital indicator tube, 14mmCH side-viewing, for use with ZM1000
• ZM1001R – ZM1001 with a red contrast filter coating, for use with ZM1000R
• ZM1002 –  ns μs ms s Hz kHz MHz  Neon-filled digital indicator tube, 13mmCH side viewing, for use with ZM1000 in digital frequency counters
• ZM1003 –  1 - +  Neon-filled digital indicator tube, 14mmCH side-viewing, for use with ZM1000
• ZM1005 –  0 1 2 3 4 5 6 7 8 9  Long-life neon-filled digital indicator tube, 14mmCH side-viewing, left decimal point, multiplex-capable
• ZM1005R – ZM1005 with a red contrast filter coating
• ZM1006 –  1 2 3 4 5 6  Neon-filled digital indicator tube, side-viewing, left and right decimal point, for use in TV receivers
• ZM1008 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 14mmCH side-viewing
• ZM1010 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 14mmCH side-viewing, left decimal point
• ZM1012 –  0 1 2 3 4 5 6 7 8  Neon-filled digital indicator tube, 14mmCH side-viewing
• ZM1015 –  0 1 2 3 4 5 6 7 8  Neon-filled digital indicator tube, 14mmCH side-viewing
• ZM1020 = Z520M – ZM1022 with a red contrast filter coating
• ZM1021 = Z521M – ZM1023 with a red contrast filter coating, for use with ZM1020
• ZM1022 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 15.5mmCH top-viewing, no decimal point
• ZM1023 –  A V Ω % + - ~  Neon-filled digital indicator tube, 15.5mmCH top-viewing, for use with ZM1022 in digital multimeters
• ZM1024 – ZM1025 with a red contrast filter coating, for use with ZM1020
• ZM1025 –  c/s Kc/s Mc/s μs ms ns s  Neon-filled digital indicator tube, 15.5mmCH top-viewing, for use with ZM1022 in digital frequency counters
• ZM1030 – ZM1032 with a red contrast filter coating
• ZM1031 – ZM1031/01 without the  ~ 
• ZM1031/01 – ZM1033/01 with a red contrast filter coating, for use with ZM1030
• ZM1032 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 15.5mmCH side-viewing, no decimal point, 5 dual cathodes and separate odd/even anode compartments for biquinary multiplexing
• ZM1033/01 –  + - ~  Neon-filled digital indicator tube, 15.5mmCH side-viewing, separate anode compartment for  + , for use with ZM1032
• ZM1040 = Z522M – ZM1042 with a red contrast filter coating
• ZM1041 – ZM1043 with a red contrast filter coating, for use with ZM1040
• ZM1041S – ZM1043S with a red contrast filter coating, for use with ZM1040
• ZM1042 = Z5220M –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 30mmCH side-viewing, no decimal point
• ZM1043 –  + -  Neon-filled digital indicator tube, 30mmCH side-viewing, for use with ZM1042
• ZM1043S –  Y X + W U Z -  Neon-filled digital indicator tube, 30mmCH side-viewing, for use with ZM1042
• ZM1047 – ZM1049 with a red contrast filter coating, for use with ZM1040
• ZM1049 –  T F S N Z Y G H M X  Neon-filled digital indicator tube, side-viewing, for use with ZM1042 in numerical control systems
• ZM1050
  

  ZM1070
  = Z550M = 8453 – Neon-filled digital indicator tube, top-viewing, dekatron-type readout with common anode and common cathodes, pulsating anode voltage, controlled by 5-volts sensitive starter electrodes, for transistorized circuits
• ZM1060 = Z505S – Argon-filled, 50 kHz decade Counter/Selector Dekatron
• ZM1070 = Z504S = 8433 – Neon-filled, 5 kHz decade Counter/Selector Dekatron
• ZM1080 – ZM1082 with a red contrast filter coating
• ZM1081 – ZM1083 with a red contrast filter coating, for use with ZM1080
• ZM1082 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 14mmCH side-viewing, no decimal point, probe electrode
• ZM1083 –  + - ~  Neon-filled digital indicator tube, 14mmCH side-viewing, for use with ZM1082
• ZM1100 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 15.5mmCH top-viewing
• ZM1120 – ZM1122 with a red contrast filter coating
• ZM1122 –  0 1 2 3 4 5 6 7 8 9  Miniature neon-filled digital indicator tube, 7.8mmCH top-viewing
• ZM1130 – ZM1132 with a red contrast filter coating
• ZM1131 – ZM1133 with a red contrast filter coating, for use with ZM1080
• ZM1132 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, side-viewing, left and right decimal point
• ZM1133 –  + - ~  Neon-filled digital indicator tube, side-viewing, for use with ZM1132
• ZM1136L/R – ZM1138L/R with a red contrast filter coating
• ZM1137 – ZM1139 with a red contrast filter coating, for use with ZM1136L/R
• ZM1138L/R –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 13mmCH side-viewing, left or right decimal points (specify)
• ZM1139 –  + - ~ Ω  Neon-filled digital indicator tube, 13mmCH side-viewing, for use with ZM1138 in digital multimeters
• ZM1162 –  0 1 2 3 4 5 6 7 8 9  Long-life neon-filled digital indicator tube, 15.5mmCH top-viewing, no decimal point, rectangular envelope for close stacking in both axes
• ZM1170 – ZM1172 with a red contrast filter coating
• ZM1172 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 15.5mmCH side-viewing, no decimal point
• ZM1174 – ZM1175 with a red contrast filter coating
• ZM1175 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 15.5mmCH side-viewing, left decimal point
• ZM1176 – ZM1177 with a red contrast filter coating
• ZM1177 – ZM1175, but right decimal point
• ZM1180 – ZM1182 with a red contrast filter coating
• ZM1181 – ZM1183 with a red contrast filter coating, for use with ZM1180
• ZM1182 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 16mmCH top-viewing, no decimal point, semi-rectangular envelope for close horizontal stacking
• ZM1183 –  + - ~ Ω  Neon-filled digital indicator tube, top-viewing, 13mmCH for use with ZM1182 in digital multimeters
• ZM1184D – ZM1185D with a red contrast filter coating
• ZM1185A (GR1420) –  1 2 3 4 5 6 U K E R  Neon-filled digital indicator tube, 16mmCH top-viewing
• ZM1185D (GR1430) –  ∇ Δ  Neon-filled digital indicator tube, 16mmCH top-viewing, for use in elevators
• ZM1185E (GR1472) –  0 1 2 3 4 5 - t kg +  Neon-filled digital indicator tube, 16mmCH top-viewing
• ZM1200 – Pandicon, multiplexed 14-digit display tube with decimal points and punctuation marks, pin connections on both ends
• ZM1202 – 12-Digit Pandicon
• ZM1204 – 10-Digit Pandicon
• ZM1206 – 8-Digit Pandicon
• ZM1210
  

  ZM1212
  – ZM1212 with a red contrast filter coating
• ZM1212 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 15.5mmCH side-viewing, left decimal point, all-glass pigtailed
• ZM1220 – ZM1222 with a red contrast filter coating
• ZM1222 –  0 1 2 3 4 5 6 7 8 9  Large neon-filled digital indicator tube, 40mmCH side-viewing
• ZM1230 – ZM1232 with a red contrast filter coating
• ZM1232 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 15.5mmCH upside-down side-viewing, no decimal point
• ZM1240 – ZM1242 with a red contrast filter coating
• ZM1241 – ZM1243 with a red contrast filter coating, for use with ZM1240
• ZM1242 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 16mmCH side-viewing, right decimal point
• ZM1243 –  + - ~ Ω  Neon-filled digital indicator tube, 16mmCH side-viewing, for use with ZM1242 in digital multimeters
• ZM1250 – Planar, neon-filled, one-character alphanumeric 5x7 dot-matrix display with a left decimal point, 9.8mmCH, all 36 cathodes directly accessible
• ZM1263 –  ~ ⚫  Neon-filled digital indicator tube, 10mmCH side-viewing
• ZM1290 – ZM1292 with a red contrast filter coating
• ZM1292 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 10mmCH side-viewing
• ZM1330 – ZM1332 with a red contrast filter coating
• ZM1331 – ZM1333 with a red contrast filter coating, for use with ZM1330
• ZM1332 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 13.1mmCH side-viewing, left and right decimal points, all-glass pigtailed
• ZM1333 –  + - ~ Ω  Neon-filled digital indicator tube, 13.1mmCH side-viewing, all-glass pigtailed, for use with ZM1332 in digital multimeters
• ZM1334 – ZM1336 with a red contrast filter coating
• ZM1335 – ZM1337 with a red contrast filter coating, for use with ZM1334
• ZM1336 –  0 1 2 3 4 5 6 7 8 9  Neon-filled digital indicator tube, 13.1mmCH side-viewing, left and right decimal points, multiplex-capable
• ZM1337 –  + - ~ Ω  Neon-filled digital indicator tube, 13.0mmCH side-viewing, right decimal point (!), all-glass pigtailed, red contrast filter coating, for use with ZM1336 in digital multimeters
• ZM1350 – Varisymbol, planar neon-filled digital 40mm x 27mm fourteen-segment display tube, right decimal point, separate underscore text cursor, keep-alive cathode, multiplex-capable, viewing angle 160°
• ZM1360 – ZM1350 with 60mm x 40mm characters
• ZM1370 – ZM1350 with 20mm x 13mm characters
• ZM1410 – ZM1412 with a red contrast filter coating
• ZM1412 – Neon-filled digital seven-segment display tube, 8.6mmCH side-viewing, right decimal point and left punctuation mark, all-glass pigtailed
• ZM1500 – Pandicon, multiplexed 12-digit, 7-segment display tube
• ZM1550 – Planar neon-filled digital two-digit seven-segment display tube, right decimal points
• ZM1551 – Planar neon-filled digital 1½-digit seven-segment display tube with  +  and  -  signs, right decimal points

Note: More Nixie tubes under standard - ZM and ETL examples

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Z - Gas-filled tubes ⟶}

ZP

• ZP1000 – Borium tri-fluoride-filled Geiger-Müller tube, thermal neutrons
• ZP1010 – Borium tri-fluoride-filled Geiger-Müller tube, thermal neutrons
• ZP1020 – Borium tri-fluoride-filled Geiger-Müller tube, thermal neutrons
• ZP1070 – Subminiature Geiger-Müller tube, all-glass pigtailed
• ZP1080 – Halogen-quenched Geiger-Müller tube, β and γ
• ZP1100 – Halogen-quenched Geiger-Müller tube, γ; pigtailed
• ZP1200 – Halogen-quenched Geiger-Müller tube, γ
• ZP1300 – Halogen-quenched Geiger-Müller tube, γ and high-energy β
• ZP1330 – Halogen-quenched Geiger-Müller tube, for use in damp and/or saline atmosphere, β and γ
• ZP1400 – Halogen-quenched Geiger-Müller tube, 9mm diameter mica window, β and γ
• ZP1430 – Halogen-quenched Geiger-Müller tube, 27.8mm diameter mica window, α, β, γ
• ZP1490 – Halogen-quenched Geiger-Müller tube, 28mm diameter mica window, low-level α, β and γ
• ZP1600 – Halogen-quenched Geiger-Müller tube, 19.8 mm diameter mica window, X-rays, 6.0 to 20 keV energy, 60 to 200 pm wavelength range
• ZP1610 – Side window, organically quenched Geiger-Müller tube. 7 x 18 mm mica window; X-rays, 2.5 to 40 keV energy, 30 to 500 pm wavelength range
• ZP1700 – Halogen-quenched, cosmic-ray guard counter tube for low-background measurements; to be used with another radiation counter tube in an anticoincidence circuit
• ZP1800 – Halogen-quenched Geiger-Müller tube for use at temperatures up to 200 °C, γ
• ZP1810 – Halogen-quenched Geiger-Müller tube for use at temperatures up to 200 °C, γ, low sensitivity, up to 40 mGy/h
• ZP1860 – Halogen-quenched Geiger-Müller tube, β and γ

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Z - Gas-filled tubes ⟶}

ZT

• ZT1000 = 8270 – 21 kV, 10 A Mercury-vapor triode thyratron
• ZT1011 = XR1/1600A = 8063 – 1 kV, 1.6 kW Inert gas-filled triode thyratron with anode top cap

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Z - Gas-filled tubes ⟶}

ZX

• ZX1000 – 800 V, 1140 A_pk, 13A_avg Ignitron
• ZX1051 – Water-cooled, 56 A_avg Ignitron
• ZX1052 – Water-cooled, 140 A_avg Ignitron
• ZX1053 – Water-cooled, 355 A_avg Ignitron
• ZX1060 – Water-cooled, 10 A_avg Ignitron
• ZX1061 – Water-cooled, 10 A_avg Ignitron
• ZX1062 – Water-cooled, 10 A_avg Ignitron
• ZX1063 – Water-cooled, 10 A_avg Ignitron

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Z - Gas-filled tubes ⟶}

ZY

• ZY1000 (872B) – High voltage, half-wave mercury-vapor rectifier
• ZY1001 = 8008A – High voltage, half-wave mercury-vapor rectifier, 4-pin base with anode top cap
• ZY1002 – High voltage, half-wave mercury-vapor rectifier, E40 Goliath Edison screw lamp base with anode top cap

_{LoVT ⟶ List of Pro Electron professional tubes ⟶ Z - Gas-filled tubes ⟶}

ZZ

• ZZ1000 = 8228 – 81 V Voltage reference, 2-pin all-glass pigtailed
• ZZ1010 – 85 V Voltage reference
• ZZ1020 (STV85-8) – 82 V Voltage reference with primer electrode, 3-pin all-glass pigtailed
• ZZ1030 (STV500-0,1) – Quad 125 V Voltage references, Noval base, used all series-connected to stabilize the dynode voltages of photomultipliers
• ZZ1031 – Quad Voltage reference, Noval base
• ZZ1040 (STV100-60Z) – 100 V Voltage reference with primer electrode
• ZZ1050 – 82 V Voltage reference, 2-pin all-glass pigtailed

List of European transmitting tubes

Note: Typecode explained above.

_{LoVT ⟶ List of European transmitting tubes ⟶}

B - Backward-wave amplifier

_{LoVT ⟶ List of European transmitting tubes ⟶ B - Backward-wave amplifier ⟶}

BA

• BA9/20 = 7635 – X-band, 20 mW, Forced-air cooled backward-wave oscillator
• BA16/10 = 7636 – K_u-band, 10 mW, Backward-wave oscillator

_{LoVT ⟶ List of European transmitting tubes ⟶}

D - Rectifier incl. grid-controlled

_{LoVT ⟶ List of European transmitting tubes ⟶ D - Rectifier incl. grid-controlled ⟶}

DA

• DA1.5/75 – 1.5 kV, 75 W Half-wave rectifier, triode TA1.5/75 without grid
• DA12/24000 – 12 kV, 24 kW Water-cooled half-wave rectifier

_{LoVT ⟶ List of European transmitting tubes ⟶ D - Rectifier incl. grid-controlled ⟶}

DC

• DC1/50 – 1 kV, 50 mA Full-wave rectifier, DC1/60 with dual anode top cap
• DC1/60 – 1 kV, 60 mA Full-wave rectifier
• DC2/200 – 2 kV, 200 mA Full-wave rectifier with dual anode top cap

_{LoVT ⟶ List of European transmitting tubes ⟶ D - Rectifier incl. grid-controlled ⟶}

DCG

• DCG1/125 – 1 kV, 125 mA Half-wave mercury-vapor rectifier with Edison screw lamp base and anode top cap
• DCG4/1000G (866A) – Mercury-vapor rectifier
• DCG5/5000GB (872A) – Mercury-vapor rectifier
• DCG5/5000GS (8008A, ZY1001) – Mercury-vapor rectifier
• DCG6/18 (6693) – Mercury-vapor rectifier
• DCG9/20 (6508) – Mercury-vapor rectifier
• DCG12/30 (5870) – 12 kV, 30 A Grid-controlled, half-wave mercury-vapor rectifier with anode top cap

_{LoVT ⟶ List of European transmitting tubes ⟶ D - Rectifier incl. grid-controlled ⟶}

DCX

• DCX4/1000 (3B28) – 4 kV, 1 kW Half-wave xenon rectifier with anode top cap
• DCX4/5000 (4B32) – 4 kV, 5 kW Half-wave xenon rectifier with anode top cap

_{LoVT ⟶ List of European transmitting tubes ⟶ D - Rectifier incl. grid-controlled ⟶}

DE

• DE2/200 – 2 kV, 200 W Full-wave rectifier with dual anode top cap

_{LoVT ⟶ List of European transmitting tubes ⟶}

J - Magnetron

_{LoVT ⟶ List of European transmitting tubes ⟶ J - Magnetron ⟶}

JNT

• JNT1/500 – 1.22 to 1.35 GHz, 600 kW Forced-air cooled, external-magnet, mechanically tunable, pulsed L-band magnetron

_{LoVT ⟶ List of European transmitting tubes ⟶ J - Magnetron ⟶}

JP

• JP8/02B – 8.8 GHz, 25 W Forced-air cooled, pulsed magnetron used in airborne X-band Doppler radar systems
• JP9/15 – 9.345 to 9.405 GHz, 15 kW Forced-air cooled magnetron for pulsed service

_{LoVT ⟶ List of European transmitting tubes ⟶ J - Magnetron ⟶}

JPG

• JPG9/01 – 9.15 to 9.60 GHz, 5 W Forced-air cooled, mechanically tunable magnetron

_{LoVT ⟶ List of European transmitting tubes ⟶ J - Magnetron ⟶}

JPT

• JPT9/01 – JPG9/01 with a different mechanical tuning arrangement

_{LoVT ⟶ List of European transmitting tubes ⟶}

K - Klystron

_{LoVT ⟶ List of European transmitting tubes ⟶ K - Klystron ⟶}

KB

• KB9/150W – X-band, 150 W Water-cooled, 2-cavity Klystron

_{LoVT ⟶ List of European transmitting tubes ⟶ K - Klystron ⟶}

KS

• KS6/1000x, KS7/1000x (YK114x) – 5.9 to 8.1 GHz, 1.2 W Reflex Klystrons
• KS7/85 – 6.5 to 7.5 GHz, 85 mW Reflex Klystron
• KS9/20 = 723A/B (2K25) – 8.7 to 9.5 GHz, 20 mW Reflex Klystron
• KS9/30 (6975) – 8.5 to 9.6 GHz, 30 mW Reflex Klystron
• KS9/40 – 9.3 to 9.5 GHz, 40 mW Reflex Klystron

_{LoVT ⟶ List of European transmitting tubes ⟶}

L - Traveling-wave tube

_{LoVT ⟶ List of European transmitting tubes ⟶ L - Traveling-wave tube ⟶}

LA

• LA4/250 = 7637 – 3.6 to 4.2 GHz, 200 mW Forward-wave amplifier
• LA9/3 = 7638 – 7 to 11.5 GHz, 6 mW Forward-wave amplifier
• LA16/2 = 7639 – 11.5 to 18 GHz, 3 mW Forward-wave amplifier

_{LoVT ⟶ List of European transmitting tubes ⟶ L - Traveling-wave tube ⟶}

LB

• LB4/8 – 3.8 to 4.2 GHz, 8 W Forward-wave amplifier
• LB6/12 – 6 GHz, 12 W Forward-wave amplifier
• LB6/25 – 5.9 to 6.5 GHz, 25 W Forward-wave amplifier

_{LoVT ⟶ List of European transmitting tubes ⟶}

M - AF modulator Triode

_{LoVT ⟶ List of European transmitting tubes ⟶ M - AF modulator Triode ⟶}

MA

• MA4/600 – 4 kV, 600 W Radiation-cooled triode

_{LoVT ⟶ List of European transmitting tubes ⟶ M - AF modulator Triode ⟶}

MB

• MB1/50 – 1 kV, 50 W Radiation-cooled triode
• MB2/200 – 2 kV, 200 W Radiation-cooled triode

_{LoVT ⟶ List of European transmitting tubes ⟶ M - AF modulator Triode ⟶}

MC

• MC1/50 – 1 kV, 50 W Radiation-cooled triode
• MC1/60 – 1 kV, 60 W Radiation-cooled triode
• MC2/200 – 2 kV, 200 W Radiation-cooled triode

_{LoVT ⟶ List of European transmitting tubes ⟶ M - AF modulator Triode ⟶}

MY

• MY3/275 – 3 kV, 275 W Radiation-cooled triode

_{LoVT ⟶ List of European transmitting tubes ⟶ M - AF modulator Triode ⟶}

MZ

• MZ2/200 – 2 kV, 200 W Radiation-cooled triode

_{LoVT ⟶ List of European transmitting tubes ⟶}

P - Pentode

_{LoVT ⟶ List of European transmitting tubes ⟶ P - Pentode ⟶}

PA

• PA12/15 – 15 kW Water-cooled shortwave pentode
• PA12/20 – 20 kW Water-cooled pentode made by Philips and used in the 1930s and 1940s

_{LoVT ⟶ List of European transmitting tubes ⟶ P - Pentode ⟶}

PAL

• PAL12/15 – Air-cooled version of PAW12/15

_{LoVT ⟶ List of European transmitting tubes ⟶ P - Pentode ⟶}

PAW

• PAW12/15 – 15 kW Water-cooled shortwave pentode

_{LoVT ⟶ List of European transmitting tubes ⟶ P - Pentode ⟶}

PB

• PB2/200 – 200 W Shortwave pentode
• PB3/1000 – 1 kW Shortwave pentode

_{LoVT ⟶ List of European transmitting tubes ⟶ P - Pentode ⟶}

PC

• PC03/3 – 3 W Shortwave pentode
• PC3/1000 – 1 kW Shortwave pentode

_{LoVT ⟶ List of European transmitting tubes ⟶ P - Pentode ⟶}

PE

• PE04/10 – 10 W Shortwave pentode
• PE1/100 (6083, YL1200) – 100 W Shortwave pentode

_{LoVT ⟶ List of European transmitting tubes ⟶}

Q - Tetrode

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QB

• QB2/75 – 75 W Beam power tetrode
• QB2/250 (813) – Beam power tetrode
• QB3/200 (8165, Eimac 4-65A) – Beam power tetrode, 5-pin Septar base with anode top cap
• QB3/300 (6155, 4D21, Eimac 4-125A) – Beam power tetrode
• QB3.5/750 (6156, 5D22, Eimac 4-250A) – Beam power tetrode
• QB4/1100 (7527) – Beam power tetrode
• QB5/1750 (6179) – Beam power tetrode
• QB5/2000 – 2 kW Beam power tetrode

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QBL

• QBL4/800 (Eimac 4X500A) – Air-cooled 800 W beam power tetrode
• QBL5/3500 (6076) – Air-cooled 3500 W beam power tetrode

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QBW

• QBW5/3500 (6075) – Water-cooled 3500 W beam power tetrode

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QC

• QC05/15 – 15 W Beam power tetrode
• QC05/35 (8042) – 35 W Beam power tetrode

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QE

• QE04/10 – 10 W Beam power tetrode
• QE05/40 (6146) – 40 W Radiation-cooled beam power tetrode, popular amongst radio amateurs as a final RF amplifier
• QE06/50 (807) – 50 W Radiation-cooled beam power tetrode
• QE08/200 (7378) – 200 W Beam power tetrode

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QEL

• QEL1/150 (7034, Eimac 4X150A) – Air-cooled 150 W beam power tetrode
• QEL1/250 – Air-cooled 250 W beam power tetrode

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QEP

• QEP20/18 – 18 W Beam power tetrode for use as a pulse modulator

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QQC

• QQC03/14 (7983) – 14 W Dual beam power tetrode
• QQC04/15 (5895) – Dual beam power tetrode

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QQE

• QQE02/5 (6939) – 5 W Dual beam power tetrode
• QQE03/12 (6360) – 12 W Dual beam power tetrode
• QQE03/20 (6252) – 20 W Dual beam power tetrode
• QQE04/5 (7377) – 5 W Dual beam power tetrode
• QQE04/20 (832A) – Dual beam power tetrode
• QQE06/40 (5894, YL1060) – 40 W dual beam power tetrode, internally neutralized, Septar base with dual anode top cap

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QQV

• QQV02/6 – 6 W Dual beam power tetrode
• QQV03/20A – 20 W Radiation-cooled split-anode tetrode made by Mullard and used in the 1940s, 1950s and 1960s as a VHF frequency-doubling output stage with balanced output
• QQV07/50 – 50 W Dual beam power tetrode

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QQZ

• QQZ03/20 (8118, YL1020) – 20 W Dual beam power tetrode
• QQZ06/40 (YL1030) – 40 W Dual beam power tetrode

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QV

• QV04/7 – 7 W Beam power tetrode
• QV05/25 (807) – 25 W Radiation-cooled beam power tetrode made by Mullard
• QV2/250C – 250 W Beam power tetrode

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QY

• QY3/65 – 65 W Beam power tetrode
• QY5/3000A – 3 kW Beam power tetrode
• QY5/3000W – Water-cooled version of QY5-3000A

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QYS

• QYS50/P40 – Pulsed power tetrode, Silica envelope, 50 kV anode voltage, considerable X-radiation, 810 °C anode temperature at 700 W anode dissipation, 40 A anode current at duty factor 0.0005, U_g1Cut-off (I_A=1 mA@U_A=55 kV): > -3.4 kV, g_m: 38 mS

_{LoVT ⟶ List of European transmitting tubes ⟶ Q - Tetrode ⟶}

QZ

• QZ06/20 – 25 W VHF power tetrode up to 175 MHz

_{LoVT ⟶ List of European transmitting tubes ⟶}

R - Rectifier

_{LoVT ⟶ List of European transmitting tubes ⟶ R - Rectifier ⟶}

RG

• RG1000/3000 – 1 kV, 3 A Half-wave mercury-vapor rectifier with anode top cap
• RG4/1250 = EnglishElectricValve AH221 = M-O GU21 – Half-wave mercury-vapor rectifier, E40 Goliath Edison screw lamp base

_{LoVT ⟶ List of European transmitting tubes ⟶ R - Rectifier ⟶}

RGQ

• RGQ7.5/0.6 – 7.5 kV, 600 mA Half-wave mercury-vapor rectifier with anode top cap
• RGQ20/5 – 20 kV, 5 A Half-wave mercury-vapor rectifier with anode top cap

_{LoVT ⟶ List of European transmitting tubes ⟶ R - Rectifier ⟶}

RR

• RR3/1250 – 3.1 kV, 1.25 A Half-wave inert-gas filled rectifier with anode top cap

_{LoVT ⟶ List of European transmitting tubes ⟶ R - Rectifier ⟶}

RY

• RY12/100 – 12.5 kV, 100 mA Half-wave vacuum rectifier with anode top cap

_{LoVT ⟶ List of European transmitting tubes ⟶}

T - AF/RF/oscillator Triode

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TA

• TA04/5 – 400 V, 50 W Radiation-cooled power triode
• TA1.5/75 – 1.5 kV, 75 W Radiation-cooled power triode
• TA4/2000K – 4 kV, 2 kW Air-cooled power triode made by Philips in the 1930s
• TA18/100000 – 18 kV, 100 kW Water-cooled power triode

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TAL

• TAL12/10 – 12 kV, 10 kW Forced-air cooled power triode
• TAL12/20 – 12 kV, 20 kW Forced-air cooled power triode
• TAL12/35 – 12 kV, 35 kW Forced-air cooled power triode

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TAW

• TAW12/10 – 12 kV, 10 kW Water-cooled power triode
• TAW12/20 – 12 kV, 20 kW Water-cooled power triode
• TAW12/35G – 12 kV, 35 kW Water-cooled power triode, 3-phase filaments

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TB

• TB04/8 – Directly heated Doorknob VHF power triode up to 600 MHz
• TB2.5/400 – 2.5 kV, 300 W Radiation-cooled power triode
• TB3/750 (5867) – Radiation-cooled power triode
• TB4/1250 (5868) – Radiation-cooled power triode
• TB5/2500 (7092) – 5 kV, 2.5 kW Radiation-cooled power triode

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TBH

• TBH6/14 – 6 kV, 14 kW Water/helix-cooled power triode
• TBH6/6000 – 6 kV, 6 kW Water/helix-cooled power triode
• TBH7/8000 – 7 kV, 8 kW Water/helix-cooled power triode
• TBH7/9000 – 7 kV, 9 kW Water/helix-cooled power triode
• TBH12/25 – 12 kV, 25 kW Water/helix-cooled power triode
• TBH12/38 – 12 kV, 38 kW Water/helix-cooled power triode

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TBL

• TBL2/300 (7004) – 2 kV, 300 W Forced-air cooled power triode
• TBL6/14 (7804) – Forced-air cooled power triode
• TBL6/4000 (7753) – Forced-air cooled power triode
• TBL6/6000 (5924) – Forced-air cooled power triode
• TBL7/8000 (6961) – Forced-air cooled power triode
• TBL12/38 (7806) – Forced-air cooled power triode
• TBL12/100 (6078) – Forced-air cooled power triode
• TBL15/125 – 15 kV, 125 kW Forced-air cooled power triode; TBL12/100 with 3-phase filaments

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TBW

• TBW6/14 (7805) – 6 kV, 14 kW Water-cooled power triode
• TBW6/6000 (5923) – Water-cooled power triode
• TBW7/8000 (6960) – Water-cooled power triode
• TBW12/38 (7807) – Water-cooled power triode
• TBW12/100 (6077) – Water-cooled power triode
• TBW15/125 – 15 kV, 125 kW Water-cooled power triode; TBW12/100 with 3-phase filaments

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TC

• TC03/5 – RF power triode up to 85 MHz, 5 W
• TC2/250 – RF power triode up to 20 MHz, 250 W

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TD

• TD03/5 – Indirectly heated disk-seal UHF power triode up to 2 GHz
• TD03/10 – Indirectly heated disk-seal UHF power triode up to 2.8 W, 3.75 GHz

• TD03/10F – TD03/10 with internal feedback for use as an oscillator

• TD04/20 – Indirectly heated disk-seal UHF power triode up to 13.5 W, 1 GHz
• TD1/100C (2C39BA) – Indirectly heated, ceramic disk-seal UHF power triode up to 24 W, 3.5 GHz^[242]
• TD2/400 – Directly heated, ceramic disk-seal UHF power triode up to 600 W, 900 MHz
• TD2/500 – Directly heated, ceramic disk-seal UHF power triode up to 500 W, 940 MHz

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TE

• TE05/10 – RF power triode up to 150 MHz

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TX

• TX12/12W – Water-cooled RF power triode
• TX12/20W – Water-cooled RF power triode
• TX10/4000 – Power triode, Silica envelope, 12 kV anode voltage, 4 kW anode dissipation, 1.6 A cathode current, g_m: 4.5 mS, for use as self-excited high-power oscillator in induction heating equipment

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TY

• TY2/125 – 135 W VHF power triode up to 200 MHz
• TY12/50A – Forced-air cooled 45 kW RF power triode up to 30 MHz
• TY12/50W – Water-cooled 50 kW RF power triode up to 30 MHz

_{LoVT ⟶ List of European transmitting tubes ⟶ T - AF/RF/oscillator Triode ⟶}

TYS

• TYS2/250 – Power triode, Silica envelope, 2.5 kV anode voltage, 250 W anode dissipation
• TYS4/500 – Power triode, Silica envelope
• TYS5/1000 – Power triode, Silica envelope
• TYS5/2000 – Power triode, Silica envelope
• TYS5/3000 – Power triode, Silica envelope, 6 kV anode voltage, 950 °C anode temperature at 3.5 kW anode dissipation, 2.8 A cathode current, g_m: 15 mS. Used in RF generators for induction hardening

_{LoVT ⟶ List of European transmitting tubes ⟶}

X - Thyratron

_{LoVT ⟶ List of European transmitting tubes ⟶ X - Thyratron ⟶}

XGQ

• XGQ2/6400 – 2 kV, 6.4 kW Mercury-vapor tetrode thyratron with anode and grid1 top caps

_{LoVT ⟶ List of European transmitting tubes ⟶ X - Thyratron ⟶}

XR

• XR1/1600 (5545) – 1 kV, 1.6 kW Inert gas-filled triode thyratron with anode top cap

• XR1/1600A = ZT1011 = 8063 – Improved XR1/1600

• XR1/3200A (7981) – 1.5 kV, 40 A Inert gas-filled triode thyratron with anode top cap
• XR1/6400 – 1 kV, 6.4 kW Inert gas-filled triode thyratron with anode top cap

List of other tubes since c. 1935

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

1

• 131QP55 (blue-green, very short persistence), 131QP56 (blue-violet, very short) – CRT-type flying-spot scanners for use in a telecine
• 175HQ – Ultra high reliability pentode for use in long-haul submarine communications cable repeaters^[243]
• 1063A – Three-phase, half-wave, Argon/Mercury-vapor Tungar bulb, a low-voltage rectifier for charging 90-cell lead-acid batteries at 6 A per phase; 1.9 V, 11 A heater
• 1069K – Full-wave Tungar bulb for DC welding service at 60 A; 3.25 V, 70 A heater, forced-air cooling
• 1533A – Three-phase, half-wave, Argon/Mercury-vapor Tungar bulb, a low-voltage rectifier for charging 110-cell lead-acid batteries at 15 A per phase; 1.9 V, 23 A heater
• 1543A – Three-phase, half-wave, Argon/Mercury-vapor Tungar bulb, a low-voltage rectifier for charging 110-cell lead-acid batteries at 25 A per phase; 1.9 V, 36 A heater
• 1553A – Three-phase, half-wave, Argon/Mercury-vapor Tungar bulb, a low-voltage rectifier for charging 110-cell lead-acid batteries at 40 A per phase; 1.9 V, 70 A heater

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ 1 ⟶}

1600s

• 1602 – Directly heated low-microphonics AF power triode, 7.5 V filament. 12 watts of AF operating in Class-A. 15 watts of low RF operating in Class-C; similar to type 10
• 1603 – Indirectly heated low-microphonics AF pentode, UX6 base; similar to types 6U7, 57, 6D6 and 6C6
• 1608 – Directly heated power triode giving 20 watts at up to 45 MHz, 2.5 V/2.5 A filament, UX4 base
• 1609 – Directly heated low-microphonics AF pentode, UY5 American 5-pin base
• 1610 – Directly heated pentode specially designed for use as a crystal oscillator, 2.5 V/1.75 A filament, American 5-pin base
• 1612 – Heptode pentagrid converter, both control grids (1 and 3) are sharp-cutoff; low-microphonics version of type 6L7
• 1619 – Beam power tetrode common in World War II battle tank transmitters; similar to 6L6 but directly heated
• 1624 (2.5 V/2 A heater), 1625 (12.6 V/450 mA heater) – Beam power tetrode; very similar to the 807, but with different heaters
• 1626 – RF power triode; very similar to 6J5 but with a 12.6 V/250 mA heater
• 1629 – Tuning indicator tube with DC amplifier triode unit
• 1630 – Indirectly heated, orbital-beam, secondary-emission, 12-pin Jumbo Acorn-type UHF hexode, 6.3 V/300 mA heater
• 1633 – Dual triode used in World War II aircraft; 6SN7 with a 25 V/150 mA heater
• 1635 – Indirectly heated, 10.4 W dual AF power triode, Octal base
• 1636 – Secondary emission UHF beam deflection tube, used as a balanced mixer up to 600 MHz^[244]
• 1650 – High-altitude version of the 955 Acorn-type triode
• 1680 – Dual-control heptode for use as a NAND gate in a coincidence circuit in IBM computers; 6BE6/EK90 with a sharp-cutoff #3 grid

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2

• 20TC4, 30TC1 – Tacitron; cf. 6441, EC860
• 24B1 – Trigatron
• 24B9 – Trigatron
• 29C1 – 100 V, 3 mA Directly heated, thermally-limited (=saturated) emission diode, 4 V/800 mA_max uncoated tungsten filament, for use as a heating current-controlled, variable series resistor in voltage/current stabilizer circuits; cf. 5845, YA1000

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200s

Note: The Cossor 200-series is here

• 203A – 40 W, Directly heated RF transmitter power triode, 4-pin base, anode on top cap
• 204A – 450 W, Directly heated RF transmitter power triode, 3-pin base, anode on top cap
• 205D – 1 W, Directly heated AF or modulator power triode, 4-pin base
• 207 – 22.5 kW, Water-cooled, directly heated RF transmitter power triode
• 210T – Directly heated RF transmitter power triode, 4-pin base; similar to type 10 triode with an Isolantite base
• 211 – 260 W, Directly heated AF or modulator power triode now favored by audiophiles; 4-pin base
• 212E – 250 W, Directly heated RF transmitter power triode, 4-pin base
• 215A – Directly heated, miniature AF/IF/detector triode, 1 V/250 mA filament, 4-terminal bayonet base
• 217C, 371B, 543, 558, 576A, 577, 578, 582, 583, 593 (All half-wave), 596 (Full-wave) – Directly heated vacuum rectifiers
• 220B – 5 kW, Water-cooled, directly heated AF/modulator power triode
• 228 – 2.5 kW, Directly heated RF/AF power triode
• 232C – 8.5 kW, Water-cooled, directly heated RF transmitter power triode
• 236A – 12 kW, Water-cooled, directly heated RF transmitter power triode
• 241B – 300 W, Directly heated AF/modulator power triode, 3-pin base, anode on top cap
• 242A – Directly heated AF/modulator power triode, 4-pin base
• 250TH – 1.1 kW, Directly heated AF/modulator power triode, 4-pin base, anode on top cap
• 254A – 14 W, Directly heated RF transmitter power triode, 4-pin base, anode on top cap
• 261A – 170 W, Directly heated AF/modulator power triode, 4-pin base
• 268A – 20 W, Directly heated power triode, 4-pin base, anode on top cap
• 270A – 585 W, Directly heated AF/RF power triode, 4-pin base, anode on top cap
• 275A – 3 W, Directly heated AF power triode, 4-pin base
• 276A – 170 W, Directly heated AF/RF power triode, 4-pin base
• 279A, 379A – 1.75 kW, Directly heated AF/RF power triode
• 287A (1.5 A, Mercury-vapor), 323A (1.5 A, Argon/Mercury-vapor), 354A (4 A, Mercury-vapor), 355A (4 A, Argon/Mercury-vapor) – Thyratrons
• 295A – 125 W, Directly heated AF/RF power triode, 4-pin base
• 298A – 5 kW, Water-cooled, directly heated power triode

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3

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300s

• 300B – 40 watt directly heated power triode, 4-pin base
• 303A – Indirectly heated dual diode + triode, 6-pin base
• 304B – 50 W, 300 MHz Directly heated VHF power triode, 4-pin base, anode and grid on top wires
• 305A – 60 W, 50 MHz Directly heated VHF power tetrode, 4-pin base, anode and both grids on top wires
• 306A – 15 W Directly heated RF/AF power pentode, 4-pin base, grid 3 internally tied to filament center-tap, grid 1 on top cap
• 307A – 15 W Directly heated RF/AF power pentode, 5-pin base, anode on top cap
• 309A – Remote-cutoff IF/AF pentode, 5-pin base, grid 1 on top cap
• 316A = VT191 – Directly heated Doorknob-type UHF power triode up to 750 MHz
• 322 – Oil can-type disk-seal UHF clipper power diode, 800 V_PIV, 15 W, 1500 MHz
• 323B – 1.25 kV, 1.5 A Argon/Mercury-vapor thyratron, 5-pin base
• 327A (2 A Half-wave), 328 (1.3 A Full-wave), 367 (6 A Full-wave) – Argon-filled Tungar bulb, a low-voltage rectifier for charging 12V lead-acid batteries
• 329 – 1.15 A, Dual (5...15 and 10...30 V) ballast tube for use with the 328 Tungar bulb
• 342A – 25 kW, 4 MHz Water-cooled, directly heated power triode
• 343A – 10 kW, 4 MHz Water-cooled, directly heated power triode
• 344H = 8111 – 3.35 to 3.65 GHz, 1.5 kW Traveling-wave tube
• 346C – Gas-filled cold-cathode trigger triode, one starter electrode, ⁸⁵Kr keep-alive, 4-pin base
• 348A (grid 1 on top cap), 349A – Pentode, 7-pin base
• 354 (Philips) – 2 A Half-wave argon-filled Tungar bulb for charging 8V lead-acid batteries
• 354A (Western Electric) See 287A
• 356A (880, 5771, 7085) – 22.5 kW, 25 MHz Water-cooled, directly heated power triode
• 357B – 400 W, 100 MHz Forced-air cooled, directly heated power triode
• 368A – Directly heated Doorknob UHF power triode, graphite anode, up to 1.7 GHz^[245]
• 371B – 25 kV, 300 mA Half-wave rectifier, Jumbo 4-pin base
• 376B = 5589 – Gas-filled cold-cathode trigger triode, one starter electrode, 6-pin base
• 378A – 30 kV, 200 mA Half-wave rectifier, 4-pin base
• 388A – Directly heated Doorknob UHF power triode, graphite anode, up to 1.7 GHz^[245]
• 393A – 1.25 kV, 1.5 A Argon/Mercury-vapor thyratron
• 395A – Small neon-filled cold-cathode thyratron for use as a latching single-dot indicator, top-viewing, all-glass pigtaled; cf. 7323, 7400, 7401, 7979, МТХ-90
• 396A = 2C51 – Dual shielded triode, indirectly heated, Noval base
• 398A = 5603 – 8 W Directly heated power pentode, 8-pin base

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4

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400s

Note: The Cossor 400-series is here

• 400 – 100 V, 25 mA Half-wave rectifier, 4-pin base, designed for studies of emission and the influence of magnetic fields
• 401A = 5590 – Pentode, miniature 7-pin base
• 403B = 5591 – UHF pentode, miniature 7-pin base
• 404A = 5847 – 120 MHz Wide band frame-grid pentode, Noval base
• 407A (2C51, 5670) – Dual medium-mu VHF triode, center-tapped 40 V/50 mA resp. 20 V/100 mA heater, Noval base; cf. 20EZ7
• 408A – Sharp-cutoff pentode, miniature 7-pin base
• 411 – 150 kV (in oil) resp. 100 kV (in air), 300 mA_peak Half-wave rectifier, 4-pin base
• 416B = 6280 – Planar SHF power triode, 500 mW output at 4 GHz
• 416D – Planar SHF power triode with BeO spacers, 5 W output at 4 GHz
• 417A – Medium-mu triode, Noval base
• 418A – IF/Video tetrode
• 423A – 100 V, 4 to 8 mA Voltage-regulator tube, Noval base
• 427A = 6141 – 100 V, 5 to 40 mA Voltage-regulator tube with a keep-alive (primer) electrode, Noval base
• 430A – Gas-filled cold-cathode trigger triode, one starter electrode, RaBr₂ keep-alive, 4-pin base
• 441 – Vacuum phototube, S4 spectral response, 4-pin base
• 446A (2C40) – Early Lighthouse UHF triode, 10 dB noise figure at 1 GHz
• 450TH – Early Eimac high-mu power triode, 450 watt anode dissipation up to 40 MHz^[246]
• 451 – Full-wave, argon-filled Tungar bulb, a low-voltage rectifier for charging 6V lead-acid batteries at 1.3 A
• 452 – 1.15 A, Dual (3.5...10 and 7...20 V) ballast tube for use with the 451 Tungar bulb^[247]
• 455A – Ultra high reliability pentode for use in submarine communications cable repeaters^[248]
• 482B = 182B – Directly heated power triode used in Sparton AC radios, circa 1929; replacements often numbered 182B/482B, similar to type 71-A, but with higher anode voltage
• 483 = 183 – Directly heated power triode used in Sparton AC radios, circa 1929; replacements often numbered 183/483; similar to type 45, but with a 5.0 V/1.25 A heater
• 485 – Indirectly heated triode used in Sparton AC radios, circa 1929; similar to types 56 and 76, but with a 3.0 V/1.3 A heater, and lower anode voltage

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5

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ 5 ⟶}

500s

• 502A – 600 V, 100 mA Thyratron, Octal base
• 527 – High-mu power triode up to 900 W
• 530 – 75 kW Water-cooled, directly heated pulsed power triode
• 531 – 50 kV, 390 mA Forced-air cooled, directly heated, half-wave vacuum rectifier
• 546 – 500 V, 20 mA Thyratron, miniature 7-pin base
• 559 – Lighthouse-type disk-seal UHF diode
• 561 – 33 kV, 1.25 A Directly heated vacuum rectifier, 4-pin Superjumbo base with anode top cap
• 572B (811A) – 225 W Directly heated RF power triode, 6.3 V/4 A filament
• 575A (4-pin Jumbo base), 673 (4-pin Superjumbo base) – 15 kV, 1.5 A Mercury-vapor rectifiers, anode on top cap
• 592 = Eimac 3-200A3 – Medium-mu power triode up to 200 W, 150 MHz

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6

• 6P10 – Ultra high reliability pentode for use in short-haul submarine communications cable repeaters^[243]
• 6P12 – Ultra high reliability pentode for use in long-haul submarine communications cable repeaters^[243]

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600s

• 604 = 7014 (4-pin Superjumbo base), 604L = 7015 (Lug/spade connectors) – 900 V, 2.5 A Full-wave Argon/Mercury-vapor rectifier
• 606 = 7016 (4-pin Superjumbo base), 606L = 7017 (Lugs) – 900 V, 6.4 A Full-wave Argon/Mercury-vapor rectifier
• 615 = 7018 – 2 kV, 2.5 A Half-wave Argon/Mercury-vapor rectifier
• 627 – 1.25 kV, 640 mA Argon/Mercury-vapor thyratron, 4-pin Superjumbo base with anode top cap
• 629 – 350 V, 40 mA Argon/Mercury-vapor thyratron, 5-pin base
• 632B – 1.5 kV, 2.5 A Mercury-vapor thyratron, 4-pin base with anode top cap and control grid side cap
• 635 = 7019 (4-pin Superjumbo base), 635L = 7020 (Lugs) – 1 kV, 6.4 A Half-wave Argon/Mercury-vapor rectifier with anode top cap
• 672 – 2.5 kV, 2.5 A Argon/Mercury-vapor thyratron, 4-pin Superjumbo base with anode top cap
• 673 – 10 kV, 1.75 A Half-wave Mercury-vapor rectifier, 4-pin Superjumbo base with anode top cap
• 676 – 2.5 kV, 6.4 A Mercury-vapor thyratron, 4-pin Superjumbo base with anode top cap
• 677 – 10 kV, 4 A Mercury-vapor thyratron, 4-pin Superjumbo base with anode top cap
• 678 – 10 kV, 1.6 A Mercury-vapor thyratron, 4-pin base with anode top cap

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700s

Western Electric types 700 to 732 were among 1940's most advanced technologies, and highly classified at the time^[249]

• 700 – Pulsed L-band magnetron
• 701A – Modulator tetrode
• 702 – TR/ATR cell
• 703A – 20 W Directly heated Doorknob UHF power triode up to 1.5 GHz, 1.15 V/4.5 A filament
• 704A – UHF diode
• 705A = 8021 – 30 kV, 100 mA Half-wave EHT rectifier, B4A 4-pin base with anode top cap
• 706 – S-band Magnetron
• 707 – S-band Klystron
• 708A – Flying saucer tube, an SHF power triode
• 709A – TR/ATR cell
• 710 = 6011 (RCA) – 1.5 kV, 2.5 A Gas/Mercury-vapor thyratron
• 710A = 8011 (Western Electric) – Micropup UHF power triode
• 713A – Indirectly heated Mushroom or Little Doorknob UHF pentode, Bakelite Octal base, 6.3 V/175 mA heater, for use as a low-noise front end in radar receivers
• 714 = 7021 (National Electronics) – 1.25 kV, 1 A Argon/Mercury-vapor thyratron, 4-pin base with anode top cap
• 714A (Western Electric) – S-band Magnetron
• 715 – Modulator tetrode
• 716 = 6855 – 1.25 kV, 1 A Gas/Mercury-vapor thyratron
• 717A (CV3594, VT269) – 713A with a metal shield and a low loss mica-filled phenolic resin ("Micanol")^[18] Octal base
• 718 – S-band Magnetron
• 719A – Half-wave EHT pulse rectifier
• 720 – S-band Magnetron
• 721 – TR/ATR cell
• 722A – Thyratron
• 723A = KS9/20 (2K25) – X-band Klystron
• 724 – TR/ATR cell
• 725A = 2J21 – X-band Magnetron
• 726 – S-band Klystron
• 727A – Thyratron
• 728 – L-band Magnetron
• 729A = 1B23 – TR/ATR cell
• 730A – X-band Magnetron
• 731A = 6AK5/EF95 – IF pentode
• 732A = 3B24 – Half-wave EHT rectifier
• 740L = 7022 – 1.5 kV, 4 A Argon/Mercury-vapor thyratron, Lug connectors and anode top cap
• 760 = 6858 (4-pin Superjumbo base), 760L = 7023 (Lugs) – 1.5 kV, 6.4 A Gas/Mercury-vapor thyratron with anode top cap
• 787 – Pliotron Demonstrator, an educational, directly heated planar triode with a phosphorized anode^[250]

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800s

• 800 – Directly heated VHF power triode, giving 35 W up to 60 MHz and 18 W at 180 MHz, UX4 American 4-pin base with side locating pin
• 801 – Directly heated power triode, used in pairs in Class-B in AM modulation sections of transmitters giving up to 45 W at 60 MHz and 22 W at 120 MHz
• 802 – Indirectly heated RF power pentode, giving 8 W up to 30 MHz and 4 W at 110 MHz
• 803 – Directly heated RF power pentode, giving 50 W up to 20 MHz and 25 W at 70 MHz
• 804 – Directly heated RF power pentode, giving 20 W up to 15 MHz and 10 W at 10 MHz
• 805 – Directly heated RF power triode, giving 140 W up to 30 MHz and 70 W at 85 MHz
• 806 – Directly heated RF power triode, giving 390 W up to 30 MHz 195 W at 100 MHz
• 807 – Indirectly heated RF beam power tetrode, 6.3 V/900 mA heater, low loss mica-filled phenolic resin ("Micanol")^[18] base, giving 25 W up to 30 MHz and 12 W at 125 MHz, originally designed as a Class-C transmitter tube, later used in pairs as push-pull outputs for high-wattage Class-AB₂ audio amplifiers. Also used as a horizontal deflection output tube in early TV receivers. One of the first commercial tubes that used the top cap to connect the anode (instead of the control grid) to the circuit; a variation of type 6L6
• 808 – Directly heated RF power triode, giving 140 W up to 30 MHz and 70 W at 130 MHz
• 809 – Directly heated RF power triode, giving 55 W up to 27 MHz and 30 W at 100 MHz
• 810 – Directly heated RF power triode, 10 V/4.5 A filament and ZrC anode. Base fits RCA UT-541A socket
• 811A – 88 W Directly heated RF power triode, 6.3 V/4 A filament
• 813 – Beam power tetrode having about 5 times the anode dissipation of an 807
• 814 – Directly heated beam power tetrode giving about 130 W at 30 MHz and 65 W at 100 MHz operating in Class-C
• 815 – Indirectly heated dual beam power pentode, Octal base
• 825 – First commercially available Klystrode, a Klystron/triode hybrid used as a VHF/UHF linear-beam transmitting tube
• 829 – Indirectly heated dual VHF beam power tetrode, center-tapped 12.6 V/1.125 A heater, Septar base with dual anode top cap
• 830 – Directly heated power triode giving about 50 W at 15 MHz and 7.5 W at 60 MHz operating in Class-C
• 831 – Directly heated power triode giving about 400 W at 20 MHz and 200 W at 60 MHz operating in Class-C. 11 V/10 A filament
• 833 – Large directly heated power triode giving about 1 kW at 30 MHz and 500 W at 45 MHz operating in Class-C. Usable up to 100 MHz at reduced power, (400 W). 10 V/10 A filament. The anode of this device is fabricated from tantalum. Anode current of 800 mA with an anode voltage of 3 kV and grid voltage of zero. Anode current of 4.3 A at a voltage of 750 with 350 volt on the grid. Uses two-part RCA socket assembly UT-103^[251]

• 833A – Improved 833

• 834 – Directly heated power triode giving 58 W at 100 MHz and 25 W at 350 MHz operating in Class-C, 7.5 V/3.1 A filament, UX4 American 4-pin base with side locating pin
• 836 – Indirectly heated high vacuum rectifier with a peak inverse voltage of 5 kV and peak anode current of 1 A, 2.5 V/5 A heater
• 837 – Indirectly heated power pentode giving 11 W at 20 MHz and 5 W at 80 MHz operating in Class-C. 12.6 V/700 mA heater
• 838 – Directly heated power triode giving about 100 W at 30 MHz operating in Class-C. 10 V/3.25 A filament
• 841 – Directly heated power triode giving about 10 W at 6 MHz and 5 W at 170 MHz operating in Class-C. 7.5 V/1.25 A filament
• 842 – Directly heated power triode giving about 3 W at 6 MHz operating in Class-C. 7.5 V/1.25 A filament
• 843 – Indirectly heated power tetrode giving gain at 6 MHz and usable up to 200 MHz operating in Class-C. 2.5 V/2.5 A heater
• 844 – Directly heated power triode giving gain at 6 MHz and usable up to 155 MHz operating in Class-C. 2.5 V filament
• 845 – Directly heated power triode giving up to 24 W of undistorted power in Class-A at audio frequency with an anode voltage of 1.25 kV. 10 V/3.25 A filament
• 849 – Directly heated power triode giving gain at 3 MHz operating in Class-C. Two 849s, working in push-pull Class-B are capable of delivering 1.1 kW of audio output with an anode voltage of 3 kV. Usable up to 30 MHz. 11 V/5 A filament
• 850 – Directly heated power tetrode giving 120 W up to 13 MHz and 50 W at 100 MHz, operating in Class-C. 10 V filament
• 851 – Directly heated power triode giving 1.5 kW up to 3 MHz operating in Class-C. 11 V/15.5 A filament
• 852 – Directly heated power triode giving 75 W up to 30 MHz operating in Class-C. 10 V filament
• 857B – Large mercury-vapor rectifier used in 50 kW class broadcast transmitters. 22 kV anode voltage, 10 A anode current. 5 V/30 A filament
• 860 – Directly heated power tetrode giving 105 W up to 30 MHz and 50 W at 120 MHz operating in Class-C. 10 V/3.25 A filament
• 861 – Directly heated power triode giving 400 W up to 20 MHz and 200 W at 60 MHz operating in Class-C. 11 V/10 A filament
• 862 – Large water-cooled power triode for broadcast/industrial applications. Used in experimental 500 kW transmitter at WLW. 33 V/207 A filament
• 864 – Directly heated general-purpose, low-microphonics triode with a maximum anode voltage of 135 V and anode current of 3.5 mA. 1.1 V/250 mA filament
• 865 – Directly heated power tetrode giving 30 W up to 15 MHz 15 W at 70 MHz operating in Class-C. 7.5 V/2 A filament
• 866
  

  866A
  – Mercury-vapor rectifier with a peak inverse voltage of 5 kV and peak anode current of 1 A. Average anode current 250 mA, forward drop 15 V, 2.5 V/5 A heater, UX4 American 4-pin base

• 866A – Improved 866 with a peak inverse voltage of 10 kV and a forward drop of 10 V

• 872 – Mercury-vapor rectifier with a peak inverse voltage of 5 kV and peak anode current of 5 A, average anode current 1.25 A, forward drop 15 V, 5.0 V/10 A heater. Base fits RCA UT-541A socket

• 872A – Improved 872 with a peak inverse voltage of 10 kV, a forward drop of 10 V and a heater current of 6.25 A

• 874 – 90 V, 10 to 50 mA Voltage-regulator tube, UX4 4-pin base
• 876 (1.7 A), 886 (2.05 A) – 40 to 60 V Barretters, E39 Mogul Edison screw lamp base
• 879 = 2X2 – CRT EHT rectifier with a peak inverse voltage of 12.5 kV and peak anode current of 100 mA, 2.5 V/1.75 A heater, UX4 American 4-pin base
• 884 = 6Q5-G (DuMont) – Indirectly heated triode thyratron once commonly used as a horizontal sweep sawtooth generator in oscilloscopes; 885 with a 6.3 V/600 mA heater and an Octal base
• 885 = 2B4 (DuMont) – 884 with a 2.5 V/1.4 A heater and an UY5 American 5-pin base
• 893 – 20 kW Water-cooled power triode with 3 independent 10 V/61 A (each) filaments for 3-phase operation in broadcast/industrial applications
• 898 – 50 kW Water-cooled power triode for broadcast/industrial applications; improved version of 862 with 3 independent 33 V/70 A (each) filaments for 3-phase operation

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9

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ 9 ⟶}

900s

• 920 – Dual gas-filled phototube, caesium-coated cathode with spectral S1 response (red/infrared, maximum sensitivity at 750 nm), 4-pin base, for use in a differential circuit to read variable-area film soundtracks
• 931 – First mass-produced photomultiplier, 9-stage, spectral S4 response, 11-pin base, still in production today
• 934 – Vacuum phototube, spectral S4 response (violet, maximum sensitivity at 400±50 nm), 3-pin Small-Shell Peewee base
• 935 – Vacuum phototube, spectral S5 response (UV-A, maximum sensitivity at 340±50 nm), 4-pin Octal base
• 950 – Power pentode with directly heated cathode, used in storage battery home radios, 2.0 V/120 mA filament; similar to types 1F4 and 1J5G
• 951 – Sharp-cutoff pentode with directly heated cathode, used in storage battery home radios with 2.0 V filament supply; similar to type 1B4P
• 953 – Acorn-type UHF diode, 6.3 V heater
• 954 (4672/E1F) – Indirectly heated Acorn-type sharp-cutoff pentode giving gains of 2...3 up to 300 MHz operating in Class-A and usable up to 600 MHz with careful stage design, 6.3 V/150 mA heater
• 955 (4671/E1C) – Indirectly heated Acorn-type triode giving a power of 135 mW up to 600 MHz operating in Class-A and 500 mW in Class-C with careful stage design, 6.3 V/150 mA heater
• 956 (4695/E2F) – Indirectly heated Acorn-type remote-cutoff pentode giving gains of 3...4 up to 600 MHz operating in Class-A with careful stage design, 6.3 V/150 mA heater
• 957 (D1C) – Directly heated Acorn-type UHF receiving triode; 1.25 V/50 mA filament for portable equipment
• 958 (D2C) – Directly heated Acorn-type UHF transmitting triode with two internally paralleled 1.25 V/50 mA (each) filaments for increased emission, for portable equipment

• 958A – 958 with tightened emission specs

• 959 (D3F) – Directly heated Acorn-type sharp-cutoff UHF pentode; 1.25 V/50 mA filament for portable equipment
• 991 – 60-Volts Voltage reference, T4½ lightbulb with dual-contact, bayonet candelabra mount

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9000s

• 9001 – 954 with a miniature 7-pin base
• 9002 – 955 with a miniature 7-pin base
• 9003 – 956 with a miniature 7-pin base
• 9004 – Acorn UHF diode
• 9005 – Acorn UHF diode with a 3.6 V/165 mA heater
• 9006 – Detector diode with a miniature 7-pin base

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

A

Edison and Swan Electric Light Company (British Mazda/EdiSwan):

• A40 – Acorn UHF triode up to 600 MHz, 4 Volts heater
• A41 – Acorn UHF pentode up to 600 MHz, 4 Volts heater

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AC*/

Mazda/EdiSwan 4-volts AC, indirectly heated ("Mains Operated") receiver tubes:

• AC/HL – AF triode, British 5-pin base
• AC/HLDD = TDD4 = MHD4 – Dual diode + AF triode, British 7-pin base
• AC/ME – Tuning indicator, British 7-pin base
• AC/P, AC/P1 – AF triode, British 5-pin base
• AC/P4 – CRT electrostatic-deflection output power triode, British 5-pin base
• AC/PEN – AF power pentode, British 7-pin base
• AC/S2PEN – RF pentode, British 7-pin base
• AC/SP1 – RF pentode for use in squelch circuits or, as the reactance tube, in AFC circuits, British 7-pin base
• AC/SP3 – RF pentode for shortwave and TV receivers, British 7-pin base
• AC/SP3/RH – Low-noise, low-microphonics RF pentode for shortwave and TV receivers, British 7-pin base
• AC/TH1 – Triode/hexode mixer, British 9-pin base
• AC/TP = TP4 – Oscillator/mixer triode/pentode, British 7-pin base
• AC/VP1, AC/VP2 – RF pentode, British 7-pin base
• AC2/HL – High-mu triode
• AC2/PEN – AF power pentode
• AC2/PEN.DD – Dual diode + AF power pentode
• AC4/PEN – AF beam power pentode
• AC5/PEN – AF beam power pentode
• AC5/PEN.DD – Dual diode + AF beam power pentode
• AC6/PEN – Beam power pentode for use as a magnetic horizontal deflection output amplifier

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ A ⟶}

ACT

Marconi-Osram Valve Company:

• ACT9 – 800 W (convection) or 1100 W (forced) Air cooled transmitting triode up to 15 MHz, with derating up to 80 MHz; 16 V/22 A heater

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

B

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ B ⟶}

BA

Industrial Electronics Engineers:

• BA-0000-P31 – Nimo tube, cathode-ray 1-digit numeric display tube, 10 stenciled electron guns aiming at a P31-phosphor (yellowish-green, medium-persistence) fluorescent screen, top-viewing, Futura Medium font, 2.5 kV anode voltage, 12-pin base

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ B ⟶}

BG

Burroughs Neon-filled planar glow-transfer plasma bar graph displays:

• BG08220-K – 120-Segment circular with five cathode strings plus a Reset cathode, 1-in-5 major/minor graduation, for use e.g. in direction-finding equipment
• BG12201 = Dale PBG12201 – Dual 201-segment linear with three cathode strings plus a Reset cathode,^[252] for use in VU meters etc.
• BG12203 = PBG12203 – Dual 203-segment linear bidirectional with three cathode strings plus two Reset cathodes
• BG12205 = PBG12205 – Dual 201-segment linear with five cathode strings plus a Reset cathode,^[253] for use in VU meters etc.
• BG16101 = PBG16101 – Dual 101-segment linear with three cathode strings plus a Reset cathode, for use in VU meters etc.; cf. ИН-33

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ B ⟶}

BT

British Thomson-Houston (General Electric subsidiary):

• BT1 – Thyratron used in Wynn-Williams' binary prescaler for the alpha particle counter that Rutherford, Chadwick et al. used for their nuclear research at the Cavendish Laboratory in the 1930s^[254]

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C

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CH

Tung-Sol:

• CH1027 – Curristor – Four types of nitrogen-filled, radioactive constant-current tubes with a current plateau from 25 to 500 V, all-glass pigtailed, active material is ²²⁶Ra with a half-life of 1601 years, for linear capacitor charging and draining in missile and ordnance mine timing circuits, instrumentation biasing, as current reference, etc.:

• CH1027-9 – 10⁻⁹ A, 18.75 μCi (694 kBq)
• CH1027-10 – 10⁻¹⁰ A, 1.875 μCi (69.4 kBq)
• CH1027-11 – 10⁻¹¹ A, 187.5 nCi (6.94 kBq)
• CH1027-12 – 10⁻¹² A, 18.75 nCi (694 Bq)

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ C ⟶}

CK

Raytheon:

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• CK1022 – 1 kV/5...55 µA Corona voltage reference, miniature 7-pin base with anode top cap
• CK1037 = 6437 – 700 V/5...125 µA Corona voltage reference, 3-pin all-glass pigtailed
• CK1038 – 900 V/5...55 µA Corona voltage reference, 3-pin all-glass pigtailed
• CK1039 = 6438 – 1.2 kV/5...125 µA Corona voltage reference, 3-pin all-glass pigtailed
• CK1366, CK1367, CK1368, CK1369 – CRTs with an unphosphored front glass but with fine wires embedded in it for use as electrostatic print heads; the wires would pass the electron beam current through the glass onto a sheet of paper where the desired content was therefore deposited as an electrical charge pattern. The paper was then passed near a pool of liquid ink with the opposite charge. The charged areas of the paper attract the ink and thus form the image.^[255][256]
• CK1383 – Dual-electron gun recording storage tube, a realtime polar, radar PPI-to-rectangular, TV-type analog video transcoder similar to the 7702, with simultaneous R/W, and storing capability. This was achieved by a CRT/camera tube combination; the CRT part writes the PPI-format image onto a thin, dielectric target; the camera part reads the generated charge pattern in TV format from the back side of this target.^[257]
• CK1414 – Symbolray character generator monoscope for text mode video rendering in early computer monitors, with a square target having letters, digits and symbols patterned on it in a customer-supplied 8x8 or 8x12 array. An electron beam selects and scans a character, both by appropriate electrostatic deflection, and generates an analog video signal;^[258][259] cf. 4560, TH9503

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ C ⟶}

CL

Ferranti:

• CL40 and CL41 – Indirectly heated, linear light source (glow modulator tube), mercury/argon-filled gas diode with primer electrode, 8-pin base, for rotating-drum FAX receivers, film soundtrack recording, etc.
• CL42 and CL43 – Indirectly heated, low-noise linear light source, helium-filled gas diode with primer electrode, 8-pin base, for film soundtrack recording, interferometers, etc.
• CL44 – Indirectly heated, low-noise linear light source, neon-filled gas diode with primer electrode, 8-pin base
• CL50 and CL52 – Indirectly heated, linear light source, gas-filled diode with primer electrode, 7-pin base, for rotating-drum FAX receivers, film soundtrack recording, etc.
• CL55 – Indirectly heated, spectrally pure light source, helium-filled gas diode with primer electrode, 7-pin base with anode top cap
• CL56 – Indirectly heated, spectrally pure light source, krypton-filled gas diode with primer electrode, 7-pin base with anode top cap
• CL57 – Indirectly heated, spectrally pure light source, neon-filled gas diode with primer electrode, 7-pin base with anode top cap
• CL58 – Indirectly heated, spectrally pure light source, xenon-filled gas diode with primer electrode, 7-pin base with anode top cap
• CL60 – Indirectly heated triode flood beam CRT-type stroboscope lamp with a green A-type phosphor with <1 μs decay time and 10 kCd light output, 20 kV anode voltage, 7-pin Duodecal base
• CL61 – CL60 with a blue P-type phosphor with 5 μs decay time and 16 kCd light output
• CL62 – CL60 with an UV Q-type phosphor with 100 ns decay time and 240 Cd light output
• CL63 – CL60 with a yellow-green C-type phosphor with 6 μs decay time and 24 kCd light output
• CL64 – CL60 with a yellow V-type phosphor with 5 μs decay time and 12 kCd light output
• CL65 – CL60 with a red R-type phosphor with 2 μs decay time and 14 kCd light output
• CL66 – CL60 with a white T-type phosphor with 5 μs decay time and 12 kCd light output

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

D

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DDR

Mullard:

• DDR100 – 100 g max., 250 Hz max., Mechanotron-type 1-axis accelerometer dual diode with elastically supported anodes, 6.3V/600mA indirect heater, f_res = 1 kHz, B8G base^[260]

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DZ

Cerberus:

• DZ10 – 3 kHz max. Decade Counter/Selector Dekatron, 14-pin Diheptal base

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E

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ECT

Elesta:

• ECT100 – 1 MHz, top-viewing, bidirectional, decade Dekatron^[261]

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EN

Ferranti:

• EN10 – Neostron, 400 A_pk Gas-filled, cold-cathode tetrode thyratron, differential trigger electrodes, 8-pin base, for use as a relay or as a reddish 700 Cd stroboscope lamp
• EN15 – 80 A_avg Neon-filled, cold-cathode tetrode thyratron, differential trigger electrodes, miniature 9-pin base, for use as a stroboscope lamp
• EN30 – 250 A_pk Gas-filled, arc-discharge cold-cathode tetrode thyratron, differential trigger electrodes, miniature 7-pin base with anode cap, for use as a relay or as a stroboscope lamp
• EN40 – 250 A_pk Gas-filled, cold-cathode tetrode thyratron, differential trigger electrodes, 8-pin base, for use as a whitish stroboscope lamp with a high actinism for photographic film
• EN55 Single, EDN10 dual xenon-filled, arc-discharge cold-cathode tetrode thyratron, external (capacitive) trigger, 12-pin base, for use as a white 140 kCd stroboscope lamp
• EN60 – Gas-filled, arc-discharge cold-cathode tetrode thyratron, external (capacitive) trigger, Edison screw lamp base with anode cap, for use as a white 900 klm@10µF@800V stroboscope lamp

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ESR

Elesta:

• ESR2 – Neon-filled, cold-cathode Trigger pentode (two starter electrodes and a primer electrode) and two voltage references, for use in precision timers^[262]

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EZ

Elesta:

• EZ10B – 1 MHz max. Decade Counter/Selector Dekatron^[263][264]

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F

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FP

General Electric:

• FP400 – Educational, directly heated, thermally-limited (=saturated) emission diode, uncoated tungsten filament up to 2600 K (bright emitter); similar to the Ferranti GRD7

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G

Standard Telephones and Cables/Brimar:

• G10/241E – Nomotron, a unidirectional Dekatron with multi-alloy cathodes

Cerberus:

• G11 – 5 mA Gas-filled, cold-cathode switching diode e.g. for relaxation oscillators, 2-pin all-glass pigtailed
• G42 – 35 mA_peak Gas-filled switching diode e.g. for relaxation oscillators, 2-pin all-glass pigtailed

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ G ⟶}

GE

Ferranti:

• GE10 – 500 V, 650 µA Directly heated, thermally-limited (=saturated) emission diode, 1.8 V/330 mA_max uncoated tungsten filament, for use as a heating current-controlled, variable series resistor in voltage/current stabilizer circuits. It has two shorted pins that can be used to disable the circuit if the tube is removed from its socket; cf. 5845, YA1000

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ G ⟶}

GK

Cerberus:

• GK11 – Touch button tube, an illuminated capacitance touch switch; a cold-cathode DC relay tube, external (capacitive) starter activated by touching; then the cathode glow is visible as an orange ring. 2-pin all-glass pigtailed

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GN

Ferranti:

• GN10 – 250 Amps pulse-current, cold-cathode tetrode thyratron. Octal base

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ G ⟶}

GR

Cerberus:

• GR15 – 15 mA Gas-filled cold-cathode DC tetrode, one starter and one electrical primer and tritium-primed (half-life: 12.32 years), Noval base, for voltage triggers, RC timers etc.
• GR16 – 20 mA Gas-filled, cold-cathode, tritium-primed AC/DC triode, one starter and an EM shield, Noval base, for voltage triggers, RC timers etc.
• GR17 – 15 mA Gas-filled cold-cathode AC triode, one starter and an EM shield, Noval base, for voltage triggers, RC timers etc.
• GR31 – 15 mA Gas-filled cold-cathode DC tetrode, one starter and one electrical primer plus a tritium primer, Noval base
• GR44 – 12 mA Subminiature gas-filled cold-cathode DC pentode, two starters and one primer electrode plus a tritium primer, 5-pin all-glass pigtailed
• GR46 – 12 mA Subminiature gas-filled cold-cathode DC tetrode, one starter and one primer electrode, 4-pin all-glass pigtailed

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ G ⟶}

GRD

Ferranti:

• GRD7 – Educational, directly heated, thermally-limited (=saturated) emission diode, uncoated tungsten filament, guard rings to ensure a homogeneous anode/cathode field; similar to the General Electric FP400

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

K

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KN

Edgerton, Germeshausen, and Grier:

• KN2 – 4 kV, 500 A_surge Krytron, a cold-cathode gas-filled tube with a primer electrode, for use as a very high-speed, high-surge current switch; similar to a thyratron, lifespan 10⁷ shots, 4-pin all-glass pigtailed^[265]
• KN4 – 5 kV, 2.5 kA_surge Krytron with a primer electrode, lifespan 25000 shots, 4-pin all-glass pigtailed
• KN6 – 5 kV, 3 kA_surge Krytron with a primer electrode, lifespan 35000 shots, 4-pin all-glass pigtailed

• KN6B – 8 kV, 3 kA_surge Krytron with a primer electrode, lifespan 35000 shots, 4-pin all-glass pigtailed

• KN9 – 4 kV, 500 A_surge Krytron with a primer electrode, lifespan 1.5⋅10⁷ shots, 4-pin all-glass pigtailed
• KN11B – 2.5 kV, 1.5 kA_surge Sprytron, lifespan 2000 shots, 3-pin all-glass pigtailed
• KN12 – 5 kV, 3 kA_surge Sprytron, lifespan 500 shots, 3-pin all-glass pigtailed
• KN22 – 5 kV, 100 A_surge Krytron with a primer electrode, lifespan 2⋅10⁷ shots, 4-pin all-glass pigtailed, for laser pumping, to drive Pockels cells, also for educational purposes^[266]
• KN26 – 5 kV, 3 kA_surge Krytron with a primer electrode, lifespan 75000 shots, 4-pin all-glass pigtailed

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ K ⟶}

KT

Note: The original Marconi-Osram Kinkless Tetrode beam power tetrodes are listed under M-OV Examples

Electro-Harmonix:

• KT90 – New production tube
• KT150 – New production tube

"Tung-Sol":

• KT120 – New production tube

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

M

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ M ⟶}

MC

Philips:

• MC6-16, MC13-16 – CRT-type flying-spot scanners, P16-type phosphor (violet/near-ultraviolet, very short persistence), for use in a telecine

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ M ⟶}

ME

Edison and Swan Electric Light Company (British Mazda/EdiSwan):

• ME91 – AC/DC mains tuning indicator

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ M ⟶}

MT

Marconi-Osram Valve Company:

• MT7A, MT7B – Large radiation-cooled transmitting triodes used in the 1920s and 1930s

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

P

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ P ⟶}

PD

Edison and Swan Electric Light Company (British Mazda/EdiSwan):

• PD220 – Dual AF power triode for battery-supplied equipment (1939)

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ P ⟶}

PL

Philips:

• PL21 = 2D21 = EN91 – 100 mA_avg, 500 mA_peak, 10 A_surge, Gas-filled, indirectly heated tetrode thyratron, negative starter voltage, miniature 7-pin base, for relay and grid-controlled rectifier service
• PL323 = 3C23 – 1.5 A_avg, 6 A_peak, Mercury-vapor triode thyratron, 4-pin base with anode top cap
• PL5727 = 5727 – 100 mA_avg, 500 mA_peak, 10 A_surge, Tetrode thyratron, miniature 7-pin base

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

Q

Philips:

• Q13-110GU – CRT-type flying-spot scanner, white phosphor, for use in a telecine

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ Q ⟶}

QK

Raytheon:

• QK329 – Beam deflection square-law tube for use as a function generator in analog computers. A flat sheet beam is electrostatically deflected across the anode which is partially covered by a parabolically stenciled screen "grid" that acts as the tube's output. Two tubes may be combined to form a 1-quadrant analog multiplier using the equation a⋅b = (a+b)² − (a−b)²/4 where the deflection electrode signals a+b and a−b can be obtained directly from a fully balanced resistor bridge;^[267][268] cf. ЛФ-2 ff.

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

R

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ R ⟶}

RK

Raytheon:

• RK61 – Miniature, gas-filled, directly heated thyratron designed specifically to operate like a vacuum triode below its ignition voltage, allowing it to both amplify analog signals and work as a relaxation oscillator, for use as a self-quenching superregenerative detector up tp 100 MHz in radio control receivers, activating a relay in its anode circuit when a carrier wave is received; 4-pin all-glass pigtailed, 1.4 V, 45 mA filament, U_a=45 V, I_a=1.5 mA.^[269]
• RK62 – RK61's predecessor, marketed since 1938;^[270] this was the major technical development which led to the wartime development of radio-controlled weapons and the parallel development of radio controlled modelling as a hobby.^[271]

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

S

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ S ⟶}

SB

Radio Corporation of America:

• SB256 – 256-bit Selectron tube, an early form of digital computer memory^[272][273]

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

T

British General Electric Company:

• TuneOn – Early neon-filled bar graph tuning indicator, a glass tube with a short wire anode and a long wire cathode that glows partially; the glow length is proportional to the tube current^[274]
• TuneOn Button – Early glow modulator used as a budget-priced tuning indicator – a neon lamp whose brightness is proportional to the tube current^[275]

Standard Telephones and Cables/Brimar:

• Tunograph – Precursor of the "Magic Eye" tuning indicator first introduced in 1933; a tiny CRT with 1-axis electrostatic deflection and a phosphored target at 45° to the electron beam, so the projected green dot can be observed from the side^[276]

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ T ⟶}

TH

Compagnie Française Thomson-Houston:

• TH9503 – Scripticon, a character generator monoscope for text mode video rendering in early computer monitors, with a square target having letters, digits and symbols patterned on it in an (optionally customer-supplied) 8x8 array. An electron beam selects and scans a character, both by appropriate magnetic deflection, and generates an analog video signal;^[277] cf. 4560, CK1414

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ T ⟶}

TT

Bendix:

• TT8, TT9, TT13, TT15, TT17, TT18, TT20, TT21, TT22 – Chronotron, integrating, balanced-bridge hot-wire/PTC time delay devices

Marconi-Osram Valve Company:

• TT11 – Low-power VHF transmitting beam power tetrode
• TT21 = 7623 (6.3 V/1.6 A heater), TT22 = 7624 (12.6 V/800 mA heater) – 37.5 W AF/RF beam power tetrode up to 30 MHz, derived from KT88
• TT100 – RF beam power tetrode

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

V

_{LoVT ⟶ List of other tubes since c. 1935 ⟶ V ⟶}

VHT

Ferranti:

• VHT1 – Pentagrid converter, 1933

_{LoVT ⟶ List of other tubes since c. 1935 ⟶}

Lettered Loctal tubes used in Philco radios

• FM1000 – Unusual pentagrid for use as oscillator and coincidence-type phase detector in a PLL FM quadrature detector. The anode signal is loosely coupled into the oscillator tank and pulls it to stay quadrature-phase-locked with the IF;^[278] manufactured by Sylvania and used in Philco AM/FM radios of the late 1940s and early 1950s. Predecessor of the nonode approach
• XXB – Medium-mu twin triode, also numbered 3C6/XXB
• XXD – Medium-mu twin triode, also numbered 14AF7/XXD
• XXFM – High-mu triode, twin diode (one shares its cathode with the triode, one with separate cathode), also numbered 7X7/XXFM
• XXL – Medium-mu triode, also numbered 7A4/XXL

List of other tubes c. 1925–35

^[279]

_{LoVT ⟶ List of other tubes c. 1925–35 ⟶}

Tubes with directly heated cathodes

_{LoVT ⟶ List of other tubes c. 1925–35 ⟶ Tubes with directly heated cathodes ⟶}

With a 1.1 Volt DC filament

Powered by a storage battery ("B+" anode), and one 1.5 volt dry cell with a rheostat ("A" filament)

• WD-11 – Triode/detector

_{LoVT ⟶ List of other tubes c. 1925–35 ⟶ Tubes with directly heated cathodes ⟶}

With a 2 Volts DC filament

Powered by a storage battery (anode), and one 2 volt lead-acid cell (filament)

• 19 – Dual power triode, also used in farm radios with 6-volt vibrator power supplies; early version of Octal type 1J6G
• 20 – Power triode; early versions numbered UX-120
• 22 – Sharp-cutoff tetrode; early versions numbered UX-222 or CX-322
• 25S = 1B5 – Dual detector diode + medium-mu triode, usually numbered 1B5/25S
• 30 – Medium-mu/power triode popular amongst amateurs of the day; an upgraded version of type 01-A, early versions numbered RCA-230 or CX-330, early UX4 based version of Octal type 1H4G
• 31 – Power triode, UX4 based; early versions numbered RCA-231 or CX-331
• 32 – Sharp-cutoff tetrode; early versions numbered RCA-232 or CX-332
• 33 – Power pentode; early versions numbered RCA-233 or C-333
• 34 – Remote-cutoff tetrode; early versions numbered RCA-234 or CX-334
• 49 – Dual-grid power triode; similar to type 46

_{LoVT ⟶ List of other tubes c. 1925–35 ⟶ Tubes with directly heated cathodes ⟶}

With a 3.3 Volts DC filament

Powered by a storage battery (anode), and three dry cells with a rheostat (filament)

• V99 – Low-mu triode; similar to X99 except for stub-pin bayonet base and different pinout
• X99 – Similar to V99, but with standard pins and different pinout

_{LoVT ⟶ List of other tubes c. 1925–35 ⟶ Tubes with directly heated cathodes ⟶}

With a 4 Volts DC filament

Powered by a storage battery (anode), and two lead-acid cells (filament)

• 3NF – Tube-based "integrated circuit" with 3 triodes + passive components (audion, AF preamp and power amp) in the same envelope, 4 V/350 mA heater^[280]

_{LoVT ⟶ List of other tubes c. 1925–35 ⟶ Tubes with directly heated cathodes ⟶}

With a 5 Volts DC filament

Powered by a storage battery (anode), and three lead-acid cells (cheap 6 volt vehicle crank battery) with a rheostat (filament)

• 00-A – Detector triode with a trace of argon - this is the number used in most tube manuals; numbers for earlier versions include UX-200-A and CX-300-A (long pins, push-in socket) and UV-200-A (stub pins, bayonet socket)
• 01-A – All-purpose low-mu triode, used as RF amplifier, detector, AF amplifier and power triode, most popular in the 1920s - this is the number used for replacements manufactured after 1930 and in tube manuals; numbers for early versions include UX-201-A and CX-301-A (long pins, push-in socket) and UV-201-A (stub pins, bayonet socket)

Note: There were four tubes in the "01" series, each with different filament current ratings:

• UV 201 and UX 201 – 1.0 A
• 01-A (UV 201-A, UX 201-A, etc.) – 250 mA, most commonly used
• UX 201-B – 125 mA
• UX 201-C – 60 mA

• 12-A – Medium-mu triode, often used as detector, audio driver or audio output, but not as an RF amplifier – this number is listed in tube manuals after 1930 for replacements purposes; also referred to as type 112-A. Many early versions are marked UX-112-A or CX-112-A
• 40 – Medium-mu triode; early versions numbered UX-240. Introduced in 1927, this was an upgraded version of the "01" series which had an amplification factor of 8, while type 40 had an amplification factor of 30 (by comparison, the two AC triodes introduced in the same time period – types 26 and 27 – had amplification factors of 8.3 and 9, respectively). Because this was the highest-amplification triode available, advertising literature of the time lists it as a high-mu triode, although it is now classified as a medium-mu triode. Type 40 had the highest amplification factor of any triode until the introduction in 1932 of 2A6 diode/triode, which had an amplification factor of 100. It also had the highest amplification factor of any DC filament triode until the introduction in 1939 of 1H5GT/DAC32 (Octal) and 1LH4 (Loctal) diode/triodes, which both had amplification factors of 65

_{LoVT ⟶ List of other tubes c. 1925–35 ⟶ Tubes with directly heated cathodes ⟶}

Directly AC-heated power tubes

Used with a small, wirewound potentiometer across the floating heater supply with its slider tied to signal ground, to cancel out mains hum

• 10 – 12 W Power triode, 7.5 V/1.25 A filament; early versions numbered UX-210 or CX-310
• 26 – Medium-mu triode, 1.5 V/1.05 A filament, used in early AC radio receivers manufactured in the late 1920s as an RF or AF amplifier, but not as a detector or power output tube; early versions numbered UX-226 or CX-326
• 45 – 2 W Power triode, 2.5 V/1.5 A filament; early versions numbered UX-245 or CX-345
• 46 – 1.25 W Dual-grid power triode, 2.5 V/1.75 A filament (technically a tetrode). Two modes of operation available:

1. Grid 2 tied to anode for use as single-tube Class-A audio driver
2. Grids 1 and 2 connected together for use as push-pull Class-B output

• 47 – 2.7 W Power pentode, 2.5 V/1.75 A filament; early versions numbered RCA-247 or C-347
• 50 – 4.6 W Power triode, 7.5 V/1.25 A filament; early versions numbered UX-250 or CX-350
• 71-A – 790 mW Power triode, 5 V/250 mA filament – this number listed in tube manuals after 1930 for replacements purposes; also referred to as 171-A. Many early versions numbered as UX-171-A or CX-371-A

_{LoVT ⟶ List of other tubes c. 1925–35 ⟶ Tubes with directly heated cathodes ⟶}

Directly AC-heated rectifier tubes

• 80 – Full-wave rectifier used in early power supplies or battery eliminators; early versions numbered UX-280 or CX-380, similar to 5Y3G
• 81 – Half-wave rectifier; early versions numbered UX-281 or CX-381
• 82 – Full-wave mercury-vapor rectifier
• 83 – Full-wave mercury-vapor rectifier

• 83-V – High-vacuum version of type 83; early UX4 based version of Octal type 5V4G

_{LoVT ⟶ List of other tubes c. 1925–35 ⟶}

Tubes with indirectly heated cathodes

_{LoVT ⟶ List of other tubes c. 1925–35 ⟶ Tubes with indirectly heated cathodes ⟶}

With a DC heater

• 15 – Sharp-cutoff pentode, 2 V/220 mA heater, designed for Autodyne circuits requiring a separate (=indirectly heated) cathode, used in farm radios
• 48 – Power tetrode, 30 V/400 mA heater, designed for use on 115-volt DC mains systems, popular in 32-volt farm radios where two parallel or push-pull-connected 48s can deliver a modest audio power with anode and screen voltages as low as 28 volt; cf. 28D7W

_{LoVT ⟶ List of other tubes c. 1925–35 ⟶ Tubes with indirectly heated cathodes ⟶}

With a 2.5 Volts heater

Powered by an AC transformer or a 2-cell NiCd

• 24 – Sharp-cutoff tetrode, UX5 based; early versions numbered UY-224 and C-324

• 24-A – Upgraded 24; early versions numbered UY-224A and C-324A

• 27 – Medium-mu triode, UX5 based, the first North American tube with an indirectly heated cathode, which is necessary for detector c