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 amplifyAF, 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, VHFlow/mid/high, UHFlow/high, SHF, EHF, THF) applications.
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.
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 tube, 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.
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)
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 VRMS 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, 4VRMS 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 control 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 have a 2-phase (Eimac 8974, RCA 891 and Philips TAW12/10) or 3-phase (RCA 893, 898 and Philips TAW12/35G, TBW15/125) heater to reduce hum.
Types for mass-produced radio and TV receivers 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 ballast resistor or barretter chosen such that the sum of the heater and ballast voltages equals the mains voltage. Some power tubes have a heater tap near one end to feed a small pilot lamp, thus shunting away from it the heater current surge when powering up.[6] 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, have a comparable warm-up time, and the heater/cathode insulation has to withstand the high voltage at the top of a series heater string (which some tubes intended for parallel heater operation can't; if a heater further down the string breaks, they even have to withstand the full mains voltage).
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 ratings, but usually the same heater power[10]
Some tubes feature a center-tapped filament/heater, providing:
Two voltage/current options by series resp. parallel wiring of their two heater sections, e.g. 2×6.3 V/150 mA (series) resp. 6.3 V/2×150 mA (parallel) (examples), or
A defined cathode current return path and reference point for directly heated tubes where signal ground, and an internal shield and/or a suppressor grid if present, are connected to; this is the only allowed use for many directly heated high-power RF tubes since their center-tap can't carry the huge heater current, except with 2-phase heater tubes
In half-indirectly heated tubes the cathode and one side of the filament share the same pin.
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
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 envelope, possibly lodging between the grids and thus changing the characteristics of the tube
Constricted envelope section to firmly hold specially shaped flakeless mica spacers in place (5920/E90CC, 6084/E80F, 6922/E88CC)
Up to 2 sequentially assigned letters, skipping the letters I and O. After the single letters were exhausted, combinations like AB, AC, AD, AE... were used, avoiding same-letter repetitions and reserving those ending in P for CRTs (see below) Wherever possible, tubes that differed only in the heater ratings had the same letters; exceptions include: the 12BR7 and 9BR7 are unrelated to the 6BR7; the 4BL8/XCF80 is the 4.6 V/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 because the 6LN8 is 6.0 volts while the 6BL8 is 6.3 volts
A number with up to 2 digits indicating the count of active elements in the tube, including any shield and the heater in indirectly heated tubes – internally connected elements count as one; the use is somewhat arbitrary:
6 – Separate cathodes dual rectifier; tetrode; pentode; heptode (pentagrid converter); common cathode dual triode; common cathode dual diode + triode; separate cathodes dual diode; common cathode quad diode; tuning indicator; Triple-Twin; Reflex Klystron
7 – Separate cathodes dual rectifier with a heater tap for a pilot lamp; pentode; heptode; nonode; triode/hexode mixer; dual triode; common cathode triode + pentode; dual diode + pentode; dual diode + triode; diode + dual-anode tetrode; common cathode dual pentode; separate cathodes triple diode; common cathode quad diode; tuning indicator
8 – Heptode; octode; triode/hexode mixer; dual or triple diode + triode; common cathode (dual) diode + pentode; separate cathodes dual triode; separate cathodes triode + tetrode; triple triode; diode + three-anode tetrode; split-anode pentode; triode + pentode; quad diode; common cathode sextuple diode; beam deflection tube
9 – Separate cathodes dual diode + pentode; separate cathodes triode + pentode; common cathode dual triode + pentode; triple triode; separate cathodes dual pentode
10 – Separate cathodes triple triode; separate cathodes dual pentode; dual diode + dual triode
11 – Separate cathodes dual triode + pentode; separate cathodes triode + dual pentode; separate cathodes dual diode + dual triode; separate cathodes dual pentode
Exceptions include the 6L6-G/GT, 12L6-GT, 25L6-G/GT, 35L6-GT and 50L6-GT with a glass envelope and 5 elements, but legacy-named after the original 6L6 and 25L6 with a metal envelope connected to pin 1, making the sixth element
Optionally, up to three Latin letters indicating various revisions and improvements to the original model or different envelope shapes; the use is somewhat arbitrary:
A, B, C – Improved backward compatible versions
E – Export version
G – Shouldered glass envelope, ST-12 to ST-16 size
GT – Glass Tubular cylindrical envelope, T-9 size
GT/G – Glass envelope, T-9 size interchangeable with G and GT types
L – Loctal base
LM – Metal envelope with an Octalox (=Loctal) base
LT – Glass tubular envelope with an Octalox base
M – Metal envelope with an Octal base
MG – Metal-glass tube, a glass envelope hidden inside a tightly fitting metal jacket to make it look like a metal envelope
Lastly, manufacturers may decide to combine two designations into a single one, such as 6DX8/ECL84 (6DX8 and ECL84 being identical tubes under different naming schemes); 3A3/3B2 (drop-in replacement 3B2 superseding 3A3); 6AC5-GT/6AC5-G (6AC5-GT superseding 6AC5-G); 6BC5/6CE5 (6BC5 and 6CE5 being sufficiently identical)
Ballast tubes/resistors and barretters were assigned the following subset:
<Voltage>A1 to <Voltage>Z1 – No filament tap, no jumper
<Voltage>A2 – Filament tap for two pilot lamps
<Voltage>B2 – Filament tap for one pilot lamp
1D2, 1E2 – With a jumper to unpower the device when the ballast is pulled from its socket
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.[15]: 2  It therefore needs backlighting or external illumination like today's electronic paper[16][17]
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[18]
5BP3 (1802-P3) – Pre-World War II, 5" CRT, electrostatic deflection, P3 yellow, medium-persistence[18]
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,[19] electrostatic deflection, P4 white, medium-persistence[18]
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[21]
7JP4 – 7" CRT common in early postwar TV receivers, electrostatic deflection, P4 white, medium-persistence[21]
7JP7 – 5½" (14 cm usable screen diameter) CRT for use in early postwar radar displays, electrostatic deflection, P7 blue/yellow, short/long-persistence[21]
7NP4 (60 ft (18 m) projection distance), 7WP4 (80 ft (24 m) projection distance) – 7" Theatric projection CRTs, 75 kV anode voltage, considerable X-radiation, magnetic deflection, P4 white, medium-persistence, cast a 20 ft × 15 ft (6.1 m × 4.6 m) image
8CP1, 8CP2, 8CP4, 8CP5 (blue, very short), 8CP7, 8CP11 – 8" (20 cm) CRT for use in oscilloscopes, electrostatic deflection
15HP22 – 15" (38 cm) Color CRT, 45° magnetic deflection, P22 RGB, medium-persistence
25AP22 – 25" (64 cm) Color CRT, 90° magnetic deflection, P22 RGB, medium-persistence
30BP4 – 30" (76 cm) CRT used in 1950s premium television receivers, 90° magnetic deflection, P4 white, medium-persistence
The system was used in 1942–44 for professional/industrial/computer/telecommunications vacuum and gas-filled tubes, and assigned numbers with the base form "1A21" (therefore also referred to as the "1A21 system")[13]
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
A four-digit system was maintained by JETEC since 1944 and by EIA since 1957, for professional/industrial/computer/telecommunications 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:
Up to 2 letters denoting the construction type and the cooling method:
- (Dash) or R – Glass envelope, radiation cooling
C – Ceramic/metal envelope
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
P – Primarily for pulse applications
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:
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 variants 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
4CW2000A/8244 – 110 MHz, 2 kW Ceramic/metal radial-beam power tetrode; water-cooled variant 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 variant of 4CW2000A/8244
4CX3000A/8169 – 150 MHz, 3 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
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
This part dates back to the joint valve code key (German: Röhren-Gemeinschaftsschlüssel) negotiated between Philips and Telefunken in 1933–34.[28]: 228 [29]
Pro Electron maintained only a subset of this part since 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- and four-digit numbers starting with 1, 2, 3, 5, 8, 9 for the base.[30]
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[31]
Wide range 0.9 V to 1.55 V DC directly heated for dry cells
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; was shifted here from O
—Until at least 1938: 4 V battery (as opposed to A for "4 V AC"; no known examples assigned)[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 around 1961 after the risk of confusing with Luftwaffe tubes had subsided
M – 1.9 V, directly heated
N – 12.6 V, indirectly heated
O –
150 mA series heater, for South American markets;[32] later shifted to H
S – Separate cathodes 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
G8G 8-pin variants derived from B8G Loctal never got past prototyping, allegedly because the evacuation tip inside the narrow spigot broke off too easily
B11G 11-pin all-glass variant with one offset pin (EAA/UAA171, EBF/UBF171, ECH/UCH171, EEL/UEL171, EF/UF17x, EL/UL17x, EM/UM171)
For examplessee below; e.g. ECC40 is a dual triode with a 6.3 V heater and a Rimlock base; PABC80/9AK8 is a single diode + dual diode + triode with a 300 mA heater and a Noval base, also registered under RETMA as 9AK8; UM34 is a "Magic eye" tuning indicator with a 100 mA heater and an Octal base. If two tubes share the same M-P designation apart from the first letter (e.g. ECL82/6BM8, LCL82/11BM8, PCL82/16A8, UCL82/50BM8, XCL82/8B8) they will usually be identical except for heater ratings; there are exceptions, particularly among output types (for example, HL84, LL86/10CW5, PL84/15CW5, UL84/45B5, and XL86/8CW5 are series-heater versions of the EL86/6CW5 which is an EL84/6BQ5 resp. XL84/8BQ5 modified for a lower anode voltage). M-P designations 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 ECC82/12AU7, whereas the triode section of an ECL86/6GW8 does happen to be similar to those of an ECC83/12AX7.
Special quality tubes
Premium/SQ tubes (also French: "Securité - Qualité") for professional/industrial/computer/telecommunications purposes featured some modifications including those listed above
—SQ numbering before c.1960: System type letter and base type number swapped;[37] most were modified versions of standard types (ECC82/12AU7 → E82CC/6189, ECC88/6DJ8 → E88CC/6922), but some were not pin-compatible (EF80/6BX6 → E80F/6084). A few SQ tubes did not have a standard equivalent (E55L/8233, E90CC/5920, E91H/6687). For examples see below, starting at DC
RY – Vacuum half wave rectifier, thoriated tungsten filament
T – RF Power triode for use as amplifier or oscillator
X – Hydrogen, mercury-vapor or noble-gas thyratron
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
—Microwave tubes: Output power <1W; signal device for use as intermediate amplifier or low-noise receiver front end
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 – S24, Bialkalipotassium-antimony-caesium cathode, spectral response from UV to red
T – S20, Trialkalisodium-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, or
Flame detector tube, a solar-blind, UV-triggerable gas-filled cold-cathode switching diode which itself emits UV when triggered (cf. Geiger-Müller tube)
The following letter indicates the filling:
G – Gas-filled
V – High-vacuum
VP – 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 – Vacuum photometric cell, Red/IR sensitive, British 4-pin base
75B1 – Voltage-regulator tube, Miniature 7-pin base
75C1 – Voltage-regulator tube, Miniature 7-pin base
83A1 = 7980 – Voltage-regulator tube, Miniature 7-pin base
85A1 = 0E3 – Voltage-regulator tube, B8G Loctal base
85A2 = 0G3 – Voltage-regulator tube, Miniature 7-pin base
90C1 – Voltage-regulator tube, Miniature 7-pin base
95A1 – Voltage-regulator tube, Miniature 7-pin base
100E1 – Voltage-regulator tube, A4A European 4-pin base
108C1 = 0B2 – Voltage-regulator tube, Miniature 7-pin base
150A1 – Voltage-regulator tube, P8A side-contact 8 base
150B2 = 6354 – Voltage-regulator tube, Miniature 7-pin base
150B3 – Voltage-regulator tube, Miniature 7-pin base
150C1 – Voltage-regulator tube, P8A side-contact 8 base
150C2 = 0A2 – Voltage-regulator tube, Miniature 7-pin base
150C4 – Voltage-regulator tube, Miniature 7-pin base
BVA code
Little is known about this code other than that BVA members such as Cossor, EdiSwan and M-OV/GEC based their early designation systems on it
B – Dual triode
D – Diode
H – High-μ/high-impedance signal triode
HL – Medium-μ/medium-impedance signal triode
L – Low-μ/low-impedance signal triode
P – Power tube
S – Screen-grid tube (tetrode or pentode)
U – Rectifier
Compagnie des Lampes (1888, "Métal") system
The first (1888) incarnation of La Compagnie des Lampes produced the TM tube since 1915 and devised one of the first French systems;[13][41] not to be confused with Compagnie des Lampes (1921, "French Mazda", see below). This system was also used by the British ETA[42]
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, 2-pin Octal base, for rotating-drum FAX receivers, etc.
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 variants of a particular type[50]: 2 [28]: 198ff [13]
B309 = 12AT7/ECC81 – Dual high-μ 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 diode, British 5-pin base
D42 – Indirectly heated, single diode, British 4-pin 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-μ triode, Octal base
H610 – Directly heated, high-μ 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 – 7.5 W Beam power tetrode, Octal base, 26 V/300 mA heater for use in AC/DC radio receivers with series heater strings; drop-in replacement for the 25L6G, 25W6GT
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 – 6 W Beam power tetrode, Octal base, 6.3 V/700 mA heater; drop-in replacement for the 6F6 power pentode
KT66 – 7.25 W Beam power tetrode, Octal base, 6.3 V/1.27 A heater; drop-in replacement for the 6L6GC
KT67 – 25 W RF beam power tetrode, B9G 9-pin Loctal 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 variant of 6J7G/EF37 with suppressor plates tied 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-μ triode, Octal base
L610 – Directly heated, low-μ 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 #4 grid 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 power pentode, British 7-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
Older Mullard tubes were mostly assigned PM ("Philips-Mullard"), followed by a number containing the filament voltage.
Many later tubes were assigned acronyms with up to three letters, followed by a number containing the heater voltage. This was phased out after 1934 when Mullard adopted the Mullard–Philips scheme.
2D4 – Dual Diode with a 4 V/650 mA heater and a British 5-pin base
AP4 = Philips 4676 – Acorn UHF Pentode up to 430 MHz, 4 Volts heater
AT4 = Philips 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, M-OV/GEC 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, M-OV/GEC 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, M-OV/GEC S12
FC4 – Octode Frequency Converter with a 4 V/650 mA heater and a British 7-pin base with #4 grid on top cap; similar to the M-OV/GEC MX40 heptode[53]
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/GEC P425 – "Super Power" triode with a 4 V/200 mA battery heater and a British 4-pin base
TDD4 = M-OV/GEC 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/GEC VP21 = VP215 – Vari-μ Pentode with a 2 V/180 mA heater and a British 7-pin base
Most tubes before 1925 were assigned a letter and an optional Roman numeral (examples). Transmitting tubes started with the letter Z (Dutch: zendbuis, zendlamp).
In 1923, Philips introduced their Miniwatt brand to indicate Dull Emitter tubes.
In 1925, the Roman numerals of tubes still in production were replaced by Arabic numerals, and since then, new tubes were assigned as explained below; new transmitting tubes were assigned according to the system above.[54]
Standard tubes 1925–34
The system consisted of one letter followed by 3 or 4 digits.[55]: 15 [3][29][13] It was phased out after 1934 when Philips adopted the Mullard–Philips scheme.
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
1561 – 1.4 kV, 2×80 mA Full-wave rectifier; AZ2 with a European 4-pin base
1927 (40 to 120 V filament for 110VDC mains), 1928 (80 to 240 V filament for 220VDC mains) – Barretters for use with 180mADC tube sets[9]
56006 – OmegatronMass spectrometer tube. An electron gun sends an electron beam through a cavity to an electron collector anode. The cavity contains the gas to be analyzed. The gas is ionized by the electron beam and a magnetic field parallel to the axis of the beam forces the gas ions into a helical path around the beam, the orbital angular velocity depending on the ion mass. An electrode inside the cavity floods it with an RF electric field perpendicular to the magnetic field, from a sweep generator. When the frequency matches an ion's angular velocity, that ion will resonate and spiral outward like in a cyclotron, eventually hitting an ion collector electrode and generating a current there, which is amplified and measured[58]
From 1924 to 1939, Philips printed a basing code on tube cartons and price lists, but not on the tubes themselves.[28]: 228  Socket designations such as "A-type" or "P-base" refer to this code, which was later (1950s) expanded to a <BasingCode><PinCount><Variant> format (where new designs were assigned the default basing codes "B" for normal tubes and "X" for microwave tubes):
A – 4-pin Continental European base, originally Franco-British
B – 4-pin Telefunken base (1920s);[55]: 16f  later 6-pin Continental European base (1930s)[3]: 15 
C – American UV base (1920s); later 7-pin Continental European base (1930s)
D – 5-pin French base, used on bi-grille tetrodes
E – 4-pin French Radiola base (1920s); later 7-pin Medium American base (1930s)
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.
Polish Lamina(pl) transmitting 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
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
The Tungsram system was composed of a maximum of three letters and three or four digits.[62][61] 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 – Diode
DD – Dual diode
DG – Tetrode with a space charge grid (the 2nd grid is the control grid)
Vacuum tubes produced in the former Soviet Union and in present-day Russia are assigned 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[61]
The Chinese 广州曙光无线电厂 (GuangzhouShuguang Radio Factory) did the reverse, adapting the GOST system (below) to Latin letters for some of their tubes.[66]
GOST standard tubes system
In 1950, a 5-element system (Russian: ГосударственныйСтандарт "State standard" ГОСТ↦GOST 5461-50 and later revisions 5461-56, 5461-59, 13393-67, 13393-76) was introduced in the (then) Soviet Union for designating receiver vacuum tubes.[67][68]
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:
П ⟼ P – All-glass Miniature 7-pin or Noval, envelope diameter 19 or 22 mm (3⁄4 or 7⁄8 in)
Р ⟼ R – Subminiature all-glass wire-ended, envelope diameter up to 5 mm (0.2 in)
А ⟼ A – Subminiature all-glass wire-ended, envelope diameter 5 to 8 mm (0.2 to 5⁄16 in)
Б ⟼ B – Subminiature all-glass wire-ended, envelope diameter 8 to 10 mm (5⁄16 to 0.4 in)
Г ⟼ G – Glass envelope, diameter 10 to 22 mm (0.4 to 7⁄8 in)
С ⟼ S – Glass envelope, diameter more than 22 mm (7⁄8 in), typically with an Octal base
The 5th element is optional. It consists of a dash 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):
ЛФ ⟼ LF – Analog function generator,(ru) an analog mask ROM + D/A converter combination consisting of an oscilloscope-type CRT with the phosphor screen replaced by an electron collector located behind a target perforated with sub-mm holes patterned such that the hole density z at any given x,y position is proportional to the value[71] of the desired f (x,y)
6M-E10 – "Magic Eye"-type tuning indicator, Miniature 7-pin base
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.[74] 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 envelope 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:
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 – Dual high-μ 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:
Used in a similar way to a Zener diode, at higher voltages
—Miniature 7-pin-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 V Voltage-regulator tube, Miniature 7-pin base
0A3 = VR75 – 75 V Voltage-regulator tube, Octal base
0B2 = 108C1 (6627) – 105 V Voltage-regulator tube, Miniature 7-pin base
0B3 = VR90 – 90 V Voltage-regulator tube, Octal base
0C2 – 75 V Voltage-regulator tube, Miniature 7-pin base
0C3 = VR105 – 105 V Voltage-regulator tube, Octal base
0D3 = VR150 – 150 V Voltage-regulator tube, Octal base
0E3 = 85A1 – 85 V Voltage-regulator tube, 3-pin base
0G3 = 85A2 – 85 V Voltage-regulator tube, Miniature 7-pin base
0A4G (Z300T) – 25 mAavg, 100 mApeak 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 fres is present
0A5 – 1 kV, 10 Apeak Gas triode with a keep-alive (primer) electrode and a shield grid, designed for relay drive and general switching service
0Y4 – 300 V, 40 ≤ I ≤ 75 mA Half-wave gas rectifier with a starter anode, 5-pin Octal base
0Z3 – 300 V, 30 ≤ I ≤ 75 mA Full-wave gas rectifier, 5-pin base. Used in vibrator power supplies in early automobile radio receivers
0Z4 – 880 V, 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
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 ca. 0.366–0.4 in (9–10 mm) (round) resp. 0.285 by 0.366–0.4 in (7 by 9–10 mm) (elliptical) in diameter, and 1+1⁄8 to 2 in (29 to 51 mm) in length
1AD4, 1AG4, 1AG5, 1AK4 and 1AK5 pentodes have a split suppressor grid, its halves tied to the positive resp. negative filament end
1AC5 – Power pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends
1AD4/DF62 – Sharp-cutoff pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends
1A3/DA90 – Indirectly heated FM discriminator diode, 1.4 V/150 mA heater, Miniature 7-pin base. Used as a detector in some portable AM/FM receivers
1A7GT/DK32 – Heptode pentagrid converter, 1.4 V/50 mA filament, Miniature 7-pin base, re-engineered variant of 1A6 and 1D7-G, designed for use in Three-way portable (AC/DC/Dry-cell battery) radios introduced in 1938
1B7GT – Heptode pentagrid converter, 1.4 V/100 mA filament, re-engineered variant of 1C6 and 1C7-G, designed for use in dry-cell battery radios with shortwave bands
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 ZenithTrans-Oceanicshortwave radio, 50 mA filament
1LB6 – Heptode pentagrid converter for battery-operated radios
1R5/DK91 – Heptode pentagrid converter, anode voltage in the 45...90 volt range, 50 mA filament, Miniature 7-pin base
1R5-SF = 1AQ5 – 1R5/DK91 with a 25 mA filament
1S4/DL91 – 270 mW AF power pentode Class-A amplifier, anode voltage in the 45...90 volt range, 1.4 V/100 mA filament, Miniature 7-pin base
1S5/DAF91 – Diode + sharp-cutoff pentode Class-A amplifier, anode voltage in the 67...90 volt range, 50 mA filament, Miniature 7-pin base, used as detector and first AF stage in battery radio receivers
1S5-SF = 1S5T = 1AR5 – 1S5/DAF91 with a 25 mA filament
1T4/DF91 – Remote-cutoff RF pentode Class-A amplifier, 50 mA filament, Miniature 7-pin base, used as RF and IF amplifier in battery radio receivers
1T4-SF = 1AM4 – 1T4/DF91 with a 25 mA filament
1U4/DF904/5910 – Sharp-cutoff RF pentode Class-A amplifier, Miniature 7-pin base, used as RF and IF amplifier in battery radio receivers; similar characteristics to 6BA6/EF93
1U5/DAF92 – Diode + AF pentode, 50 mA filament, Miniature 7-pin base
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 diode + medium-μ 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-μ 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
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 = 1Ц7С↦1C7S – CRT EHT rectifier with 1.25 V filament, peak inverse voltage of 30 kV, anode current 2 mA average, 17 mA peak, Octal base, common in monochrome TV receivers of the 1950s and early 1960s; derived from the earlier industrial type 8016
1BC2 – CRT EHT rectifier with 1.25 V/200 mA filament, Noval base
1BC2A, 1BC2B – 1BC2 with internal X-radiation shielding
1BG2/DY51 – Subminiature 15 kV portable-TV CRT EHT rectifier, half-indirect (filament internally tied to cathode sleeve) 1.4 V/575 mA heater, all-glass, heater wires on one end, anode wire on the other
1BQ2/DY802 – 20 kV CRT EHT rectifier, half-indirect 1.4 V/600 mA heater, Noval base, silicone-coated envelope to avoid flush-over in high-humidity and low atmospheric-pressure conditions
1BY2 – Compactron CRT EHT rectifier with 1.25 V/200 mA filament
1BY2A – 1BY2 with internal X-radiation shielding
1H2 – CRT EHT rectifier with half-indirect 1.4 V/550 mA heater, Noval base
1J3GT/1K3GT – CRT EHT rectifier, Octal base. Same characteristics as 1B3GT/DY30. Has filament-anode shorting protection
1S2/DY86 = 1Ц21Б↦1C21B – 18 kV CRT EHT rectifier, half-indirect 1.4 V/550 mA heater, Noval base; 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 CRT EHT rectifier with 1.4 V/140 mA filament, filament wires on one end, anode wire on the other
1V2 – CRT EHT rectifier with 0.625 V/300 mA filament, Miniature 7-pin base
1X2 – CRT EHT rectifier with 1.25 V/200 mA filament, Noval base
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 – CRT EHT rectifier with 0.7 V/180 mA filament, Octal base
1Z2 – CRT EHT rectifier with 1.25 V/265 mA filament, Noval base
2B6 – Triple-Twin AF signal + zero bias power triode, internally connected as a cathode follower like today's Darlington transistors; cf. 295, 6AC6, 6B5, 6N6G
2B7 – Dual diode + remote-cutoff pentode; 6B7 with a different heater
2E5 – Top-view, "Magic Eye"-type tuning indicator; 2G5 with a sharp-cutoff driver triode; 6E5 with a different heater
2G5 – Top-view, "Magic Eye"-type tuning indicator; 2E5 with a remote-cutoff driver triode; 6G5/6U5 with a different heater
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, Miniature 7-pin base
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
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 – 700 mW 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 tied 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 – 200 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 tied 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, 2.8 V/50 mA resp. 1.4 V/100 mA filament, Miniature 7-pin base
3S4-SF = 3S4T = 3W4 – 3S4/DL92 with a 2.8 V/25 mA resp. 1.4 V/50 mA filament
3V4/DL94 – 270 mW AF power pentode, Miniature 7-pin base
3AT2 – Compactron CRT EHT rectifier for color TV, half-indirect 3.15 V/220 mA heater
3AT2B – 3AT2 with internal X-radiation shielding
3AW2 – Compactron CRT EHT rectifier for color TV, half-indirect 3.15 V/350 mA heater
3AW2A – 3AW2 with internal X-radiation shielding
3BF2 - Compactron CRT EHT rectifier for color TV, indirect 3.6 V/225 mA heater
3BL2 – Compactron CRT EHT rectifier for color TV, 3.3 V/285 mA filament
3BL2A – 3BL2 with internal X-radiation shielding
3BM2 – Compactron CRT EHT rectifier for color TV, 3 V/300 mA filament
3BM2A – 3BM2 with internal X-radiation shielding
3BN2 – Compactron CRT EHT rectifier for color TV, half-indirect 3.15 V/300 mA heater
3BN2A – 3BN2 with internal X-radiation shielding
3BS2 – Compactron CRT EHT rectifier for color TV, half-indirect 3.15 V/480 mA quickstart heater
3BS2A, 3BS2B – 3BS2 with internal X-radiation shielding
3BT2 – Compactron CRT EHT rectifier for color TV, half-indirect 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 – Compactron CRT EHT rectifier for color TV, half-indirect 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, half-indirect 3.6 V/225 mA heater
3CN3 – CRT EHT rectifier with a diffusion-bonded cathode for color TV, Octal base, half-indirect 3.15 V/480 mA quickstart heater
3CU3 – CRT EHT rectifier for color TV, Octal base, 3.15 V/280 mA filament
3CZ3 – CRT EHT rectifier for color TV, Octal base, half-indirect 3.15 V/480 mA quickstart heater
More of these tubes are listed as equivalents under M-P G - Miscellaneous
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 resp. 2 V filament
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 (Octal base; PH4, M-OV/GEC X63) – Heptode pentagrid converter with control grid (#4 grid) on top cap; based on 2A7, which had a 2.5 volt heater; Loctal version: 7B8
6AB5/6N5 – Top-view, "Magic Eye"-type tuning indicator with a sharp-cutoff driver triode
6AC5-G – Zero bias high-μ power triode designed for operation with positive grid bias up to +13 V supplied from a cathode follower driver triode such as 76, 6J5, 6P5, or half a 6AE7; cf. 295, 2B6, 6AC6, 6B5, 6N6G Triple-TwinDarlington triodes
6AC6 – Triple-Twin AF signal + zero bias power triode with a common, single anode, internally connected as a cathode follower
6AC7 = 1852 – TV sharp-cutoff RF pentode, often encountered in a black metal envelope (not to be confused with the 6CA7/EL34)
6AD6-G (100 to 150 V target for AC/DC radios), 6AF6-G (250 V target for larger AC radios) – Top-view, driverless "Magic Eye"-type tuning indicators with two independent "pie wedge" shadow indicators on opposite sides of a single circular target, a 6.3 V/150 mA heater and an Octal base Both shadows may be used in tandem or may be driven by two different signal sources. Type 6AE6-G is specifically made to drive 6AD6-G and 6AF6-G, but they may also be driven by a sharp-cutoff pentode like a 6J7-G/EF37 (highly sensitive to weak signals) for one shadow and a remote-cutoff pentode like a 6K7/EF39 (reacting only to stronger signals) for the other
6AE6-G – Split-anode driver triode for tuning indicators 6AD6-G and 6AF6-G, 6.3 V/150 mA heater, common cathode, common grid with a high-μ section for one anode and a vari-μ section for the other. The high-μ grid reacts to weak signals while the vari-μ grid reacts only to stronger signals
6AE7-GT – Common-anode, separate cathodes dual triode for use as a cathode follower driver for two zero bias power triodes such as 6AC5 in push-pull service; cf. 295, 2B6, 6AC6, 6B5, 6N6G Triple-Twin Darlington triodes
6AF4/EC94 – UHF Medium-μ oscillator triode, commonly found in TV tuners and converters
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, unusual low-power consumption output tube with 150 mA heater; 6G6-G with a Miniature 7-pin base
6AK8/EABC80 – Triple diode + high-μ triode on common cathode with two of the diodes, used as AM detector/AVC rectifier/FM ratio detector/AF amplifier in AM/FM radios manufactured outside of North America, Noval base, triode μ = 70; 6T8 with a longer glass envelope
6AK10 – Compactron Triple high-μ triode for use as NTSC chroma signal demodulator matrix in analog color TV receivers
6AL3/EY88 = 6Д20П↦6D20P – 6 kV, 220 mA CRT horizontal deflection output booster/damper/efficiency diode, Noval base with cathode on top cap
6AL5/EAA91 = M-OV/GEC D77 = 6Х2П↦6H2P – 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; 6L6-G with a different pinout and anode on 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/GEC Z77 (M8083) – Sharp-cutoff RF pentode used in receiver front ends and test gear such as VTVMs and TV broadcast modulation monitors
6AN8 – Triode + pentode used in CRT vertical deflection timebase circuits; electrically fairly similar to ECL80 but with a different pinout
6AQ5/EL90 (6П1П↦6P1P) – Beam power pentode, Miniature 7-pin; similar to 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
6AV6/EBC91 – Common cathode dual diode + high-μ AF triode for use in FM ratio detectors, triode μ = 100 (triode section similar in characteristics to one half of a 12AX7/ECC83); Miniature 7-pin version of type 75
6AX5 – 1.25 kV, 2×375 mA Full-wave rectifier, Octal base; similar in structure to 6X5, but with higher voltage and current ratings which are comparable to those of 5Y3 and 80
6B5 (UX6 base), 6N6G (Octal base) – Triple-Twin AF signal + 4-Watts zero bias power triode, internally connected as a cathode follower like today's Darlington transistors; cf. 295, 2B6, 6AC6
6B6-G – Dual diode + high-μ triode, grid on top cap; 75 with an Octal base, later 6SQ7 (without top cap), Miniature 7-pin version: 6AV6/EBC91
6B7 (UX7 base), 6B8 (EBF32, Octal base) – Dual diode + semiremote-cutoff pentode with control grid on top cap. The diodes were most commonly used as AM detector and AVC rectifier in superheterodyne receivers. The pentode was used as variable-gain IF or AF amplifier, or in reflex receivers - in a typical 2B7/6B7/6B8 reflex circuit, the IF signal from the converter is injected into the pentode and amplified. The diodes then extract 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;[76] based on 2B7 which had a 2.5 volt heater
6BA6/EF93 = M-OV/GEC W727 = 6К4П↦6K4P (5749) – Semiremote-cutoff RF pentode, popular in car radios
6BA11 – Compactron triode + split-anode pentode for use as TV vertical deflection oscillator and sync sep
6BC5/6CE5 – Semiremote-cutoff VHF pentode up to 400 MHz, Miniature 7-pin base; 6AG5/EF96 with a higher gain
6BK4 = 6С20С↦6S20S – High voltage beam power triode, Ua=27 kV, Ia=1.5 mA, Pa=25 W, Uh-c=-200 V, used as shunt regulator in color TV receivers and in measurement equipment such as high voltage meters
6BK11 – Compactron 2× High-μ + 1× medium-μ triple triode preamplifier, 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 = 6Ф1П↦6F1P – 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 = 6Ф3П↦6F3P – Triode + pentode used as driver and output stages in AF or TV vertical deflection amplifiers and has even been seen in an electronic nerve stimulator
6BN6/6KS6 = 6А3П↦6A3P, 6DT6 – Gated-beam discriminator pentode, used in radar, dual channel oscilloscopes and FM quadrature detectors where the suppressor grid is connected to ground via an LC tank circuit tuned for a 90° phase lag to the IF at center frequency;[77] cf. Nonode
6BQ5/EL84 = M-OV/GEC N709 = 6П14П↦6P14P – 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 with diagonal screen sizes less than 19 in (48 cm), however, may be found in some larger models which more often used similar type 6DQ6
6BQ6-GTB/6CU6 – Improved 6BQ6-GT
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 6AQ8/ECC85, 6BK7, 6BZ7
6BQ7A/ECC180 (6Н1П↦6N1P) – Improved 6BQ7 capable of operation at UHF frequencies
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 6AQ8/ECC85, 6BK7, 6BQ7
6C4/EC90 – 3.6 W small-power VHF triode up to 150 MHz; single 12AU7/ECC82 system
6C6 (UX6 base), 6J7G/EF37 (Octal base) – Sharp-cutoff RF pentode, suppressor grid on a separate pin, control grid on top cap, for use as tuned RF amplifier or biased detector or AF amplifier, also used in test equipment; based on type 57, which had a 2.5 volt heater; similar to types 1603, 77 and Octal type 6SJ7 (control grid on pin 4)
6C10 – Compactron Triple high-μ triode – not related to the Mazda/EdiSwan 6C10 triode-hexode
6CM5/EL36 = 6П31С↦6P31S – AF or CRT horizontal deflection output beam power tetrode
6CW4 – Nuvistor High-μ 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 mAavg, 100 mApeak 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 (UX6 base), 6U7-G (Octal base) – Remote-cutoff RF pentode, suppressor grid on a separate pin, control grid on top cap, for use as an IF amplifier or as a mixer, also used in test equipment; based on type 58, which had a 2.5 volt heater; similar to types 78, 6K7/EF39 and 6SK7 (control grid on pin 4)
6D8-G – Heptode pentagrid converter, Octal base with 2nd control grid on top cap, 150 mA heater, used in pre-war 6-volt farm radios; similar to 6A8
6D10 – Compactron Triple high-μ triode for use as oscillator, mixer, amplifier or AFCreactance tube
6DA6/EF89 – RF Pentode used in AM/FM radios manufactured outside North America
6DJ8/ECC88 = 6Н23П↦6N23P = Shuguang6N11 (↤6Н11) – Dual RF/AF triode for use 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 in (43 cm). Smaller receivers often used similar type 6BQ6-GT. Also used as audio output tubes in Standel guitar amplifiers
6DQ6-B/6GW6 – 6DQ6 with higher ratings and a higher zero-bias anode current
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 Semiremote-cutoff 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
6DV4 – Medium-μ Nuvistor triode for UHF oscillators; some versions had a gold-plated envelope
6DX8/ECL84 = 6Ф4П↦6F4P – TV sync sep triode + CRT cathode drive power 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 = 6К8П↦6K8P (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 RF cascode amplifier in TV tuners and VHF receiver front ends, also used as general-purpose dual triode in test gear; similar to 6DJ8/ECC88
6EZ8 – Triple high-μ VHF triode for use in FM tuners, Noval base, cathodes 1 and 2 and one side of the heater share pin 4
6F4 – Acorn UHF triode up to 1.2 GHz, for use as an oscillator
6F5 – High-μ triode, equal to triode section of 6Q7
6F6 (metal envelope), 6F6-G (shouldered glass envelope; M-OV KT63), 6F6-GT (cylindrical glass envelope) – 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), sometimes used as a transformer-coupled audio driver for 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 (UX7 base), 6P7-G (Octal base) – Common-cathode, remote-cutoff pentode + medium-μ triode with the pentode control grid on top cap, for use as triode/pentode mixer/oscillator, or as combination IF amplifier (pentode) and AM detector or AF amplifier (triode)
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-μ 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), Miniature 7-pin base; cf. DAH50, EF8, EF38
6G5/6U5 (UX6 base), 6G5G/6U5G (Octal base) – Top-view, "Magic Eye"-type tuning indicator; 6E5 with a remote-cutoff driver triode; 2G5 with a different heater
6G6-G – 1.1 W Power pentode, Octal base, 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 sep or AGC service
6GV8/ECL85 = 6Ф5П↦6F5P – 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 – Triple high-μ VHF triode for use as Autodyne or AFC reactance circuit in FM tuners, Noval base, cathode 3, control grid 1 and one side of the heater share pin 4
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 = 6Х6С↦6H6S (EB34, M-OV/GEC 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, 6MK8 – Dual-anode pentode for TV receiver sync sep service or as a two-channel VCA
6HZ5/6JD5/6JH5 – Compactron High voltage beam power triode with a 2nd grid ("beam plate") connected to the cathode (technically a tetrode), Ua=3.5 kV, Iapeak=300 mA, Pa=35 W, Uh-c=-200...+450 V, used as shunt regulator in color TV receivers
6J5 = 6С2Б↦6S2B (Metal), 6J5GT = 6С2С↦6S2S (Glass, M-OV/GEC L63) – Indirectly heated medium-μ triode; 12J5GT with a different heater
6J6/ECC91 – Dual VHF triode with common cathode up to 600 MHz, Miniature 7-pin base
6JU8A – 9 mA Quad diode, units 1&2 and 3&4 internally series-connected, for use in FM-stereo demuxers or in phase detectors
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. Also used in test equipment; Octal version of type 78, later 6SK7 (control grid on pin 4)
6K8 – American triode/hexode mixer, 1938; 12K8 with a different heater
6K11/6Q11 – Compactron 2× High-μ + 1× medium-μ triple triode for use as a sync clipper and gated AGC amplifier in TV receivers
6KM8 – Diode + three-anode sharp-cutoff tetrode for use in musical instruments, frequency dividers and complex wave generators
There are several variations. Except for 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 (6W6-GT is the 6.3 volt heater version of 12L6-GT, 25L6-GT and 50L6-GT)
6L6GA – Post-war version of 6L6-G, in smaller ST-14 shape with Shouldered Tubular (ST) shaped envelope, revision A
6L6GB – Post-war improved version in a cylindrical glass envelope; similar to 5881
6L6GTB – 6L6 with Glass Tubular envelope, 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 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, low loss ceramic base for improved RF performance, max. output 30 watts
6L7 – Heptode pentagrid converter often used in console radios of the late 1930s. Because of low conversion transconductance, radios using 6L7 typically have either a tuned RF pre-amplifier stage, or at least two stages of IF amplification (a few models have both); similar in structure to heptodes 6SA7 and 6BE6, except that a separate oscillator – usually 6C5 – is required, as #1 grid is the remote-cutoff RF signal input grid and #3 grid is the oscillator input grid (in types 6SA7 and 6BE6, #1 grid is the internal oscillator grid, #3 grid is the signal input grid)
6N7, 6N7-G, 6N7-GT = 6Н7С↦6N7S – 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 – Dual diode + remote-cutoff pentode for use as detector plus RF or AF amplifier in radios
6P5-G/GT – Medium-μ triode, often used as cathode follower driver for the 6AC5-G zero bias power triode; Octal version of type 76
6P7-G – Rarely seen Octal version of 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
6R3/EY81 – 4.5 kV, 150 mA CRT horizontal deflection output booster/damper/efficiency diode, Noval base with cathode on top cap
6R7, 6R7-G, 6R7-GT – Dual diode + medium-μ triode, Octal base with top cap, μ = 16; Miniature 7-pin version: 6BF6
6S7-G – Remote-cutoff RF pentode, Octal base with control grid on top cap, 150 mA heater, used in pre-war 6-volt farm radios; similar to 6K7
6S8-GT – Triple diode + high-μ triode sharing a cathode with two of the diodes, Octal base with triode grid on top cap. 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
6SC7 – Common cathode dual high-μ triode, Octal base
6SK7 = 6К3П↦6K3P – Remote-cutoff pentode used in IF stages of North American radios, Octal base; Miniature 7-pin version: 6BD6
6SL7/ECC35 (6Н9С↦6N9S) – General purpose dual triode, Octal base
6SN7/ECC32 (6Н8С↦6N8S, M-OV/GEC B65, Brimar 13D2, CV1986, 6042, 6180) – Dual medium-μ triode, each section is equivalent to a 6J5, Octal base, used in audio amplifiers, Hammond organs, television, and extensively in World War II radar; similar with first grid on top cap: 6F8G; Noval version: 6CG7/6FQ7, later 12AU7
6SR7 – Dual diode + triode, Octal base; 12SR7 with a different heater
6SS7 – Remote-cutoff pentode, Octal base, 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; 6SK7 with a 150 mA heater
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-μ triode, Octal base with control grid on top cap, 150 mA heater, used in pre-war farm radios; similar to 6Q7
6T8 – Triple diode + high-μ triode on common cathode with two of the diodes, Noval base, triode μ = 70, used as AM detector/AVC rectifier/FM ratio detector/AF amplifier in North American AM/FM radios; 6AK8/EABC80 with a shorter glass envelope
6V4/EZ80 – 1 kV, 2×45 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; 5V6 or 12V6 with a different heater; electrically similar to 6AQ5/EL90
6V6G – 6V6 with Shouldered Tubular (ST) shaped envelope
6V6GT – 6V6 with Glass Tubular envelope
6V7-G – Dual diode + medium-μ triode, μ = 8.3; Octal version of type 85, similar to 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 = 6Ц4П↦6C4P (Miniature 7-pin base) and 6X5/EZ35 (Octal base) – 1.25 kV, 2×210 mA Full-wave rectifiers with indirectly heated common cathode, based on type 84/6Z4
More of these tubes are listed as equivalents under M-P E - 6.3 V heater
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-μ triode; Loctal version of 6J5, often numbered 7A4/XXL
7A5 – Beam power pentode; Loctal version of 6U6GT
7A6 – Dual diode; similar to 6H6
7A7 – Remote-cutoff pentode; Loctal version of 6SK7
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
—with a straight heater:
12A7 – Half-wave rectifier + power pentode, UX7 base with top cap. Pentode section is similar to type 38. Rectifier has a low power rating – 120 V/30 mA – that limits the number of tubes that can be connected 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. Not related to 2A7 and 6A7
Parallel heater circuits - the same tube may be wired for 6.3 or 12.6V,
Series heater strings - the same tube may be wired for e.g. 150 or 300mA
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, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, UX7 base. Mostly used in pre-war car radios
12AD7 – Dual high-μ triode, center-tapped 12.6 V/225 mA resp. 6.3 V/450 mA heater, Noval base
12AT7/ECC81 = M-OV/GEC B309 (6060, 6201, M8162) – Dual high-μ 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[78]
12AU7/ECC82 = M-OV/GEC B329 (6067, 6189, M8136) – Dual medium-μ triode with a center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater.[78] Two 6C4/EC90s in one envelope;[80] however, it is only specified as an audio frequency tube. Commonly used in audio applications and TV receivers
12AV7 (5965) – Dual medium-μ triode with a center-tapped 12.6 V/225 mA resp. 6.3 V/450 mA heater. Principally designed for VHF amplifier/mixer operation[81]
12AX7/ECC83 = M-OV/GEC B339 (6Н2П↦6N2P, 6057, 6681, M8137) – Dual high-μ 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[78]
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[78]
12AZ7 – Dual medium-μ 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[82][78]
12B4A – Power triode with a center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base[78]
12BH7 – Dual medium-μ power triode with a center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater[83][78]
12BR7 – Dual diode + triode with a center-tapped 12.6 V/225 mA resp. 6.3 V/450 mA heater; 9BR7 with a different heater
12BZ7 – Dual high-μ triode for use as sync sep and amplifier, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base
12DF5 – Dual 1.275 kV, 350 mA rectifier with separate cathodes, center-tapped 12.6 V/450 mA resp. 6.3 V/900 mA heater, Noval base, for use as a voltage doubler
12DF7 – Dual triode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater, Noval base; low-microphonics version of 12AX7
12DM7 – Dual high-μ 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-μ 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, Miniature 7-pin 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
12AE7 – Low (12.6-16 V) anode voltage dissimilar (medium-μ + low-μ) 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, Miniature 7-pin base
12AL8 – Low (12.6-30 V) anode voltage medium-μ 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, Miniature 7-pin 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 + dual dissimilar, low (12.6-16 V) anode voltage triode, 12.6 V/450 mA heater, Noval base
12DY8 – Low (12.6-16 V) anode voltage medium-μ 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, Miniature 7-pin base
12EA6 – Low (12.6-16 V) anode voltage IF pentode, 12.6 V/175 mA heater, Miniature 7-pin base
12EC8 – Low (12.6-16 V) anode voltage medium-μ triode + semiremote-cutoff pentode, 12.6 V/225 mA heater, Noval base
12EG6 – Low (12.6-30 V) anode voltage heptode pentagrid converter, both control grids #1 and #3 are sharp-cutoff, 12.6 V/150 mA heater, Miniature 7-pin base
12EL6 – Dual diode + low (12.6-30 V) anode voltage, high-μ triode, 12.6 V/150 mA heater, Miniature 7-pin 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, Miniature 7-pin base; car radio version of 12BE6/HK90
12FM6 – Dual diode + low (12.6-30 V) anode voltage, medium-μ triode, 12.6 V/150 mA heater, Miniature 7-pin 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, Miniature 7-pin 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, Miniature 7-pin base; similar to 12FA6, but with lower conversion transconductance
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, Miniature 7-pin 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 – Dual low (26.5-300 V) anode voltage 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
12U7 – Dual low (12.6-30 V) anode voltage, medium-μ triode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater, Noval base
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-μ triode; Loctal version of 12J5
14A5 – Beam power pentode
14A7 – Remote-cutoff pentode, often numbered 14A7/12B7
14AF7 – Dual medium-μ triodes, often numbered 14AF7/XXD
14B6 – Dual diode + high-μ triode; similar to 12AV6/HBC91 and 12SQ7
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
25B5 (UX6 base), 25N6G (Octal base) – Triple-Twin AF signal + 4-Watts zero bias power triode, internally connected as a cathode follower like today's Darlington transistors; 6B5 resp. 6N6G with a different heater
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 keypunchsolenoid 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 (UX6 base), 25Z6 (Octal base) – Dual 700 V, 450 mA rectifier with separate cathodes for use as a voltage doubler
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
117Z3 – Half-wave rectifier; 117Z4GT with a Miniature 7-pin base
117Z4GT – Half-wave rectifier
117Z6GT – Dual rectifier with separate cathodes for use as a voltage doubler; some versions have a center-tapped heater that can also be wired for 150 mA/58.5 V
14GT8/7724, 14JG8 – Dual diode + high-μ triode for use as FM detector and AF amplifier in fixed, series-heated, or mobile, parallel-heated equipment
17EW8/HCC85 – Dual triode for use as VHF oscillator/mixer up to 200 MHz, Noval base; 6AQ8/ECC85, 9AQ8/PCC85 or UCC85 with a 17.5 V heater
19T8/HABC80 – Triple diode + high-μ triode on common cathode with two of the diodes, Noval base, triode μ = 70, used as AM detector/AVC rectifier/FM ratio detector/AF amplifier in series-heated post-war AM/FM radios; 5T8, 6T8, 6AK8/EABC80, 9AK8/PABC80 or 27AK8/UABC80 with an 18.9 V 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
Most are series heater versions of respective 6-prefix tubes; used in TV receivers with series heater strings
4HK5 – VHF frame-grid, vari-μ triode; 2HK5, 3HK5 or 6HK5 with a 4.0 V heater
6AU7 – Dual medium-μ AF triode; 12AU7/ECC82 with a center-tapped 300 mA/6.3 V resp. 600 mA/3.15 V heater
6AX7 – Dual high-μ AF triode; 12AX7/ECC83 with a center-tapped 300 mA/6.3 V resp. 600 mA/3.15 V heater
6CN7 – Dual common cathode diode + triode for use as horizontal phase detector and reactance tube in TV receivers; 8CN7 with a center-tapped 300 mA/6.3 V resp. 600 mA/3.15 V heater
7AU7/XCC82 – Dual triode; 6AU7 with a center-tapped 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 lamps
42B2, 49B2, 55B2, 80B2, 86B2, 92B2 – Straight ballast resistors with tap for 1 pilot lamp
50A2 (with tap for 2 pilot lamps), 50B2 (with tap for 1 pilot lamp) – 50 V Barretter, 4-pin base, to stabilize against mains voltage fluctuations
58HE7 – Compactron High-perveance horizontal deflection output booster/damper/efficiency diode + beam power pentode; 6HE7, 12HE7 or 38HE7 with a 58 V heater
More of these tubes are listed as equivalents under M-P P - 300 mA heater
8CG7/8FQ7 – Dual triode; 6CG7/6FQ7, 12FQ7 with an 8.4 V heater
8CN7 – Dual common cathode diode + triode for use as horizontal phase detector and reactance tube in TV receivers; 6CN7 with a center-tapped 225 mA/8.4 V resp. 450 mA/4.2 V heater
9AU7 – Dual triode; 7AU7/XCC82 with a center-tapped 225 mA/9.4 V resp. 450 mA/4.7 V heater
11DS5 – Beam power tetrode; 50B5 or 35B5 with an 11.2 V heater
13J10/13Z10 – Compactron Quadrature detector pentode + power pentode, used as FM audio demodulator and power stage; 6J10/6Z10, 10Z10 with a 13.2 V heater
Most are series heater versions of respective 6-prefix tubes; used in color TV receivers with series heater strings
2AF4 – UHF Medium-μ oscillator triode; 6AF4/EC94 with a 2.35 V heater
2BN4 – VHF triode
2CY5 – VHF sharp-cutoff tetrode
2EA5 – VHF sharp-cutoff tetrode
2EG4 – Nuvistor High-μ VHF triode, 1.7 volt heater
2ER5/XC95 – Vari-μ VHF triode; 4ER5/PC95 or 6ER5/EC95 with a 2.3 V 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 2.4 V heater
5J6 – Dual VHF triode; 6J6/ECC91 with a 4.7 V/600 mA controlled warm-up heater[87]
5T8 – Triple diode + high-μ triode on common cathode with two of the diodes, Noval base, triode μ = 70, used as AM detector/AVC rectifier/FM ratio detector/AF amplifier in series-heated post-war AM/FM radios; 6T8, 6AK8/EABC80, 9AK8/PABC80, 19T8/HABC80 or 27AK8/UABC80 with a 4.7 V heater
10DE7 – Dual dissimilar triode for use as vertical deflection oscillator and amplifier; 6DE7 or 13DE7 with a 9.7 V heater
30KD6 – Compactron Horizontal deflection beam power pentode; 6KD6 or 36KD6/40KD6 with a 30 V heater
More of these tubes are listed as equivalents under M-P X - 600 mA heater
20EZ7 – Dual high-μ 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 – Dual low (26.5-50 V) anode voltage 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 1.375 kV, 300 mA rectifier with separate cathodes for use as a voltage doubler
28D7W – Dual low (28-100 V) anode voltage 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
2B23 – Indirectly heated, magnetically controlled diode. An external, variable magnetic field from a solenoid spirals the electron stream away from the anode like in a Magnetron, driving the tube into cut-off with a sensitivity of -2 mA/G (-20 mA/mT), Octal base[90]
2C21 – Separate cathodes dual RF triode, indirectly heated, low lossmica-filled phenolic resin ("Micanol")[14] UX7 base, one grid on top cap
2C22 – Triode, indirectly heated, Octal base, grid and anode on separate top caps
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, Panode = 100 W
2C39B – 2C39A with ceramic spacers
2C40 – Lighthouse-type disk-seal UHF power triode for continuous operation, Panode = 6.5 W at 3370 MHz
2C41 – Oil can UHF power triode for pulsed operation, 2200 Wpeak at 3 GHz
2C42 – Lighthouse UHF power triode for pulsed operation, 1750 Wpeak 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
2C50 – Separate cathodes dual triode, indirectly heated, Octal base, for use in servo amplifiers
2C51 – Separate cathodes dual shielded VHF triode, indirectly heated, Noval base
2C52 – Separate cathodes dual triode, indirectly heated, Octal base
2C53 – Indirectly heated, 8 kV triode, Octal base with anode on top cap
2D21/EN91 (CV797, Philips PL21, PL2D21, 5727) – 650 V, 100 mAavg, 500 mApeak, 10 Asurge, Xenon-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 envelope with 5 long inline wire-ends
2E32 – Similar to 2E31, all-glass elliptical cross-section envelope with 5 short inline wire-ends
2E35 – 6 mW Subminiature directly heated power pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends
2E36 – Similar to 2E35, all-glass elliptical cross-section envelope with 5 short inline wire-ends
2E41 – Diode + pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends
2E42 – Similar to 2E41, all-glass elliptical cross-section envelope with 5 short inline wire-ends
2G21 – Directly heated triode/heptode mixer, all-glass elliptical cross-section envelope with 7 short inline wire-ends
2G41 – Triode/heptode mixer, all-glass elliptical cross-section envelope with 5 long inline wire-ends
2G42 – Similar to 2G41, all-glass elliptical cross-section envelope with 5 short inline wire-ends
2H21 – Phasitron, a magnetically controlled beam deflection phase modulator tube[91] similar to the 5593, used in early FM broadcast transmitters[92][93][94]
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
5331, 5332, 5514 – Directly heated power triodes, 4-pin base with anode on top cap
5556 – Directly heated power triode, 4-pin base
5593 – Phasitron, a magnetically controlled beam deflection phase modulator tube[98] similar to the 2H21, used in early FM broadcast transmitters[92][93][94]
5608 – Dual power triode, designed for use with AC anode voltage and critical grid leak requirements
5651 – 86-volts, cold-cathode, glow-discharge voltage-regulator tube, 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/DF60 – Subminiature, directly heated, shielded RF pentode with a split suppressor grid, its halves tied to the positive resp. negative filament end, all-glass elliptical cross-section envelope with 5 long inline wire-ends
5691 – Special Red ruggedized long-life dual high-μ triode; industrial version of the 6SL7GT
5692 – Special Red ruggedized long-life dual medium-μ triode; industrial version of the 6SN7GT
5693 – Special Red ruggedized long-life sharp-cutoff pentode; industrial version of the 6SJ7
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;[99] cf. 5738, 6090, 6091, 6170, 6324
5731 – Narrow-tolerance selected 955Acorn 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, Fres = 12 kHz[100][101][69]
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;[102] cf. 5729, 6090, 6091, 6170, 6324
5749 – RF pentode; premium version of 6BA6/EF93, M-OV/GEC W727
5750 – Heptode pentagrid converter; premium version of 6BE6/EK90, M-OV/GEC X727
5751 – Low-voltage, low-noise avionics dual triode with separate cathodes
5814A – Dual triode, no cathode interface/poisoning after prolonged periods in cut-off, shock/vibration resistant; industrial/computer-rated version of 12AU7/ECC82
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
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-regulator tube, Miniature 7-pin base with anode on top cap
5963 (Noval base), 5964 (Miniature 7-pin base, common cathode), 5965 (Noval base) – Dual triode, high zero-bias anode current, no cathode poisoning after prolonged periods in cut-off; industrial/computer-rated versions of 12AV7
5998, 6336A, 6394, 6520, 6528, 7802 – Dual power triodes, designed for series voltage regulator applications
6021/ECC70, 6112, 6690, 6832 – Subminiature, separate cathodes dual triode, all-glass round cross-section envelope, circular 8-pin/wire-ends base
6042 (25 V/150 mA heater), 6180 (6.3 V/600 mA heater) – Separate cathodes dual triodes, Octal base; derived from the 6SN7
6047 – Additron, a triple-control grid, split-anode tetrode for use as a single-bit digital full adder[103] (technically a hexode)
6057, M8137 – Dual high-μ triode; premium version of 12AX7/ECC83, M-OV/GEC B339
6059 – Low-microphonics pentode; premium version of 6BR7, 6J7
6060, M8162 – Dual high-μ triode; premium version of 12AT7/ECC81, M-OV/GEC B309
6064, M8083 – Sharp-cutoff RF pentode; premium version of 6AM6/EF91 = M-OV/GEC Z77
6067, M8136 – Dual medium-μ triode; premium version of 12AU7/ECC82, M-OV/GEC B329
6080 – Very-low impedance dual power triode, designed for series voltage regulator applications, now popular for output transformerless audio amplifiers; premium version of 6AS7G/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;[104] 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;[105] 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;[106] 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[107]
6353 – 19.3 kV/25...1000 µA Corona voltage-regulator tube, Miniature 7-pin base with anode on 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
6441 – 650 V, 100 mAavg, 300 mAsurgeTacitron, 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;[112] cf. EC860, 20TC4, 30TC1
6462 – Magnetic pickup tube, a 1-axis beam deflectionmagnetometer 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[113]
6498 – Memotron, a bistable direct-view storage tube for use in analog storage oscilloscopes[114]
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 cut-off, 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[123]
6835, 7570, 7571 – Single-electron gunrecording storage tube, an analog videoframe 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[124][125][126]
7199 – AF triode + AF pentode, Noval base; similar to 6U8
7229,[128]7230,[129]7231,[130]7232,[131]7439, 7440, 7441, 7595, 7596, 7597, 7598, 7599, 7600, 7602 – Krytrons, gas-filled cold-cathode trigger tubes with a primer electrode for use as a very high-speed, high-surge current switch[132] – second source to EG&G
7236 – Dual power triode for use as long-life power amplifier in computer applications
7241, 7242 – Triple-cathode power triodes, designed for hi-rel cathode follower series voltage regulator applications where the cathode is split into 3 sections connected together via balancing resistors to equalize the emission along the cathode
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 wire-ended; cf. 395A, МТХ-90
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[136]
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 variant of the 6AK5/EF95 sharp-cutoff pentode for use on PCBs in Radiosonde weather balloon transmitters
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 gunrecording storage tube, a realtime analog videoframe 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[137][138][139]
7586 – First Nuvistor available on the market, medium-μ triode, 6.3 V/140 mA heater
7588 – Miniature ceramic/metal disk-seal planar UHF triode for use on PCBs
7591 – 19 W Beam power pentode found in many guitar amps made by Gibson and Ampeg; 6GM5 or 7868 with a 7-pin Octal base
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;[140] cf. XQ1200, XQ1340, ЭПЛ-1
7625 – Miniature ceramic/metal disk-seal planar AF triode for use on PCBs
7868 – 19 W Beam power pentode found in many of the once popular Challenger series PA amps made by Bogen Communications, also found in some guitar amplifiers made by Ampeg; 6GM5 or 7591 with a B9E Novar base
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-μ triode, used in Tektronixoscilloscopes; 7586 with a 13.5 V/60 mA 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-glass wire-ended, 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-μ triode for use in sonobuoys
8456 – Nuvistor medium-μ 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
8514 – 1 kV/10...800 µA Corona voltage-regulator tube, 7-pin with anode on top cap
8515 – 1.6 kV/20...950 µA Corona voltage-regulator tube, 7-pin with anode on top cap
8525, 8526, 8527 – Nuvistor dual medium-μ triode
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 wire-ended, 700 mV/35 mA filament; cf. 6977/DM160
8627 – Nuvistor power triode up to 1.2 GHz
8628 – Nuvistor high-μ AF triode for use in valve microphones and piezoelectric pickup preamplifiers up to 200 kHz
8808 – Nuvistor high-μ 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
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 RETMA/RMA/EIA equivalent.
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 = Philips 4686 – 3 mAavg, 300 mApeak, Argon-filled triode thyratron, 4 V/600 mA heater, side-contact 8 base with grid on top cap, for relaxation oscillators up to 50 kHz
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
AN1 = M-OV/GEC GT1C – -1300 to +650 Va, 300 mAavg, 2 Apeak, 15 Asurge, Gas-filled triode thyratron with negative control characteristic, 4 V/1.45 A heater, O5A European 5-pin base, for industrial control applications
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
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), center-tapped 2.8 V/25 mA resp. 1.4 V/50 mA filament, Octal base with control grid on top cap; cf. 6FS5, 6GU5, EF8, EF38
DC51 – Directly heated miniature AF triode, 1.5 V/70 mA filament, B4B 4-pin subminiature base, for use in hearing aids;[151] cf. KC50, KC51, Mullard DB1
DC70/6375 – Subminiature UHF triode for walkie-talkies, all-glass round cross-section envelope, circular 8-pin/wire-ends 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[146]
DF51 – Miniature, 1.5 V/70 mA half-indirectly heated, sharp-cutoff RF/IF pentode, B4B 4-pin subminiature base with anode on top cap;[156] cf. KE50
Note: DF60, DF61, DF62, DF63 and DF703 have a split suppressor grid, its halves tied to the positive resp. negative filament end
DF60/5678 – Subminiature shielded sharp-cutoff RF/IF/AF pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, 1.25 V/50 mA filament
DF61 – Subminiature shielded sharp-cutoff RF or mixer pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, 1.25 V/25 mA filament
DF62/1AD4 – Subminiature shielded sharp-cutoff RF pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, 1.25 V/100 mA filament, for use as RF/IF stage
DF63 – Subminiature shielded remote-cutoff RF pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, 1.25 V/25 mA filament, for use as RF/IF stage
DF64 – Subminiature AF pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, 0.625 V/10 mA filament, for use in hearing aids
DF65 – Subminiature AF pentode, all-glass round cross-section envelope, circular 5-pin/wire-ends base, 0.625 V/13.3 mA filament, for use in hearing aids
DF66 – Subminiature AF pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, 0.625 V/15 mA filament, for use in hearing aids
DF67/6008 – DF65 with round cross-section envelope, but 5 inline wire-ends
DF70 – Subminiature AF pentode, all-glass round cross-section envelope, circular 8-pin/wire-ends base, 0.625 V/25 mA filament, for use in hearing aids
DF72 – Subminiature sharp-cutoff RF pentode, all-glass round cross-section envelope, circular 8-pin/wire-ends base, for use as RF/IF stage
DF73 – Subminiature remote-cutoff RF pentode, all-glass round cross-section envelope, circular 8-pin/wire-ends base, for use as RF/IF stage
DF97/1AN5 – Remote-cutoff RF/IF/mixer pentode with the suppressor grid on a separate pin, Miniature 7-pin base, 1.4 V/25 mA filament
DF161 – Subminiature AF pentode, all-glass wire-ended, for use in hearing aids
DF167 – Subminiature AF pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, 0.625 V/13.3 mA filament, for use in hearing aids
DF650 = Raytheon CK538DX – Subminiature AF pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, for use in hearing aids[157]
DF651 = Raytheon CK549DX – Subminiature AF pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, for use in hearing aids
DF668 – Subminiature RF pentode, all-glass elliptical cross-section envelope with 5 inline wire-ends, 1.25 V/100 mA filament; similar to DF62/1AD4
DF669 – Subminiature RF/IF pentode, all-glass elliptical cross-section envelope with 5 inline wire-ends, 1.25 V/50 mA filament; similar to DF60/5678
DF703 (5886) – Subminiature electrometer pentode, envelope has a moisture-repellent coating, all-glass elliptical cross-section envelope with 5 long inline wire-ends, 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
DL51 – Miniature, 1.5 V/130 mA half-indirectly heated power pentode, B4B 4-pin subminiature base with anode on top cap
DL64 – Subminiature AF power pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, for use in hearing aids, UA = 15 V, UAmax = 45 V, 1.25 V/10 mA filament
DL65 – Subminiature AF power pentode, all-glass round cross-section envelope, circular 5-pin/long wire-ends base, UA = 22.5 V, UAmax = 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 envelope with 5 long inline wire-ends, for use in hearing aids, UA = 22.5 V, UAmax = 45 V, 1.25 V/15 mA filament
DL67/6007 – DL65 with round cross-section envelope, but 5 inline wire-ends
DL68 – Subminiature AF power pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, for use in hearing aids, UA = 22.5 V, UAmax = 45 V, 1.25 V/25 mA filament
DL69 – Subminiature power pentode with a split suppressor grid, its halves tied to the positive resp. negative filament end, all-glass elliptical cross-section envelope with 5 long inline wire-ends, UA = 90 V, 1.25 V/25 mA filament
DL70 – Subminiature VHF power pentode up to 200 MHz, all-glass round cross-section envelope, circular 8-pin/wire-ends base, for use in walkie-talkies, UA = 150 V, 1.25 V/110 mA filament
DL71 – Subminiature AF power pentode, all-glass round cross-section envelope, circular 8-pin/wire-ends base, for use in hearing aids, UA = 22.5 V, UAmax = 45 V, 1.25 V/25 mA filament
DL72 – Subminiature AF power pentode, all-glass round cross-section envelope, circular 8-pin/wire-ends base, for use in hearing aids, UAmax = 45 V, 1.25 V/25 mA filament
DL73 (CV2299) – Subminiature VHF power pentode up to 200 MHz, all-glass round cross-section envelope, circular 8-pin/wire-ends base, for use in walkie-talkies, UA = 150 V, 1.25 V/200 mA filament
DL75 – Subminiature AF power pentode, all-glass round cross-section envelope, circular 8-pin/wire-ends base[163]
DL91/1S4 – 270 mW AF power pentode, 1.4 V/100 mA filament, Miniature 7-pin base
DL92/3S4 – 270 mW AF power pentode with a center-tapped 2.8 V/50 mA resp. 1.4 V/100 mA filament, Miniature 7-pin base
DL93/3A4 – 700 mW RF/AF power pentode with a center-tapped 2.8 V/100 mA resp. 1.4 V/200 mA filament, Miniature 7-pin base
DL94/3V4 – 270 mW AF power pentode with a center-tapped 2.8 V/50 mA resp. 1.4 V/100 mA filament, Miniature 7-pin base
DL95/3Q4 – 270 mW AF power pentode with a center-tapped 2.8 V/50 mA resp. 1.4 V/100 mA filament, Miniature 7-pin base
DL96/3C4 – 200 mW AF power pentode with a center-tapped 2.8 V/25 mA resp. 1.4 V/50 mA filament, Miniature 7-pin base
DL97/3Y4 – Power pentode with a center-tapped filament, Miniature 7-pin base[164]
DL98/3B4 – 1.25 W RF power pentode with a center-tapped 2.5 V/165 mA resp. 1.25 V/330 mA filament, up to 100 MHz, Miniature 7-pin base
DL161 – Subminiature AF power pentode, all-glass wire-ended, for use in hearing aids
DL167 – 1.8 mW Subminiature AF power pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, 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 resp. 1.4 V/100 mA 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 envelope with 5 long inline wire-ends, UAmax = 90 V, 1.25 V/50 mA filament
DL650 = Raytheon CK532DX – 45 mW Subminiature power pentode, all-glass elliptical cross-section envelope with 5 long inline wire-ends, UAmax = 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 wire-ended
DL907 – SW/VHF power pentode, Miniature 7-pin base
DL962 – 150 mW AF power pentode with a center-tapped 2.4 V/60 mA resp. 1.2 V/120 mA filament, Miniature 7-pin base
DL963 – RF/AF power pentode with a center-tapped 2.4 V/100 mA resp. 1.2 V/200 mA filament, Miniature 7-pin base
DLL21 (Octal base, filament between 7 and nonstandard pins 1, 8), DLL25 (B8G Loctal base) – 1.5 W Dual AF power pentode, center-tapped 2.8 V/100 mA resp. 1.4 V/200 mA filament
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 wire-ended, 1 V/30 mA filament; cf. 8569
DY30/1B3GT = 1Ц7С↦1C7S – 30 kV CRTEHT rectifier, Octal base with anode on top cap
DY51/1BG2 – Half-indirectly (filament internally tied to cathode sleeve) heated 15 kV portable-TV CRT EHT rectifier, all-glass, filament wires on one end, anode wire on the other
DY70 – 10 kV CRT EHT rectifier, all-glass with 3 wire-ends, anode on top wire
DY80/1X2A – 23 kV CRT EHT rectifier, Noval base
DY86/1S2 = 1Ц21Б↦1C21B – Half-indirectly heated 18 kV CRT EHT rectifier, Noval base; 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; EY802 or GY802 with a different heater
EAA91/6AL5 = M-OV/GEC D77 = 6Х2П↦6H2P – 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
E91AA/5726/6AL5W = EAA901S – Dual RF diode, Miniature 7-pin base, no cathode interface/poisoning after prolonged periods in cut-off, shock/vibration resistant
EABC80/6AK8 = M-OV/GEC DH719 (6T8, 6T8A) – Triple diode + high-μ triode on common cathode with two of the diodes, Noval base, triode μ = 70, used as AM detector/AVC rectifier/FM ratio detector/AF amplifier in post-war European AM/FM radios; 5T8, HABC80/19T8, PABC80/9AK8 or UABC80/27AK8 with a different heater
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
EBC1 – Dual diode + AF triode, side-contact 8 base with triode grid on top cap; ABC1 with a different heater
EBC3 – Common cathode dual diode + AF triode, side-contact 8 base with triode grid on top cap
EBC11 – Common cathode dual diode + AF triode, Y8A steel tube base
EBC33 (6Q7G) – Common cathode dual diode + AF triode; EBC3 with an Octal base
EBC41/6CV7 – Shielded common cathode 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 common cathode dual diode + AF triode; UBC81 with a different heater; EBC41 with a Noval base
EBC90/6AT6 – Common cathode dual diode + high-μ AF triode for use in FM ratio detectors, triode μ = 70, Miniature 7-pin base; HBC90/12AT6 with a different heater
EBC91/6AV6 – Common cathode dual diode + high-μ AF triode for use in FM ratio detectors, triode μ = 100 (triode section similar in characteristics to one half of a ECC83/12AX7), Miniature 7-pin base; HBC91/12AV6 with a different heater
EBF32 (6B8) – EBF2G with heater between standard pins 2 and 7
EBF35 – EBF2G with different cathode, suppressor grid and shield connections on pins 2 and 7
EBF80/6N8 = M-OV/GEC 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,[167] prototype only
EC40 – VHF Triode up to 500 MHz; EC80 with a Rimlock base
EC41 – UHF oscillator triode; EC81 with a 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 9-pin Loctal base
EC53 – VHF triode for use as an oscillator up to 600 MHz, 3-pin base with grid and anode on top pins
EC70/6K4/6778 – Subminiature UHF triode for use as an oscillator in the 500 MHz range, all-glass round cross-section envelope, circular 8-pin/wire-ends 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 envelope, circular 8-pin/wire-ends base
EC80/6Q4 – VHF Triode up to 500 MHz, Noval base
EC81/6R4 – UHF oscillator triode, Noval base
EC84/6AJ4 – High-μ 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
EC92/6AB4/6664 – VHF triode for FM receiver front ends, Miniature 7-pin base, single ECC81/12AT7 system; UC92/9AB4 with a different heater
EC1030 – Indirectly heated UHF triode, all-glass round cross-section envelope with 8 circular, tinned, 38 mm long wire-ends, hot-standby resistant (no cathode interface/poisoning after prolonged periods in cut-off)
EC1031 – EC1030 with 5.5 mm long, gold-plated pins for insertion into a special socket, no cathode poisoning after prolonged periods in cut-off
EC8010/8556 – UHF triode for use as amplifier or oscillator up to 1 GHz, Noval base, shock/vibration resistant
EC8020 – UHF triode, Noval base, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant
E86C = EC806S – UHF triode up to 800 MHz, dual anode and cathode pins and triple grid pins for use as grounded-grid amplifier, Noval base with gold-plated pins, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant
E88C/8255 – UHF triode up to 1 GHz, quintuple grid pins for use as grounded-grid amplifier, Noval base, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant
(6060, 6201, M8162) – Dual high-μ triode with a center-tapped heater, for use as RF amplifier/mixer in VHF circuits, Noval base
ECC82/12AU7 = M-OV/GEC B329 (6067, 6189, M8136) – Dual medium-μ 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;[80] however, it is only specified as an audio frequency tube
ECC83/12AX7 = M-OV/GEC B339 (6Н2П↦6N2P, 6057, 6681, M8137) – Dual high-μ triode with a center-tapped heater for use as a high-gain AF amplifier, Noval base
ECC84/6CW7 = 6Н14П↦6N14P – Dual VHF triode for grounded-grid/cascode amplifiers in TV tuners, section 1 cathode is tied to two adjacent pins and the screen between the two sections is internally tied 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 = 6Н27П↦6N27P – Dual low (6.3-25 V) anode voltage triode, Noval base, for use in VHF tuners in vehicle equipment
ECC87 (E80CC/6085) – ECC40 with a Noval base, allowing for a heater center-tap[174]
ECC88/6DJ8 = 6Н23П↦6N23P – Dual triode used as RF cascode 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 = 6Н24П↦6N24P – Dual triode used as RF cascode 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 & 87 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 = 6H15П↦6N15P – 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[147] 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 (6Н1П↦6N1P) – Separate cathodes dual VHF triode for use as cascode amplifier, Noval base
ECC186/7316 – Separate cathodes dual triode for use in digital computers, Noval base, no cathode interface/poisoning after prolonged periods in cut-off
ECC189/6ES8 – Separate cathodes dual vari-μ VHF triode for use as cascode amplifier, Noval base; PCC189/7ES8, XCC189/4ES8 or YCC189/5ES8 with a different heater
ECC230/6AS7G = 6Н13С↦6N13S (6080) – Separate cathodes dual low-μ power[147] triode for use as series regulator in DC power supplies, servo applications, or as a horizontal booster triode in TV monitors, Octal base
ECC802 – Separate cathodes dual triode, Noval base
ECC803 – Separate cathodes dual triode, Noval base
ECC804/6GA8 – Separate cathodes dual triode, Noval base[175]
ECC807 – 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
ECC863 – Separate cathodes dual triode with an internal screen between the sections
ECC865 – Long-life version of the ECC85
ECC960, ECC962 – Common cathode dual triode for use as a flip-flop in computers, Miniature 7-pin base
ECC2000 – Separate cathodes dual VHF triode with neutralization screen, for use as cascode amplifier up to 300 MHz, Decal base with gold-plated pins, shock/vibration resistant
ECC8100 – Separate cathodes dual VHF triode with neutralization screen ("Neutrode") connected to the heater, for use as cascode amplifier, Noval base, no cathode interface/poisoning after prolonged periods in cut-off, shock/vibration resistant
E80CC/6085 – Separate cathodes dual triode for use as DC or AF amplifier, center-tapped 6.3 V/600 mA resp. 12.6 V/300 mA heater, Noval base, shock/vibration resistant
E81CC/6201 = ECC801S = 12AT7WA (6060) – Separate cathodes dual triode for AF and RF amplifiers, mixers up to 300 MHz, oscillators or impulse circuits, center-tapped 6.3 V/300 mA resp. 12.6 V/150 mA heater, Noval base, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant; premium version of ECC81/12AT7
E82CC/6189 = ECC802S = 12AU7WA (6067) – Separate cathodes dual triode for use as amplifier or multivibrator, center-tapped 6.3 V/300 mA resp. 12.6 V/150 mA heater, Noval base, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant; premium version of ECC82/12AU7
E83CC/6681 = 12AX7WA (ECC803S/6057) – Separate cathodes low-microphonics dual triode, center-tapped 6.3 V/300 mA resp. 12.6 V/150 mA heater, Noval base, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant; premium version of ECC83/12AX7
E86CC/6463 – Separate cathodes dual triode for computer circuits, heaters internally series-connected, with the midpoint on a separate pin, Noval base
E88CC/6922 – Separate cathodes dual triode, Noval base with gold-plated pins, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant
E90CC/5920 – Common cathode dual triode for use as a flip-flop in computers, Miniature 7-pin base, no cathode poisoning after prolonged periods in cut-off
E92CC – Common cathode dual triode for use as a flip-flop in computers, Miniature 7-pin base, no cathode poisoning after prolonged periods in cut-off, not recommended where low hum or microphony or noise is critical
E180CC/7062 – Separate cathodes dual triode for use as a flip-flop in computers, center-tapped 6.3 V/400 mA resp. 12.6 V/200 mA heater, Noval base, no cathode poisoning after prolonged periods in cut-off, not recommended where low hum or microphony or noise is critical
E181CC/7118 – Separate cathodes dual triode for use in digital computers, center-tapped 6.3 V/400 mA resp. 12.6 V/200 mA heater, Noval base, no cathode poisoning after prolonged periods in cut-off, not recommended where low hum or microphony or noise is critical
E182CC/7119 – Separate cathodes dual triode for use as a flip-flop in computers, center-tapped 6.3 V/640 mA resp. 12.6 V/320 mA heater, Noval base, no cathode poisoning after prolonged periods in cut-off, not recommended where low hum or microphony or noise is critical
E188CC/7308 – Separate cathodes dual low-microphonics triode for use as RF/IF/AF amplifier, Noval base, shock/vibration resistant
E283CC – Separate cathodes dual low-hum, low-microphonics triode for use as AF or instrumentation amplifier, Noval base, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant
E288CC/8223 – Separate cathodes dual triode for use in wideband, low-noise IF, RF and cascode amplifiers, Noval base, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant
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; LCF200/5X9 or 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 SECAMchroma signaldemodulators in analog color TV receivers, Decal base
ECF801/6GJ7 – Frame-grid 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, XCF802/4JW8 or 5JW8 with a different heater
ECF803 – ECF801/6GJ7 with separate cathodes
ECF804 – Triode + sharp-cutoff pentode for use as wideband 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;[176] PCF812 (=30FL2) with a different heater
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 = 6Ф3П↦6F3P – AF Triode + AF power pentode; LCL82/11BM8, PCL82/16A8, UCL82/50BM8 or XCL82/8B8 with a different heater
ECL83 – AF Triode + AF power pentode; PCL83 with a different heater
ECL84/6DX8 = 6Ф4П↦6F4P – TV sync sep triode + CRT cathode drive power pentode; LCL84/10DX8, PCL84/15DQ8 or XCL84/8DX8 with a different heater
ECL85/6GV8 = 6Ф5П↦6F5P – 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; 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 or XCL86/8GW8 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
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, Noval base[178]
ED8000 – Power triode for use in series-pass voltage regulators, Noval base, no cathode interface/poisoning after prolonged periods in cut-off, shock/vibration resistant
EE1 = EEP1 = Philips 4696 – Single-ended secondary emission amplifier for use as a wideband amplifier and phase inverter, side-contact 8 base with control grid on top cap
EE50 – Single-ended secondary emission amplifier, B9G 9-pin Loctal base, for use in TV receivers
EF1 – Sharp-cutoff RF/IF pentode, side-contact 8 base with control grid on top cap[145]
EF2 – Remote-cutoff RF/IF pentode, side-contact 8 base with control grid on top cap[145]
EF3 – Remote-cutoff RF/IF pentode, side-contact 8 base with control grid on top cap[145]
EF5 – Remote-cutoff pentode, side-contact 8 base with control grid on top cap
EF6, EF6N – 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;[145]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
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[179]
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
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, EF50N, EF53 – Remote-cutoff pentode for use in the IF stages of 1940s TV and radar receivers, B9G 9-pin Loctal 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 9-pin Loctal base
EF55 – Sharp-cutoff RF/video pentode, B9G 9-pin Loctal base
EF59 – RF pentode, B9G 9-pin Loctal base
EF70 – Subminiature sharp-cutoff pentode, suppressor grid available on separate wire 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 envelope, circular 8-pin/wire-ends base
EF80/6BX6 = M-OV/GEC 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/GEC W719 – Remote-cutoff wideband RF pentode, Noval base; HF85 or XF85 with a different heater
EF86/6BK8/6CF8 = M-OV/GEC/GEC Z729 (6267) – Sharp-cutoff AF pentode, also for use in Transitron circuits in TV receivers, Noval base; PF86, UF86 or XF86 with a different heater
EF96/6AG5 = 6Ж3П↦6J3P – Sharp-cutoff VHF pentode up to 400 MHz, Miniature 7-pin base
EF97/6ES6 = 6К8П↦6K8P – 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 = 6К13П↦6K13P – Frame-grid, remote-cutoff IF pentode for use in TV receivers; LF183/YF183/4EH7 or XF183/3EH7 with a different heater[180]
EF184/6EJ7 = 6Ж51П↦6J51P – Frame-grid, sharp-cutoff IF pentode for use in TV receivers; LF184/YF184/4EJ7 or XF184/3EJ7 with a different heater[181]
EF190/6CB6 – Remote-cutoff RF pentode for use in video IF circuits
EF410 – RF/IF Pentode, Rimlock 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 envelope, circular 8-pin/wire-ends base; similar to 5784
E180F/6688 = 6Ж9П↦6J9P – Wideband pentode for use as amplifier in professional equipment
E186F/7737 – Wideband, low-microphonics pentode for use as amplifier, shock/vibration resistant
E280F/7722 – Wideband pentode for use as low-noise amplifier up to 300 MHz, no cathode interface/poisoning after prolonged periods in cut-off, shock/vibration resistant
E282F – Wideband pentode for use as amplifier up to 250 MHz, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant
E810F/7788 – Wideband pentode, gold-plated pins, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant
EFM1 – Vari-μ AF pentode + top-view, "Magic Eye"-type tuning indicator with 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, side-contact 8 base
EFM11 – Vari-μ AF pentode + top-view, "Magic Eye"-type tuning indicator with beam control rods internally tied to the floating screen grid, Y8A steel tube base
EH900S/5915 = EH960 – Dual-control switching heptode, designed for high speed digital computers, no cathode interface/poisoning after prolonged periods in cut-off
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 envelope, circular 8-pin/wire-ends base
EL71/5902 – Subminiature 4 W AF power pentode, all-glass round cross-section envelope, circular 8-pin/wire-ends 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[192]
EL82/6DY5 = 6П18П↦6P18P – CRT vertical deflection or AF power pentode
EL83/6CK6 = 6П15П↦6P15P – CRT cathode drive power pentode
EL84/6BQ5 = M-OV/GEC N709 = 6П14П↦6P14P – 6 W AF power pentode; XL84/8BQ5, 10BQ5 with a different heater
EL85/6BN5 – 6 W RF/AF power pentode up to 120 MHz, for use in mobile equipment; EL42 with a Noval base
EL86/6CW5 = 6П33П↦6P33P – 5.3 W AF or CRT vertical deflection output power pentode; EL84/6BQ5 modified for a lower power supply voltage; HL84, LL86/10CW5, PL84/15CW5,[193][194] UL84/45B5 or XL86/8CW5 with a different heater
EL88 – 2.6 W AF power pentode
EL89 – 3.9 W AF power pentode
EL90/6AQ5 = M-OV/GEC N727 (6П1П↦6P1P, 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
EL150 – Power pentode, Y8A steel tube 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
EL300/6FN5 – CRT horizontal deflection power pentode, Octal base; PL300/35FN5 with a different heater
EL360 – Power pentode for use in radar 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 = 6П36С↦6P36S – 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, EL506 – AF power pentode, Magnoval base
EL504 – CRT horizontal deflection output power pentode, Magnoval base; LL504/18GB5A or PL504 or XL504/13GB5A 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 = 6П45С↦6P45S – EL505/6KG6 with an increased max. anode dissipation, Magnoval base; LL509/26KG6A or 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
EL520 – AF beam power tetrode, Magnoval base
EL802/6LD6 – CRT cathode drive power pentode for color TV, Noval base; LL802/10LD6 or PL802 with a different heater
EL803 – Wideband power pentode
EL804 – Wideband power pentode
EL805 – CRT vertical deflection output power pentode; PL805 with a different heater
EL3010 – 16.5 W Linear power pentode, center-tapped 6.3 V/2.2 A resp. 12.6 V/1.1 A heater, Octal base, no cathode interface/poisoning after prolonged periods in cut-off, shock/vibration resistant
EL5000 – AF power pentode, Magnoval base
EL5070/8608 – Frame-grid, 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, shock/vibration resistant, long-life >10000h
E81L/6686 – Long-life 1 W power pentode for use in telephone equipment, Noval base with gold-plated pins, long-life >10000h (no relationship to EL81)
E84L/7320 – 6 W Power pentode for use in AF amplifiers and stabilized power supplies, Noval base, no cathode interface/poisoning after prolonged periods in cut-off, shock/vibration resistant
E130L/7534 – Wideband power pentode, Octal base
E235L/7751 – Wideband power pentode, Octal base, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant
E236L – Wideband power pentode, Octal base, no cathode poisoning after prolonged periods in cut-off, shock/vibration resistant
EM34/6CD7 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator; EM4(N) 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[198]
EM71 – Top-view, fan-type tuning indicator with an unusual offset cathode,[199] 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 = 6Е1П↦6Ye1P – Side-view, fan-type tuning indicator for AM receivers, Noval 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 base, mainly for stereo use in tape recorders
EM84/6DH7/6FG6 = 6Е3П↦6Ye3P – Side-view, band-type tuning/level indicator, Noval base
EM84a – Improved EM84 with twice the sensitivity[200]
EM85 – Side-view, fan-type tuning indicator; HM85 or UM85 with a different heater
E82M – Side-view, rectangle-type dual-channel level indicator, two DC amplifier triodes control separate deflection rods before a 17 × 20 mm screen anode, Noval base
EN31 – 10 mAavg, 750 mApeak, Helium-filled, indirectly heated triode thyratron for high-frequency timebases and control equipment, Octal base with anode cap
EN32/6574 – 300 mAavg, 2 Apeak, 10 Asurge, Gas-filled, indirectly heated tetrode thyratron with negative control characteristic, for industrial control applications, Octal base
EN70 (5643) – 20 mAavg, 100 mApeak, Subminiature, xenon-filled, indirectly heated tetrode thyratron with negative control characteristic, all-glass round cross-section envelope, circular 8-pin/wire-ends base
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.[204][205][206][207] Y8A steel tube base with 2 unused pins, screen grid on top cap; compare US111
EY86/6S2, EY806 – 24 kV, 800 µA Half-indirectly heated CRT EHT rectifier, anode on top cap; DY86/1S2 or GY86 with a different heater
EY87/6S2A, EY807 – 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 = 6Д20П↦6D20P – 6 kV, 220 mA CRT horizontal deflection output booster/damper/efficiency diode, cathode on top cap; LY88/20AQ3, PY88/30AE3 or XY88/16AQ3 with a different heater
EY91 – 250 V, 75 mA Half-wave rectifier, Miniature 7-pin base
EY189 – Rectifier, Noval base
EY500/6EC4 – 5.6 kV, 440 mA CRT horizontal deflection output booster/damper/efficiency diode for color TV, Magnoval base, cathode on top cap, guardian shield between filament and cathode to improve high voltage properties; PY500/42EC4 with a different heater
EY500A/6EC4A – EY500/6EC4 without the guardian shield because of an improved filament/cathode insulation
EY802 – 20 kV, 500 µA Half-indirectly heated CRT EHT rectifier, silicone-coated envelope, Noval base with anode on top cap; DY802/1BQ2 or GY802 with a different heater
FDD20 – Common cathode dual power triode, 12.6 V/350 mA heater, side-contact 8 base - available with two different pinouts;[209] similar to 53, 6A6, 6N7G
GY11 – 2 kV, 100 mA Half-wave rectifier, 2.5 V/5 A heater, Y8A steel tube base with anode on top cap
GY86 – Half-indirectly heated CRTEHT rectifier, Noval base with anode on top cap; DY86/1S2 or EY86/6S2 with a 2.6 V/300 mA heater
GY501/3BH2 = 3Ц2С↦3C2S – 35 kV, 1.7 mA Half-indirectly heated CRT EHT rectifier for color TV, 3.15 V/400 mA heater, Magnoval base with anode on top cap
GY521 – CRT EHT rectifier, Magnoval base with anode on top cap
GY802 – Half-indirectly heated 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
HABC80/19T8 – Triple diode + high-μ triode on common cathode with two of the diodes, Noval base, triode μ = 70, used as AM detector/AVC rectifier/FM ratio detector/AF amplifier in series-heated post-war AM/FM radios; 5T8, 6T8, EABC80/6AK8, PABC80/9AK8 or UABC80/27AK8 with a different heater
LCF80/6LN8 – VHF oscillator/mixer triode/pentode; ECF80/6BL8, PCF80/9A8, UCF80 or XCF80/4BL8 with a different heater[216]
LCF86/5HG8 – VHF oscillator/mixer triode/pentode; ECF86/6HG8, PCF86/7HG8, 8HG8 or XCF86/4HG8 with a different heater[217]
LCF200/5X9 – Triode + pentode for use as IF amplifier in TV receivers, Decal base; ECF200/6X9 or PCF200/8X9 with a different heater
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[218]
LCF801/5GJ7 – Frame-grid 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[219]
LCF802/6LX8 – Medium-μ triode + sharp-cutoff pentode for use as reactance and sinewave oscillator in TV receivers, Noval base; ECF802/6JW8, PCF802/9JW8, XCF802/4JW8 or 5JW8 with a different heater[220]
LCL82/11BM8 – AF triode + AF power pentode; ECL82/6BM8, PCL82/16A8, UCL82/50BM8 or XCL82/8B8 with a different heater
LCL84/10DX8 – TV sync sep triode + sharp-cutoff CRT cathode drive power pentode; ECL84/6DX8, PCL84/15DQ8 or XCL84/8DX8 with a different heater[221]
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; ECL85/6GV8, PCL85/18GV8 or XCL85/9GV8 with an 11.6 V heater[222]
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: OBC1, OBC3/12SQ7GT, OBF2, OCH4, OH4/12A8GT, OF1/6S7G, OF5/12K7GT, OF9 and OM5, used in combination with RETMA types 35Z5 and 50L6[32]
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[239]
ORP63 – 75 Vmax CdS photoresistor, side window, all-glass with 2 wire-ends, max. sensitivity at λ = 675 nm
ORP80/RPY13 – Vactrol-type opto-isolator, a small 24 V/60 mA incandescent lamp surrounded by four 200 Vmax CdS photoresistors in a black-tinted glass envelope, Noval base[240]
ORP90, ORP93, ORP94 – 350 Vmax CdS photoresistor, side window, Miniature 7-pin base, max. sensitivity at λ = 675 nm
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[32]
PABC80/9AK8 – Triple diode + high-μ triode on common cathode with two of the diodes, Noval base, triode μ = 70, used as AM detector/AVC rectifier/FM ratio detector/AF amplifier 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
PCF80/9A8 = 9Ф8П↦9F8P – 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
PCF84 – Triode + pentode
PCF86/7HG8 – VHF oscillator/mixer frame-grid triode/pentode; ECF86/6HG8, LCF86/5HG8, 8HG8 or XCF86/4HG8 with a different heater
PCF87 = EdiSwan 30C17 – Frame-grid triode + remote-cutoff pentode for use as VHF mixer in TV receivers[241]
PCF200/8X9 – Triode + pentode for use as IF amplifier in TV receivers, Decal base; ECF200/6X9 or LCF200/5X9 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) – Frame-grid triode + pentode for use as VHF mixer in TV receivers
PCF801/8GJ7 – Frame-grid 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, XCF802/4JW8 or 5JW8 with a different heater
PCF803 – PCF801/8GJ7 with separate cathodes
PCF805/7GV7 – Frame-grid 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
PCF808 – Triode + pentode for use as RF amplifier and scanning oscillator in TV receivers, Noval base[48]
PCF810 – Triode + pentode
PCF812 = EdiSwan 30FL2 – Triode + low-power semiremote-cutoff beam tetrode, Noval base;[176] ECF812 (=6FL2) with a different heater
PCL82/16A8 = 16Ф3П↦16F3P – AF triode + AF power pentode; ECL82/6BM8, LCL82/11BM8, UCL82/50BM8 or XCL82/8B8 with a different heater
PCL83 – Triode + power pentode; ECL83 with a different heater
PCL84/15DQ8 = 15Ф4П↦15F4P – TV sync sep triode + CRT cathode drive power pentode; ECL84/6DX8 or LCL84/10DX8 or XCL84/8DX8 with a different heater
PCL85/18GV8 = 18Ф5П↦18F5P – 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; 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 or XCL86/8GW8 with a different heater
PCL88 = EdiSwan 30PL14 – Triode + power pentode[242]
PCL200 – Triode + CRT drive power pentode, Decal base; ECL200 with a different heater
PCL501 – Triode + power pentode, Magnoval base
PCL800 = EdiSwan 30PL13 – Triode + power pentode[243]
PCL802 – Triode + power pentode
PCL805 – Triode + power pentode; ECL805 with a different heater
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,[75] and therefore should never be replaced by a PD500 in equipment designed for the PD510[244]
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[245]
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/GEC N309 – CRT cathode drive power pentode
PL84/15CW5 – AF or CRT vertical deflection output power pentode; EL86/6CW5,[193][194] HL84, LL86/10CW5, UL84/45B5 or XL86/8CW5 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 or LL504/18GB5A or XL504/13GB5A 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 or LL509/26KG6A 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, Magnoval base; LL521/21KQ6 with a different heater
PL802 – CRT cathode drive output pentode for color TV, Noval base; EL802/6LD6 or LL802/10LD6 with a different heater
PL805 – CRT vertical deflection output power pentode; EL805 with a different heater
PL820 – CRT horizontal deflection output power pentode[245]
PL841 – AF or CRT vertical deflection output power pentode
PY31 – 1 kV, 125 mA Half-wave rectifier, Octal base
PY32 – 700 V, 325 mA Half-wave rectifier, Octal base
PY33 – 700 V, 325 mA Half-wave rectifier, Octal base
PY71 – Half-wave rectifier, B8G Loctal base
PY80/19X3 – CRT horizontal deflection output booster/damper/efficiency diode, Noval base; EY80 with a different heater
PY81/17Z3 – 4.5 kV, 150 mA CRT horizontal deflection output booster/damper/efficiency diode, cathode on top cap; EY81/6R3 with a different heater
PY82/19Y3 – 700 V, 180 mA Half-wave rectifier; EY82/6N3 with a different heater
PY83 – 5 kV, 150 mA CRT horizontal deflection output booster/damper/efficiency diode, cathode on top cap; EY83 with a different heater
PY88/30AE3 – 6 kV, 220 mA CRT horizontal deflection output booster/damper/efficiency diode, cathode on top cap; EY88/6AL3, LY88/20AQ3 or XY88/16AQ3 with a different heater
PY500/42EC4 – 5.6 kV, 440 mA CRT horizontal deflection output booster/damper/efficiency diode for color TV, Magnoval base, cathode on top cap, guardian shield between filament and cathode to improve high voltage properties; EY500/6EC4 with a different heater
PY500A/42EC4A – PY500/42EC4 without the guardian shield because of an improved filament/cathode insulation
PY800 – 5.75 kV, 175 mA CRT horizontal deflection output booster/damper/efficiency diode, Noval base with cathode on top cap
PY801 – 5.5 kV, 175 mA CRT horizontal deflection output booster/damper/efficiency diode, Noval base with cathode on top cap[246]
PZ30 – Dual 200 mA rectifier with separate cathodes, center-tapped 300 mA/52 V resp. 600 mA/26 V heater, Octal base, for use as a voltage doubler in TV receivers
TY86F – 7.4 V/77 mA heater version of the EY86 18-kV CRTEHT rectifier,[245] for use as a hotfix in early-production Ferguson Radio Corporation TV receivers 306T and 308T[257] where the horizontal-output transformer produced excessive heater voltage which destroyed the originally fitted EY86's
U30 – Barretter with a 70 to 122.5 V filament, used to adapt standard 116-Volts Rimlock tube sets such as UCH42+UF41+UBC41+UL41+UY41 or UCH42+2×UAF42+UL41+UY41 to 220V mains, Octal base because the power dissipation is too high for Rimlock
UABC80/27AK8 – Triple diode + high-μ triode on common cathode with two of the diodes, Noval base, triode μ = 70, used as AM detector/AVC rectifier/FM ratio detector/AF amplifier in series-heated post-war European AM/FM radios; EABC80/6AK8, 5T8, 6T8, HABC80/19T8, PABC80/9AK8 and DH719 with a different heater
UM80/19BR5 – Side-view, fan-type tuning indicator for AM receivers
UM81 – Side-view, fan-type tuning indicator
UM83 – 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 base; EM83 with a different heater
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;[259] EM171 with a different heater
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
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
XCF802/4JW8 – Triode + pentode for use as reactance and sinewave oscillator in TV receivers, Noval base; ECF802/6JW8, LCF802/6LX8, PCF802/9JW8 or 5JW8 with a different heater
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
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
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
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
Z50T – Subminiature, 6 mAavg, 24 mApeak, Gas-filled, cold-cathode trigger triode, 1 starter, all-glass with 3 wire-ends, for use as switch in bang–bang controllers
Z300T = PL1267 (0A4G) – 25 mAavg, 100 mApeak, Gas-filled, cold-cathode DC trigger triode, one starter, Octal base
Z900T = 5823 – 25 mAavg, 100 mApeak, Gas-filled, cold-cathode AC trigger triode, one starter, Miniature 7-pin base
Z0.7/10U – 700 V, 500 mAavg, 10 Apeak, Gas-filled, cold-cathode DC arc trigger tetrode, one starter and a primer electrode, positive starter voltage[147]
Z0.7/100U – 700 V, 2 Aavg, 100 Apeak, Gas-filled, cold-cathode DC arc trigger tetrode, one starter and a primer electrode, positive starter voltage, for triggering ignitrons[147]
Z1/100U – 1 kV, 2 Aavg, 100 Apeak, Gas-filled, cold-cathode DC arc trigger tetrode, one starter and a primer electrode, positive starter voltage, for use in welding machines[147]
Z70U = 7710 – Subminiature, 3 mAavg, 12 mApeak, Gas-filled, cold-cathode DC trigger tetrode, one starter and a primer electrode, positive starter voltage, all-glass with 4 wire-ends
Z71U = 7711 – Subminiature, 7 mAavg, 12 mApeak, Gas-filled, cold-cathode DC trigger tetrode, two starters, positive starter voltage, all-glass with 4 wire-ends, low impedance at audio frequencies for use in a telephone exchange
Z700U – Subminiature, 4 mAavg, 16 mApeak, Gas-filled, cold-cathode DC trigger tetrode, one starter and a primer electrode, positive starter voltage, all-glass wire-ended, for use in Dekatron circuits up to 2...5 kHz
Z800U – 2.5 mAavg, 10 mApeak, 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 mAavg, 10 mApeak, 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 mAavg, 100 mApeak, 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 mAavg, 25 mApeak, 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 UA > 0
Z805U = 7714 – 5 mAavg, 25 mApeak, 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.
Z70W = 7709 – 4 mA, Gas-filled, cold-cathode DC trigger pentode, two starters and a primer electrode, positive starter voltage, all-glass with 5 wire-ends, for use in bidirectional counters
Z660W (Cerberus GR43) – 12 mAavg, 50 mApeak, Gas-filled, cold-cathode DC trigger pentode, two starters and a primer electrode, positive starter voltage, all-glass with 5 wire-ends, envelope inside radioactively coated for a constant ignition voltage, for use in bidirectional counters
Z661W (ZC1010) – 8 mAavg, 50 mApeak, Gas-filled, cold-cathode AC trigger pentode, two starters and a primer electrode, positive starter voltage, all-glass with 5 wire-ends, 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, all-glass with 5 wire-ends, 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 mAavg, 200 mApeak 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
Z860X – 40 mAavg, 200 mApeak, 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 mAavg, 200 mApeak, 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 mAavg, 200 mApeak, 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
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
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 10−5mmHg (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
XQ1070/L/B/G/R – 1" Color TV broadcast-grade Plumbicon, resolution ≥600 TV lines
XQ1071/B/G/R – XQ1070 for industrial use
XQ1073R – 1" Plumbicon, extended red response, resolution ≥750 TV lines
XQ1073X – 1" Plumbicon, matched to X-ray image intensifiers with P20 phosphor
XQ1074 – XQ1073 for industrial use
XQ1075/R – XQ1073 with extended red response and an IR reflection filter
XQ1076/R – XQ1075 for industrial use
XQ1200 – Electron Bombarded Silicon Tube, a Vidicon with a silicon target; cf. 7610, XQ1340, ЭПЛ-1
XQ1270 (≥400 TV lines), XQ1271 (≥550 TV lines), XQ1272 (≥500 TV lines) – ⅔" Commercial-grade Vidicon, Sb2S3 target, overall length 10.8 cm (4+1⁄4 in)
XQ1274 – ⅔" Newvicon, magnetic focussing and deflection, ZnSe + CdZnTe target, for use in low-light security cameras, resolution ≥650 TV lines
XQ1275 – ⅔" Newvicon camera tube
XQ1276 – XQ1274 with extended red response
XQ1277 – XQ1275 with extended red response
XQ1278 – XQ1275 with better geometry and uniform signal
XQ1285 – 1" Vidicon, magnetic focusing and deflection, precision electron gun, Sb2S3 target, fiber optic interface to X-ray image intensifiers with P11 or P20 phosphors and fiber optic output, for use in medical equipment
XQ1290 – 1" Resistron camera tube, Sb2S3 target, for use with X-ray image intensifiers in medical equipment
XQ1340 – Electron Bombarded Silicon Tube, a low-light Vidicon with a silicon target;[262] cf. 7610, XQ1200, ЭПЛ-1
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
XQ1410/L/B/G/R, XQ1413R (extended red response), XQ1415L/R (extended red response and IR filter) – XQ1020 with fiber optics and ≥650 TV lines resolution
XQ1412 – 30mm Plumbicon, low lag, unity gamma matched to X-ray image intensifiers with P20 phosphor
XQ1427/B/G/R (color TV broadcast-grade), XQ1428 (industrial-grade) – ⅔" Plumbicon, low lag
XQ1500/L/B/G/R, XQ1503R (extended red response), XQ1505R (extended red response and IR filter) – 1" Color TV broadcast-grade Plumbicon
XQ1560 – 1" Saticon camera tube
XQ1565 – 1" Saticon camera tube
XQ1570/L/B/G/R (color TV broadcast-grade), XQ1571 (industrial-grade), XQ1573R (extended red response), XQ1574 (industrial-grade), XQ1575R (extended red response and IR filter), XQ1576 (industrial-grade) – 1" Plumbicon
XQ1585 – 1" Saticon camera tube
XQ1600 – ½" Commercial-grade Vidicon, separate mesh, electrostatic focusing and magnetic deflection
XQ1601, XQ1602 (radiation-resistant) – ½" Newvicon, separate mesh, electrostatic focusing and magnetic deflection
XQ2070/L/B/G/R (color TV broadcast-grade), XQ2071 (industrial-grade), XQ2073R (extended red response), XQ2074 (industrial-grade), XQ2075R (extended red response and IR filter), XQ2076 (industrial-grade) – 1" Plumbicon
XQ2172/X – 1" Plumbicon, wide dynamic range matched to X-ray image intensifiers with P20 phosphor, for use in digital radiography applications
XQ2182 – 1" Plumbicon, wide dynamic range matched to digital radiography applications
XQ2427/B/G/R (color TV broadcast-grade), XQ2428 (industrial-grade) – ⅔" Plumbicon
XQ3070/L/B/G/R (color TV broadcast-grade), XQ3071 (industrial-grade), XQ3073R (extended red response), XQ3074 (industrial-grade), XQ3075R (extended red response and IR filter), XQ3076 (industrial-grade) – 1" Plumbicon
XQ3427/B/G/R – ⅔" Color TV broadcast-grade Plumbicon
XQ3430B/G/R – Color TV broadcast-grade Plumbicon
XQ3435B/G/R – Color TV broadcast-grade Plumbicon
XQ3440/L/B/G/R, XQ3443R (extended red response), XQ3445R (extended red response and IR filter) – 30mm Color TV broadcast-grade Plumbicon
XQ3457/B/G/R – ⅔" Color TV broadcast-grade Plumbicon
XQ3467/B/G/R – ⅔" Color TV broadcast-grade Plumbicon
XQ3477B/G/R – Color TV broadcast-grade Plumbicon
XQ3487/B/G/R – Color TV broadcast-grade Plumbicon
XQ3550B/G/R – Color TV broadcast-grade Plumbicon
XQ3555B/G/R – Color TV broadcast-grade Plumbicon
XQ4187/B/G/R – ⅔" Color TV broadcast-grade Plumbicon
XQ4502/A – 30mm/45mm Plumbicon, highest resolution, low lag, for use with X-ray image intensifiers in medical equipment
YD1352S = 8867 = Amperex DX334 – 5 MHz, 2 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
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
YL1070 = 8117 (Center-tapped 12.6 resp. 6.3 V heater), YL1071 = 8116 (center-tapped 26.5 resp. 13.25 V heater) – 60 MHz, 100 W Dual linear RF power tetrode, Septar base
YL1080 = 8348 – 200 MHz, 5 W Dual VHF power tetrode, internally neutralized, 1.6 V/2.5 A quickstart heater, Noval base
YL1120 = 8429 – 60 MHz, 4 kW Forced-air cooled, coaxial, ceramic/metal, linear RF power tetrode, 16 V/16.5 A heater
YL1130 = 8408 – 200 MHz, 4 W Dual VHF power pentode, internally neutralized, 1.1 V/2.9 A quickstart heater, Noval base
YL1150 = 8579 – 60 MHz, 75 W Linear RF beam power tetrode, center-tapped 12.6 resp. 6.3 V heater, Septar base
YL1190 = 8580 – 500 MHz, 8 W Dual UHF power tetrode, internally neutralized, 1.1 V/4.2 A quickstart heater, Magnoval base
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 wire-ended
ZA1002 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode, large difference between burning and ignition voltage, meshed cylinder anode, all-glass with 3 wire-ends
ZA1003 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode for use as indicator tube in transistorized circuits, meshed cylinder anode, all-glass with 3 wire-ends
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-regulator tube, meshed cylinder anode, all-glass with 3 wire-ends
ZA1005 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode for use like a DIAC in thyristor circuits, meshed cylinder anode, all-glass with 2 wire-ends
ZC1010 (Z661W) – 8 mAavg, 50 mApeak, Gas-filled, cold-cathode AC trigger pentode, two starters and a primer electrode, positive starter voltage, all-glass with 5 wire-ends, envelope inside radioactively coated for a constant ignition voltage, for use in bidirectional counters
ZC1030 – 4 mA, Gas-filled, cold-cathode trigger tetrode, one starter and a primer, positive starter voltage, all-glass with 4 wire-ends, for use in high-speed counting and switching circuits[267]: 719ff 
ZC1031 – 3 mA, Neon-filled, cold-cathode, luminescent trigger tetrode, one starter and a primer, 0.0018 ft-c (19.368 mlx) light output for use as self-displaying shift register cells in large-format, crawling-text dot-matrix displays, all-glass wire-ended[267]: 725ff 
ZC1040 – 25 mA, Gas-filled, cold-cathode AC trigger tetrode, one starter and a primer, positive starter voltage, Noval base
ZC1050 – 2 mA, Gas-filled, cold-cathode, luminescent trigger tetrode, one starter and a primer, 300 mlm light output[268] for use as self-displaying shift register cells in large-format, crawling-text dot-matrix displays,[269] all-glass wire-ended
ZC1060 – 20 mAavg, 5 kApeak, Gas-filled, cold-cathode, high-current trigger triode for e.g. capacitor discharge circuits. One external (capacitive) starter electrode
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 cathode, pulsating anode voltage, controlled by 5-volts sensitive starter electrodes, for transistorized circuits
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 wire-ended
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 5×7 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
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 wire-ended
ZM1333 – + - ~ Ω Neon-filled digital indicator tube, 13.1mmCH side-viewing, all-glass wire-ended, 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 wire-ended, red contrast filter coating, for use with ZM1336 in digital multimeters
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, Xenon-filled organically quenched Geiger-Müller tube. 7 × 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
QQV03/20A – 20 W Radiation-cooled dual tetrode made by Mullard and used in the 1940s, 1950s and 1960s as a VHF frequency-doubling output stage with balanced output
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, Ug1Cut-off (IA=1 mA@UA=55 kV): > -3.4 kV, gm: 38 mS
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, gm: 15 mS. Used in RF generators for induction hardening
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, noise, and hum, AF pentode, 6.3 V/300 mA heater, UX6 base; similar to types 57, 6C6, 6D6 and 6U7
1604 – Remote-cutoff RF/IF pentode, U6A base, control grid on top cap; premium version of type 78[272][273]
1605 – Directly heated triode, 1.25 V/100 mA filament[274]
1606 – Directly heated pentiode, 1.25 V/100 mA filament[275]
1607 – Directly heated power triode, 2.5 V/2.5 A filament, UX4 base; similar to type 2A3[276]
1608 – Directly heated power triode giving 20 watts at up to 45 MHz, 2.5 V/2.5 A filament, UX4 base; similar to type 801
1609 – Directly heated low-microphonics AF pentode, 1.1 V/250 mA filament, UY5 base
1610 – Directly heated pentode specially designed for use as a crystal oscillator, 2.5 V/1.75 A filament, American 5-pin base
1611 – Power pentode for use in maritime, automatic SOStransmitters; 6F6 with tightened specs
1612 – Heptode pentagrid converter, both control grids #1 and #3 are sharp-cutoff; low-microphonics version of type 6L7
1613 – 17.5 W Indirectly heated RF power pentode, 6.3 V/700 mA heater, Octal base
1614 – 21 W Indirectly heated RF beam power tetrode, 6.3 V/900 mA heater, Octal base
1615 – Indirectly heated pentode, 6.3 V/700 mA heater, U6A base; premium version of type 42[277]
1616 – 6.5 kV, 130 mA Half-wave rectifier, UX4 base with anode on top cap
1619 – RF Beam power tetrode, 2.5 V/2 A filament, Octal base, common in World War II battle tank transmitters; similar to type 6L6 but directly heated
1620 – Indirectly heated low-microphonics AF pentode, 6.3 V/300 mA heater, Octal base; very similar to type 6J7
1621 – 8.3 W Indirectly heated AF power pentode, 6.3 V/700 mA heater, Octal base; long-life version of the 6F6
1622 – 13.8 W Indirectly heated AF beam power tetrode, 6.3 V/900 mA heater, Octal base; long-life version of the 6L6
1623 – 25 W Directly heated power triode, 6.3 V/2.5 A filament, UX4 base; similar to type 809
1624 (2.5 V/2 A heater), 1625 (12.6 V/450 mA heater) – Indirectly heated RF beam power tetrode, low lossmica-filled phenolic resin ("Micanol")[14] Octal base with anode on top cap; very similar to type 807, but with different heaters
1626 – RF power triode; very similar to type 6J5 but with a 12.6 V/250 mA heater
1627 – Directly heated power triode, Jumbo 4-pin base with anode on top cap and control grid on side cap; 810 with a 5 V/9 A heater[279]
1628 = VT140 – 500 MHz, 40 W Directly heated UHF power triode, tantalum anode, center-tapped 3.5 V/3.25 A thoriated tungsten filament[280]
1629 – Tuning indicator tube with DC amplifier triode unit; 6E5 with an Octal base and a 12.6 V/150 mA heater
1651 = UV218 – 50 kV, 750 mA Half-wave rectifier, 3-pin base with anode on top cap[288]
1654 – 7 kV, 1 mA Half-wave rectifier, Miniature 7-pin base with anode on top cap
1655 – Common cathode dual high-μ AF triode, Octal base; premium version of type 6SC7[289]
1659 – Dual diode + high-μ triode; selected 2A6 for use in Boonton Q meters - then further selected and assigned 535A or 535B for their 260-A meter[290]
1664 – Dual diode + semiremote-cutoff pentode; premium version of type 12C8[291]
1677 = 25L6GT Code M-34 – Beam power tetrode; 25L6GT with a custom-designed screen grid, and further selected by exclusive customer Bristol Co. for their industrial furnace-control equipment; rejects were returned and sold off as regular 25L6GT[292]
1679 – Common cathode dual triode, sold exclusively to IBM for their computers; 6J6/ECC91 selected for improved cutoff and high zero-bias anode current; rejects were sold off as regular 6J6; superseded by type 1684[293]
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
1681 – Beam power tetrode, sold exclusively to IBM for their computers; 6AQ5/EL90 with a custom-designed control grid, no cathode poisoning after prolonged periods in cut-off, and further selected for cutoff and zero-bias anode current; rejects were sold off as regular 6AQ5[294]
1682 – Common cathode dual triode, sold exclusively to US Air Force, Sperry Gyroscope Co., and WE, for use in radar and computer equipment aboard B-36 aircraft; 6J6 selected for balance between sections after aging; superseded by type 6099[295]
1684 – Common cathode dual medium-μ triode, sold exclusively to IBM for their computers; 1679 with a 300 mA heater; superseded by types 5844 and 6211 (separate cathodes)[296]
1699 – Indirectly heated hexode monoscope, 6-pin base with dual top caps for #4 grid and anode; 2F21 with a customer-supplied test pattern