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; all filaments in a device are connected in parallel and rated the same voltage. 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.Types for hand-held/portable devices are usually 1 to 2 V 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.Types for mobile devices (installed in land/marine/aerial vehicles) are indirectly heated from the 6, 12, or 24 volts engine crank battery resp. the alternator or APU; a high-output radio alternator option to meet the additional power demand, was offered for cars (not to be confused with the Alexanderson alternator).
6.3 V, indirectly heated, from four dry cells or from three lead-acid cells[5] (used in 6-Volts vehicle equipment; examples)
5 V, directly heated, via a rheostat (used in home radios; examples)
12.6 V, indirectly heated, from six lead-acid cells (used in 12-Volts vehicle equipment; examples)
26.5 V, indirectly heated, from twelve lead-acid cells, used in 24-Volts vehicle equipment, also on the standard avionics 28-Volts DC bus
Types for AC-only equipment with a mains transformer; dull-emitter signal and low-power tubes are indirectly heated (except for some 1920s power tubes and rectifiers) and all heaters in a device are rated the same voltage and fed in parallel from a transformer secondary winding.In North America, a 2.5VRMS standard was used 1929–34 (examples); elsewhere, nominal heater voltages from 1920's lead-acid/"battery eliminator" era (multiples of 2 or 2.1V) were kept, 4VRMS in the UK (examples),[1] but since the 1940s the 6.3V and 12.6V car radio standards prevailed everywhere; 5VRMS became a standard for full-wave rectifiers (examples) fed from a separate transformer winding because their filament/cathode is on anode supply potential.
However, most RF power tubes are bright-emitter 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 capable of slowly ramping up the heater voltage to smooth out the otherwise destructive heater inrush current, and to minimize thermal stress to the vacuum seals, when powering up.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.Some microwave power tubes require heater voltage derating above a specified maximum operating frequency where electron transit time effects start causing back bombardment heating of the cathode.
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; all tubes in a device need to:
be rated the same heater current, typically 50, 100, 150, 200, 300, 450 or 600 mA, depending on mains voltage and device tube count
have the same warm-uptime constant, typically 11 seconds, controlled by increasing the cathode's thermal capacity so it wouldn't overheat when powering up
have a heater/cathode insulation that withstands 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
Some power tubes have a heater tap near one end to feed a small pilot lamp, thus shunting away from it the heater inrush current when powering up.[6]
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.
Dual-control pentode: The suppressor grid has a short grid base (=fine pitch) like the control grid and is available on a separate base pin (instead of internally tied to the cathode) so it can be used as a second control grid; anode current flows only if neither grid is negative; derived from the dual-grid mixer triode and precursor of the Gated-beam discriminator and hexode/heptode/octode/nonode approaches
Strap frame-grid: While a normal grid is a thin wire wound to a helix around two swaged metal posts, a frame-grid is a thin wire wrapped around a rectangular stamped sheet metal frame; except in planar microwave tubes, one such frame on either side of the cathode is needed to form a grid
Shadow-grid: Beam pentode with a beam-forming extra grid between control and screen grids (technically a beam hexode), aligned to cast an electron shadow on the screen grid wire and thus reduce screen grid current and hence anode/screen grid distribution noise
The anodes of high-power tubes are usually made from Copper because of its high electrical and thermal conductivity.[11] Their maximum power dissipation 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. [Im]pulse-rated anodes are optimized for anode voltage surges and heat-up time constant, compared to their CW-rated counterparts.[12]
Due to dielectric losses, tube efficiency decreases with increasing operating frequency; the maximum anode voltage is therefore derated above a specified maximum frequency, which in turn reduces the available output power.[13]: 143 Usual cooling methods are:
—Internal anode:
Natural convection: Air moves freely along the tube; modest power levels only
Radiation: The (at maximum anode power) orange-red glowing anode, made from Graphite or from a high-work functionrefractory metal such as Molybdenum or Tantalum, optionally Zirconium-coated ("Pyrovac"), dissipates heat by its infrared radiation through the envelope, which in the case of high-power tubes, is made from an infrared-transparent hard glass (softening point ≥750 °C) such as Silica. The vacuum seals may still need forced-air cooling through special ventilated (=blow-through) bases such as the B4A or the B8F Eimac/JEDEC B8-236
—External anode protruding through the envelope so a good electrical and thermal contact can be made:
Improved Alumina insulation between the heater and cathode sleeve so the cathode could be elevated to a higher voltage above the heater supplyNote that a cathode positive to the heater was less detrimental to the oxide insulation between heater and cathode than the reverse, helping to prevent pyrometallurgicalelectrolytic 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
Ruggedized (more rigid) electrode supports to reduce microphonics and improve mechanical shock and vibration 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 and starting amplifier tubes from the letter A, working forward through the alphabet, while starting rectifier tubes from the letter Z, working backwards; since the two met (first the numerous 6-prefix, low elements-count tubes c. 1937), the single-letter namespace became exhausted, so combinations like AB, AC, AD, AE... were used, avoiding same-letter repetitions, reserving those ending in P for CRTs (see below) and henceforth assigning rectifiers also in forward-orderWherever possible, different-heater versions retained the original's letter combination; exceptions include: the 12BR7 and 9BR7 are unrelated to the 6BR7; the series heater versions of the 6.3 V/450 mA 6BL8/ECF80 are the 9.0 volts 9A8/PCF80 for 300mA strings, the 6.0 volts (thus requiring a different letter combination) 6LN8/LCF80 with controlled warm-up for 450mA strings, and the 4.6 volts 4BL8/XCF80 for 600mA stringsThe development of new tubes ended with the combination MY, although already by the end of the one-letter era, when the control grid top cap was discontinued and replaced by a regular base pin ("single-ended tube" - all connections on one end; not to be confused with the single-ended amplifier circuit), so-modified existing tubes, and the first new ones thereafter, were marked with a preceding letter S (6F5/12F5 → 6SF5/12SF5, 6K7/12K7 → 6SK7/12SK7, 1SA6-GT, 1SB6-GT, 6SB7Y, 6SC7/12SC7, 6SL7-G, 6SU7-GTY).[16] Similarly in the 1940s, 1.4 volt DC filament tubes (and the 2.8 volts center-tapped 3LE4, 3LF4) with a Loctal base were marked with a preceding letter L; 6.3 resp. 12.6 volts Loctal tubes were all assigned the prefixes 7 resp. 14 instead of 6 resp. 12, except 12B7 (=14A7)
A number with up to 2 digits: Count of active elements, 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; Sutton tube (=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 + split-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 + triple-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 (Compactron limit) – 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, a possible dash ("-") followed by a suffix of up to three Latin letters: Upgrades to the original model or different envelope outlines; the use is somewhat arbitrary:
X – Low loss ceramic base for improved RF performance
Y – Low loss Micanol base for improved RF performance
Optionally, 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
2AP1, 2BP1 – 2" (5.1 cm) CRT used in oscilloscopes, electrostatic deflection
3ABP1, 3ABP2, 3ABP7 (blue/yellow, short/long), 3ABP11 – Dual-beam 3" (7.6 cm) CRT used 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.[19]: 2 It therefore needs backlighting or external illumination like today's electronic paper[20][21]
4DP1, 4DP2, 4DP7, 4DP11 – Dual-beam 4" CRT used in oscilloscopes, electrostatic deflections
5AZP4 – 5" Projection CRT, 40 kV anode voltage, considerable X-radiation, 50° magnetic deflection, P4 white, medium-persistence, casts an 8 ft × 6 ft (2.4 m × 1.8 m) image
5BP1 (1802-P1) – 5" (13 cm) CRT used in pre-World War II oscilloscopes, electrostatic deflection, P1 green, medium-persistence[22]
5BP3 (1802-P3) – Pre-World War II, 5" CRT, electrostatic deflection, P3 yellow, medium-persistence[22]
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,[23] electrostatic deflection, P4 white, medium-persistence[22]
6DP1, 6DP2, 6DP7, 6DP11, 6DP14 (purple/orange, medium/long), 6DP19 (orange, long), 6DP25 (orange, very long) – Triple-beam 6" (15 cm) CRT used in oscilloscopes, electrostatic deflections
7JP1 – 7" (18 cm) CRT used in early postwar oscilloscopes, electrostatic deflection, P1 green, medium-persistence[25]
7JP4 – 7" CRT common in early postwar TV receivers, electrostatic deflection, P4 white, medium-persistence[25]
7JP7 – 5½" (14 cm usable screen diameter) CRT used in early postwar radar displays, electrostatic deflection, P7 blue/yellow, short/long-persistence[25]
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 used 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")[18]
Nullodes (discharge tubes which have no electrodes and interact only with electromagnetic fields passing through them) such as:
TR (Transmit/receive) cell, a water vapor discharge tube for use with waveguides in radar systems, short-circuits the receiver input to protect it while the transmitter operates on a shared antenna
ATR (Anti-transmit/receive) cell, decouples the radar transmitter from the antenna while not operating, to prevent it from wasting received energy
PTR (Pre-transmit/receive) cell, a low-Q discharge tube, precedes the main TR cell and produces a preliminary reflection to reduce the power level at the main TR cell
A four-digit system from 5500 to 8999 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:
S24 – Photocathode, high-temperature/low-noise Bialkali K-Cs-Sb (Potassium-Caesium-Antimony) or Na2KSb (Sodium-Potassium-Antimony), Lime, UV to red, λmax=385 nm, used in oil well logging at up to 175 °C; very low dark current at room temperature, making it ideal for use in photon counting
S25 – S20 with a special cathode activation to extend the range to 930 nm
Where k = Conversion factor (lm/W); Styp = typical luminous sensitivity @2780K (µA⁄lm); Smax = max. luminous sensitivity (µA⁄lm) at wavelength λmax (nm); σtyp = typical radiant sensitivity (mA⁄W);[30] QE = typical quantum efficiency (%);[31] DE = typical photocathode dark emission @25°C (fA⁄cm2)
Eimac transmitting tubes
Pre-Eimac, developed by Bill Eitel (W6UF) and Jack McCullough (W6CHE) while still working for Heintz & Kaufman:
HK354 – 150 W, 15 MHz Gammatron Radiation-cooled power triode, μ=14, 5 V/10 A filament, Tantalum anode, Nonex hard glass envelope, B4F/U4J Jumbo base with anode on top cap; predecessor of the 150T (=250TL), the first Eimac tube
Before 1945
From 1934 to 1945, Eimac made only convection/radiation-cooled, directly heated rectifiers and power triodes.[32] Eimac soon found that their early anode dissipation ratings were too cautious[33]
15E = 3-15A3 = 4C30 = 8023 – 20 W, 600 MHz Miniature pulse power triode, μ=25, 5 V/4 A filament, grid on top pin and anode on side pin,[34] used as power oscillator, also popular as thermally-limited (=saturated) emissionnoise diode[35]: 321
15R = 4B30 – 20 kV, 20 Apeak, 30 mAavg Pulse rectifier, 5 V/4 A filament, anode on top cap[36]
25T = 3-25A3 = 3C34 – 25 W Power triode, μ=24, 6.3 V/3 A filament, UX4 base with anode on top pin
35T = 35TL = 3-50A4 (Grid on base), 35TG = 3-50D4 (grid on side pin) – 50 W, 100 MHz Power triode, μ=39, 5 V/4 A filament, UX4 base with anode on top pin
75TL = 3-75A2 (μ=12), 75TH = 3-75A3 (μ=20) – 75 W, 40 MHz Power triode, 5 V/6.25 A filament, UX4 base with grid on side pin and anode on top pin
100R = 2-100A = 8020 – 40 kV, 100 mA Thermally-limited emission rectifier, 5 V/6.5 A filament, UX4 base with anode on top cap
100T = 100TL = 3-100A2 (=up-rated 50T; μ=14), 100TH = 3-100A4 (μ=38) – 100 W, 40 MHz Power triode, 5 V/6.3 A filament, UX4 base with grid on side pin and anode on top pin
152TL = 3-150A2 (μ=12), 152TH = 3-150A3 (μ=20) – 150 W, 40 MHz Power triode, center-tapped 10 V/6.25 A resp. 5 V/12.5 A filament, 4-pin Bayonet base with anode on top pin
250R = 2-250A – 60 kV, 250 mA Thermally-limited emission rectifier, 5 V/10.5 A filament, B4F/U4J Jumbo base with anode on top cap
250T = 250TL = 3-250A2 (=up-rated 150T; μ=14), 250TH = 3-250A4 (μ=37)[37] – 250 W, 40 MHz Power triode, 5 V/10.5 A filament, B4F/U4J Jumbo base with grid on side pin and anode on top cap
304TL = 3-300A2 (μ=12), 304TH = 3-300A4 (μ=20) – 300 W, 40 MHz Power triode, center-tapped 10 V/12.5 A resp. 5 V/25 A filament, 4-pin Bayonet base with grid on side cap and anode on top cap
450T = 450TL = 3-450A2 (=up-rated 300T; μ=18), 450TH = 3-450A4 (μ=38)[38] – 450 W, 40 MHz Power triode, 7.5 V/12 A filament, B4F/U4J Jumbo base with grid on side cap and anode on top cap
750T = 750TL = 3-750A2 (=up-rated 500T) – 750 W, 40 MHz Power triode, μ=15.5, 7.5 V/21 A filament, B4F/U4J Jumbo base with grid on side cap and anode on top cap
1000T = 3-1000A4 (6C21) – 1 kW, 50 MHz Power triode, μ=35, 7.5 V/17 A filament, B4F/U4J Jumbo base with grid on side cap and and anode on top cap
1500T = 3-1500A3 – 1.5 kW, 40 MHz Power triode, μ=24, 7.5 V/24 A filament, B4F/U4J Jumbo base with grid on side cap and anode on top cap
2000T = 3-2000A3 – 2 kW, 40 MHz Power triode, μ=23, 10 V/25 A filament, B4F/U4J Jumbo base with grid on side cap and anode on top cap
This scheme was phased out in favor of the system below in 1945, when the FCC reallocated the VHF-FM broadcast band from 42-50 MHz to 87.5-108 MHz where tetrode transmitters were better suited at the time
UH50 = 3-50G2 = 304B = 834 – 50 W Radiation-cooled power triode, μ=10.6, 7.5 V/3.25 A filament, UX4 base with grid and anode on top cap. The up to cherry-red anode glow was recommended as tank/antenna tuning indicator
Since 1945
Eimac and other manufacturers of high-power RF tubes use the following code:[39]
3CW25000A3 – 25 kW, 100 MHz Water-cooled, ceramic/metal medium-μ power triodes, 6.3 V/152-172 A filament
3CW30000H3 (Medium-μ), 3CW30000H7 (High-μ) – 30 kW, 90 MHz Water-cooled, ceramic/metal power triodes, 6.3 V/152-172 A filament with flexible filament leads
3CW40000H3 – 40 kW, 90 MHz Water-cooled, ceramic/metal medium-μ power triodes, 10 V/152-168 A filament with flexible filament leads
3CX100A5/7289 (6.0 V/1 A heater), 3CX100F5/8250 (26.5 V/220 mA heater) – 100 W, 3 GHz Oil can-type forced-air cooled, ceramic/metal disk-seal, coaxial, planar, high-μ UHF power triode, 6.3 V/1 A heater, popular among radio amateurs for 23cm-band microwave amplifiers; 2C39A with different heaters
3CX300A1 – 300 W Forced-air cooled, ceramic/metal, low-μ power triode, 6.3 V/2.65 A heater
3CX400A7/8874 (EIA E11-81, 11-pin with ring base), 3CX400U7/8961 (Coaxial) – 400 W, 500 MHz Forced-air cooled, ceramic/metal, high-μ power triode, 6.3 V/3 A heater
3CX800A7 – 800 W, 350 MHz Forced-air cooled, ceramic/metal, high-μ power triode, 13.5 V/1.5 A heater
3CX1000A7/8283 – 1 kW, 220 MHz Forced-air cooled, ceramic/metal, high-μ power triode, 5 V/30.5 A filament
3CX1500A7/8877 – 1.5 kW, 110 MHz Forced-air cooled, ceramic/metal high-μ power triode, 5 V/10.5 A filament
3CX2500A3/8161 (75 MHz), 3CX2500F3/8251 (30 MHz, with flexible grid and filament leads), 3CX2500H3 (75 MHz, with flexible filament leads) – 2.5 kW Medium-μ triode, 7.5 V/49-53 A filament; ceramic/metal variants of 3X2500s; forced-air cooled variants of 3CW5000A3 and 3CW5000F3
3CX3000A1/8238, 3CX3000F1/8239 (with flexible grid and filament leads) – 3 kW Forced-air cooled, low-μ AF power triode, 7.5 V/49-54 A filament; ceramic/metal variants of 3X3000s
3CX3000A7 (110 MHz), 3CX3000F7/8162 (30 MHz, with flexible grid and filament leads) – 3 kW Forced-air cooled, ceramic/metal, Zero-Bias, high-μ power triode, 7.5 V/50.5-51.5 A filament
3CX4500F3 – 4.5 kW, 75 MHz Forced-air cooled, ceramic/metal medium-μ power triode, 7 V/78 A filament with flexible leads
3CX10000H3 – Medium-μ, with flexible filament leads
3CX10000U7 – 10 kW, 260 MHz Forced-air cooled, ceramic/metal, coaxial, high-μ power triode, 15 V/3.5 A heater
3CX15000A3 (Low-μ, 100 MHz), 3CX15000A7 (Medium-μ, 110 MHz), 3CX15000H3 (Low-μ, 90 MHz, with flexible filament leads) – 15 kW Forced-air cooled, ceramic/metal power triode, 6.3 V/160 A filament
3CX20000A3 (Low-μ, 90 MHz), 3CX20000A7 (Medium-μ, 110 MHz), 3CX20000H3 (Low-μ, 90 MHz, with flexible filament leads) – 20 kW Forced-air cooled, ceramic/metal power triode, 10 V/160 A filament
3W5000s – 5 kW, 75 MHz Water-cooled power triodes, 7.5 V/49-54 A filament; glass/metal variants of 3CW5000s
3W5000A1/8240 – Low-μ
3W5000A3/8242 – Medium-μ
3W5000F1/8241 – Low-μ, with flexible filament leads
3W5000F3/8243 – Medium-μ, with flexible filament leads
3X100A5 – Factory stress-tested 2C39A
3X2500A3/8161 (75 MHz), 3X2500F3/8251 (30 MHz, with flexible grid and filament leads) – 2.5 kW Forced-air cooled, low-μ power triode, 7.5 V/51 A filament; glass/metal variants of 3CX2500s
3X3000A1/8238 (AF, Low-μ), 3X3000A7 (AF/RF, Medium-μ), 3X3000F1/8239 (AF, Low-μ, with flexible grid and filament leads) – 3 kW Forced-air cooled power triode, 7.5 V/51 A filament; glass/metal variants of 3CX3000s
3X12500A3 – 12.5 kW, 110 MHz Forced-air cooled, glass/metal low-μ power triode, 7.5 V/192 A filament
4-65A/8165 – 65 W, 150 MHz Glass beam power tetrode, 6.0 V/3.2-3.8 A filament, 5-pin Septar base with anode on top cap
4-125A/6155/4D21 – 125 W, 120 MHz Glass beam power tetrode, 5 V/6.5 A filament, B5E Giant 5-pin UY base with metal shell and anode on top cap
4-250A/6156/5D22 – 250 W, 110 MHz Glass beam power tetrode, 5 V/14.5 A filament, B5E Giant 5-pin UY base with anode on top cap
4-400A/8438, 4-400C/6775 – 400 W, 110 MHz Glass radial-beam power tetrode, 5 V/14.5 A filament, B5E Giant 5-pin UY base with anode on top cap
4-500A – 500 W, 110 MHz Glass radial-beam power tetrode, 10 V/10.2 A filament, B5E Giant 5-pin UY base with anode on top cap
4-1000A/8166 – 1 kW, 110 MHz Glass beam power tetrode, 7.5 V/20-22.7 A filament, B5K Supergiant 5-pin UY base with a metal shell and anode on top cap, popular in broadcast and amateur transmitters
4CM300000G = 9000 – 300 kW, 50 MHz Water/vapor ("Multiphase") cooled, ceramic/metal power tetrode used in broadcast transmitters, 15 V/480 A filament
4CN15A – 15 Wavg Coolerless variant of the 4CX300A/8167 for low duty or pulse service, but may be operated immersed in a liquid coolant
4CPX250K/8590 – 250 Wavg, 17.5 kWpeak, 500 MHz Forced-air cooled, ceramic/metal radial-beam grid-pulsed power tetrode, 6.0 V/2.5 A heater
4CS100L – 100 W, 250 MHz Contact/conduction-cooled, ceramic/metal power tetrode + control diode to monitor the emission of the quickstart 2.1 V/7.15-8.10 A filament
4CS250R – 250 W, 500 MHz Ruggedized, contact/conduction-cooled, ceramic/metal power tetrode with a Beryllia heat sink coupler, quickstart 6.0 V/2.6 A filament
4CV8000A – 8 kW, 150 MHz Water/vapor cooled, ceramic/metal power tetrode, 9 V/41.5 A filament
4CV20000A – 20 kW, 30 MHz Water/vapor cooled, ceramic/metal power tetrode, 7.5 V/73-78 A filament
4CV35000A – 35 kW, 110 MHz Water/vapor cooled, ceramic/metal power tetrode, 6.3 V/152-168 A filament
4CV50000E, 4CV50000J – 50 kW, 110 MHz Water/vapor cooled, ceramic/metal power tetrode, 12 V/220 A filament
4CV75000A – 75 kW, 30 MHz Water/vapor cooled, ceramic/metal power tetrode, 10 V/300 A filament
4CV100000C/8351 – 100 kW, 30 MHz Water/vapor cooled, ceramic/metal power tetrode, 10 V/300 A filament
4CV250000 (30 MHz, 12.0 V/640 A filament), 4CV250000A (30 MHz, 12.0 V/660 A filament), 4CV250000B (50 MHz, 12.0 V/660 A filament) – 250 kW Water/vapor cooled, ceramic/metal power tetrode
4CW800B (6.0 V/4.4 A heater), 4CW800F (26.5 V/1.1 A heater) – 800 W, 800 MHz Water-cooled, ceramic/metal power tetrode
4CW2000A/8244 – 2 kW, 110 MHz Ceramic/metal radial-beam power tetrode, 6.0 V/9 A heater; water-cooled variant of 4CX1000A/8168
4CW10000A/8661 – 10 kW, 110 MHz Water-cooled, ceramic/metal power tetrode, 7.5 V/73-78 A filament
4CW25000A – 25 kW, 110 MHz Water-cooled, ceramic/metal power tetrode, 6.3 V/160 A filament
4CW50000C/8350 (30 MHz, 10 V/300 A filament), 4CW50000E (110 MHz, 12 V/220 A filament), 4CW50000J (110 MHz, 12 V/220 A filament) – 50 kW Water-cooled, ceramic/metal power tetrode
4CW100000D (30 MHz, 10 V/295 A filament), 4CW100000E (110 MHz, 15.5 V/215 A filament), 4CW100000G (110 MHz, 15.0 V/170 A filament) – 100 kW Water-cooled, ceramic/metal power tetrode
4CW150000E – 150 kW, 110 MHz Water-cooled, ceramic/metal power tetrode, 15.5 V/215 A filament
4CW250000A, 4CW250000B, 4CW250000V – Water-cooled variants of 4CV250000A, 4CV250000B
4CX125C (6.0 V/2.6-3.1 A heater), 4CX125F (26.5 V/600-700 mA heater) – 125 W, 500 MHz Forced-air cooled, ceramic/metal radial-beam power tetrode
4CX250s – 250 W, 500 MHz Forced-air cooled, ceramic/metal radial-beam power tetrodes, favored by radio amateurs as a final amplifier
4CX250B/7203 = QEL2/275 – 6.0 V/2.6 A heater, B8F/JEDEC B8-236 9-pin blow-through base
4CX250BC/8957 – Long-life, tighter specs variant of 4CX250B
4CX250F/7204 = 4CX250FG/8621 = QEL2/275H – 26.5 V/540 mA heater
4CX250K/8245 – Coaxial variant of 4CX250B for use with a cavity resonator, 6.0 V heater
4CX250M/8246 – 26.5 V heater variant of 4CX250K
4CX250R/7580-W – Ruggedized variant of 4CX250B, 6.0 V heater
4CX300A/8167 – 300 W, 500 MHz Forced-air cooled, ceramic/metal power tetrode, 6.0 V/2.6-3.1 A heater
4CX300Y/8561 – 400 W, 110 MHz Forced-air cooled, ceramic/metal power tetrode, 6.0 V/3-3.85 A heater
4CX350A/8321/YL1340 (6.0 V/2.9-3.6 A heater), 4CX350F/8322/YL1341 (26.5 V/660-810 mA heater) – 350 W Forced-air cooled, ceramic/metal radial-beam AF power tetrode; ruggedized 26.5 V heater variant: 4CX350FJ/8904
4CX600s – 600 W Forced-air cooled, ceramic/metal radial-beam power tetrode
4CX600F – 500 MHz, 26.5 V/1.05 A heater for use in distributed wideband amplifiers
4CX600J/8809 – 6.0 V/5.4 A heater, Larger anode cooler
4CX600JA/8921 – 6.0 V/5.4 A heater, Larger anode cooler
4CX1000A/8168 (110 MHz), 4CX1000K/8352 (with a solid screen ring for UHF use) – 1 kW Ceramic/metal radial-beam power tetrode, 6.0 V/9 A heater; forced-air cooled variant of 4CW2000A/8244
4CX1500A (150 MHz, 5.0 V/38.5 A filament), 4CX1500B/8660 (6.0 V/9-11 A filament) – 1.5 kW Forced-air cooled, ceramic/metal radial-beam power tetrode
4CX3000A/8169 – 3 kW, 150 MHz Forced-air cooled, ceramic/metal radial-beam power tetrode, 9 V/41.5 A filament
4CX3500A – 3.5 kW, 220 MHz Forced-air cooled, ceramic/metal radial-beam power tetrode, 5.0 V/90 A filament
4CX5000J/8909 – 6 kW, 100 MHz Forced-air cooled, ceramic/metal, linear radial-beam power tetrode, 7.5 V/103 A filament
4CX7500A – 7.5 kW, 220 MHz Forced-air cooled, ceramic/metal radial-beam power tetrode, 7.0 V/103 A filament
4CX10000D/8171 (7.5 V/75 A filament), 4CX10000J (7.5 V/103 A filament) – 10 kW, 110 MHz Forced-air cooled, ceramic/metal radial-beam power tetrode; 4CX5000A/8170 with a larger cooler
4CX12000A/8989 – 12 kW, 220 MHz Forced-air cooled, ceramic/metal radial-beam power tetrode, 7.5 V/120 A filament
4CX15000A/8281 – 15 kW, 110 MHz Forced-air cooled, ceramic/metal radial-beam power tetrode, 6.3 V/160 A filament
4CX15000J/8910 = 9019 = YC-130 – More linear 4CX15000A/8281 with a 7.5 V/160 A dense mesh-type filament
4CX20000A/8990, 4CX20000B, 4CX20000C – 20 kW, 110 MHz Forced-air cooled, ceramic/metal radial-beam power tetrode, 10 V/140 A filament
4CX25000A – 25 kW, 230 MHz Forced-air cooled, ceramic/metal radial-beam power tetrode, 9.5 V/150 A filament
4CX35000A, 4CX35000C/8349 (longer screen/anode insulator for Class-C screen grid or anode modulation), 4CX35000D – 35 kW, 110 MHz Forced-air cooled, ceramic/metal power tetrode, 10 V/300 A filament, used in numerous 50-kW broadcast transmitters, often in a Doherty configuration as in the Continental Electronics 317C series
4CX40000G, 4CX40000GM (Different grid pattern to reduce intermodulation distortion, made for Marconi Company Ltd) – 40 kW, 220 MHz Forced-air cooled, ceramic/metal power tetrode, pyrolytic graphite grids, 15 V/170 A filament
4PR60A, 4PR60B/8252 – 60 Wavg, 300 kWpeak Radiation+forced-air cooled, glass, pulse-rated power tetrode used as modulator/amplifier, 26.0 V/2.1 A heater; supersedes 715C and 5D21; ruggedized variant: 4PR60C/8252-W
4PR65A/8187 – 65 Wavg Radiation+forced-air cooled, glass, pulse-rated power tetrode with a Pyrovac anode, used as modulator/amplifier, 6.0 V/3.2-3.8 A filament
4PR125A/8247 – 125 Wavg Radiation+forced-air cooled, glass, pulse-rated power tetrode with a Pyrovac anode, 5.0 V/6-7 A filament, B5E Giant 5-pin UY base with anode on top cap
4PR250C/8248 – 250 Wavg Radiation+forced-air cooled, glass, pulse-rated power tetrode with a Pyrovac Tantalum anode, 5.0 V/14 A filament, B5E Giant 5-pin UY base with anode on top cap
4PR400A/8188 – 400 Wavg Radiation+forced-air cooled, glass, pulse-rated power tetrode with a Pyrovac anode, 5.0 V/13.5-14.7 A filament, B5K Supergiant 5-pin UY base with anode on top cap
4PR1000A/8189 – 1 kWavg Radiation+forced-air cooled, glass, pulse-rated power tetrode with a Pyrovac anode, 7.5 V/20.0-22.7 A filament, B5K Supergiant 5-pin UY base with anode on top cap
4W300B/8249 – 300 W, 500 MHz Water-cooled, glass/metal power triode, 6.0 V/2.6 A heater, B8F/JEDEC B8-236 9-pin base
4W20000A/8173 – 20 kW, 220 MHz Water-cooled, glass/metal power triode, 10 V/30 A heater
4X150A/7034 = QEL1/150 – 6.0 V/2.6 A heater, B8F/JEDEC B8-236 9-pin base
4X150D/7035 – 26.5 V/580 mA heater, B8F/JEDEC B8-236 9-pin base
4X150G/8172 – 2.5 V/6.2-7.3 A heater, coaxial
4X150R/8296 – Ruggedized, 6.0 V/2.4-3.0 A heater, B8F/JEDEC B8-236 9-pin base
4X150S/8297 – Ruggedized, 26.5 V/560-680 mA heater, B8F/JEDEC B8-236 9-pin base
4X250B (6.0 V/2.3-2.9 A heater), 4X250F (26.5 V/500 mA heater) – 150 W, 175 MHz Forced-air cooled, glass/metal beam power tetrode, B8F/JEDEC B8-236 9-pin base
4X500A – 500 W, 120 MHz Forced-air cooled, glass/metal beam power tetrode, 5.0 V/12.2-13.7 A filament
4X5000A – 5 kW, 30 MHz Forced-air cooled, glass/metal beam power tetrode, 7.5 V/75 A filament
5-125B/4E27A – 125 W, 75 MHz Glass power pentode, 5 V/7.5 A filament, B7D/U7G Giant 7-pin base with anode on top cap
5-500A – 500 W Glass radial-beam power pentode, 10 V/10.2 A filament, B5E Giant 5-pin UY base with anode on top cap
5CX1500A, 5CX1500B – 1.5 kW, 110 MHz Forced-air cooled, ceramic/metal radial-beam power pentode, 5.0 V/40 A filament
5CX3000A – 4.0 kW, 150 MHz Forced-air cooled, ceramic/metal radial-beam power pentode, 9.0 V/39.5-43.5 A filament
5K50CB – 10 kW, 4.4 to 5.0 GHz Ethylene glycol-cooled, electromagnet-focused linear-beam, 5-cavity Klystron used in C-band troposcatter systems
5K70SH – 30 kW, 2.45 GHz Forced-air and water-cooled, electromagnet-focused linear-beam, 5-cavity Klystron used for industrial, microwave dielectric heating
5KM300SI – 100 kW, 2.1 to 2.4 GHz Forced-air and water-cooled, electromagnet-focused linear-beam, 5-cavity Klystron used in Unified S-band ground transmitters of spacecraft communications systems
6K50000LQ – 10 kW, 720 to 980 MHz Forced-air and water-cooled, permanent magnet-focused linear-beam, 6-cavity Klystron
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.[47]
D – 1.4 V DC filament for Leclanché cells, later low-voltage/low-power filament/heater:
625 mV 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[48]
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 DC filament for a 2-cell lead-acid battery[3]: 2 (no known examples assigned)
I – 20 V heater
K – 2.0 V filament/heater for a single lead-acid cell, 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;[49] later shifted to H
Then informally used for imported RETMA 0-prefixnoble gas-filled cold-cathode tubes although their letter is meaningless; domestic types were shifted to Z before their mass production started
Lastly assigned to semiconductors, as these also had no heater
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 backronymed to French: "Sécurité - Qualité") for professional/industrial/computer/telecommunications purposes featured some modifications including those listed above
—SQ numbering before c. 1960: Function/type letter and base type number swapped;[54] 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
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 1920s code other than that BVA/BRVMA 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;[18][58] not to be confused with Compagnie des Lampes (1921, "French Mazda", see below). This system was also used by the British ETA[59]
An optional number (may also appear at the end of the designation): Filament/heater voltage:[18]
4, 40–49, 400–499, 506 – 4 V, Mostly indirect, heaterNote: Some power tubes in the low 40s and 400s have a 40 V/200 mA indirect heater for use in a series heater string
13 – 13 V/200 mA Indirect heater for use in vehicle equipment or in a series heater string
200–299 – 2 V Filament/heater
600–699 – 6 V Indirect heater
825 – 7.5 V/2 A Direct heater
An optional prefix:
D – 16 V/250 mADC, indirectly heated ("DC mains operated") receiver tube for use in a series heater string running on a then-still commonplace municipal DC mains system; cf. 180mADC standard
M – 4-volts AC, indirectly heated ("Mains Operated") receiver tube fed in parallel from a mains transformer
V – Vari-μ = remote-cutoff tube
X – Upgraded power rating
Letter(s): Function/type (derived from the BVA code):
B – Dual power triode
BU (Full-wave), SU (Half-wave) – High-vacuum rectifier
4XP – Directly heated power triode, 4 V/1 A filament, European 4-pin base
41MDG – Indirectly heated dual-grid triode, 4 V/1 A heater, O5A European 5-pin base
41MP – Indirectly heated power triode, 4 V/1 A heater, O5A European 5-pin base
41MPG = Brimar 15A2 = Ferranti VHT4 = M-OV/GEC MX40 – Indirectly heated, remote-cutoff heptode pentagrid converter, 4 V/1 A heater, M7A British 7-pin base
41MXP = Brimar PA1 = EdiSwan AC/P1 = Mullard O54V – Indirectly heated power triode, 4 V/1 A heater, O5A European 5-pin base
41STH = Brimar 20A1 = EdiSwan AC/TH1 = M-OV/GEC X41 = Mullard TH4A – Triode/hexode oscillator/mixer, 4 V/1.15 A heater, M7A British 7-pin base
210DET – Directly heated, gas-filled triode used as AM detector, 2 V/100 mA filament, European 4-pin base
210HF – Directly heated triode, 2 V/100 mA filament, European 4-pin base
210HL – Directly heated triode, 2 V/100 mA filament, European 4-pin base
210LF – Directly heated triode, 2 V/100 mA filament, European 4-pin base
210PG – Directly heated remote-cutoff heptode pentagrid converter, 2 V/100 mA filament, M7A British 7-pin base
210RC – Directly heated very high-μ triode, 2 V/100 mA filament, European 4-pin base
210SPT – Directly heated sharp-cutoff RF pentode, 2 V/100 mA filament, M7A British 7-pin base
210VPT – Directly heated shielded remote-cutoff RF pentode, 2 V/100 mA filament, M7A British 7-pin base
215P – Directly heated AF power triode, 2 V/150 mA filament, European 4-pin base
220B – Directly heated dual power triode, 2 V/200 mA filament, M7A British 7-pin base (not to be confused with the Western Electric 220B single power triode)
220PA – Directly heated power triode, 2 V/200 mA filament, European 4-pin base
220PT – Directly heated power triode, 2 V/200 mA filament, European 4-pin base
230XP – Directly heated power triode, 2 V/300 mA filament, European 4-pin base
240B – Directly heated dual AF power triode, 2 V/400 mA filament, M7A British 7-pin base (not to be confused with the Amperex 240B single power triode)
402P – Indirectly heated power triode, 40 V/200 mA heater, M7A British 7-pin base
410HF – Directly heated triode, 4 V/100 mA filament, European 4-pin base
610RC – Directly heated signal triode, 5.5 V/100 mA filament, European 4-pin base
660SU – Directly heated 1 kV, 150 mA half-wave rectifier, 6 V/4.5 A filament, European 4-pin base
825BU – Directly heated 500 V, 120 mA full-wave rectifier, 7.5 V/2 A filament, European 4-pin base
DD/PEN – Indirectly heated dual diode + remote-cutoff AF pentode used as feed-forwardAGC, 4 V/1 A heater, M7A British 7-pin base
DDT = Brimar 11A2 = EdiSwan AC/HLDD = M-OV/GEC MHD4 = Mullard TDD4 – Indirectly heated dual diode + triode, 4 V/1 A heater, M7A British 7-pin base
DDT16 – Indirectly 16 V/250 mADC heated dual diode + high-μ triode, M7A British 7-pin base
DHL – Indirectly 16 V/250 mADC heated medium-μ triode, O5A European 5-pin base
DP – Indirectly 16 V/250 mADC heated power triode, O5A European 5-pin base
DP/PEN – Indirectly 16 V/250 mADC heated power pentode, M7A British 7-pin base
DS/PEN – Indirectly 16 V/250 mADC heated pentode, O5A European 5-pin base
DVS/PEN – Indirectly 16 V/250 mADC heated, remote-cutoff pentode, O5A European 5-pin base
DVSG – Indirectly 16 V/250 mADC heated, remote-cutoff tetrode, O5A European 5-pin base
PT41 – Directly heated power pentode, 4 V/1 A filament, O5A European 5-pin base
SU25 – 25 kV, 1 mA EHT rectifier, 2 V/500 mA filament, Octal base
SU2150 (CV1120) – 8 kV, 2 mA EHT rectifier used in CRT power supplies, 2 V/1.15 A filament, European 4-pin base
Most EdiSwan tube designations were based on the BVA code; phased out in the 1950s
Notes:
K8B MazdaOctal bases have a larger spigot than K8A InternationalOctal, to better protect the evacuation tip, and the filament/heater is between pins 1 and 8 (IO: 2 and 7)
"AC*/" types are 4-volts AC, indirectly heated ("AC mains operated") receiver tubes fed in parallel from a mains transformer
"DC*/" types are indirectly heated ("DC mains operated") receiver tubes for use in a series heater string running on a then-still commonplace municipal DC mains system;[65]: 113 cf. 180mADC standard
AC/HL – Medium-μ AF triode, 4 V/1 A heater, O5A European 5-pin base
AC/HLDD = Brimar 11A2 = Cossor DDT = M-OV/GEC MHD4 = Mullard TDD4 – Dual diode + AF triode, 4 V/1 A heater, M7A British 7-pin base with control grid on top cap
AC/ME – "Magic Eye"-type tuning indicator, 4 V/500 mA heater; ME41 with a Shouldered envelope and a M7A British 7-pin base
AC/P (4 W, μ=10), AC/P1 = Brimar PA1 = Cossor 41MXP = Mullard O54V (5 W, μ=5.4) – AF power triodes, 4 V/1 A heater, O5A European 5-pin base
AC/P4 – CRT electrostatic-deflection output power triode, 4 V/1 A heater, O5A European 5-pin base with anode on top cap, binned into grades Q (μ<20), R (μ=20), S (μ>20)
AC/PEN = Brimar 7A2 = Cossor MP/PEN = Mullard PEN4VA – AF power pentode, 4 V/1 A heater, M7A British 7-pin base
AC/S2PEN = Brimar 8A1 = Cossor MS/PEN = Ferranti SPT4 = M-OV/GEC MSP4 = Mullard SP4 – RF pentode, 4 V/1 A heater, M7A British 7-pin base with anode on top cap
AC/SP1 – Dual-control RF pentode used in squelch circuits or as the reactance tube in AFC circuits, suppressor grid on a separate pin to feed a gain-control voltage to,[66] 4 V/1 A heater, M7A British 7-pin base
AC/SP3 – Dual-control RF pentode used in shortwave and TV receivers, 4 V/1 A heater, M7A British 7-pin base with control grid on top cap
AC/SP3/RH – AC/SP3 upgraded for low-hum, low-microphonics and low-noise, binned into grades A (15 dB less hum, 18 dB less microphonics) and B
AC/TH1 = Brimar 20A1 = Cossor 41STH = M-OV/GEC X41 = Mullard TH4A – Triode/hexode oscillator/mixer, 4 V/1.3 A heater, M7A British 7-pin base with hexode control grid #1 on top cap
AC/TP = Mullard TP4 – 2 MHz Triode/remote-cutoff pentode oscillator/mixer, 4 V/1.25 A heater, B9H British 9-pin base with the pentode control grid on top cap
AC/VP1 = Brimar 9A1 = Cossor MVS/PEN = M-OV/GEC VMP4 = Mullard VP4 = Ferranti VPT4 (Anode on top cap), AC/VP2 (control grid on top cap) – RF Remote-cutoff pentode, 4 V/650 mA heater, M7A British 7-pin base
AC2/HL = Brimar HLA2 = Cossor 41MH = Ferranti D4 = M-OV/GEC MH41 = Mullard 904V – Medium-μ triode, 4 V/1 A heater, O5A European 5-pin base
AC2/PEN = Brimar 7A3 = Cossor 42MP/PEN = Ferranti PT4 = Mullard PEN4VB – AF power pentode, 4 V/1.75 A heater, M7A British 7-pin base
AC2/PENDD – Dual diode + AF power pentode, 4 V/2 A heater, M7A British 7-pin base with control grid on top cap
AC4/PEN – AF beam power pentode, 4 V/1.75 A heater, M7A British 7-pin base
AC5/PEN – AF beam power pentode, 4 V/1.75 A heater, M7A British 7-pin base
AC5/PENDD – Dual diode + AF beam power pentode, 4 V/2 A heater, M7A British 7-pin base with control grid on top cap
AC6/PEN – Beam power pentode used as a magnetic horizontal deflection output amplifier, 4 V/1.75 A heater, M7A British 7-pin base with anode on top cap
DC/HL – Medium-μ triode, 6 V/500 mADC heater, O5A European 5-pin base
DC/P – AF power triode, 8 V/500 mADC heater
DC/PEN – AF power pentode, 8 V/500 mADC heater, O5A European 5-pin base
DC/SG – RF tetrode, 6 V/500 mADC heater, O5A European 5-pin base
FC141 – Heptode pentagrid converter with British grid topology, 1.4 V/50 mA filament, MazdaOctal base
H141D – Diode + AF triode, 1.4 V/50 mA filament, MazdaOctal base
HL41DD (Medium-μ), HL42DD (Vari-μ for feed-forwardAGC) – Dual diode + AF triode, 4 V/650 mA heater, MazdaOctal base with control grid on top cap
ME41 – "Magic Eye"-type tuning indicator, 4 V/500 mA heater, MazdaOctal base, Glass Tubular envelope; Shouldered version with M7A British 7-pin base: AC/ME
ME91 – "Magic Eye"-type tuning indicator used in AC/DC series heater radios, 9 V/200 mA heater, MazdaOctal base, Glass Tubular envelope
ME920 – "Magic Eye"-type tuning indicator used in AC/DC series heater radios, 9 V/200 mA heater, M7A British 7-pin base, Shouldered envelope
P41 (4 V/950 mA heater), P61 (6.3 V/600 mA heater) – RF triode, μ = 17, MazdaOctal base
P220 (μ = 12.5), P220A (μ = 6.5) – AF Power triode used as driver for the PD220, 2 V/200 mA filament, A4A European 4-pin base
PD220(gm = 900 µS), PD220A(gm = 1.6 mS) – Directly heated dual AF power triode designed for operation with positive grid bias, 2 V/200 mA filament, M7A British 7-pin base (1939); cf. Triple-Twin
Pen24 – 440 mW Class-A output AF power pentode, 2 V/300 mA filament, MazdaOctal base
Pen25 – 400 mWout AF Power pentode, 2 V/150 mA filament, MazdaOctal base
Pen44 – 18 W AF Beam power tetrode, 4 V/2.1 A heater, MazdaOctal base
Pen45 – 5.8 Wout AF Beam power tetrode, 4 V/1.75 A heater, MazdaOctal base
Pen45DD – Pen45 + Dual diode, 4 V/2 A heater, MazdaOctal base with control grid on top cap
Pen46 – 20 W Beam power tetrode used as CRT horizontal deflection amplifier, 4 V/1.75 A heater, MazdaOctal base with anode on top cap
Pen141 – 240 mWout AF Power pentode, 1.4 V/100 mA filament, MazdaOctal base
Pen220 – 290 mWout AF Power pentode, 2 V/200 mA filament, O5A European 5-pin base
Pen231 – 350 mWout AF Power pentode, 2 V/300 mA filament, O5A European 5-pin base
Pen383 – 10 W AF Beam power tetrode, 38 V/200 mA heater, MazdaOctal base
Pen384 – 10 W AF Beam power tetrode for use on 110V mains, 38 V/200 mA heater, MazdaOctal base
Pen453DD – Dual diode + 10 W AF Beam power tetrode, 45 V/200 mA heater, MazdaOctal base with control grid on top cap
Pen3520 – 8 W AF Power pentode, 35 V/200 mA heater, M7A British 7-pin base
Pen3820 – 10 W AF Beam power tetrode, 38 V/200 mA heater, M7A British 7-pin base
PenDD4020 – Dual diode + 10 W AF power pentode, 40 V/200 mA heater, M7A British 7-pin base
PenDD4021 – Dual diode + 10 W AF Beam power tetrode, 45 V/200 mA heater, M7A British 7-pin base
QP25 – Quiescent Push-Pull Directly heated dual AF power pentode, gm = 3 mS, 2 V/200 mA filament, MazdaOctal base
QP230 – QPP Directly heated dual AF power pentode, gm = 3 mS, 2 V/300 mA filament, M7A British 7-pin base
QP240 – QPP Directly heated dual AF power pentode, gm = 4 mS, 2 V/450 mA filament, B9H British 9-pin base
SP41 (4 V/950 mA heater), SP61 (6.3 V/600 mA heater) – Sharp-cutoff RF pentode, gm = 8.5 mS, MazdaOctal base
SP141 – Sharp-cutoff RF pentode, gm = 900 µS, 1.4 V/50 mA filament, MazdaOctal base
TH41 (4 V/1.3 A heater), TH233, TH2320, TH2321 (23 V/200 mA heater) – Triode/heptode oscillator/mixer, MazdaOctal base with heptode control grid on top cap
TP22, TP23, TP25, TP26 (2 V/200 mA filament), TP2620 (26 V/200 mA heater) – Triode/pentode oscillator/mixer, pentode control grid on top cap
6FL2 = ECF812 – Triode + low-power beam tetrode, Noval base; 30FL2 (=PCF812) with a 6.3 V/500 mA heater
6H1 – 20 MHz Hexode, 6.3 V/200 mA heater, Miniature 7-pin base
6L1 – Dual triode, 6.3 V/400 mA heater, Rimlock base
6L12 = 6AQ8/ECC85 – Dual triode, 6.3 V/435 mA heater, Noval base
6L18 – Triode, 6.3 V/300 mA heater, Rimlock base
6L19 – Dual triode, 6.3 V/400 mA heater, Rimlock base
6LD20 – Dual diode + triode, 6.3 V/250 mA heater, Rimlock base
6M2 = EM35 – Dual-sensitivity tuning indicator, 6.3 V/200 mA heater, Octal base
6P15 = 6BQ5/EL84 – Power pentode, 6.3 V/760 mA heater, Noval base
6P25 (6M6-G/EL33) – Beam power tetrode, 6.3 V/1.1 A heater, Octal base
10M2 = UM35 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator, 12.6 V/100 mA heater, Octal base
10PL12 = 50BM8/UCL82 – Triode + power pentode, 50 V/100 mA heater, Noval base
11A1 – 15 W, 300 V Power triode used as series-pass regulator in stabilized DC power supplies, 6.3 V/950 mA heater, Noval base
11E2 – Pulse-rated beam power tetrode, 6.3 V/900 mA heater, Octal base
11E3 – Pulse-rated beam power tetrode, 4 V/2.5 A heater, M7A British 7-pin base
12E1 – Beam power tetrode used as series-pass regulator in stabilized DC power supplies, 6.3 V/1.6 A heater, Octal base
12E12 – Pulse-rated beam power tetrode, 26 V/1.6 A heater, A4A European 4-pin base
13E1 = 7972 = EEV C1158 – 90 W Beam power tetrode used in DC power supplies, center-tapped 26 V/1.3 A resp. 13 V/2.6 A heater, Septar base
19G3 – Half-wave rectifier, 4 V/1.4 A heater, Octal base
19G6 – Half-wave rectifier, 4 V/500 mA heater, Miniature 7-pin base
30C17 = PCF87 – Triode + remote-cutoff pentode used as VHF oscillator/mixer in analog TV receivers
30FL2 = PCF812 – Triode + low-power beam tetrode, Noval base; 6FL2 (=ECF812) with a different heater
30PL13 = 16GK8/PCL800 – Triode + beam power tetrode
30PL14 = PCL88 – Triode + power pentode
—Special quality:
S2P20 (5A6, 100 MHz), S2P21 (200 MHz) – 5 W VHF beam power tetrode, directly heated with a center-tapped 5.0 V/230 mA resp. 2.5 V/460 mA filament, Noval base
S11E12 = 7971 – Beam power tetrode used as series-pass or shunt regulator in stabilized DC power supplies, 6.3 V/1.6 A heater, Octal base
S19G6F – 6 kV, 30 mA Half-wave rectifier, 4 V/500 mA heater, Miniature 7-pin base
EdiSwan used more freeform designations for rectifiers and trigatrons; examples are:
19E2 – Pulse rectifier, 4 V/2 A heater, Octal base
19H1 (A4A European 4-pin base), 19H4 (Octal base) – CRT EHT rectifier, 4 V/2 A filament
19H5 – Damper/rectifier diode, 4 V/4 A heater, E40 Goliath Edison screw lamp base
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, gas-filled, linear, blue-violet light source (glow modulator tube) diode for rotating-drum FAX receivers, etc., modulation up to 1 MHz, 2-pin Octal base
Optional preceding letter(s) before the 1936 update:
D – 16 V/250 mADC, indirectly heated ("DC mains operated") receiver tube for use in a series heater string running on a then-still commonplace municipal DC mains system; cf. 180mADC standard
M – 4-volts AC, indirectly heated ("Mains operated") receiver tube fed in parallel from a mains transformer
In most cases, the first digit of the following number is the heater rating:
2 – 2 V
3 – 13 V or 300 mA
4 – 4 V
5 – 5 V (Rectifiers)
6, 7 – 6 V
An optional letter: Variant
Examples:
B30 – Dual Class-B power triode, 13 V/300 mA heater, M7A British 7-pin base
B36 (13 V/300 mA heater), B65 (6.3 V/600 mA heater) – Dual AF triode, μ = 20, 300 V anode, Octal base
B309 = 12AT7/ECC81 – Dual high-μ triode used as amplifier/mixer in VHF circuits, μ = 55, 300 V anode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater, Noval base
B319 – Dual RF triode, 7.4 V/300 mA heater, μ = 24, 250 V anode, Noval base
B329 = 12AU7/ECC82 – Dual medium-μ triode, μ = 17, 250 V anode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater
B339 = 12AX7/ECC83 – Dual high-μ AF triode, μ = 100, 250 V anode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater
B719 = 6AQ8/ECC85 – Dual VHF triode used as amplifier/mixer in FM receivers, μ = 58, 300 V anode, 6.3 V/435 mA heater, Noval base
D41 = EdiSwan V914 – Indirectly heated dual diode, 4 V/300 mA heater, O5A European 5-pin base
D42 – Indirectly heated single diode, 4 V/600 mA heater, A4A European 4-pin base
D63 = 6H6-G – Indirectly heated separate-cathode dual diode, 6.3 V/300 mA heater, Octal base
D77 = 6AL5/EAA91/EB91 – Indirectly heated separate-cathode dual diode, 6.3 V/300 mA heater, Miniature 7-pin base
DG2 – Directly heated dual-grid triode used as mixer, 2 V/200 mA filament, 80 V anode, O5A European 5-pin base, technically a tetrode
DH – Indirectly 16 V/250 mADC heated high-μ AF triode, O5A European 5-pin base
DH30 – Indirectly heated dual diode + triode, 13 V/300 mA heater, M7A British 7-pin base with control grid on top cap
DH63 – Indirectly heated dual diode + AF triode, 6.3 V/300 mA heater, Octal base
DH77 = 6AT6/EBC90 – Indirectly heated, common cathode dual diode + high-μ AF triode used in FM ratio detectors, triode μ = 70, 6.3 V/300 mA heater, Miniature 7-pin base
DH107 – Indirectly heated, common cathode dual diode + high-μ AF triode, triode μ = 70, 19 V/100 mA heater, Miniature 7-pin base
DH719 = 6AK8/EABC80 – Indirectly heated, triple diode + triode, triode μ = 70, 6.3 V/450 mA heater, Noval base
DHD – Indirectly 16 V/250 mADC heated dual diode + high-μ triode, M7A British 7-pin base
DL – Indirectly 16 V/250 mADC heated low-μ triode, O5A European 5-pin base
DN41 – Indirectly heated dual diode + power pentode, 4 V/2.1 A heater, M7A British 7-pin base
DPT – Indirectly 16 V/250 mADC heated power pentode, available in O5A European 5-pin or M7A British 7-pin base
DS – Indirectly 16 V/250 mADC heated RF/IF tetrode, O5A European 5-pin base
H2 = Cossor 210RC – Directly heated high-μ AF triode, μ = 35, 150 V anode, 2 V/100 mA filament, A4A European 4-pin base
H11, H12 – Directly heated miniature high-μ AF triodes used in hearing aids, 2 V/60 mA filament; similar to KC50, KC51, Mullard DA1
H30 – Indirectly heated dual diode + high-μ AF triode, μ = 80, 250 V anode, 13 V/300 mA heater, M7A British 7-pin base with control grid on top cap
H42 – Indirectly heated dual diode + high-μ AF triode, μ = 100, 250 V anode, 4 V/600 mA heater, M7A British 7-pin base with control grid on top cap
H63 = 6F5 – Indirectly heated high-μ AF triode, 6.3 V/300 mA heater, Octal base
H410 (4 V/100 mA filament), H610 (6.0 V/100 mA filament) – Directly heated high-μ AF triode, μ = 40, 150 V anode, A4A European 4-pin base
HA1 (4 V/250 mA heater), HA2 (6.3 V/150 mA heater) – 600 MHz Acorn UHF triodes
HD22 – Directly heated dual diode + AF triode, 2 V/200 mA filament, μ = 27, 150 V anode, O5A European 5-pin base
HD23 – Directly heated dual diode + triode, 2 V/150 mA filament, μ = 28, 150 V anode, O5A European 5-pin base
HL2 – Directly heated high-μ AF triode, 2 V/100 mA filament, μ = 27, 150 V anode, A4A European 4-pin base
HL210 = Cossor 210HF (2 V/100 mA filament, μ = 40), HL410 = Telefunken RE034 (4 V/100 mA filament, μ = 2.5), HL610 (6.0 V/100 mA filament, μ = 30) – Directly heated high-μ AF triode, 150 V anode, A4A European 4-pin base
KTW21 – Remote-cutoff RF/IF beam tetrode, 2 V/100 mA filament, A4A European 4-pin base with control grid on top cap; upgraded drop-in replacement for the older W21 pentode
KTW61, KTW62 – Remote-cutoff RF/IF beam tetrode, 6.3 V/300 mA heater, Octal base with control grid on top cap; upgraded drop-in replacement for the older W61 pentode
KTW61M – KTW61 with a metal particles spray-shielded envelope
KTW63 – Remote-cutoff RF/IF beam tetrode, 6.3 V/300 mA heater, Octal base with control grid on top cap; upgraded drop-in replacement for the older W63 pentode
KTW73, KTW73M (Spray-shielded) – Remote-cutoff RF/IF beam tetrode, 6.3 V/160 mA heater, Octal base with control grid on top cap
KTZ41 – Sharp-cutoff RF/IF beam tetrode, 4 V/1.5 A heater, M7A British 7-pin base with control grid on top cap
KTZ61 – Sharp-cutoff RF/IF beam tetrode, 6.3 V/300 mA heater, Octal base with control grid on top cap
KTZ63 – Sharp-cutoff RF/IF beam tetrode, 6.3 V/300 mA heater, Octal base with control grid on top cap; upgraded drop-in replacement for the older Z63 pentode; beam variant of 6J7-G/EF37 with suppressor plates tied to cathode, not to a separate pin
KTZ73, KTZ73M (Spray-shielded) – Sharp-cutoff RF/IF beam tetrode, 6.3 V/160 mA heater, Octal base with control grid on top cap
L2B – Directly heated low-μ AF triode, μ = 15.5, 150 V anode, 2 V/100 mA filament, A4A European 4-pin base
L11, L12 – Directly heated miniature AF power triodes used in hearing aids, 2 V/60 mA filament; similar to KD50, Mullard DA2, DA3
L21 – Directly heated low-μ AF triode, 2 V/100 mA filament, A4A European 4-pin base
L30 – Indirectly heated low-μ AF triode, μ = 12, 200 V anode, 13 V/300 mA heater, M7A British 7-pin base
L63 = 6J5-G – Indirectly heated low-μ triode, 6.3 V/300 mA heater, Octal base
L77 = 6C4/EC90 – Indirectly heated low-μ triode, μ = 17, 6.3 V/150 mA heater, Miniature 7-pin base
L410 = Mullard PM4X = Philips B406 (4 V/100 mA filament), L610 (6.0 V/100 mA filament) – Directly heated AF power triode, 50-150 V anode, μ = 15, A4A European 4-pin base
LN309 = PCL83 – Low-μ AF triode + AF power pentode, 12.6 V/300 mA heater, Noval base
LP2 – Directly heated AF power triode, 150 V anode, μ = 15, 2 V/200 mA filament, A4A European 4-pin base
LS5A – Directly heated AF power triode, 400 V anode, μ = 2.5, 4.25-5.25 V/800 mA filament, A4A European 4-pin base
LS6A – Directly heated AF power triode, 400 V anode, μ = 3, 6.0 V/2 A filament, A4A European 4-pin base
LZ319 = 9A8/PCF80 – VHF Triode/pentode oscillator/mixer, Noval base
MH4 = CdL DW4011 = Cossor 41MHF = LaRadiotechnique TE24 = Telefunken REN904 = Valvo A4110 = CV399 – Indirectly heated AF triode, μ = 40, 200 V anode, 4 V/1 A heater, O5A European 5-pin base
MH40 – Indirectly heated microphone preamplifier triode, 4 V/1 A heater, O5A European 5-pin base
MH41 = Cossor 41MH – Indirectly heated AF triode, μ = 80, 200 V anode, 4 V/1 A heater, O5A European 5-pin base
MHD4 = Hivac ACDDT – Indirectly heated dual diode + triode, μ = 40, 250 V anode, 4 V/1 A heater, M7A British 7-pin base
MHL4 – Indirectly heated AF triode, μ = 20, 200 V anode, 4 V/1 A heater, O5A European 5-pin base
MKT4 – 3.2 W Indirectly heated AF beam power tetrode, 4 V/1 A heater, available in O5A European 5-pin or M7A British 7-pin base
ML4 – Indirectly heated AF triode, μ = 12, 250 V anode, 4 V/1 A heater, O5A European 5-pin base
MPT4 – Indirectly heated AF power pentode, μ = 100, 250 V anode, 4 V/1 A heater, available in O5A European 5-pin or M7A British 7-pin base
MS4 (μ = 550), MS4B (μ = 1120) – Sharp-cutoff RF/IF tetrode, 4 V/1 A heater, O5A European 5-pin base with anode on top terminal
MSP4 (100 V screen grid), MSP41 (240 V screen grid) – Indirectly heated RF/AF pentode, 4 V/1 A heater, M7A British 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, A4A European 4-pin base
MX40 = Brimar 15A2 = Cossor 41MPG = Ferranti VHT4 – Remote-cutoff heptode pentagrid converter with British grid topology and control (#4) grid on top cap, indirect 4 V/1 A heater, M7A British 7-pin base; similar to the Mullard FC4 octode
N17 = 3S4/DL92 – Power pentode
N18 = 3Q4/DL95 – Power pentode
N19 = 3V4/DL94 = EdiSwan 1P11 – Power pentode
N30, N30G – Indirectly heated Catkin AF power pentode, 13 V/300 mA heater, M7A British 7-pin base
N31 – Indirectly heated AF power pentode, 26 V/300 mA heater, M7A British 7-pin base
N37 – Indirectly heated AF power pentode, 13 V/300 mA heater, Miniature 7-pin base
N40 – First commercially available beam power tetrode, 4 V/1.3 A heater, O5A European 5-pin base[70]
N41 = KT41 – Power pentode, 4 V/2 A heater, M7A British 7-pin base
N42 – Power pentode, 4 V/1 A heater, M7A British 7-pin base
N43 – Power pentode, 4 V/2 A heater, M7A British 7-pin base
N77 = 6AM5/EL91, N78 = 6BJ5 – Power pentodes, 6.3 V/200 mA heater, Miniature 7-pin base
N108 – Power pentode, 40 V/100 mA heater, Miniature 7-pin base
N309 = 15A6/PL83 – Power pentode used as CRT cathode driver, 15 V/300 mA heater, Noval base
N329 = 16A5/PL82 – Power pentode used as CRT vertical deflection or AF amplifier, 16.5 V/300 mA heater, Noval base
N339 – Horizontal deflection power pentode, 20 V/300 mA heater, Noval base
N709 = 6BQ5/EL84 – AF Power pentode, 6.3 V/760 mA heater, Noval base
N727 = 6AQ5/EL90 – Beam power pentode, 6.3 V/450 mA heater, Miniature 7-pin base
P2 – Directly heated AF power triode, 150 V anode, μ = 7.5, 2 V/200 mA filament, A4A European 4-pin base
P240 – Directly heated AF power triode, 150 V anode, μ = 4, 2 V/400 mA filament, A4A European 4-pin base
P410 = Philips B409 = Telefunken RE134 = Valvo L414 (4 V/100 mA filament), P415 (4 V/150 mA filament), P425 = Mullard PM254 = Philips B405 (4 V/250 mA filament) – Directly heated AF power triode, μ = 7.5, 150 V anode, A4A European 4-pin base
P610 (6.0 V/100 mA filament, 150 V anode), P625 (6.0 V/250 mA filament, 250 V anode), P625A (200 V anode) – Directly heated AF power triodes, A4A European 4-pin base
PT2 – Directly heated AF power pentode, 2 V/200 mA filament, O5A European 5-pin base
PT4 – Directly heated AF power pentode, μ = 40, 200 V anode, 4 V/1 A filament, O5A European 5-pin base
PT15 – Directly heated RF power pentode, 6.3 V/1.3 A filament, O5A European 5-pin base with anode on top cap
PT25H – 25 W Directly heated AF power pentode, 400 V anode, 4 V/2 A filament, O5A European 5-pin base
PT240 = KT24 – Directly heated AF power pentode, 2 V/200 mA filament, O5A European 5-pin base
PT425 (4 V/250 mA filament), PT625 (6 V/250 mA filament) – Directly heated AF power pentode, O5A European 5-pin base
PX4 – 12 W Directly heated AF power triode, 4 V/1 A filament, A4A European 4-pin base
PX25, PX25A – 25 W Directly heated AF power triode, 4 V/2 A filament, A4A European 4-pin base
S12 – Directly heated miniature AF tetrode used in hearing aids, 2 V/60 mA filament; similar to KE50, Mullard DAS1
S21 (μ = 220, 2 V/100 mA filament), S22 = Philips B262 (μ = 350, 2 V/200 mA filament) – Directly heated sharp-cutoff tetrodes, 150 V anode, A4A European 4-pin base and top terminal
S23, S24 – Directly heated sharp-cutoff tetrodes, 150 V anode, 2 V/100 mA filament, A4A European 4-pin base with anode on top terminal
S410 (4 V/100 mA filament), S610 (6.0 V/100 mA filament) – Directly heated sharp-cutoff RF tetrode, A4A European 4-pin base
U10 = Telefunken RGN1054 = Mullard DW2X = EdiSwan D380B = Tungsram PV495 – Full-wave rectifier, A4A European 4-pin base
U12 – Full-wave rectifier, A4A European 4-pin base
U14 – Full-wave rectifier, A4A European 4-pin base
U16 – CRT EHT rectifier, A4A European 4-pin base
U17 – Half-wave rectifier, A4A European 4-pin base
U18/20 – Full-wave rectifier, A4A European 4-pin base
U19 – Half-wave rectifier, A4A European 4-pin base
U31 – Half-wave rectifier, Octal base
U37 – CRT EHT rectifier, wire-ends
U41 = 1B3-GT/1G3-GT/DY30 – CRT EHT rectifier, Octal base
U43 – CRT EHT rectifier, wire-ends
U45 – CRT EHT rectifier, wire-ends
U50 = 5Y3-G – Full-wave rectifier, Octal base
U52 = 5AS4A/5U4-GB – Full-wave rectifier, Octal base
U54 = GZ37 – Full-wave rectifier, Octal base
U78 = 6X4/EZ90 – Full-wave rectifier, Miniature 7-pin base
U107 – Half-wave rectifier, Miniature 7-pin base
U309 – CRT horizontal deflection output booster/damper/efficiency diode for analog color TV receivers, Noval base
U319 – Half-wave rectifier, Noval base
U329 – CRT horizontal deflection output booster/damper/efficiency diode for analog color TV receivers, Noval base
U709 = 6CA4/EZ81 – Full-wave rectifier, Noval base
VDS – Remote-cutoff tetrode, indirect 16 V/250 mADC heater, O5A European 5-pin base with anode on top terminal
VMP4G – Remote-cutoff pentode, indirect 4 V/1 A heater, M7A British 7-pin base with anode on top cap
VMS4 = Philips E445 = Telefunken RENS1214 = Valvo H4125D (semiremote-cutoff), VMS4B (remote-cutoff) – RF/IF Tetrode, indirect 4 V/1 A heater, O5A European 5-pin base with anode on top cap
VP21 – Remote-cutoff pentode, direct 2 V/100 mA filament, M7A British 7-pin base with anode on top cap
VS24, VS24K (smaller envelope) – Remote-cutoff RF tetrode, direct 2 V/150 mA filament, A4A European 4-pin base with anode on top cap
W17 = 1T4/DF91 = EdiSwan 1F3 – Remote-cutoff RF/IF pentode, 1.4 V/50 mA filament, Miniature 7-pin base
W21 – Remote-cutoff RF/IF tetrode, 2 V/100 mA filament, A4A European 4-pin base with control grid on top cap
W30 – Catkin Remote-cutoff RF/IF tetrode, 13 V/300 mA heater, M7A British 7-pin base with anode on top cap
W31 = Ferranti VPTS – Remote-cutoff RF/IF pentode, 13 V/300 mA heater, M7A British 7-pin base with anode on top cap
W42 – Remote-cutoff RF/IF pentode, 4 V/600 mA heater, M7A British 7-pin base with control grid on top cap
W77 = 6CQ6/EF92 = Brimar 9D6 – Remote-cutoff RF/IF pentode, 6.3 V/200 mA heater, Miniature 7-pin base
W107 – Remote-cutoff RF/IF pentode, 12.6 V/100 mA heater, Miniature 7-pin base
W727 = 6BA6/EF93 – Remote-cutoff RF pentode, 6.3 V/300 mA heater, Miniature 7-pin base
X18 = 1AC6/DK92 – Heptode pentagrid converter, 1.4 V/50 mA filament, Miniature 7-pin base
X21 – Remote-cutoff heptode pentagrid converter with British grid topology and control (#4) grid on top cap, 2 V/100 mA filament, M7A British 7-pin base
X22 – Heptode pentagrid converter with British grid topology and control (#4) grid on top cap, 2 V/150 mA filament, 7-pin base
X23 – Triode/hexode oscillator/mixer, 2 V/300 mA filament, M7A British 7-pin base with hexode control grid #1 on top cap
X30, X32 (Low hum) – Remote-cutoff heptode pentagrid converter with British grid topology and control (#4) grid on top cap, 13 V/300 mA heater, M7A British 7-pin base
X31 – Remote-cutoff triode/hexode oscillator/mixer, 13 V/300 mA heater, M7A British 7-pin base with hexode control grid #1 on top cap
X41 = Brimar 20A1 = Cossor 41STH = EdiSwan AC/TH1 = Mullard TH4A – 60 MHz Triode/hexode oscillator/mixer, 4 V/1.2 A heater, M7A British 7-pin base; upgraded drop-in replacement for the older MX40 pentagrid converter
X41C – X41 with a ceramic base for better frequency stability in VHF Band I analog TV tuners
X42 – Remote-cutoff heptode pentagrid converter with British grid topology and control (#4) grid on top cap, 4 V/600 mA heater, M7A British 7-pin base
X61 = 6J8-G, X61M (Spray-shielded) – Triode/heptode oscillator/mixer, 6.3 V/300 mA heater, Octal base
X63 = 6A8-G/PH4 – Remote-cutoff heptode pentagrid converter, 6.3 V/300 mA heater, Octal base
X64 = 6L7-G – Mixing heptode requiring a separate oscillator, 6.3 V/300 mA heater, Octal base
X65 – Remote-cutoff triode/hexode oscillator/mixer, 6.3 V/300 mA heater, Octal base with hexode control grid #1 on top cap
X79 = 6AE8 – Remote-cutoff triode/hexode oscillator/mixer, 6.3 V/300 mA heater, Noval base
X109 – Remote-cutoff triode/hexode oscillator/mixer, 19 V/100 mA heater, Noval base
X719 = 6AJ8/ECH81 – Remote-cutoff triode/heptode oscillator/mixer, 6.3 V/300 mA heater, Noval base
X727 = 6BE6/EK90 – Pentagrid converter with American grid topology, 6.3 V/300 mA heater, Miniature 7-pin base
Z21 – Sharp-cutoff RF/IF tetrode, 2 V/100 mA filament, M7A British 7-pin base with anode on top cap
Z77 = 6AM6/EF91 – Sharp-cutoff RF pentode, 6.3 V/300 mA heater, Miniature 7-pin base
Z319 = EEV E2133 (6351) – Secondary emission, sharp-cutoff wideband pentode, 6.3 V/300 mA heater, Noval base
Z359 (12.6 V/300 mA heater between pins 4, 5), Z759 (6.3 V/600 mA heater between pins 5, 6) – Sharp-cutoff video pentodes, 6.3 V/300 mA heater, Noval base
Z719 = 6BX6/EF80 – Sharp-cutoff RF pentode, 6.3 V/300 mA heater, Noval base
Z729 = 6BK8/6CF8/EF86 – Sharp-cutoff, low-noise AF pentode, 6.3 V/200 mA heater, Noval base
ZA1 (4 V heater), ZA2 (6.3 V heater) – Acorn sharp-cutoff pentodes
ZD17 = 1S5/DAF91 = EdiSwan 1FD9 – Diode + AF pentode, 1.4 V/50 mA filament, Miniature 7-pin base
Marconi also traded some Mullard-Philips tubes, with a preceding letter M: MAZ1, MAZ41, MCL4, MCY1, MCY2, MDAC21, MDAF40, MDAF41, MDF21, MDK21, MDK40, MDL21, MDL41, MDM21, MEB4, MEBC3, MECH3, MECH21, MECH42, MEF5, MEF6, MEF9, MEK2, MEL3, MEL41, MEM1, MEM34, MKBC1, MUBC41, MUCH42, MUF9, MUF41, MUL41, MUM4, MUY41
A537 – Microphone preamplifier triode, indirect 4 V/400 mA heater, British side-contact 4 base with control grid on top cap
A577 – Triode used as cathode follower rectifier in vacuum tube RF voltmeters, indirect 4 V/1 A heater, O5A European 5-pin base with control grid on top cap, use as AF amplifier not recommended
A1714 (CV408) – Planar UHF triode, indirect 6.3 V/490 mA heater, Miniature 7-pin base; similar to 9002
A1834 = 6AS7-G/ECC230 (CV2523) – Dual power triode used as series-pass regulator in DC power supplies, indirect 6.3 V/2.5 A heater, Octal base
GT1C = AN1 – Argon-filled, 500 V, 300 mAavg, 500 mARMS, 1 Apeak variant extensively used in the Colossus computer
GU20 (8.75 kV, 4 A, superseded by GU20/21), GU21 = EnglishElectricValve AH221 = Mullard RG4-1250 (11 kV, 4.75 A) – Half-wave Mercury-vapor rectifier, E40 GoliathEdison screw lamp base
KT2 – 1 W Beam power tetrode, 2 V/200 mA filament, O5A European 5-pin base
KT21 – 1.25 W Beam power tetrode, 2 V/300 mA filament, O5A European 5-pin base
KT32 – 7.5 W Beam power tetrode used in AC/DC radio receivers with series heater strings, 26 V/300 mA heater, Octal base; drop-in replacement for the 25L6-G, 25W6-GT
KT33 (25A6-GT) – 5 W Beam power tetrode used in AC/DC radio receivers with series heater strings, 26 V/300 mA heater, Octal base
KT33C – KT33 with a center-tapped heater, so it can also be wired for 13 V/600 mA
KT36 – 10 W Beam power tetrode used in AC/DC radio receivers with series heater strings, 26 V/300 mA heater, Octal base
KT41 – 8.6 W Beam power tetrode, 4 V/2 A heater, M7A British 7-pin base
KT55 – 25 W Beam power tetrode used in AC/DC radio receivers with series heater strings, 52 V/300 mA heater, Octal base
KT61 (6M6-G, EL33) – 4.3 W Beam power tetrode, 6.3 V/950 mA heater, Octal base
KT63 – 6 W Beam power tetrode, 6.3 V/700 mA heater, Octal base; drop-in replacement for the 6F6 power pentode
KT66 – 7.25 W Beam power tetrode, 6.3 V/1.27 A heater, Octal base; drop-in replacement for the 6L6-GC
KT67 – 25 W RF beam power tetrode, 6.3 V/1.5 A heater, B9G 9-pin Loctal base
KT71 (50L6-GT) – 5 W Beam power tetrode used in AC/DC radio receivers with series heater strings, 48 V/160 mA heater, Octal base
KT77 – 30 W Beam power tetrode, 6.3 V/1.4 A heater, Octal base; 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, 6.3 V/1.6 A heater, Octal base
QP21 – Directly heated dual AF power pentode, M7A British 7-pin base
TT10 (813 = QY2-100) – 100 W, 30 MHz Beam power tetrode, 10 V/5 A filament, special 7-pin base with anode on top cap
TT11 – 2.7 W, 100 MHz Beam power tetrode, 6.3 V/800 mA heater, Octal base with anode on top cap
TT12 – 2.7 W, 20 MHz Beam power tetrode, 19 V/420 mA heater, B9G 9-pin Loctal base with anode on top cap
TT15 – 15 W, 160 MHz Beam power tetrode, 6.3 V/1.6 A heater, B9G 9-pin Loctal base
TT16D = QY3-125 – 125 W, 120 MHz Beam power tetrode, 5 V/6.5 A filament, B5F Giant 5-pin UY base with anode on top cap
TT20 = QQE03/20 – 2×10 W, 200 MHz Dual beam power tetrode, center-tapped 12.6 V/650 mA resp. 6.3 V/1.3 A heater, Septar base with anodes on top pins
TT21 = 7623 (6.3 V/1.6 A heater), TT22 = 7624 (12.6 V/800 mA heater) – 37.5 W, 30 MHz Beam power tetrode, Octal base with anode on top cap; derived from KT88
TT24 – 10 W, 225 MHz Dual beam power tetrode, center-tapped 6.3 V/830 mA heater, Noval base
TT100 – 100 W, 20 MHz beam power tetrode, center-tapped 12.6 V/1.6 A resp. 6.3 V/3.2 A heater, 12-pin base with anode on top cap
Early, directly heated Mullard tubes were mostly assigned PM ("Philips-Mullard"), followed by a number containing the filament voltage; Examples:[2]
PM1, PM1A = Cossor 210RC – AF Triode for use in RC-coupled amplifiers, 2 V/100 mA filament, A4A European 4-pin base
PM1HF = Cossor 210HF – RF/IF Triode, 2 V/100 mA filament, A4A European 4-pin base
PM1HL = Cossor 210HL = Dario TB282 = Tungsram HR210 – RF/AF Triode, 2 V/100 mA filament, A4A European 4-pin base
PM1LF = Cossor 210LF = Dario TB102 – AF Triode, 2 V/100 mA filament, A4A European 4-pin base
PM2, PM2A – Power triode for Class-A amplifiers, 2 V/200 mA filament, A4A European 4-pin base
PM2B, PM2BA – Power triode for Class-B amplifiers, 2 V/200 mA filament, M7A British 7-pin base
PM2DX = Dario TB172 – AF Triode, 2 V/100 mA filament, A4A European 4-pin base
PM4 – Power triode, 4 V/100 mA filament, A4A European 4-pin base
PM6 – Power triode, 6 V/100 mA filament, A4A European 4-pin base
PM12 (Sharp-cutoff), PM12V (remote-cutoff) – Tetrode, 2 V/150 mA filament, A4A European 4-pin base
PM16 – Sharp-cutoff tetrode, 6 V/75 mA filament, A4A European 4-pin base
PM22, PM22A, PM22C – "Super Power" pentode, 2 V/300 mA filament, A4A European 4-pin or O5A European 5-pin base
PM24A (4 VAC/275 mA filament), PM24B (4 VAC/1 A filament), PM24C (4 VAC/1 A filament), PM24D (4 VAC/2 A filament) – Power pentode used with a small, wirewound potentiometer across the floating AC heater supply with its slider tied to signal ground, to cancel out mains hum, O5A European 5-pin base
PM202 – "Super Power" triode, 2 V/200 mA filament, A4A European 4-pin base
PM252 – "Super Power" triode, 2 V/400 mA filament, A4A European 4-pin base
PM254 = M-OV/GEC P425 – "Super Power" triode, 4 V/200 mA filament, A4A European 4-pin base
PM256 – "Super Power" triode, 6 V/250 mA filament, A4A European 4-pin base
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.
Examples:
2D4 = AB1 – Dual Diode, 4 V/650 mA heater, O5A European 5-pin base with one anode on top cap
2D13, 2D13A (V5A Side-contact 5 base), 2D13C (O5A European 5-pin base) – Dual Diode, 13 V/200 mA heater, one anode on top cap
DA1 (2 V/50 mA filament), DB1 (1.5 V/70 mA filament) – Directly heated miniature AF triodes used in Deaf Aids; similar to 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 used in hearing aids; similar to 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 used in hearing aids; similar to DF51, KE50, M-OV/GEC S12
FC4 – Octode Frequency Converter, 4 V/650 mA heater, M7A British 7-pin base with #4 grid on top cap; similar to the M-OV/GEC MX40 heptode[80]
FC13 – FC4 with a 13 V/200 mA heater and a P8A side-contact 8 base
FC13C – FC13 with a M7A British 7-pin base; similar to Brimar 15D1, Cossor 13PGA, Ferranti VHTA heptodes
GT4A (4 V/1.2 A heater), GT4C (EC50 with a 4 V/2.4 A heater) – Gas Triodes, P8A Side-contact 8 base with grid on top cap
HL13 (P8A Side-contact 8 base), HL13C (M7A British 7-pin base) – Triode, 13 V/200 mA heater, grid on top cap
HVR1 (2 V/290 mA filament), HVR2 (4 V/650 mA filament) – Half-wave, High-Voltage Rectifier, A4A European 4-pin base with anode on top cap
PenA4 (4 V/1.95 A heater, M7A British 7-pin base), Pen4VA (4 V/1.35 A heater, O5A European 5-pin base with screen grid on a side terminal), Pen4VB (slow-heating PenA4) – Power Pentodes
Pen20 – Power Pentode, 20 V/180 mA heater, B6H European 6-pin base
Pen26 – Power Pentode, 24 V/200 mA heater, P8A side-contact 8 base with control grid on top cap
Pen36C – Power Pentode, 33 V/200 mA heater, M7A British 7-pin base
Pen40DD – Power Pentode + dual Diode, 44 V/200 mA heater, M7A British 7-pin base with control grid on top cap
SP13 – (Screen grid) RF Pentode, 13 V/200 mA heater, P8A side-contact 8 base with control grid on top cap
T4D – Subminiature Television Diode, 4 V/200 mA heater, all-glass wire-ended
TDD4 = Brimar 11A2 = Cossor DDT = EdiSwan AC/HLDD = M-OV/GEC MHD4 (4 V/550 mA heater), TDD13C (13 V/200 mA heater) – Triode + dual Diode, M7A British 7-pin base with grid on top cap
TH4, TH4A (4 V/1 A heater), TH13C (13 V/310 mA heater), TH21C (21 V/200 mA heater), TH22C, TH30C (29 V/200 mA heater) – Triode/Hexode oscillator/mixer, M7A British 7-pin base with #1 Hexode grid on top cap
TP4 = EdiSwan AC/TP – Triode + Pentode, 4 V/1.25 A heater, B9H British 9-pin base with the pentode control grid on top cap
TSE4 – Television Secondary Emission pentode, 4 V/1.1 A heater, M7A British 7-pin base with control grid on top cap
TSP4 – Television high-Slope Pentode, 4 V/1.3 A heater, M7A British 7-pin base with control grid on top cap
VP2 = EdiSwan VP215 = M-OV/GEC VP21 – Vari-μ Pentode, 2 V/180 mA heater, M7A British 7-pin base
VP13A (P8A Side-contact 8 base), VP13C (M7A British 7-pin base) – Vari-μ Pentode, 13 V/200 mA heater, control grid on top cap
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.[81]
Standard tubes 1925–34
The system consisted of one letter followed by 3 or 4 digits.[82]: 15 [3][46][18] It was phased out after 1934 when Philips adopted the Mullard–Philips scheme.
A106 – Directly heated AF triode, 1.0-1.3 V/60 mA filament, 20-100 V anode, μ = 6, A4A European 4-pin (default) base
A109 – Directly heated AF/RF triode, 1.0-1.3 V/60 mA filament, 20-120 V anode, μ = 9, A4A European 4-pin (default) base
A141 – Directly heated AF/RF space charge grid tetrode, 1.0-1.3 V/60 mA filament, 2-20 V anode, μ = 4.5, A4A European 4-pin base with the space charge grid on a lateral terminal (default)
A241 – Directly heated AF/RF space charge grid tetrode, 1.7-2.0 V/60 mA filament, 2-20 V anode, μ = 4.5, A4A European 4-pin base with the space charge grid on a lateral terminal (default)
A306 – Directly heated AF triode, 2.7-3.3 V/60 mA filament, 20-100 V anode, μ = 6, A4A European 4-pin (default) base
A310 – Directly heated AF/RF triode, 2.7-3.3 V/60 mA filament, 20-100 V anode, μ = 10, A4A European 4-pin (default) base
A341 – Directly heated AF/RF space charge grid tetrode, 2.7-3.3 V/60 mA filament, 2-20 V anode, μ = 4.5, A4A European 4-pin base with the space charge grid on a lateral terminal (default)
A406 – Directly heated AF triode, 3.4-4.0 V/60 mA filament, 20-100 V anode, μ = 6, A4A European 4-pin (default) base
A409 = Mullard PM3X – Directly heated AF triode, 4 V/60 mA filament, 20-150 V anode, μ = 9, A4A European 4-pin (default) base
A410 – Directly heated AF/RF triode, 3.4-4.0 V/60 mA filament, 20-100 V anode, μ = 10, A4A European 4-pin (default) base
A415 – Directly heated AF triode, 4 V/80 mA filament, 50-150 V anode, μ = 15, A4A European 4-pin (default) base
A425 = Mullard PM3DX = Telefunken RE034 = Tungsram HR406 – Directly heated RF triode, 4 V/60 mA filament, 50-150 V anode, μ = 25, A4A European 4-pin (default) base
A430 (AF), A435 (RF) – Directly heated triode, 4 V/60 mA filament, 50-150 V anode on top terminal, μ = 35, A4A European 4-pin (default) base
A441 (2-20 V anode), A441N (2-100 V anode) – Directly heated space charge grid tetrode, 4 V/80 mA filament, μ = 4.5, A4A European 4-pin base with the space charge grid on a lateral terminal (default)
A442 = Telefunken RES094 = Tungsram S406 – Directly heated screen grid tetrode, 4 V/60 mA filament, gm = 700 µS, μ = 150, 50-150 V anode on top terminal, A4A European 4-pin base
B105 – Directly heated AF power triode, 1.0-1.3 V/150 mA filament, 20-120 V anode, μ = 5, A4A European 4-pin (default) base
B217 – Directly heated triode, 2 V/100 mA filament, 150 V anode, μ = 17, A4A European 4-pin base
B228 = Cossor 210RC = M/OV H210 – Directly heated triode, 2 V/100 mA filament, 150 V anode, μ = 28, A4A European 4-pin base
B240 = Telefunken RE402B – Directly heated, dual AF power triode, 2 V/200 mA filament, 120 V anode, output power 1.3 W, C7H European 7-pin base
B255 = Ferranti S2 = LaRadiotechnique TB452 – Directly heated, remote-cutoff, screen grid tetrode, 2 V/180 mA filament, gm ≤ 1.2 mS, μ ≤ 400, 150 V anode, A4A European 4-pin base and top terminal
B262 = M-OV/GEC S22 – Directly heated screen grid tetrode, 2 V/180 mA filament, gm = 1.3 mS, μ = 500, 150 V anode, A4A European 4-pin base and top terminal
B403 – Directly heated AF power triode, 4 V/150 mA filament, 50-150 V anode, μ = 3, A4A European 4-pin base
B405 – Directly heated AF power triode, 4 V/150 mA filament, 50-150 V anode, μ = 5, A4A European 4-pin base
B406 = Mullard PM4X = M-OV/GEC L410 – Directly heated AF power triode, 4 V/100 mA filament, 50-150 V anode, μ = 6, A4A European 4-pin base
B409 = LaRadiotechnique TB09 = M-OV/GEC P410 = Telefunken RE134 = Tungsram L414/L415 = Valvo L413 – Directly heated AF power triode, 4 V/150 mA filament, 250 V anode, μ = 9, A4A European 4-pin base
B424 = Mullard PM3D – Directly heated AF power triode, 4 V/100 mA filament, 200 V anode, μ = 24, A4A European 4-pin base
B438 = Valvo W410 – Directly heated AF power triode, 4 V/100 mA filament, 200 V anode, μ = 38, A4A European 4-pin base
B442 = CdL DZ2 = LaRadiotechnique TB42=R81 = Valvo H410D – Directly heated screen grid tetrode, 4 V/100 mA filament, gm = 900 µS, μ = 350, 200 V anode, A4A European 4-pin base and top terminal
B443 = CdL DX3 = Cossor 415PT = LaRadiotechnique B443O = M-OV/GEC 425PT = Tungsram PP415 – Directly heated power pentode, 4 V/150 mA filament, gm = 1.3 mS, μ = 100, 50-150 V anode, A4A European 4-pin base
B443S = Telefunken RES164 = Tungsram PP416 – Directly heated power pentode, 4 V/150 mA filament, gm = 1.4 mS, μ = 70, 200 V anode, O5A European 5-pin base
B543 – Directly heated power pentode, 5 V/100 mA filament, gm = 1.3 mS, μ = 60, 200 V anode, O5A European 5-pin base
B2006 = LaRadiotechnique CT06 = Telefunken REN1822 = Tungsram P2018 = Valvo L2218 – Indirectly heated power triode, 20 V/180 mA DC series heater, μ = 6, 200 V anode, O5A European 5-pin base
B2038 = Telefunken REN1821 = Tungsram R2018 = Valvo A2118 – Indirectly heated triode, μ = 33, 200 V anode, O5A European 5-pin base; E438 with a 20 V/180 mA DC series heater
B2041 = Telefunken REN1817D = Tungsram DG2018 = Valvo U1718D – Indirectly heated dual-grid triode for use as mixer, 20 V/180 mA DC series heater, 100 V anode, O5A European 5-pin base with one grid on a lateral screw terminal, technically a tetrode
B2042 = Telefunken RENS1820 = Valvo H2018D – Indirectly heated sharp-cutoff RF/IF screen grid tetrode, 20 V/180 mA DC series heater, gm = 1 mS, μ = 400, 100 V anode on top terminal, O5A European 5-pin base
B2043 = Telefunken RENS1823D = Tungsram PP2018D = Valvo L2318D – Indirectly heated power pentode, 20 V/180 mA DC series heater, gm = 1.7 mS, μ = 70, 200 V anode, O5A European 5-pin base with the screen grid on a lateral screw terminal
B2044 = LaRadiotechnique CT44 = Mullard SD20 = Telefunken RENS1854 = Tungsram DS2218 = Valvo AN2127 – Indirectly heated diode + tetrode, gm = 2.8 mS, μ = 700, 200 V anode on top terminal, B6H European 6-pin base; E444 with a 20 V/180 mA DC series heater
B2044S = Telefunken REN1826 – Indirectly heated diode + AF triode, 20 V/180 mA DC series heater, μ = 30, 200 V anode, O5A European 5-pin base with diode on top terminal
B2045 = Telefunken RENS1819 – Indirectly heated remote-cutoff RF/IF screen grid tetrode, 20 V/180 mA DC series heater, gm ≤ 1 mS, μ ≤ 400, 200 V anode on top terminal, O5A European 5-pin base
B2046 = Telefunken RENS1884 = Tungsram HP2018 = Valvo H2518D – Indirectly heated RF/IF pentode, 20 V/180 mA DC series heater, gm = 2.2 mS, μ = 5000, 200 V anode on top terminal, O5A European 5-pin base
B2047 = Telefunken RENS1894 = Mullard VP20 = Tungsram HP2118 = Valvo H2618D – Indirectly heated remote-cutoff RF/IF pentode, 20 V/180 mA DC series heater, gm ≤ 2 mS, μ ≤ 2000, 200 V anode on top terminal, O5A European 5-pin base
B2048 = Telefunken RENS1824 = Tungsram MH2018 = Valvo X2818 – Indirectly heated sharp-cutoff hexode mixer, 20 V/180 mA DC series heater, 200 V anode, C7H European 7-pin base
B2049 = Telefunken RENS1834 = Valvo X2918 – Indirectly heated remote-cutoff hexode mixer, 20 V/180 mA DC series heater, 200 V anode, C7H European 7-pin base
B2052T = Mullard SG20 = Telefunken RENS1818 = Valvo H1818D – Indirectly heated sharp-cutoff RF/IF tetrode, 20 V/180 mA DC series heater, 250 V anode on top terminal, O5A European 5-pin base
B2099 = Telefunken REN1814 – Indirectly heated AF triode, 20 V/180 mA DC series heater, μ = 99, 200 V anode, O5A European 5-pin base
C142 = Valvo H125D – Directly heated screen grid tetrode, 1 V/250 mA filament, gm = 1 mS, μ = 150, 50-150 V anode on top terminal, A4A European 4-pin base
C243N – Directly heated power pentode, 2 V/200 mA filament, gm = 2.4 mS, μ = 100, 150 V anode, O5A European 5-pin base
C405 = Tungsram P430 – Directly heated AF power triode, 4 V/300 mA filament, 250 V anode, μ = 5, A4A European 4-pin base
C443 = LaRadiotechnique TC43 = Telefunken RES364 = Tungsram PP430 = Valvo L425D – Directly heated power pentode, 4 V/250 mA filament, gm = 1.7 mS, μ = 60, 300 V anode, A4A European 4-pin base with lateral screw terminal; optionally O5A European 5-pin base
C443N = Mullard PM24DC = Telefunken RES374 = Tungsram PP431 = Valvo L427D – Directly heated power pentode, 4 V/250 mA filament, gm = 1.4 mS, μ = 50, 300 V anode, O5A European 5-pin base
C443N (Serie 250) – μ = 32
C453 – Slightly changed or only renamed C443
C509 = American 01-A – Directly heated AF power triode, 4.5-5.3 V/250 mA filament, 20-120 V anode, μ = 9, American UX4 4-pin base for use in imported radios with a rheostat filament supply for a 3-cell lead-acid battery; optionally A4A European 4-pin base
D143 = Valvo L160D – Directly heated power pentode, 1 V/650 mA filament, gm = 1.8 mS, μ = 100, 50-150 V anode, A4A European 4-pin base
D404 = Mullard AC044X = Telefunken RE604 = Tungsram P460 = Valvo LK460 – Directly heated AF power triode, 4 V/650 mA filament, 250 V anode, μ = 3.5, A4A European 4-pin base
E406 – Directly heated AF power triode, 4 V/1 A filament, 150-250 V anode, μ = 6, A4A European 4-pin base
E408 – Directly heated AF/modulator power triode, 4 V/900 mA filament, 200-400 V anode, μ = 8, A4A European 4-pin base
E408N = Telefunken RE614 – Directly heated AF power triode, 4 V/1 A filament, 400 V anode, μ = 8, A4A European 4-pin base
E409 = LaRadiotechnique TE09 = Valvo L4100 – Indirectly heated AF power triode, 4 V/1 A heater, 200 V anode, μ = 9, O5A European 5-pin base
E414 – Indirectly heated AF triode, 4 V/1 A heater, 200 V anode, μ = 14, A4A European 4-pin base
E415 = Telefunken REN804 = Valvo A4100/H4100 – Indirectly heated AF triode, 4 V/900 mA heater, 50-150 V anode, μ = 15, A4A European 4-pin base
E424 = LaRadiotechnique TE24 – Indirectly heated AF triode, 4 V/1 A heater, 200 V anode, μ = 24, O5A European 5-pin base; optionally A4A European 4-pin base with lateral screw terminal
E424N = E428 = LaRadiotechnique TE24N = Telefunken REN904 = Tungsram AG495 – Indirectly heated AF triode, 4 V/1 A heater, 200 V anode, μ = 28, O5A European 5-pin base
E430 – Indirectly heated AF triode, 4 V/1 A heater, 50-150 V anode, μ = 30, O5A European 5-pin base; optionally A4A European 4-pin base with lateral screw terminal
E435 – Indirectly heated AF triode, 4 V/900 mA heater, 50-150 V anode, μ = 35, O5A European 5-pin base; optionally A4A European 4-pin base with lateral screw terminal
E438 = Telefunken REN1004 = Valvo W4080/W4100 – Indirectly heated triode, μ = 38, 200 V anode, O5A European 5-pin base; B2038 with a 4 V/1 A heater
E441 = CdL DW1 = Tungsram DG4101 = Valvo U4100D – Indirectly heated dual-grid triode used as mixer, 4 V/900 mA heater, 100 V anode, O5A European 5-pin base with one grid on a lateral screw terminal, technically a tetrode
E441N = Telefunken REN704D – Indirectly heated dual-grid triode used as mixer, 4 V/900 mA heater, 100 V anode, O5A European 5-pin base with one grid on a lateral screw terminal, technically a tetrode
E442 = Valvo H4100D – Indirectly heated RF/IF screen grid tetrode, 4 V/900 mA heater, gm = 900 µS, μ = 700, 150-200 V anode, O5A European 5-pin base and top terminal
E442S = Cossor 41MSG = Telefunken RENS1204 = Valvo H4080D – Indirectly heated RF/IF screen grid tetrode, 4 V/1 A heater, gm = 1 mS, μ = 400, 200 V anode, O5A European 5-pin base and top terminal
E443 – Directly heated power pentode, 4 V/900 mA filament, gm = 1.8 mS, μ = 60, 300-400 V anode, O5A European 5-pin base
E443H = LaRadiotechnique TE43H = Telefunken RES964 = Tungsram PP4101 = Valvo L496D = Fivre RTP4 – Directly heated power pentode, 4 V/1.1 A filament, gm = 3 mS, μ = 130, 250 V anode, O5A European 5-pin base
E443N = LaRadiotechnique TE43N = Tungsram PP4100 = Valvo L491D – Directly heated power pentode, 4 V/900 mA filament, gm = 1.9 mS, μ = 75, 400 V anode, O5A European 5-pin base
E444 = LaRadiotechnique TE44/TE444 = Telefunken RENS1254 = Tungsram DS4100 = Valvo AN4126 – Indirectly heated diode + tetrode, B6H European 6-pin base; B2044 with a 4 V/1.1 A heater
E444S = LaRadiotechnique TE44S = Telefunken REN924 = Valvo AN4092 – Indirectly heated diode + AF triode, 4 V/1 A heater, μ = 30, O5A European 5-pin base
E445 = LaRadiotechnique TE45 = M-OV/GEC VMS4 = Mullard VM4V = Telefunken RENS1214 = Tungsram AS4104 = Valvo H4125D – Selektode, a remote-cutoff RF/IF screen grid tetrode, indirect 4 V/1 A heater, gm ≤ 1 mS, μ ≤ 300, 200 V anode, O5A European 5-pin base and top terminal
E446 = Cossor MS/Pen = LaRadiotechnique TE46 = Mullard SP4 = Telefunken RENS1284 = Tungsram HP4100/HP4101 = Valvo H4128D – Indirectly heated RF pentode, 4 V/1.1 A heater, gm = 2.5 mS, μ = 5000, 200 V anode, O5A European 5-pin base and top terminal
E447 = LaRadiotechnique TE47 = M-OV/GEC VMP4 = Telefunken RENS1294 = Tungsram HP4106 = Valvo H4129D – Indirectly heated remote-cutoff RF pentode, 4 V/1.1 A heater, gm ≤ 2 mS, μ ≤ 2000, 200 V anode, O5A European 5-pin base and top terminal
E448 = LaRadiotechnique TE48 = Telefunken RENS1224 = Tungsram MH4100 = Valvo X4122 – Indirectly heated sharp-cutoff hexode mixer, 4 V/1.2 A heater, 200 V anode, C7H European 7-pin base and top cap
E449 = LaRadiotechnique TE49 = Telefunken RENS1234 = Tungsram FH4105 = Valvo X4123 – Indirectly heated remote-cutoff hexode mixer, 4 V/1.2 A heater, C7H European 7-pin base and top cap
E452T = LaRadiotechnique TE52 = Telefunken RENS1264 = Valvo H4111D – Indirectly heated screen grid tetrode, 4 V/1 A heater, gm = 2 mS, μ = 900, 200 V anode, O5A European 5-pin base and top terminal
E453 = LaRadiotechnique TE53/TE534 = Telefunken RENS1374D = Tungsram APP4100 = Valvo L4150D – Indirectly heated power pentode, 4 V/1.1 A heater, gm = 2.5 mS, μ = 175, 250 V anode, O5A European 5-pin base
E455 = LaRadiotechnique TE55 = Mullard MM4V = Telefunken RENS1274 = Valvo H4115D – Indirectly heated remote-cutoff RF pentode, 4 V/1 A heater, gm ≤ 2 mS, μ ≤ 700, 200 V anode, O5A European 5-pin base and top terminal
E462 = LaRadiotechnique TE424 = Tungsram AS495 – Indirectly heated sharp-cutoff RF pentode, 4 V/1 A heater, gm = 2 mS, μ = 900, 200 V anode, O5A European 5-pin base and top terminal
E463 = LaRadiotechnique TE63 = Mullard ME463 = Telefunken RENS1384 = Tungsram APP4130 = Valvo L4138D – Indirectly heated power pentode, 4 V/1.35 A heater, gm = 2.7 mS, μ = 100, 250 V anode, B6H European 6-pin base
E499 = Telefunken REN914 = Valvo W4110 – Indirectly heated AF triode, 4 V/1 A heater, μ = 99, 200 V anode, O5A European 5-pin base
F215 (Valvo A2200W) – Indirectly heated triode, 2.5 V/1.5 A heater, μ = 15, 20-150 V anode, A4A European 4-pin base with the cathode on a lateral terminal
F410 = Valvo LK4200 – Directly heated power triode, 4 V/2 A filament, μ = 10, 400-550 V anode, A4A European 4-pin base
F443 = Valvo L495D – Directly heated power pentode, 4 V/2 A filament, gm = 3 mS, μ = 100, 550 V anode, O5A European 5-pin base
F443N = Valvo L497D – Directly heated power pentode, 4 V/2 A filament, gm = 3.9 mS, μ = 80, 300 V anode, O5A European 5-pin base
F704 – Directly heated AF/modulator power triode, 7.5 V/1.25 A filament, μ = 3.8, 400-450 V anode, A4A European 4-pin base or American UX4 base for use in imported devices
F708 (American 10 = CX-310 = UX-210) – Directly heated AF/modulator power triode, 7.5 V/1.25 A filament, μ = 8, 250-450 V anode, A4A European 4-pin base
The Milan branches of Philips and Siemens-Telefunken sold Philips and M-P tubes on the Italian market, some modified:
WE11 – EBC3
WE12 – EM4
WE13 – ECL11 w/P8A base
WE14 = EL6
WE15 = EL3N
WE16 – EF11 w/P8A base
WE17 – EF6
WE18 = EFM1
WE19 – EBF2
WE20 – ECH11 w/P8A base
WE21 = AK1
WE22 = WE40 = ACH1
WE23 = E446 = RENS1284
WE24 = E447 = RENS1294
WE25 – (AF2)
WE26 = E444 = RENS1254
WE27 = E424N = REN904
WE28 = E499 = REN914
WE29 = E444S = REN924
WE30 = E443H = RES964
WE31 = AB1
WE32 = AK2
WE33 = AF3
WE34 = AF7
WE35 = AL1
WE36 = AB2
WE37 = ABC1
WE37F – ABF1
WE38 = AL4
WE39 = AC2
WE41 = ABL1
WE42 = AL5
WE43 = ACH1C
WE44 – Triode+hexode
WE51 = 1805 = RGN1064
WE52 = 1561 = RGN2004
WE53 = AZ2
WE54, WE55 – AZ1
WE56 = AZ4
WE65 – Full-wave rectifier
Professional tubes
Philips used a 4/5-digit system for professional/industrial/telecommunications tubes, which they phased out in the 1960s in favor of PE Professional tubes:
1063A – 3-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 filament
1069K – Forced-air cooled, full-wave Tungar bulb used in 60 A DC welding power supplies, 3.25 V/70 A filament
1533A – 3-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 filament
1543A – 3-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 filament
1553A – 3-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 filament
1561 = Telefunken RGN2004 – 1.4 kV, 2×80 mA Full-wave rectifier, 4 V/2 A filament; AZ2 with an A4A European 4-pin base
1805 = RGN1064 – 1.4 kV, 2×50 mA Full-wave rectifier, 4 V/1 A filament, A4A 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]
3520 – Early 3-stage, S1 photomultiplier, side-contact 8 base
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[85]
Philips used more freeform designations for thyratrons and ignitrons; examples are:
PL5 – 1.5 kV, 3.5 Aavg, 100 ApeakSendytron,(de) a Mercury-vapor thyratron with an auxiliary anode and capacitive ignition by an isolated control rod dipping into the cathode pool[86][87]
PL323 = PL3C23 = 3C23 – 1.25 kV, 1.5 Aavg, 6 Apeak Argon/Mercury-vapor triode thyratron, UX4 base with anode on top cap
PL435 = PL4C35 = 4C35, PL522 = PL5C22 = 5C22 – Half-indirectly heated, Hydrogen triode thyratrons used in radar modulators, B4D Superjumbo base with anode on top cap
From 1924 to 1939, Philips printed a basing code on tube cartons and price lists, but not on the tubes themselves.[45]: 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 Transcontinental European base, originally Franco-British
B – 4-pin Telefunken base (1920s);[82]: 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 Medium 7-pin American U7A base (1930s)
Y – 8-pin Continental European base, originally German steel tubes a.k.a. "German Metal Octal"
On cartons and tube lists, this basing code was followed by a number giving the maximum envelope diameter in mm
STC systems
"Brimar" standard tubes
For their Brimar ("British Manufactured American Radio" [tubes]) brand, WE-STC used the following scheme until the 1950s, when they phased it out in favor of the RETMA, EIA and Mullard–Philips systems:[18]
20 – Triode/hexode or triode/heptode oscillator/mixer
A letter: Filament/heater rating
A – 4 V, Indirectly heated
B – 2 V, Directly heated
C – Other directly heated
D – Other indirectly heated
A sequentially assigned number
Examples:
1D5 – Half-wave rectifier; 25Z4-G with a 40 V/200 mA heater and an O5A European 5-pin base (not to be confused with the RETMA 1D5 remote-cutoff pentode)
1D6 – Half-wave rectifier; 25Z4-G with a U6A American 6-pin base
4D1 – Triode, 13 V/200 mA heater, M7A British 7-pin base
7A2 – Power pentode, 4 V/1.2 A heater, M7A British 7-pin base
7A3 = Cossor 42MP/PEN = EdiSwan AC2/PEN = Ferranti PT4 = Mullard PEN4VB – Power pentode, 4 V/2 A heater, M7A British 7-pin base
7D3 – Power pentode, 40 V/200 mA heater, M7A British 7-pin base
7D6 – Power pentode, 40 V/200 mA heater, M7A British 7-pin base
7D8 – Power pentode, 13 V/650 mA heater, M7A British 7-pin base
7D10 = 6CH6/EL821 – Power pentode, 6.3 V/750 mA heater, Noval base
8A1 = Cossor MS/PEN = EdiSwan AC/S2PEN = Ferranti SPT4 = M-OV/GEC MSP4 – Sharp-cutoff pentode, 4 V/1 A heater, O5A European 5-pin base
8D2 – Sharp-cutoff pentode, 13 V/200 mA heater, M7A British 7-pin base
8D3 = 6AM6/EF91 – Sharp-cutoff pentode, 6.3 V/300 mA heater, Miniature 7-pin base
8D5 = 6BR7, 8D8 – Low-hum, low-microphonics, sharp-cutoff pentodes, 6.3 V/150 mA heater, Noval base
9A1 = Cossor MVS/PEN = EdiSwan AC/VP1 = Ferranti VPT4 = M-OV/GEC VMP4 = Mullard VP4 – Remote-cutoff RF/IF pentode, 4 V/1 A heater, O5A European 5-pin base with anode on top cap
9D2 – Remote-cutoff RF/IF pentode, 13 V/200 mA heater, M7A British 7-pin base with grid on top cap
9D6 – Remote-cutoff RF/IF pentode, 6.3 V/200 mA heater, Miniature 7-pin base
9D7 – Remote-cutoff RF/IF pentode, 6.3 V/300 mA heater, Noval base
10D1 – Common cathode dual diode, 13 V/200 mA heater, O5A European 5-pin base
11A2 = Cossor DDT = EdiSwan AC/HLDD = M-OV/GEC MHD4 = Mullard TDD4 – Common cathode dual diode + triode, 4 V/1 A heater, M7A British 7-pin base
11D3 – Common cathode dual diode + triode, 13 V/200 mA heater, M7A British 7-pin base
11D5 – Common cathode dual diode + triode, 13 V/150 mA heater, M7A British 7-pin base
13D1 = 25SN7-GT, 13D2 = 6SN7-GT – Separate cathodes, dual triodes, Octal base
13D3 – Separate cathodes, dual triode, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base
13D7 = ECC807 – Separate cathodes, dual triode, 6.3 V/300 mA heater, Noval base
13D8 (12AU7/ECC82) – Separate cathodes, dual AF triode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater, Noval base
13D9 – Separate cathodes, dual triode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater, Noval base
15A2 = Cossor 41MPG = Ferranti VHT4 = M-OV/GEC MX40 (4 V/650 mA heater), 15D1 (13 V/200 mA heater), 15D2 (13 V/150 mA heater) – Heptode pentagrid converter with British grid topology and control (#4) grid on top cap, M7A British 7-pin base
20A1 – Triode/heptode oscillator/mixer, 4 V/1.2 A heater, M7A British 7-pin base
20D2 – Triode/hexode oscillator/mixer, 13 V/150 mA heater, M7A British 7-pin base
20D4 – Triode/heptode oscillator/mixer, 6.3 V/300 mA heater, Noval base
Professional tubes
Besides their "4000" system with incorporated Western Electric 3-digit type numbers (examples), STC used the following system:[89]
An optional number if none preceded the letter (notably with cold-cathode tubes):—Gas-filled trigger tubes: Max. ignition voltage—Voltage-regulator tubes: Burning voltage
A slash followed by a number:—High-vacuum tubes: 2-digit power rating followed by a sequentially assigned digit
A letter: Base
A – American base
B – British base
C – Edison screw base
D – Octal base
E – Special base
G – Wire-ends
J – Disk-seal tube
K – Miniature base
M – B8F Eimac/JEDEC B8-236 9-pin blow-through base
An optional letter Y: Tightened specs
Examples:
3J-187E (Glass/metal), 3JC-187E (ceramic/metal) – Forced-air cooled power triode
3RM-215G – 10 MHz, 8 kW, Water/helix-cooled Neotron, used as RF power amplifier or oscillator; similar to YD1352S/8867
4G/280K = 2D21/EN91 – 650 V, 100 mAavg, 500 mApeak, 10 Asurge, Xenon-filled, indirectly heated tetrode thyratron used as relay driver or grid-controlled rectifier, negative starter voltage, Miniature 7-pin base
22V/310A – 1.4 kV, 250 mA Full-wave Mercury-vapor rectifier
G10/241E – Nomotron, a unidirectional Dekatron with multi-alloy cathodes
G75/2D = 0A3 = M-OV/GEC QS75/40 – 75 V Voltage-regulator tube, Octal base
P535-1E = WE 715B (15 kV), P552-1E = 5D21 (20 kV) – Pulse-rated power tetrodes used in hard-tube pulser radar modulators
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.
A letter: Function/type:Note: Two equal letters indicate a dual-system tube
P – Pentode
Q – Tetrode
T – Triode
A number: Maximum anode power dissipation in kW
An optional letter: Cooling method:
<none> – Radiation
P – Forced-air
W – Water
A slash followed by a digit:
1 – Tube for radio broadcasting and radiocommunication equipment
2 – Tube for industrial equipment
3 – Tube used in analog TV broadcasting equipment
4 – Tube for radiocommunication equipment with unbalanced modulation
Rundfunk- und Fernmelde-Technik(de, sv) was the brand of a group of telecommunications manufacturers in the German Democratic Republic. RFT used the Mullard–Philips and RETMA schemes for their signal and low-power tubes.
Transmitting tubes
The designation consists of 3 letters and a 3 or 4-digit number
A number: Filament/heater voltage, as in the RETMA system
Letter(s): Function/type, subset of the Mullard–Philips system
A digit: Base
1 – K8A Octal
2 – B8G Loctal
3 – B7G Miniature 7-pin
4 – B9A Noval
5 – Special, mostly 9 out of 10 1.25mm pins on a 25mm-diameter circle
6 – B11A Submagnal
7 – B12A Duodecal
8 – B14A Diheptal
9 – Wire-ends
A sequentially assigned digit
Examples:
1AF33 = 1AH5/DAF96 (1.4 V/25 mA filament), 1AF34 (1.2 V/30 mA filament) – Diode + AF pentode, Miniature 7-pin base
1F33 = 1AJ4/DF96 (1.4 V/25 mA filament), 1F34 (1.2 V/30 mA filament) – Remote-cutoff RF/IF pentode, Miniature 7-pin base
1H33 = 1R5-SF = 1AQ5 (=1R5/DK91 with a 1.4 V/25 mA filament), 1H34 (1.2 V/30 mA filament) – Heptode pentagrid converter with American grid topology, anode voltage in the 45...90 volt range, Miniature 7-pin base
1H35 = 1AB6/DK96 – Heptode pentagrid converter with suppressor (#5) grid internally tied to the positive 1.4 V/25 mA filament end, Miniature 7-pin base
1Y32T – 1Y32 with a wide-range, 1.19 V to 1.61 V oxide-coated filament
3L31, 3L32 – Power pentodes, center-tapped 2.8 V/50 mA resp. 1.4 V/100 mA filament, Miniature 7-pin base
4L20 = 4П1Л↦4P1L – 120 MHz Directly heated power pentode, center-tapped 4.2 V/325 mA resp. 2.1 V/650 mA filament; Telefunken RL4,2P6 with a Loctal base
6B31, 6B32 = 6AL5/EAA91/EB91 = 6Х2П↦6H2P (Different pinout) – 700 MHz Dual diode, 6.3 V/300 mA heater, Miniature 7-pin base
6BC32 = 6AV6/EBC91 – Dual diode + triode, 6.3 V/300 mA heater, Miniature 7-pin base
6CC10 = 6SN7-GT – Dual triode, 6.3 V/600 mA heater, Octal base
6CC31 = 6J6/ECC91 = 6H15П↦6N15P – 600 MHz Dual VHF triode, 6.3 V/450 mA heater, Miniature 7-pin base
6CC42 = 2C51 = 6Н3П↦6N3P (5670) – Dual VHF triode, 6.3 V/350 mA heater, Noval base
6F24 – Telecom pentode, 6.3 V/450 mA heater, Loctal base
6F31 = 6BA6/EF93 – Remote-cutoff pentode, 6.3 V/300 mA heater, Miniature 7-pin base
6F32 = 6AK5/EF95 = 6Ж1П↦6J1P – Sharp-cutoff pentode, 6.3 V/175 mA heater, Miniature 7-pin base
6F35 = 6AJ5/6АЖ5 – Low (6.3-80 V) anode voltage, sharp-cutoff pentode, 6.3 V/175 mA heater, Miniature 7-pin base
6F36 = 6AH6 = 6Ж5П↦6J5P – Sharp-cutoff IF/video pentode, 6.3 V/450 mA heater, Miniature 7-pin base
6H31 = 6BE6/EK90 = 6А2П↦6A2P – Pentagrid converter, 6.3 V/300 mA heater, Miniature 7-pin base
6L31 = 6AQ5/EL90 – Power pentode, 6.3 V/450 mA heater, Miniature 7-pin base
6L41 = 5763 (6П1П↦6P1P) – Beam power tetrode, 6.3 V/750 mA heater, Noval base
6L43 = 6CL6 – Power pentode used as CRT cathode driver, 6.3 V/650 mA heater, Noval base
6L50 – VHF power pentode; derived from Telefunken/Luftwaffe LS50
6Z31 = 6X4/6BX4/EZ90 = 6Ц4П↦6C4P – Full-wave rectifier, 6.3 V/600 mA heater, Miniature 7-pin base
12BC32 = 12AV6/HBC91 – 6BC32 Dual diode + triode with a 12.6 V/150 mA heater
12F31 = 12BA6/HF93 – 6F31 Remote-cutoff pentode with a 12.6 V/150 mA heater
12H31 = 12BE6/HK90 – 6H31 Pentagrid converter with a 12.6 V/150 mA heater
35Y31 – Half-wave rectifier, 35 V/150 mA series heater; UY1(N) with Miniature 7-pin base
The Tungsram system was composed of a maximum of three letters and three or four digits.[91][90] 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(s): Function/type:
Note: A preceding letter A indicates an indirectly heated tube
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 cyrillic letter(s) and a sequentially assigned number with up to 3 digits[90]
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.[95]
GOST 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.[96][permanent dead link][97]
A number: Filament/heater voltage rounded to the nearest whole number; 06 means 625 mV
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
An optional dash followed by one or more letters indicating special characteristics; in most cases this means construction upgrades rather than product binning:
Л ⟼ L – Beam deflection tube incl. CRTs (Russian: Электронно-лучевыеприборы "Electron beam device", "CRT"), ≥two-lettered; most CRT designations are preceded by a number giving the screen diagonal or diameter in cm (rounded-off to the nearest whole number)
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-collecting target located behind an aperture mask perforated with sub-mm holes patterned such that the hole density z at any given x,y position is proportional to the value[100] of the desired f (x,y)
US-6A8 = 6A8 – Heptode pentagrid converter with British grid topology and control (#4) grid on top cap, 6.3 V/800 mA heater, Octal base
US-6F7-A = 6F7A – Triode + pentode, 6.3 V/300 mA heater, Octal base; Metal version of 6F7
US-6J7 = 6J7 – Dual-control, sharp-cutoff RF pentode, 6.3 V/300 mA heater, Octal base with control grid on top cap
US-6K7 = 6K7 – Dual-control, remote-cutoff RF pentode, 6.3 V/300 mA heater, Octal base with control grid on top cap
US-6L7-G = 6L7-G – Mixing heptode requiring a separate oscillator, 6.3 V/300 mA heater, Octal base
US-6305 – VHF Pentode, 6.3 V/300 mA heater
Ut-6L7-G – US-6L7-G with an U7A base
UV-102 – Directly heated triode, 2.0 V/750 mA filament, UV4 base
UX-10-A – Directly heated triode, 7.5 V/1.25 A filament, UX4 base
UX-12-A = 12-A = UX-112-A = CX-112-A – Directly heated medium-μ triode, 5 V/250 mA filament, UX4 base
UX-30 – Directly heated triode, 2 V/60 mA filament, UX4 base
UX-31-A – Directly heated triode, 2.0 V/130 mA filament, UX4 base
UX-32 = 32 = RCA-232 = CX-332 – Directly heated, sharp-cutoff tetrode, 2 V/60 mA filament, UX4 base with control grid on top cap
UX-47-A (2.5 V/1.75 A filament), UX-47-C (5.0 V/500 mA filament) – Directly heated power pentode, UX4 base; similar to 47
UX-71-A = 71-A = UX-171-A = CX-371-A – Directly heated power triode, 5 V/250 mA filament, UX4 base
UX-99 = X99 = UX-199 – Directly heated low-μ triode, 3.3 V/60 mA filament, UX4 base
UX-109 (1.3 V/80 mA filament), UX-109-A (1.1 V/60 mA filament) – Directly heated triode, UX4 base
UX-110 – Directly heated power triode, 1.3 V/160 mA filament, UX4 base
UX-111, UX-111-B – Directly heated space charge grid tetrode, 1.3 V/80 mA filament, UX4 base
UX-167 – Directly heated, sharp-cutoff RF pentode, UX4 base
UX-201-A = 01-A – Directly heated, general-purpose low-μ triode, 5 V/250 mA filament, UX4 base
UX-202-A – Directly heated power triode, 7.5 V/1.25 A filament, UX4 base
UX-226 = 26 = CX-326, UX-26-B – Directly heated medium-μ RF triode, 1.5 V/1.05 A filament, UX4 base
UX-6202 – Directly heated RF tetrode, 1.9 V/50 mA filament, UX4 base
UY-6A3-B – Power triode, 6.3 V/1.6 A heater, UY5 base; indirectly heated variant of 2A3
UY-10-H – Triode, 6.3 V/800 mA heater, UY5 base
UY-11-A – Directly heated pentode, 1.1 V/60 mA filament, UY5 base
UY-36-A – RF Tetrode, 6.3 V/300 mA heater, UY5 base
UY-37-A – Triode, 6.3 V/300 mA heater, UY5 base
UY-38-A – Power pentode, 6.3 V/300 mA heater, UY5 base
UY-39-A – RF Pentode, 6.3 V/300 mA heater, UY5 base
UY-45-H – Power triode, 6.3 V/800 mA heater, UY5 base; indirectly heated variant of 45
UY-46-C – Directly heated Class-B tetrode, 2.5 V/500 mA filament, UY5 base
UY-47 = 47 = RCA-247 = C-347, UY-47-A (2.5 V/1.75 A filament), UY-47-B (2.5 V/500 mA filament) – 2.7 W Directly heated power pentode, UY5 base; 46 with a suppresser grid connected to a filament center-tap
UY-56-A – Triode, 2.5 V/800 mA heater, UY5 base
UY-57-S – Pentode, 2.5 V/1.0 A heater, UY5 base
UY-76-A – Triode, 6.3 V/300 mA heater, UY5 base
UY-133 (1.1 V/125 mA filament), UY-133-A (1.1 V/60 mA filament) – Directly heated power pentode, UY5 base
UY-169 – Directly heated power pentode, 2 V/120 mA filament, UY5 base
UY-224 = 24 = C-324, UY-224-A = 24-A = C-324A, UY-24-B – Sharp-cutoff tetrode, 2.5 V/1.75 A heater, UY5 base with control grid on top cap
UY-227 = 27 = C-327 (2.5 V/1.75 A heater), UY-27-A (2.5 V/1.5 A heater), UY-27-B (2.5 V/1.0 A heater) – Medium-μ triode, UY5 base
UY-233 = 33 = RCA-233 = C-333 – Power pentode, 2 V/260 mA filament, UY5 base
UY-235 = 35/51 = C-335, UY-35-B – Remote-cutoff RF tetrode, 2.5 V/1.75 A heater, UY5 base; variant of the UY-224-A tetrode
UY-247 = 47 = RCA-247 = C-347 – Directly heated power pentode, 2.5 V/1.75 A filament, UY5 base
UY-536 – Tetrode, 6.3 V/300 mA heater, UY5 base
UY-537 – Triode, 6.3 V/300 mA heater, UY5 base
UY-538 – Power pentode, 6.3 V/300 mA heater, UY5 base
UY-539 – RF Pentode, 6.3 V/300 mA heater, UY5 base
UY-807 = 807, UY-807-A (6.3 V/900 mA heater), UY-807-B (12.0 V/450 mA heater) – Transmitting beam power tetrode, UY5 base
UY-6301 – Triode, 6.3 V/600 mA heater, UY5 base
Uy-11-M – Directly heated tetrode, 1.1 V/60 mA filament, Peanut 5-pin base
Uy-14-M – Directly heated RF pentode, 1.1 V/60 mA filament, Peanut 5-pin base
UZ-12-C – Directly heated dual triode, 5.0 V/500 mA filament, U6A base; dual unit of 12A
UZ-30-C, UZ-30-MC – Directly heated dual triode, 2.0 V/120 mA filament, U6A base; dual unit of 30
UZ-31-MC – Directly heated dual power triode, 2.0 V/260 mA filament, U6A base; dual unit of 31
UZ-33-A – Directly heated dual triode, 2.0 V/260 mA filament, U6A base; dual unit of 33
UZ-42 = 42 – Power pentode, U6A base; 2A5 with a 6.3 V/700 mA heater
UZ-47-D (5.0 V/500 mA filament), UZ-47-G (5.0 V/250 mA filament), UZ-47-H (5.0 V/1.65 A filament), UZ-47-K (5.0 V/500 mA filament) – Directly heated modulator pentode, U6A base
UZ-55 = 55 – Dual diode + medium-μ triode, 2.5 V/1 A heater, U6A base
UZ-57 = 57, UZ-57-A – Sharp-cutoff pentode, 2.5 V/800 mA heater, U6A base
UZ-58 = 58, UZ-58-A – Remote-cutoff RF/IF pentode, 2.5 V/1 A heater, U6A base
UZ-75 = 75 – 6H6-type Dual diode + 6F5-type high-μ triode, 6.3 V/300 mA heater, U6A base
UZ-77 = 77 – Sharp-cutoff pentode, 6.3 V/300 mA heater, U6A base
UZ-78 = 78 – Remote-cutoff pentode, 6.3 V/300 mA heater, U6A base
UZ-79 = 79 – Dual power triode, 6.3 V/600 mA heater, U6A base
UZ-89 = 89 – 3.4 W Power pentode, 6.3 V/400 mA heater, U6A base
UZ-109 – Directly heated dual triode, 1.1 V/100 mA filament, U6A base
UZ-130-C – Directly heated dual triode, 1.1 V/240 mA filament, U6A base
UZ-133-D – Directly heated triode + pentode, 1.1 V/125 mA filament, U6A base
UZ-135 – Directly heated heptode pentagrid converter, 1.1 V/130 mA filament , U6A base
UZ-1C6-B (1C6) – Directly heated heptode pentagrid converter with British grid topology and control (#4) grid on top cap, 2.0 V/120 mA filament, U6A base
UZ-2A5 = 2A5 – Power pentode, 2.5 V/1.75 A heater, U6A base
UZ-2A6 = 2A6 – Dual diode + high-μ triode, 2.5 V/800 mA heater, U6A base with control grid on top cap
UZ-6C6 = 6C6 – Dual-control, sharp-cutoff RF pentode, 6.3 V/300 mA heater, U6A base with control grid on top cap
UZ-6D6 = 6D6 – Dual-control, remote-cutoff RF pentode, 6.3 V/300 mA heater, U6A base with control grid on top cap
UZ-6E5 – See EZ-6E5
UZ-6L6-A (6L6-G) – Beam power tetrode, 6.3 V/900 mA heater, U6A base
UZ-6001 – Pentode, 6.3 V/300 mA heater, U6A base
UZ-6302 – Video pentode, 6.3 V/600 mA heater, U6A base
UZ-6304 – Power pentode, 6.3 V/700 mA heater, U6A base
JIS C 7001 System
JIS C 7001 was published in 1951 and revised in 1965 and 1970[101]
A number: Filament/heater voltage category, as in the RETMA scheme
5F60R – 450 W, 500 MHz Coaxial power tetrode, 6.0 V/5.5 A heater
5G44 = 5544 – Gas-filled triode thyratron
5T20 = 250TL – 250 W, 40 MHz Low-μ power triode
5T21 = 250TH – 250 W, 40 MHz High-μ power triode
5T30 = 450TL – 450 W, 40 MHz Low-μ power triode
5T31 = 450TH – 450 W, 40 MHz High-μ power triode
6AV60 – 3 kW, 6.325-6.425 GHz, 4-cavity Klystron
6G45 = 5545, 6G45A – Gas-filled triode thyratron
6G67 = 6807 – Gas-filled triode thyratron
6G68 = 6808 – Gas-filled triode thyratron
6T35 = 750TL – 750 W, 40 MHz Low-μ power triode
7F64R – 4 kW, 250 MHz Coaxial power tetrode, 6.0 V/68 A heater
7F71RA – 3.5 kW, 250 MHz Coaxial power tetrode, 4.0 V/78 A filament
7T40 = 1000T – 1 kW, 40 MHz High-μ power triode
8F76R – 15 kW, 250 MHz Coaxial power tetrode, 7.5 V/120 A filament
8T33 (Water-cooled), 8T39 (Water/vapor-cooled) – 10 kW, 250 MHz Power triode, 7.5 V/60 A filament
9T40 – 150 kW, 2 MHz Water/vapor-cooled power triode, 18 V/315 A filament
Military naming systems
British CV and M8000s naming systems
This system prefixes a three- or four-digit number with the letters "CV", meaning "common valve" (common to all three armed services), later "civilian valve".[108] 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 = 6SN7-GT = 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 indicates 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 used 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
Since the 1920s, several manufacturers introduced proprietary numbering systems (examples), some of which grew into informal standards adopted by other manufacturers; the use was not rigorously systematic.
The American two-digit system, starting with the UV-201-A triode, which was abbreviated as "type '01-A", and extended almost continuously up into the 1980s
Several manufacturers used acronym prefixes to indicate the function or type for (mostly professional) tubes (ex.1, ex.2, ex.3, ex.4), or as a manufacturer's code:
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
0A4-G (Z300T) – 25 mAavg, 100 mApeak Gas triode, Octal base, 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 tetrode with a keep-alive (primer) electrode and a shield grid, Miniature 7-pin base, designed for relay drive and general switching
These tubes have directly heated cathodes, usually running on a single NiCd cell; pentodes and heptodes specify the filament polarity because the suppressor grid is internally connected to the negative filament end; 1AD4, 1AG4, 1AG5, 1AK4 and 1AK5 pentodes have a split suppressor grid, its halves tied to the positive resp. negative filament end
1E3 – UHF Triode, 220 mA filament, Noval base
1AB5 – 1LN5 with higher transconductance and a 1.20 V/130 mA filament, Loctal base
1AE4 – Sharp-cutoff pentode, 100 mA filament, Miniature 7-pin base
The following Pencil subminiature tubes were used in post-World War II walkie-talkies, pocket-sized portable radios, and hearing aids; all have all-glass envelopes 1+1⁄8 to 2 in (29 to 51 mm) long and with diameters of:
—Elliptical cross-section envelope with Flat-Press inline base/wire-ends: 0.285 by 0.366–0.4 in (7 by 9–10 mm)
—Round cross-section envelope with circular base/wire-ends: ca. 0.366–0.4 in (9–10 mm)
1C8 – Heptode pentagrid converter with American grid topology, 40 mA filament, round/circular, 8-pin/wire-ends
1D3 – Low-μ UHF triode, 300 mA filament, round/circular, 8-pin/wire-ends
1E8 – Heptode pentagrid converter with American grid topology, 40 mA filament, Sub-Minar round/circular, 8-pin/wire-ends
1Q6 – Diode + AF pentode, 40 mA filament, round/circular, 8-pin/wire-ends; similar to 1LD5/DAF26, 1S5/DAF91, but rated for lower voltages
Designed for use in dry cell battery-only or in Three-way portable (AC/DC/Dry-cell) radio receivers; most are directly heated, pentodes and heptodes specify the filament polarity
1A3/DA90 – Indirectly heated FM discriminator diode used as a detector in some portable AM/FM receivers, 150 mA heater, Miniature 7-pin base
1A7-GT/DK32 – Heptode pentagrid converter with British grid topology and control (#4) grid on top cap, 50 mA filament, Octal base, introduced in 1938; re-engineered variant of 1A6, 1D7-G
1AF4 – Sharp-cutoff pentode, 25 mA filament, Miniature 7-pin base
1AF5 – Diode + sharp-cutoff pentode, 25 mA filament, Miniature 7-pin base
1B7-GT – Heptode pentagrid converter with British grid topology and control (#4) grid on top cap, 100 mA filament, Octal base; re-engineered variant of 1C6, 1C7-G for shortwave use
1B8-GT, 1D8-GT – Diode + triode + power pentode, 100 mA filament, Octal base with triode grid on top cap
1C5-GT/DL35 – Power pentode, 100 mA filament, Octal base; similar to 3Q5-GT/DL33
1E4-G (μ = 14), 1G4-GT/G (μ = 8.8) – AF triode, 50 mA filament, Octal base
1G6-G, 1G6-GT – Dual power triode, 100 mA filament, Octal base
1H5-GT/DAC32 – Diode + high-μ AF triode, 50 mA filament, Octal base with triode grid on top cap
1N6-G – Diode + power pentode, 50 mA filament, Octal base
1P5-G, 1P5-GT – Sharp-cutoff pentode, 50 mA filament, Octal base with control grid on top cap
1R5/DK91 – Heptode pentagrid converter with American grid topology, anode voltage in the 45...90 volt range, 50 mA filament, Miniature 7-pin base; ruggedized version: 1R5-WA
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, 100 mA filament, Miniature 7-pin base
1S5/DAF91 – Diode + sharp-cutoff pentode used as detector and first AF amplifier, anode voltage in the 67...90 volt range, 50 mA filament, Miniature 7-pin base
1S5-SF = 1S5T = 1AR5 – 1S5/DAF91 with a 25 mA filament
These tubes were made for home storage battery receivers manufactured during the early to mid-1930s; all are directly heated with a 2.0 volt DC filament despite the 1-prefix, intended to distinguish them from the 2.5 volt AC heated tubes listed below
1A4 = 1A4P – Remote-cutoff pentode, suppressor grid internally tied to 60 mA filament negative or center-tap, UX4 base with control grid on top cap
1A4T – Remote-cutoff tetrode; 1A4P without a suppressor grid
1A6 (U6A base), 1D7-G (Octal base) – Heptode pentagrid converter with British grid topology and control (#4) grid on top cap, 60 mA filament, up to only 10 MHz due to low heater power and consequent low emission in the oscillator section, also occasionally used as a grid-leak detector
1B4 = 1B4P – Sharp-cutoff pentode, suppressor grid internally tied to the negative 60 mA filament end, UX4 base with control grid on top cap
1B4T – Sharp-cutoff tetrode; 1B4P without a suppressor grid
1C4 – Remote-cutoff pentode, 120 mA filament, UX4 base with control grid on top cap
1C6 (U6A base), 1C7-G (Octal base) – Heptode pentagrid converter with British grid topology and control (#4) grid on top cap, 120 mA filament; 1A6, 1D7-G with double the heater power and double the frequency range
1D4 – Power pentode, 240 mA filament, UY5 base
1D5-G = 1D5-GP – 1A4P with an Octal base
1D5-GT – 1A4T with an Octal base (Note: This is a shouldered "G" Octal, not a cylindrical "GT" Octal)
1E5-G = 1E5-GP – 1B4P with an Octal base
1E5-GT – 1B4T with an Octal base (Note: This is a shouldered "G" Octal, not a cylindrical "GT" Octal)
1E7-G, 1E7-GT – Dual power pentode used as a driver when parallel-connected, or as a push-pull output, 240 mA filament, Octal base
1F4 (UY5 base), 1F5-G (Octal base) – Power pentode, suppressor grid internally tied to the negative 120 mA filament end
1F6 (U6A base), 1F7-G (Octal base) – Dual diode + sharp-cutoff pentode with control grid on top cap, suppressor grid internally tied to the negative 60 mA filament end
1G5-G – Power pentode, suppressor grid internally tied to the negative 120 mA filament end, Octal base
1H4-G, 1H4-GT – Medium-μ triode, 60 mA filament, can be used as a power triode; type 30 (=upgraded type 01-A) with an Octal base
1H6-G, 1H6-GT – See 1B5/25S
1J5-G – AF power pentode, suppressor grid internally tied to the negative 120 mA filament end, Octal base; similar to 950
1J6-G, 1J6-GT – Dual power triode, 240 mA filament; type 19 with an Octal base
1K4 (UX4 base), 1K5-G (Octal base) – AF power pentode with control grid on top cap, suppressor grid internally tied to the negative 120 mA filament end
1K6 (U6A base), 1K7-G (Octal base) – Dual diode + AF power pentode with control grid on top cap, suppressor grid internally tied to the negative 120 mA filament end
1L5-G – Power pentode, suppressor grid internally tied to the negative 240 mA filament end, Octal base
1M5-G – Remote-cutoff pentode with control grid on top cap, suppressor grid internally tied to the negative 120 mA filament end, Octal base
1AJ2 – Compactron CRT EHT rectifier, 1.25 V/200 mA filament
1AY2 – Duopin 2-pin base CRT EHT rectifier; similar to 1B3-GT/DY30
1B3-GT/1G3-GT/DY30 = 1Ц7С↦1C7S – CRT EHT rectifier, 1.25 V filament, peak inverse voltage of 30 kV, anode current 2 mA average, 17 mA peak, Octal base, common in 1950s and early 1960s monochrome TV receivers; derived from the earlier industrial type 8016
1BC2 – CRT EHT rectifier, 1.25 V/200 mA filament, Noval base
1BC2A, 1BC2B – 1BC2 with internal X-radiation shielding
1BG2/DY51 – 15 kV Subminiature CRT EHT rectifier used in portable TV receivers, half-indirect 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 prevent flush-over in high-humidity and low atmospheric-pressure conditions
1BY2 – Compactron CRT EHT rectifier, 1.25 V/200 mA filament
1BY2A – 1BY2 with internal X-radiation shielding
1H2 – CRT EHT rectifier, half-indirect 1.4 V/550 mA heater, Noval base
1S2/DY86 = 1Ц21П↦1C21P – 22 kV, 800 µA Half-indirectly heated CRT EHT rectifier, Noval base with anode on top cap; 6S2/EY86 with a 1.4 V/550 mA heater
1S2A/DY87 – 1S2/DY86 variant for operation at high altitudes with a silicone-coated envelope to prevent flush-over in high-humidity and low atmospheric-pressure conditions; 6S2A/EY87 with a 1.4 V/550 mA heater
1T2 = Brimar R16 – Subminiature CRT EHT rectifier, 1.4 V/140 mA filament, filament wires on one end, anode wire on the other
1V2 – CRT EHT rectifier, 625 mV/300 mA filament, Miniature 7-pin base
1X2 – CRT EHT rectifier, 1.25 V/200 mA filament, Noval base
1X2A, 1X2B, 1X2C – 1X2 with internal X-radiation shielding
1Y2 – 50 kVPIV, 10 mApeak, 2 mAaverage CRT EHT rectifier usable up to 1 MHz, 1.5 V/290 mA filament, UX4 base
1Z1 – CRT EHT rectifier, 0.7 V/180 mA filament, Octal base
1Z2 – CRT EHT rectifier, 1.25 V/265 mA filament, Noval base
Tubes used in AC-powered radio receivers of the early 1930s; most are indirectly heated
2A3 – 15 W Directly heated AF power triode used in 1930s–40s audio amplifiers and radios, 2.5 A filament
2A5 – Power pentode, U6A base; types 42, 6F6 with a 2.5 V/1.75 A heater
2A6 – Dual diode + high-μ triode, U6A base with control grid on top cap; types 75, 6B6-G with a 2.5 V/800 mA heater
2A7 – Remote-cutoff heptode pentagrid converter with British grid topology and control (#4) grid on top cap, U7A base; 6A7, 6A8, 12A8 with a 2.5 V/800 mA heater
2B6 – Triple-Twin AF signal + zero bias power triode, 2.25 A heater, internally connected as a cathode follower like today's Darlington transistors; cf. 295, 6AC6, 6B5, 6N6-G
2B7 – Dual diode + remote-cutoff pentode, U7A base with control grid on top cap; 6B7, 6B8-G with a 2.5 V/800 mA heater
2E5 – Top-view, "Magic Eye"-type tuning indicator; 2G5 with a sharp-cutoff driver triode; 6E5 with a 2.5 V/800 mA heater
2G5 – Top-view, "Magic Eye"-type tuning indicator; 2E5 with a remote-cutoff driver triode; 6G5/6U5 with a 2.5 V/800 mA heater
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 dry batteries) radio receivers
3A4/DL93 – 700 mW RF/AF power pentode, 100 resp. 200 mA filament, Miniature 7-pin base
3A5/DCC90 – 2×1 W, 40 MHz Dual RF power triode, 110 resp. 220 mA filament, Miniature 7-pin base
3A8-GT – Diode + triode + pentode, 50 resp. 100 mA filament with internal shield tied to center-tap, Octal base; 1H5-GT/DAC32 + 1N5-GT/DF33 in one envelope
3B4/DL98 – 1.25 W, 100 MHz RF power pentode, 2.5 V/165 mA resp. 1.25 V/330 mA filament with suppressor grid tied to center-tap, Miniature 7-pin base
3B5-GT – AF beam power pentode, 67.5 V anode voltage, 50 resp. 100 mA filament with beam plates tied to center-tap, Octal base
3B7 – 1.4 W, 125 MHz Dual VHF power triode, 110 resp. 220 mA filament, Loctal base
3C4/DL96 – 200 mW AF power pentode, 25 resp. 50 mA filament with suppressor grid tied to center-tap, Miniature 7-pin base
3C6 = Philco XXB – Medium-μ dual triode, 50 resp. 100 mA filament, Loctal base
3E5 – 200 mW AF beam power pentode, 25 resp. 50 mA filament with beam plates tied to center-tap, Miniature 7-pin base
3E6 – Sharp-cutoff pentode, 50 resp. 100 mA filament with internal shield tied to center-tap, Loctal base
3LE4 – 325 mW AF power pentode, 25 resp. 50 mA filament with suppressor grid tied to center-tap, Loctal base
3LF4 – 3Q5-GT/DL33 with a Loctal base
3Q4/DL95 – 270 mW AF power pentode, 25 resp. 50 mA filament with suppressor grid tied to center-tap, Miniature 7-pin base
3Q5-GT/DL33 – 330 mW AF beam power pentode, 50 resp. 100 mA filament with beam plates tied to center-tap, Octal base
3S4/DL92 – 1S4/DL91 AF power pentode with the suppressor grid tied to the center-tap of the 50 resp. 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 – 3Q4/DL95 AF power pentode with a different Miniature 7-pin base pinout; ruggedized version: 3V4-WA
3AT2 – Compactron CRT EHT rectifier for analog color TV receivers, half-indirect 3.15 V/220 mA heater
3AT2B – 3AT2 with internal X-radiation shielding
3AW2 – Compactron CRT EHT rectifier for analog color TV receivers, half-indirect 3.15 V/350 mA heater
3AW2A – 3AW2 with internal X-radiation shielding
3BF2 - Compactron CRT EHT rectifier for analog color TV receivers, indirect 3.6 V/225 mA heater
3BL2 – Compactron CRT EHT rectifier for analog color TV receivers, 3.3 V/285 mA filament
3BL2A – 3BL2 with internal X-radiation shielding
3BM2 – Compactron CRT EHT rectifier for analog color TV receivers, 3 V/300 mA filament
3BM2A – 3BM2 with internal X-radiation shielding
3BN2 – Compactron CRT EHT rectifier for analog color TV receivers, half-indirect 3.15 V/300 mA heater
3BN2A – 3BN2 with internal X-radiation shielding
3BS2 – Compactron CRT EHT rectifier for analog color TV receivers, half-indirect 3.15 V/480 mA quickstart heater
3BS2A, 3BS2B – 3BS2 with internal X-radiation shielding
3BT2 – Compactron CRT EHT rectifier for analog color TV receivers, 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 analog color TV receivers, 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 analog color TV receivers, Octal base, half-indirect 3.6 V/225 mA heater
3CN3 – CRT EHT rectifier with a diffusion-bonded cathode for analog color TV receivers, Octal base, half-indirect 3.15 V/480 mA quickstart heater
3CU3 – CRT EHT rectifier for analog color TV receivers, Octal base, 3.15 V/280 mA filament
3CZ3 – CRT EHT rectifier for analog color TV receivers, Octal base, half-indirect 3.15 V/480 mA quickstart heater
3DA3 – CRT EHT rectifier, 3.15 V/480 mA heater, Octal base
3DB3/3CY3 – CRT EHT rectifier, 3.15 V/245 mA heater, Octal base
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
4A6-G – Directly heated, dual power triode, center-tapped 4.0 V/60 mA resp. 2.0 V/120 mA filament, Octal base
These tubes all have a 6.3 V filament/heater. Note: 6-prefix tubes with center-tapped heaters are listed under 300 mA series heater tubes
6A3 – 15 W AF Power triode, 1 A heater, UX4 base
6A4 = Raytheon LA (Commonly branded 6A4/LA) – Directly heated power pentode, 300 mA filament with suppressor grid internally tied to a center-tap, UY5 base
6A5-G – 15 W Power triode, 1 A heater with cathode internally tied to a center-tap, Octal base
6A6 – 2×5.5 W Dual power triode used as a Class-A audio driver or a Class-B audio output, U7B base; 6.3 V/800 mA heater version of type 53 which had a 2.5 V/2 A heater; Octal version: 6N7
6A7 (U7A base), 6A7S (U7A base with external shield tied to cathode), 6A8-G/PH4 (Octal base), 6A8-GTX (Ceramic base) – Remote-cutoff heptode pentagrid converter with British grid topology and control (#4) grid on top cap; 2A7, 12A8 with a 6.3 V/800 mA heater; Loctal version: 7B8; similar to M-OV/GEC X63
6B3 – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, Noval base with cathode on top cap
6B4-G – 15 W Power triode, 1 A heater, Octal base
6B5 (U6A base), 6N6-G (Octal base) – Triple-Twin AF signal + 4-watts zero bias power triode, internally connected as a cathode follower like today's Darlington transistors, 800 mA heater; cf. 295, 2B6, 6AC6
6B6-G – Dual diode + high-μ triode, grid on top cap, 300 mA heater; type 75 with an Octal base, later 6SQ7 (without control grid top cap); Miniature 7-pin version: 6AV6/EBC91
6B7 (U7A base), 6B8, 6B8-G, 6B8-GT (Octal base) – Dual diode + semiremote-cutoff pentode with control grid on top cap. The diodes were mostly 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-G 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;[110] 2B7 with a 6.3 V/300 mA heater; similar to EBF32
6B10 – Compactron Dual diode + medium-μ dual triode used as horizontal phase detector and horizontal oscillator, 600 mA heater
6C5, 6C5-G, 6C5-GT – Triode, 300 mA heater, 6-pin Octal base
6C6 (U6A base), 6J7-G/EF37 (Octal base) – Dual-control, sharp-cutoff RF pentode used as tuned RF amplifier or biased detector or AF amplifier, also used in test equipment, 300 mA heater, control grid on top cap; derived from type 57, which had a 2.5 volt heater; similar to types 1603, 77 and Octal type 6SJ7 (control grid on pin 4)
6C7 – Dual diode + medium-μ triode used as renewal type for Majestic receivers, 300 mA heater, U7A base with shield on pin 3 and grid on top cap; similar to later Octal types 6R7 and 6SR7
6C8-G – Dual triode, 300 mA heater, Octal base with one control grid on top cap
6C9 – VHF Dual tetrode, 400 mA heater, B10G Decar base (=Noval plus center pin)
6C10 – Compactron Triple high-μ triode, 600 mA heater – not related to the Mazda/EdiSwan 6C10 triode-hexode
6D4 – 25 mAavg, 100 mApeak Indirectly heated, Argon triode thyratron, negative starter voltage, 250 mA heater, 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 (U6A base), 6U7-G (Octal base) – Dual-control, remote-cutoff RF pentode used as an IF amplifier or as a mixer, also used in test equipment, control grid on top cap, 300 mA heater; derived from type 58, which had a 2.5 volt heater; similar to types 78, 6K7/EF39 and 6SK7 (control grid on pin 4)
6D7 – Sharp-cutoff pentode; 6C6, 6J7-G with U7A base with shield on pin 5 and control grid on top cap
6D8-G – Heptode pentagrid converter with British grid topology and control (#4) grid on top cap, used in pre-war 6-volt farm radios, 150 mA heater, Octal base; similar to 6A8
6D10 – Compactron Triple high-μ triode used as oscillator, mixer, amplifier or AFCreactance[66] tube, 450 mA heater
6E5 – Top-view, "Magic Eye"-type tuning indicator, U6A base; 6G5/6U5 with a sharp-cutoff driver triode; 2E5 with a 6.3 V/300 mA heater
6E5-M – Top-view, "Magic Eye"-type tuning indicator, 150 mA heater, Miniature 7-pin base; similar to Japanese 6M-E5
6E6 – Dual power triode used in car radios, 600 mA heater, U7A base
6E7 – Remote-cutoff pentode, 300 mA heater; 6D6, 6U7-G with U7A base with shield on pin 5 and control grid on top cap
6E8-G – Triode/hexode oscillator/mixer, 300 mA heater, Octal base with hexode control grid #1 on top cap
6F4 – 1.2 GHz Acorn UHF triode used as an oscillator, 225 mA heater
6F5, 6F5-G, 6F5-GT – High-μ triode, 300 mA heater, Octal base with control grid on top cap, equal to triode section of 6Q7
6F6 (Metal envelope), 6F6-G (Shouldered Tube glass envelope; M-OV/GEC KT63), 6F6-GT (Glass Tubular envelope) – 11 W AF Power pentode, 700 mA heater, Octal base, 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; type 42 with an Octal base
6F7 (U7A base), 6P7-G (Octal base) – Common cathode, medium-μ triode + remote-cutoff pentode used as triode/pentode oscillator/mixer, or as combination IF amplifier (pentode) and AM detector or AF amplifier (triode), 300 mA heater, U7A base with the pentode control grid on top cap
6F8-G – Dual medium-μ triode, 600 mA heater, Octal base with one control grid on top cap; two 6J5 in one envelope
6G5/6U5 (U6A base), 6G5-G/6U5-G (Octal base) – Top-view, "Magic Eye"-type tuning indicator; 6E5 with a remote-cutoff driver triode; 2G5 with a 6.3 V/300 mA heater
6G6-G – 2.75 W Power pentode used in pre-war 6-volt farm radios, 150 mA heater, Octal base; Miniature 7-pin version: 6AK6
6G8-G – Dual diode + remote-cutoff pentode used as detector and first AF amplifier in Australian 1940s radios, 300 mA heater, Octal base with control grid on top cap
6G11 – Compactron Dual-control, sharp-cutoff pentode + 6.5-watts beam power pentode used as FM quadrature demodulator and AF power amplifier, 1.2 A heater
6H4-GT – 100 V/4mA Diode, 150 mA heater, 5-pin Octal base
6H5 – Top-view, "Magic Eye"-type tuning indicator, 300 mA heater, U6A base; 6G5/6U5 with an extra grid tied to the cathode and a fixed 90° shadow oppopsite the controllable one
6H6 = 6Х6С↦6H6S ("Stubby" metal envelope), 6H6-G, 6H6-GT (Glass envelope) – Dual diode, 300 mA heater, Octal base; similar to EB34, M-OV/GEC D63, RFT HF/OSW3109
6H7S – Triode + power pentode with a metal particles spray-shielded envelope, 500 mA heater, U7A base with triode control grid on top cap
6H8-G – Common cathode dual diode + pentode, 300 mA heater, Octal base with control grid on top cap
6J4/EC98 = 6С2П↦6S2P – UHF triode used in grounded-grid amplifiers, 400 mA heater, Miniature 7-pin base; ruggedized version: 6J4-WA/8532
6J5 (Metal envelope), 6J5-G (Shouldered Tube glass envelope), 6J5-GT = 6С2С↦6S2S (Glass Tubular envelope), 6J5-GTX (Ceramic base) – Medium-μ triode; 12J5-GT with a 6.3 V/300 mA heater; similar to M-OV/GEC L63; avionics version: 6J5-WGT
6J6/ECC91 – 600 MHz Dual VHF triode with common cathode, 450 mA heater, Miniature 7-pin base; ruggedized versions: 6J6-W, 6J6-WA, 6J6L/6927, 6030
6J7, 6J7-G/EF37, 6J7-GT, 6J7-GTX (Ceramic base) – See 6C6
6J8-G, 6J8-GA – Triode/heptode oscillator/mixer, 300 mA heater, Octal base with heptode control grid #1 on top cap
6J9 – Triple VHF triode used as Autodyne mixer in FM tuners, 450 mA heater, B10G Decar base (=Noval plus center pin 10 for cathodes 1 and 2)
6J10/6Z10 – Compactron Dual-control pentode + 10-watts power pentode used as FM quadrature demodulator and AF power amplifier, 950 mA heater; similar to 6AD10
6J11 – Compactron Dual sharp-cutoff IF pentode, 800 mA heater
6K5-G, 6K5-GT – High-μ triode, 300 mA heater, 7-pin Octal base with grid on top cap
6K6-G, 6K6-GT – 8.5 W Power pentode, 400 mA heater; type 41 with an Octal base
—Single-ended Class-A circuit: 0.35 to 4.5 watts
—Push-pull Class-A circuit: 10.5 watts max.
6K7, 6K7-G/PF9 (EF39), 6K7-GT, 6K7-GTX (Ceramic base) – Dual-control, remote-cutoff RF pentode, 300 mA heater, 7-pin Octal base with control grid on top cap. Most common commercial uses were as an IF amplifier or as a superheterodyne mixer. Also used in test equipment; type 78 with an Octal base, later 6SK7 (control grid on pin 4)
6K8, 6K8-G, 6K8-GT, 6K8-GTX (Ceramic base) – Triode/hexode oscillator/mixer introduced in 1938, Octal base with hexode control grid #1 on top cap; 12K8 with a 6.3 V/300 mA heater
6K11/6Q11 – Compactron 2× High-μ + 1× medium-μ triple triode used as a combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, 600 mA heater
6L4 – Acorn UHF triode used as an oscillator, 225 mA heater
6L5-G – Medium-μ triode available only in ST envelope, 150 mA heater, 6-pin Octal base; similar to 6J5-G
6L6 (Metal envelope), 6L6-G (Shouldered Tube glass envelope; EL37), 6L6-GT* (Glass Tubular envelope) – AF Beam power tetrodes, 900 mA heater, Octal base The original types 6L6 and 25L6 were derived from the M-OV/GEC N40 and introduced in April 1936 as the first American-made, commercially available 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).There are variants with e.g. thicker and/or ultra-black coated anode sheets, grids of larger diameter wire and/or with cooling fins; all variants up to revision A have the same maximum output ratings:
—Single-ended Class-A circuit: 11.5 watts
—Push-pull Class-A circuit: 14.5 watts
—Push-pull Class-AB1 circuit: 34 watts
—Push-pull Class-AB2 circuit: 60 watts
6L6-GA – Post-war version of 6L6-G, smaller Shouldered Tube ST-14 shaped envelope
6L6-GAY – 6L6-GA with a Micanol base for improved RF performance
6L6-WGA/5932 – Ruggedized version of 6L6-GA
6L6-GB – Post-war upgraded version in a cylindrical glass envelope; similar to 5881
6L6-GTB – 6L6 with a Glass Tubular envelope and a higher power rating; the 6L6-GTB can always replace the 6L6, 6L6-G, and 6L6-GT, but a 6L6-GTB running at maximum rating should not be replaced with a lower subvariant
6L6-WGB – Ruggedized version of 6L6-GB
6L6-GC – Final and highest-powered audio version of the tube. Max. output ratings:
—Single-ended Class-A circuit: 17.5 watts
—Push-pull Class-A circuit: 32 watts
—Push-pull Class-AB1 circuit: 55 watts
—Push-pull Class-AB2 circuit: 60 watts
6L6-GX – Class-C oscillator/amplifier used in transmitters, low loss ceramic base for improved RF performance, max. output 30 watts
6L7, 6L7-G – Remote-cutoff heptode pentagrid converter with American grid topology but control (#1) grid on top cap (requiring a separate oscillator – usually 6C5 – on the #3 grid), popular in late 1930s console radios, 300 mA heater, Octal base. Because of low conversion transconductance, radios using 6L7 typically have at least two IF amplifiers and/or a tuned RF pre-amplifier
6M3 – CRT horizontal deflection output booster/damper/efficiency diode, 3 A heater, Octal base with cathode on top cap
6M5/EL80 – 9 W AF power pentode used as Class-A or AB output amplifiers of 1950s Australian radiograms, 710 mA heater, Noval base; similar to 6BQ5/EL84
6M6-G – Power pentode, 1.2 A heater, Octal base
6M7-G – Remote-cutoff RF pentode with a metal particles spray-shielded envelope, 300 mA heater, Octal base with control grid on top cap
6M8-GT – Common cathode diode + AF triode + RF/IF pentode, 600 mA heater, Octal base with pentode control grid on top cap
6M11 – Compactron Dual triode + IF pentode, 750 mA heater
6N3/EY82 – 850 V, 360 mA Half-wave rectifier, 900 mA heater, Noval base
6N4 – UHF Triode, 200 mA heater, Miniature 7-pin base
6N7, 6N7-G, 6N7-GT = 6Н7С↦6N7S – 2×5.5 W Dual power triode used as Class-A audio driver or as Class-B power output, 800 mA heater, max. output (Class-B): 10 watts; 6A6 with an Octal base
6N8/EBF80 – Dual diode + remote-cutoff pentode used as detector plus RF or AF amplifier in radios, 300 mA heater, Noval base
6P5-G/GT – Medium-μ triode, 300 mA heater, often used as cathode follower driver for the 6AC5-G zero bias power triode; type 76 with an Octal base
6R3/EY81 – 4.5 kV, 150 mA CRT horizontal deflection output booster/damper/efficiency diode, 810 mA heater, Noval base with cathode on top cap
6R4/EC81 – UHF oscillator triode, 175 mA heater, Noval base
6R6-G – Remote-cutoff pentode, 300 mA heater, Octal base with control grid on top cap
6R7, 6R7-G, 6R7-GT – Dual diode + medium-μ triode, μ = 16, 300 mA heater, Octal base with control grid on top cap; Miniature 7-pin version: 6BF6
6R8 – Triple diode + low-μ triode used as AM/FM demodulator and AF amplifier, 450 mA heater, Noval base
6S2/EY86 – 22 kV, 800 µA Half-indirectly heated CRT EHT rectifier, Noval base with anode on top cap; 1S2/DY86 with a 6.3 V/90 mA heater
6S2A/EY87 – 6S2/EY86 variant for operation at high altitudes with a silicone-coated envelope to prevent flush-over in high-humidity and low atmospheric-pressure conditions; 1S2A/DY87 with a 6.3 V/90 mA heater
6S4, 6S4A – Medium-μ triode used as CRT vertical deflection amplifier, 600 mA heater, Noval base
6S5 – Tuning indicator, 300 mA heater, U6A base
6S6-GT – Remote-cutoff RF pentode, 450 mA heater, 7-pin Octal base with control grid on top cap
6S7, 6S7-G – Remote-cutoff RF pentode used in pre-war 6-volt farm radios, 150 mA heater, Octal base with control grid on top cap; similar to 6D6, 6K7
6S8-GT – Triple diode + high-μ triode sharing a cathode with two of the diodes, used as a combined AM detector/AVC rectifier/FM ratio detector/AF amplifier in AM/FM radios, 300 mA heater, Octal base with triode grid on top cap. Typically, all sections of this tube are arranged around a single heater
6T4 – Low-μ triode used as UHF oscillator, 225 mA heater, Miniature 7-pin base
6T5 – Top-view, "Magic Eye"-type tuning indicator with a remote-cutoff driver triode, 300 mA heater, U6A base; 6G5/6U5 with a ring-shaped indicating area that varies its inner diameter with the signal strength
6T6-GM – RF Pentode, 450 mA heater, Octal base with control grid on top cap
6T7-G – Dual diode + high-μ triode used in pre-war farm radios, 150 mA heater, Octal base with control grid on top cap; similar to 6Q7
6T8, 6T8A – 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 North American AM/FM radios, triode μ = 70, 450 mA heater, Noval base; 6AK8/EABC80 with a shorter glass envelope
6T9 – Compactron Triode + 12-watts power pentode, 930 mA heater
6T10 – Compactron Dual-control, sharp-cutoff pentode + 10-watts power pentode used as FM quadrature demodulator and AF power amplifier, 950 mA heater
6TE8-GT – Triode/hexode oscillator/mixer, 300 mA heater, Octal base
6U3/EY80 – CRT horizontal deflection output booster/damper/efficiency diode, 900 mA heater, Noval base
6U4-GT – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, 5-pin Octal base
6U8/ECF82, 6U8A – VHF Triode/pentode oscillator/mixer also used as audio preamplifier, 450 mA heater, Noval base
6U9/ECF201 – Triode + remote-cutoff pentode used as CRT vertical deflection oscillator or combined sync sep/clipper/amplifier/phase detector, and video-IF amplifier, Decal base; 5U9/LCF201 or 8U9/PCF201 with a 6.3 V/410 mA heater
6V3, 6V3A – CRT horizontal deflection output booster/damper/efficiency diode, 1.75 A heater, Noval base with cathode on top cap
6V4/EZ80 – 1 kV, 2×45 mA Full-wave rectifier, 600 mA heater, Noval base
6V5-GT – 12 W Beam power tetrode, half-indirect 450 mA heater, Octal base
6V6 (Metal envelope), 6V6-G (Shouldered Tube glass envelope), 6V6-GT, 6V6-GTA (Glass Tubular envelope) – 12 W Beam power tetrode used in single-ended Class-A audio output amplifiers of radios and sometimes seen in Class-B audio amplifiers; 5V6 or 12V6 with a 6.3 V/450 mA heater; electrically similar to 6AQ5/EL90; ruggedized version: 6V6S
6V7-G – Dual diode + medium-μ triode, μ = 8.3, 300 mA heater; similar to 6R7-G; type 85 with an Octal base and grid on top cap
6W2 – Subminiature CRT EHT rectifier, anode on top wire, half-indirect 80 mA heater
6W4-GT, 6W4-GTA – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, 5-pin Octal base
6W5-G – Full-wave rectifier, 900 mA heater, 6-pin Octal base
6W6-GT – 10 W Beam power pentode used as CRT vertical deflection amplifier in 1950s monochrome TV receivers or as an audio output tube; 12L6-GT or 25L6-GT or 50L6-GT with a 6.3 V/1.2 A heater
6W7-G – Pentode, 150 mA heater, 7-pin Octal base with control grid on top cap
6X2/EY51 – 17 kV, 3 mA CRT EHT rectifier, half-indirect 90 mA heater, wire-ended
6X4/6BX4/EZ90 = 6Ц4П↦6C4P (Miniature 7-pin base) and 6X5/EZ35, 6X5-G, 6X5-GT (6-pin Octal base) – 1.25 kV, 2×210 mA Full-wave rectifiers, 600 mA heater; derived from type 84/6Z4; ruggedized versions: 6X4-W, 6X4-WA, 6X4-WS, 6X5-WGT
6X6-G – Tuning indicator, 300 mA heater, Octal base
6X8, 6X8A – Medium-μ triode + sharp-cutoff pentode used as VHF oscillator/mixer, 450 mA heater, Noval base
6X9/ECF200 – Triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and audio-IF or video amplifier, 410 mA heater, Decal base
6Y3-G – 5 kV CRT EHT rectifier, half-indirect 700 mA heater, Octal base
6Y5 – Full-wave rectifier, 800 mA heater; similar to type 84/6Z4, but with U6A base with shield on pin 2
6Y6-G, 6Y6-GA, 6Y6-GT – 12.5 W AF Beam power pentode, 1.25 A heater, 7-pin Octal base
6Y7-G – 11.5 W Dual power triode, 600 mA heater; 79 with an Octal base
6Y9/EFL200 – Pentode + 5-watts power pentode used as audio-IF amplifier or combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and CRT cathode driver, 800 mA heater, Decal base
6Y10 – Compactron Dual-control, sharp-cutoff pentode + 4.8-watts power pentode used as FM quadrature demodulator and AF power amplifier, 830 mA heater
6AB4/6664/EC92 – High-μ triode, single ECC81/12AT7 system, 150 mA heater, Miniature 7-pin base
6AB5/6N5 – Top-view, "Magic Eye"-type tuning indicator with a sharp-cutoff driver triode, 150 mA heater, U6A base
6AB6-G – Triple-Twin AF signal + zero bias power triode internally connected as a cathode follower, 500 mA heater, U6A base; low-power variant of the 6B5 used in car radios
6AB7/1853 – Semiremote-cutoff RF/IF pentode, 450 mA heater, Octal base
6AB8/ECL80 – Triode + 3.5-watts power pentode, 300 mA heater, Noval base
6AB9 – Dual VHF tetrode, 365 mA heater, Decal base
6AC5-G = CV844 – 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, 400 mA heater, Octal base; cf. 295, 2B6, 6AC6, 6B5, 6N6-GTriple-TwinDarlington triodes
6AC6-G, 6AC6-GT – Triple-Twin AF signal + zero bias power triode with a common, single anode, internally connected as a cathode follower, 1.1 A heater, Octal base
6AC7 = 1852 – Sharp-cutoff RF pentode used in analog TV receivers, 450 mA heater, Octal base (not to be confused with the 6CA7/EL34)
6AC9 – Compactron Dual diode + pentode used as IF amplifier and phase detector, 600 mA heater
6AD5-G – High-μ triode used as driver for electrostatic CRT deflection plates, 300 mA heater, Octal base
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 150 mA heater and an Octal baseBoth 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
6AD7-G – Triode + 8.5-watts power pentode, 850 mA heater, Octal base
6AD8/EBF81 – Common cathode dual diode + remote-cutoff RF/IF/AF pentode, 300 mA heater, Noval base
6AE5-G, 6AE5-GT – Low-μ triode, 300 mA heater, 6-pin Octal base
6AE6-G – Split-anode driver triode for tuning indicators 6AD6-G and 6AF6-G, 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 used as a cathode follower driver for two push-pull zero bias power triodes such as 6AC5, 500 mA heater; cf. 295, 2B6, 6AC6, 6B5, 6N6-GTriple-Twin Darlington triodes
6AE8 – Triode/hexode oscillator/mixer, 300 mA heater, Noval base
6AF3 – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, Noval base with cathode on top cap
6AF4/EC94, 6AF4A/6DZ4 – Medium-μ UHF oscillator triode used in analog TV tuners and set-top converters, 225 mA heater, Miniature 7-pin base
6AF5-G – Triode, 300 mA heater, 6-pin Octal base
6AF7-G – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator, 300 mA heater, Octal base
6AF9 – Dual dissimilar pentode used as sound IF amplifier or combined sync sep/clipper/amplifier/phase detector or phase inverter/splitter/comparator or gated AGC DC voltage amplifier/keyer/noise inverter, and CRT cathode driver, 850 mA heater, Decal base
6AG6-G – 10 W Power pentode, 1.2 A heater, Octal base
6AG7/6AK7 – 9 W Power pentode used as CRT cathode driver, 650 mA heater, Octal base
6AG9 – Compactron Medium-μ triode + frame-grid pentode used as gated AGC amplifier/keyer/noise inverter, and video amplifier in analog color TV receivers, 820 mA heater
6AH4-GT – Medium-μ triode, 750 mA heater, 6-pin Octal base
6AH5-G – 18.5 W Beam power tetrode for early TV use in some Philco receivers, 900 mA heater, Octal base; 6L6-G with a different pinout
6AH6, 6AH6S (external shield tied to cathode) – Wideband, sharp-cutoff IF pentode, 450 mA heater, Miniature 7-pin base; avionics version: 6AH6-WA
6AH7-GT – Dual triode, 300 mA heater, Octal base
6AH9 – Compactron Medium-μ triode + sharp-cutoff frame-grid pentode used as video amplifier and color blanker in analog color TV receivers, 900 mA heater
6AJ4/EC84 – High-μ triode, 225 mA heater, Noval base
6AJ5 (7755, 414A) – Low (6.3-80 V) anode voltage, sharp-cutoff pentode, 175 mA heater, Miniature 7-pin base
6AJ7 – Pentode, 450 mA heater, Octal base
6AJ8/ECH81 – Triode/remote-cutoff heptode oscillator/mixer, 300 mA heater, Noval base
6AK5/EF95/6069 = 6Ж1П↦6J1P – 400 MHz Sharp-cutoff pentode used in old Radiosonde weather balloon transmitters, receiver front ends and contemporary audio equipment, 175 mA heater, Miniature 7-pin base; avionics versions: 6AK5-W/5654/6096/E95F, 6028/408A, CV4010
6AK6 – 2.75 W Power pentode, unusual low-power consumption output tube with 150 mA heater; 6G6-G with a Miniature 7-pin base; ruggedized version: 6AK6S
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, 450 mA heater, Noval base, triode μ = 70; 6T8 with a longer glass envelope
6AK9 – Compactron high-μ triode + medium-μ triode + 10-watts beam power pentode, 1.6 A heater
6AK10 – Compactron Triple high-μ triode used as NTSC chroma signal demodulator matrix in analog color TV receivers, 900 mA heater
6AL3/EY88 = 6Д20П↦6D20P – 6 kV, 220 mA CRT horizontal deflection output booster/damper/efficiency diode, 1.55 A heater, Noval base with cathode on top cap
6AL5/EAA91 = M-OV/GEC D77 = 6Х2П↦6H2P – Dual diode with separate cathodes used as detector, also in vacuum tube volt meters; 6H6 with a Miniature 7-pin base; 12AL5/HAA91, UAA91 or 3AL5/XAA91 with a 6.3 V/300 mA heater; avionics versions: 6AL5-W/5726/6097/E91AA
6AL6-G – 18.5 W Beam power tetrode for early TV use, 900 mA heater, Octal base; 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, 150 mA heater, Octal base
6AL11 – Compactron Dual-control, sharp-cutoff pentode + 10-watts beam power pentode used as FM quadrature demodulator and AF power amplifier, 900 mA heater
6AM4 – High-μ UHF triode used as grounded-grid amplifier, 225 mA heater, Noval base
6AM5/EL91 – 4 W Power pentode, 200 mA heater, Miniature 7-pin base
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, 300 mA heater, Miniature 7-pin base; ruggedized version: 6AM6S
6AM8, 6AM8A – Diode + sharp-cutoff pentode used as video detector and IF amplifier, 450 mA heater, Noval base
6AN4 – High-μ triode used as UHF mixer or amplifier, 225 mA heater, Miniature 7-pin base
6AN8, 6AN8A – Triode + pentode used as combined sync sep/clipper/amplifier/phase detector or phase inverter/splitter/comparator or gated AGC amplifier/keyer/noise inverter, and reactance tube or IF amplifier, 450 mA heater, Noval base
6AQ4/EC91 – 250 MHz VHF triode, 300 mA heater, Miniature 7-pin base
6AQ5/EL90, 6AQ5A/6669 (12 W, tolerant to vehicle heater voltage fluctuations), 6BM5 (9 W), 6HG5 (12 W), 6HR5 – Beam power pentodes used as CRT vertical deflection or audio power amplifier, 450 mA heater; 6CM6 = 6П1П↦6P1P with a Miniature 7-pin base; similar to 6V6; ruggedized versions: 6AQ5L/6928 (long life), 6AQ5-W/6005
6AQ6 – Dual diode + high-μ AF triode, 150 mA heater, Miniature 7-pin base
6AQ7-GT – Dual diode + high-μ triode, 300 mA heater, Octal base
6AQ8/ECC85 – 200 MHz Dual RF/VHF triode used as oscillator/mixer (the heater to cathode insulation is inadequate for use in cascode operation) in FM receivers, separate cathodes, internal shield between the two sections, 435 mA heater, Noval base; similar to 6BK7, 6BQ7, 6BZ7
6AR5 – 8.5 W Power pentode, 400 mA heater, Miniature 7-pin base
6AR6 – 19 W Beam power pentode, 1.2 A heater, 6-pin Octal base; avionics versions: 6AR6-WA/6098, 6384
6AR7-GT – Dual diode + remote-cutoff pentode, 300 mA heater, Octal base
6AR11 – Compactron Semiremote-cutoff dual IF pentode, 800 mA heater
6AS5 – 5.5 W AF Beam power pentode, 800 mA heater, Miniature 7-pin base
6AS6 = Western Electric 409A = 6Ж2П↦6J2P – Dual-control pentode used e.g. in radar phantastron circuits, 175 mA heater, Miniature 7-pin base; similar to EF80; avionics version: 6AS6-W/5725/6187
6AS7 = 6Н5С↦6N5S, 6AS7-G/ECC230 = 6Н13С↦6N13S (6080), 6AS7-GYB (Micanol base) – 13 W Dual low impedance, low-μ triode designed as series-pass regulator in stabilized DC power supplies, 2.5 A heater, Octal base
6AS8 – High-perveance diode + sharp-cutoff pentode used as audio/video detector or gated AGC amplifier/keyer/noise inverter or DC restorer and IF or video amplifier, 450 mA heater, Noval base
6AU8, 6AU8A – Medium-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector and IF or video amplifier, 600 mA heater, Noval base
6AV4/EZ91 – 1 kV, 2×45 mA Full-wave rectifier, 950 mA heater, Miniature 7-pin base
6AV5-GA, 6AV5-GT – 11 W Beam power pentode used as CRT horizontal deflection amplifier, 1.2 A heater, Octal base
6AV6/EBC91 – Common cathode dual diode + high-μ AF triode used in FM ratio detectors, triode μ = 100 (triode section similar in characteristics to one half of a 12AX7/ECC83), 300 mA heater; type 75 with a Miniature 7-pin base
6AV11 – Compactron Triple medium-μ triode, 600 mA heater
6AW7-GT – Dual diode + triode, 300 mA heater, Octal base
6AW8, 6AW8A – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector and video amplifier, 600 mA heater, Noval base
6AX4, 6AX4-GTA, 6AX4-GTB – 4.4 kV, 137 mA CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, 6-pin Octal base
6AX5 – 1.25 kV, 2×375 mA Full-wave rectifier, 1.2 A heater, Octal base; similar in structure to 6X5, but with higher voltage and current ratings which are comparable to those of 5Y3 and 80
6AX6-G – Dual rectifier with separate cathodes, 2.5 A heater, 7-pin Octal base
6AX8 – Medium-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector and video amplifier, 450 mA heater, Noval base
6AY3, 6AY3A, 6AY3B – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, Novar base
6AY11 – Compactron Dual diode + dual high-μ triode used as FM demodulator and AF amplifier, 690 mA heater
6AZ5 – Subminiature dual diode, separate cathodes, 150 mA heater, all-glass round cross-section envelope, circular 8-pin/wire-ends
6AZ6 – Subminiature, ruggedized, dual UHF diode with separate cathodes, 150 mA heater, all-glass round cross-section envelope, circular 8-pin/wire-ends
6AZ8 – Medium-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or phase inverter/splitter/comparator or gated AGC amplifier/keyer/noise inverter and IF or video amplifier, 450 mA heater, Noval base
6BA3 – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, Novar base
6BA8, 6BA8A – Medium-μ triode + sharp-cutoff pentode with controlled anode knee characteristic, used as combined sync sep/clipper/amplifier/phase detector and video amplifier, 600 mA heater, Noval base
6BA11 – Compactron Triode + split-anode pentode used as CRT vertical deflection oscillator and combined sync sep/clipper/amplifier/phase detector, 600 mA heater
6BC4 – Medium-μ RF triode, 225 mA heater, Noval base
6BC5/6CE5 – 400 MHz Semiremote-cutoff VHF pentode, 300 mA heater, Miniature 7-pin base; 6AG5/EF96 with a higher μ
6BC7 – Separate cathodes triple diode, 450 mA heater, Noval base
6BC8 – Dual semiremote-cutoff VHF triode used as cascode amplifier, 400 mA heater, Noval base
6BD4 (20 kV, 20 W), 6BD4A (27 kV, 25 W) – 1.5 mA Beam power triode used as EHV shunt regulator in analog color TV receivers, 500 mA heater, 6-pin Octal base with anode on top cap
6BD5-GT – 10 W Beam power pentode used as CRT horizontal deflection amplifier, 900 mA heater, 6-pin Octal base
6BD6 – Remote-cutoff RF/IF pentode, 300 mA heater, Miniature 7-pin base
6BD7/EBC80 – Shielded dual diode + AF triode, 230 mA heater, Noval base
6BE6/EK90 = M-OV/GEC X727 = 6А2П↦6A2P (5750) – Remote-cutoff heptode pentagrid converter with American grid topology, 300 mA heater, Miniature 7-pin base, popular in car radios
6BE8, 6BE8A – VHF Medium-μ triode/sharp-cutoff pentode oscillator/mixer, 450 mA heater, Noval base
6BF5 – 5.5 W Beam power tetrode, 1.2 A heater, Miniature 7-pin base
6BF6 – Dual diode + medium-μ triode, 300 mA heater; 6R7 with a Miniature 7-pin base
6BF7, 6BF7A – Subminiature, separate cathodes dual triode, 300 mA heater, all-glass round cross-section envelope with 8 long inline wire-ends; similar to 6J6/ECC91
6BF8 – Sextuple diode with a common cathode, 450 mA heater, Noval base
6BF11 – Compactron Dual-control, sharp-cutoff pentode + 6.5-watts beam power pentode used as FM quadrature demodulator and AF power amplifier, 1.2 A heater
6BG6 (ST envelope), 6BG6-GA (GT) – 20 W Beam power pentode used in early TV magnetic-deflection horizontal-output amplifiers, 900 mA heater, Octal base; 6L6-G with the anode on top cap
6BH3, 6BH3A – CRT horizontal deflection output booster/damper/efficiency diode, 1.6 A heater, Novar base
6BH5/EF81 – Remote-cutoff RF/IF/video pentode, 200 mA heater, Noval base
6BH6 (7693/E90F, 6265) – Sharp-cutoff RF pentode, 150 mA heater, Miniature 7-pin base
6BH8 – Medium-μ triode + sharp-cutoff pentode used as CRT vertical deflection oscillator or combined sync sep/clipper/amplifier/phase detector, and IF or video amplifier, 600 mA heater, Noval base; 6AU8 with a lower-μ triode
6BJ5 – 9 W Power pentode, 200 mA heater, Miniature 7-pin base
6BJ6, 6BJ6A – Remote-cutoff RF/IF pentode, 150 mA heater, Miniature 7-pin base
6BJ7 – Triple diode used as DC restorer in analog color TV receivers, 450 mA heater, Noval base
6BJ8 – Dual diode + medium-μ triode used as phase inverter/splitter/comparator and CRT vertical deflection amplifier, 600 mA heater, Noval base
6BK4 = 6С20С↦6S20S – 27 kV, 25 W, 1.5 mA Beam power triode used as EHV shunt regulator in analog color TV receivers and in measurement equipment such as high voltage meters, 200 mA heater, Uh-c=-200 V, Octal base with anode on top cap
6BK5 – 9 W Beam power pentode, 1.2 A heater, Noval base
6BK6 – Common cathode dual diode + high-μ AF triode used as detector and AF amplifier, Miniature 7-pin base; 12BK6 or 26BK6 with a 6.3 V/300 mA heater
6BK7, 6BK7A, 6BK7B – Dual RF/VHF triode with separate cathodes and an internal shield between the two sections, 450 mA heater; similar to 6AQ8/ECC85, 6BQ7, 6BZ7
6BM6 – 150 mW, 0.55-3.8 GHz Reflex Klystron, 650 mA heater, 4-pin PeeWee base with external-cavity contact rings and top cap; CW-only variant of 6BM6A/5837
6BM8/ECL82 = 6Ф3П↦6F3P – Triode + pentode used as CRT vertical deflection or AF amplifier and has even been seen in an electronic nerve stimulator, 780 mA heater, Noval base
6BN4, 6BN4A – Medium-μ VHF triode, 200 mA heater, Miniature 7-pin base
6BN5/EL85 – 6 W, 120 MHz RF/AF power pentode, 200 mA heater, Noval base
6BN6/6KS6 = 6А3П↦6A3P – Gated-beam discriminator pentode used in radar, dual channel oscilloscopes and FM quadrature demodulators 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, Miniature 7-pin base;[111][112] precursor of the Nonode approach; 3BN6, 4BN6, 12BN6 with a 6.3 V/300 mA heater
6BN7 – Dual triode used as CRT vertical deflection oscillator+amplifier, 750 mA heater, Noval base
6BN8 – Dual diode + high-μ triode used as phase/ratio discriminator, AF/burst amplifier or oscillator, 600 mA heater, Noval base
6BN11 – Compactron Dual sharp-cutoff IF pentode, 800 mA heater
6BQ5/EL84 = M-OV/GEC N709 = 6П14П↦6P14P – 5.7 Watts AF power pentode, 760 mA heater, Noval base
6BQ6-G, 6BQ6-GA, 6BQ6-GT – 12 W Beam power pentode used as a horizontal deflection output tube in 1950s monochrome TV receivers 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, 1.2 A heater, Octal base
6BQ6-GTB/6CU6 – Upgraded 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 amplifier, 400 mA heater, Noval base; similar to 6AQ8/ECC85, 6BK7, 6BZ7
6BQ7A/ECC180 – Upgraded 6BQ7 capable of operation at UHF frequencies; similar to 6Н1П↦6N1P
6BR3 = 6RK19 – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, Noval base
6BR5/EM80 – Side-view, fan-type tuning indicator, 300 mA heater, Noval base
6BR7 (Control grid on base), 6BS7 (control grid on top cap) – Low-hum, low-microphonics AF pentode, 150 mA heater, Noval base
6BR8/6FV8, 6BR8A/6FV8A – Medium-μ triode + sharp-cutoff pentode used as CRT vertical deflection oscillator and IF amplifier, 450 mA heater, Noval base
6BS3, 6BS3A – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, Novar base
6BS5 – 12.5 W Beam power tetrode used as AF or CRT cathode driver, or CRT vertical deflection amplifier, 750 mA heater, Noval base
6BS7 – See 6BR7
6BS8 – Medium-μ dual VHF triode used as cascode amplifier, 400 mA heater, Noval base
6BT4/EZ40 – 780 V, 2×45 mA Full-wave rectifier, 600 mA heater, Rimlock base
6BT6 – Dual diode + high-μ triode, 300 mA heater, Miniature 7-pin base
6BT8 – Dual diode + sharp-cutoff pentode used as gated AGC amplifier/keyer/noise inverter, or IF or video amplifier/detector, 450 mA heater, Noval base
6BU4 – 25 kV, 25 W, 1 mA Beam power triode used as EHV shunt regulator in analog color TV receivers, 450 mA heater, Octal base with anode on top cap
6BU5 – 20 kV, 20 W, 1 mA Beam power pentode used as EHV shunt regulator in analog color TV receivers, 150 mA heater, Octal base with anode on top cap
6BU6 – Dual diode + triode, 300 mA heater, Miniature 7-pin base
6BU8/6GS8, 6BU8A, 6HS8, 6LE8, 6MK8 – Split-anode pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, 300 mA heater, Noval base
6BV7 – Dual diode + 10-watts power pentode, 800 mA heater, Noval base
6BV8 – Dual diode + triode, 600 mA heater, Noval base
6BV11 – Compactron Dual sharp-cutoff dual-dontrol pentode used as color demodulator, 900 mA heater
6BZ6 – Sharp-cutoff RF pentode used in 1960s video-IF circuits, 300 mA heater, Miniature 7-pin base
6BZ7 – Dual RF/VHF triode with separate cathodes and an internal shield between the two sections, 400 mA heater, Noval base; similar to 6AQ8/ECC85, 6BK7, 6BQ7
6BZ8 – Dual medium-μ VHF triode, 400 mA heater, Noval base
6CA4/EZ81 – 1 kV, 2×450 mA Full-wave rectifier, 1 A heater, Noval base
6CA7/EL34 = 6П27С↦6P27S – 25 W AF power pentode, 1.5 A heater, Octal base
6CA11 – Compactron Dual high-μ triode + frame-grid, sharp-cutoff video pentode, 1.02 A heater
6CB5 (ST envelope, 23 W), 6CB5A (GT, 26 W) – Beam power pentode used as CRT horizontal deflection amplifier, 2.5 A heater, Octal base
6CB6, 6CB6A/6CF6/6676/EF190 – Sharp-cutoff RF pentode used in 1950s and early 1960s video-IF circuits, 300 mA heater, Miniature 7-pin base
6CD6-G (ST envelope, 15 W), 6CD6-GA (GT, 20 W) – Beam power pentode used as CRT horizontal deflection amplifier, 2.5 A heater, Octal base with anode on top cap
6CD7/EM34 – Dual-sensitivity, top-view, "Magic Eye"-type tuning indicator, 200 mA heater, Octal base
6CG6 – Remote-cutoff pentode, 300 mA heater, Miniature 7-pin base
6CG7/6FQ7 (7026) – Dual triode used in analog TV receivers and some audio amplifiers including modern solid-state designs, often as a cathode follower, 600 mA heater; 6SN7 with a Noval base
6CG8, 6CG8A – Medium-μ triode + sharp-cutoff pentode used as VHF oscillator/mixer, 450 mA heater, Noval base
6CH3/6CJ3 – CRT horizontal deflection output booster/damper/efficiency diode, 1.8 A heater, Novar base
6CH6/EL821 (6132) – 12 W Power pentode used as CRT cathode driver in high definition television equipment, 750 mA heater, Noval base
6CH7 – Medium-μ dual RF triode used as cascode amplifier, 400 mA heater, Noval base
6CH8 – Medium-μ triode + sharp-cutoff pentode, 450 mA heater, Noval base
6CJ3 – See 6CH3
6CJ5/EF41 – Remote-cutoff RF/IF pentode, 200 mA heater, Rimlock base
6CJ6/EL81 – 8 W Power pentode used as CRT horizontal deflection amplifier, 1.05 A heater, Noval base
6CK3/6CL3 – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, Novar base
6CK4 – Low-μ triode used as CRT vertical deflection amplifier, 1.25 A heater, 6-pin Octal base
6CK5/EL41 – 9 W AF Power pentode, 700 mA heater, Rimlock base
6CK6/EL83 – 9 W Power pentode used as CRT cathode driver, 710 mA heater, Noval base
6CL3 – See 6CK3
6CL6 – 7.5 W Power pentode used as CRT cathode driver, 650 mA heater, Noval base
6CL8, 6CL8A – Medium-μ triode + sharp-cutoff VHF tetrode used as oscillator/mixer, 450 mA heater, Noval base
6CM3 – CRT horizontal deflection output booster/damper/efficiency diode, 2.4 A heater, Novar base
6CM4/EC86 – UHF triode, Noval base; 4CM4/PC86 with a 6.3 V/170 mA heater
6CM5/EL36 = 6П31С↦6P31S – 10 W Beam power tetrode used as AF or CRT horizontal deflection amplifier, 1.25 A heater, Octal base
6CM7 – Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, 600 mA heater, Noval base
6CM8 – High-μ triode + sharp-cutoff pentode, 450 mA heater, Noval base
6CN6/EL38 – 25 W Power pentode used as CRT horizontal deflection amplifier, 1.4 A heater, Octal base
6CQ4/6DE4 – CRT horizontal deflection output booster/damper/efficiency diode, 1.6 A heater, Octal base
6CQ6/EF92 (6CQ6S) – Remote-cutoff RF pentode, 200 mA heater, Miniature 7-pin base
6CQ8 – Medium-μ triode + sharp-cutoff tetrode used as VHF oscillator/mixer, 450 mA heater, Noval base
6CR4 = M-OV/GEC A2521 – grounded-grid UHF triode used as cascode amplifier, 370 mA heater, Noval base
6CR5 – 11 W Beam power tetrode used as CRT horizontal deflection amplifier, 1.2 A heater, Noval base
6CR6 – Diode + remote-cutoff pentode, 300 mA heater, Miniature 7-pin base
6CR8, 6CS8 (Different pinout) – Triode + IF pentode, 450 mA heater, Noval base
6CS5 – 11 W AF Beam power pentode, 1.2 A heater, Noval base; similar to 6W6-GT
6CS6/EH90 – Sharp-cutoff heptode with American grid topology, used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, 300 mA heater, Miniature 7-pin base
6CS7 – Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, or in tube audio amplifiers, 600 mA heater, Noval base
6CT3 – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, Noval base
6CT7/EAF42 – Diode + remote-cutoff RF/IF/AF pentode, 200 mA heater, Rimlock base
6CU5 – 7 W AF Beam power pentode, 1.2 A heater, Miniature 7-pin base
6CU7/ECH42 – Triode/remote-cutoff hexode oscillator/mixer, 230 mA heater, Rimlock base
6CU8 – Medium-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and IF or video amplifier, 450 mA heater, Noval base
6CV7/EBC41 – Shielded common cathode dual diode + AF triode, 230 mA heater, Rimlock base
6CW5/EL86 – 12 W AF Beam power pentode, 760 mA heater, Noval base
6CX7 – Medium-μ dual triode, 400 mA heater, Noval base
6CX8 – Medium-μ triode + sharp-cutoff pentode used as CRT deflection oscillator or amplifier and video amplifier, 750 mA heater, Noval base
6CY5/7717 (6CY5/CATV) – Sharp-cutoff VHF tetrode, 200 mA heater, Miniature 7-pin base
6CY7 – Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, 750 mA heater, Noval base
6CW4 – Nuvistor High-μ VHF triode, 135 mA heater, most common one in consumer electronics
6CZ5 (6973) – 10 W Beam power pentode used as CRT vertical deflection or audio amplifier, 450 mA heater, Noval base
6DA4/6DM4, 6DA4A/6DM4A – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, 5-pin Octal base
6DA5/EM81 – Tuning indicator, 300 mA heater, Noval base; 6BR5/EM80 with 25% greater sensitivity
6DA6/EF89 – RF Pentode used in AM/FM radios manufactured outside North America, 200 mA heater, Noval base
6DA7 – Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, 1 A heater, Noval base
6DB5 – 10 W Beam power tetrode, 1.2 A heater, Noval base
6DC6 – Semiremote-cutoff pentode, 300 mA heater, Miniature 7-pin base
6DC8/EBF89 – Common cathode dual diode + semiremote-cutoff RF/IF pentode, 300 mA heater, Noval base
6DE6 – Sharp-cutoff IF pentode, 300 mA heater, Miniature 7-pin base
6DE7 – Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, 900 mA heater, Noval base
6DG6-GT – 10 W AF Beam power pentode, 1.2 A heater, Octal base
6DG7 – Remote-cutoff RF/IF pentode, 300 mA heater, Noval base
6DH7/6FG6/EM84 = 6Е3П↦6Ye3P – Side-view, band-type tuning/level indicator, 270 mA heater, Noval base
6DJ8/ECC88 = 6Н23П↦6N23P = Shuguang6N11 (↤6Н11) – Dual VHF triode used as cascode amplifier in TV broadcast equipment, test gear, oscilloscopes and audiophile gear, 365 mA heater, Noval base; similar to 6ES8/ECC189, 6922/E88CC
6DK3 – CRT horizontal deflection output booster/damper/efficiency diode, 1.8 A heater, Novar base with cathode on top cap
6DK6 – Sharp-cutoff IF pentode, 300 mA heater, Miniature 7-pin base
6DL3 – CRT horizontal deflection output booster/damper/efficiency diode, 2.3 A heater, Novar base with cathode on top cap
6DL5/EL95 – 6 W AF Power pentode used in car radios, 200 mA heater, Miniature 7-pin base
6DL7 – Tuning indicator, 300 mA heater, Octal base
6DQ4 – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, 5-pin Octal base
6DQ5 – 24 W Beam power pentode used as CRT horizontal deflection amplifier, 2.5 A heater, Octal base
6DQ6A – 18 W Beam power pentode used as a horizontal deflection output tube in 1950s monochrome TV receivers, mostly those with diagonal screen sizes larger than 17 in (43 cm), 1.2 A heater, Octal base. Smaller receivers often used similar type 6BQ6-GT. Also used as audio output tubes in Standel guitar amplifiers
6DQ6B/6GW6 – 6DQ6 with higher ratings and a higher zero-bias anode current
6DR4 – High-μ triode, 150 mA heater, Miniature 7-pin base; similar to one section of 12AX7/ECC83
6DR6 – 8 W Power pentode, 1.05 A heater, Noval base
6DR7 – Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, 900 mA heater, Noval base
6DR8/EBF83 – Common cathode dual diode + low (6.3-50 V) anode voltage pentode used as IF amplifier, detector and AGC diode in vehicle equipment, 300 mA heater, Noval base
6DS4 – Nuvistor Semiremote-cutoff VHF triode used in analog TV tuners immediately prior to the introduction of solid state tuning circuits (RCA TV receivers equipped with a 6DS4 tuner bore the trademark "Nu-Vista Vision"), 135 mA heater; successor of type 6CW4
6DS5 – 9 W AF Beam power pentode, 800 mA heater, Miniature 7-pin base
6DS8/ECH83 – Low (6.3-25 V) anode voltage, triode/sharp-cutoff heptode oscillator/mixer used in vehicle equipment, 300 mA heater, Noval base
6DV4 – Medium-μ Nuvistor triode for UHF oscillators, 135 mA heater; some variants had a Gold-plated envelope
6DW4, 6DW4A, 6DW4B – CRT horizontal deflection output booster/damper/efficiency diode, 1.2 A heater, Novar base
6DW5 – 11 W Power pentode used as CRT vertical deflection amplifier, 1.2 A heater, Noval base
6DX4 – UHF triode, 200 mA heater, Miniature 7-pin base
6DX8/ECL84 = 6Ф4П↦6F4P – Triode + 4-watts power pentode used as combined sync sep/clipper/amplifier/phase detector, and CRT cathode driver, 720 mA heater, Noval base
6DY4, 6DY4A – UHF frame-grid triode, 125 mA heater, Miniature 7-pin base
6DY5/EL82 – 9 W Power pentode used as CRT vertical deflection or AF amplifier, 800 mA heater, Noval base
6DY7 – 2×15 W Dual AF beam power pentode used in Stereo amplifiers, 1.2 A heater, Octal base
6DZ7 – 2×13.2 W Dual AF power pentode used in Hi-Fi Stereo amplifiers, 1.52 A heater, Octal base
6DZ8 – High-μ AF triode + 6.5-watts AF power pentode, 900 mA heater, Noval base
6EA4 – 27 kV, 30 W, 1.6 mA Compactron Beam power triode used as EHV shunt regulator in analog color TV receivers, 200 mA heater, anode on top cap
6EA5 – Sharp-cutoff tetrode, 200 mA heater, Miniature 7-pin base
6EA7 (6EM7) – Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, 1.05 A heater, Octal base
6EA8 – Medium-μ triode + sharp-cutoff pentode used as VHF oscillator/mixer, 450 mA heater, Noval base
6EB5 – Dual diode, 300 mA heater, Miniature 7-pin base
6EB8/6GN8 – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and video amplifier, 750 mA heater, Noval base
6EC4/EY500 – CRT horizontal deflection output booster/damper/efficiency diode for analog color TV receivers, Magnoval base with cathode on top cap, guardian shield between filament and cathode to improve high voltage properties; 42EC4/PY500 with a 6.3 V/2.1 A heater
6EC4A/EY500A – 6EC4/EY500 without the guardian shield because of an improved filament/cathode insulation
6EC7 – Remote-cutoff RF pentode, 200 mA heater, Noval base
6EF4 – Compactron Beam power triode used as EHV shunt regulator in analog color TV receivers, 200 mA heater, anode on top cap
6EF6 – 10 W Compactron Beam power pentode used as CRT vertical deflection amplifier, 200 mA heater
6EH4A – 27 kV, 40 W, 1.5 mA Compactron Beam power triode used as EHV shunt regulator in analog color TV receivers, 200 mA heater, anode on top cap
6EH5 – 5.5 W AF Beam power pentode, 1.2 A heater, Miniature 7-pin base
6EH7/EF183 – Frame-grid, remote-cutoff IF pentode, 300 mA heater, Noval base
6EH8 – Triode + sharp-cutoff pentode used as VHF oscillator/mixer, 450 mA heater, Noval base
6EJ4A – 27 kV, 40 W, 1.5 mA Compactron Beam power triode used as EHV shunt regulator in analog color TV receivers, 200 mA heater, anode on top cap
6EJ7/EF184 – Frame-grid, sharp-cutoff IF pentode, 300 mA heater, Noval base
6ES5 – High-μ VHF triode, 200 mA heater, Miniature 7-pin base
6ES6/EF97 = 6К8П↦6K8P (remote-cutoff), 6ET6/EF98 (sharp-cutoff) – Low (6.3-50 V) anode voltage RF pentodes used in car radios, 300 mA heater, Miniature 7-pin base
6ES8/ECC189 – Dual VHF triode used as cascode amplifier in analog TV tuners and receiver front ends, also used as general-purpose dual triode in test gear, 365 mA heater, Noval base; similar to 6DJ8/ECC88
6ET6/EF98 – Low (6.3-50 V) anode voltage, sharp-cutoff pentode used as oscillator or IF/AF amplifier in vehicle equipment, 300 mA heater, Miniature 7-pin base
6ET7 – Dual diode + sharp-cutoff pentode used as horizontal phase detector and video amplifier, 750 mA heater, Noval base
6EU7 – High-μ dual triode used as AF amplifier or phase inverter, 300 mA heater, Noval base
6EU8 – Medium-μ triode + sharp-cutoff pentode used as oscillator/mixer, 450 mA heater, Noval base
6EV5 – Sharp-cutoff VHF tetrode, 200 mA heater, Miniature 7-pin base
6EV7 – Dual triode, 600 mA heater, Noval base
6EW6 – Sharp-cutoff IF pentode, 400 mA heater, Miniature 7-pin base
6EW7 – Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, 900 mA heater, Noval base
6EX6 – 22 W Beam power tetrode used as CRT horizontal deflection amplifier, 2.25 A heater, 6-pin Octal base
6EY6 – 11 W Beam power pentode used as CRT vertical deflection amplifier, 680 mA heater, 6-pin Octal base
6EZ5 – 12 W Beam power pentode used as CRT vertical deflection amplifier, 800 mA heater, Octal base
6EZ8 – Triple high-μ VHF triode used in FM tuners, 450 mA heater, Noval base, cathodes 1 and 2 and one side of the heater share pin 4
6FA7 – Diode + sharp-cutoff split-anode tetrode used as frequency divider or complex-wave generator, 300 mA heater, Noval base
6FC7/ECC89 – 220 MHz Dual frame-grid VHF triode used as cascode amplifier in analog TV tuners and receiver front ends, or as general-purpose instrumentation amplifier, 340 mA heater, Noval base
6FD7 – Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, 925 mA heater, Noval base
6FG5, 6FS5, 6GU5 – Shadow-grid Sharp-cutoff VHF beam pentodes, 200 mA heater, Miniature 7-pin base
6FG7 – Medium-μ triode + semiremote-cutoff pentode used as VHF oscillator/mixer, 450 mA heater, Noval base
6FH5 – High-μ VHF triode, 200 mA heater, Miniature 7-pin base
6FH6 – 17 W Beam power pentode used as CRT horizontal deflection amplifier, 1.2 A heater, 7-pin Octal base
6FH8 – Medium-μ triode + triple-anode sharp-cutoff tetrode used in harmonic-waveformgenerators and analog TV receivers, 450 mA heater, Noval base
6FJ7 – Compactron Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, 900 mA heater
6FM7 – Compactron Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, 1.05 A heater
6FM8 – Dual diode + high-μ triode used as FM demodulator and AF amplifier, 450 mA heater, Noval base
6FN5/EL300 – 17.6 W Power pentode used as CRT horizontal deflection amplifier, Octal base with anode on top cap; 35FN5/PL300 with a 6.3 V/1.65 A heater
6FQ5, 6FQ5A/6GK5 – VHF Semiremote-cutoff triode used as local oscillator in some analog TV turret tuners, 180 mA heater, Miniature 7-pin base
6FW5 – 18 W Beam power tetrode used as CRT horizontal deflection amplifier, 1.2 A heater, 6-pin Octal base
6FW7 – Subminiature, shielded dual medium-μ VHF triode with a base anticipating the Nuvistor, used as oscillator/mixer, 300 mA heater
6FX4 – 1.25 kV, 2×270 mA Full-wave rectifier, 800 mA heater, Miniature 7-pin base
6FX7 – Subminiature, shielded dual medium-μ VHF triode with a base anticipating the Nuvistor, used as cascode amplifier, 300 mA heater
6FY5/EC97 – Frame-grid, high-μ VHF triode, Miniature 7-pin base; 2FY5/XC97 or 4FY5/PC97 with a 6.3 V/200 mA heater
6FY7 – Compactron Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, 1.05 A heater
6GA8/ECC804 – Separate cathodes dual triode, 300 mA heater, Noval base
6GB5/EL500/EL504 – 17 W Beam power pentode used as CRT horizontal deflection amplifier, 1.38 A heater, Magnoval base with anode on top cap
6GC5 – 12 W AF Beam power pentode, 1.2 A heater, Neonoval base
6GC6 – 17.5 W Beam power pentode used as CRT horizontal deflection amplifier, 1.2 A heater, 6-pin Octal base with anode on top cap
6GD7 – Medium-μ triode + sharp-cutoff pentode used as VHF oscillator/mixer, 380 mA heater, Noval base
6GE5 – 17.5 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 1.2 A heater
6GE8 (7734) – Low-μ triode + sharp-cutoff pentode used as voltage regulator, 900 mA heater, Noval base
6GF5 – 9 W Compactron Beam power pentode used as CRT horizontal deflection amplififer, 1.2 A heater
6GF7, 6GF7A – Dual dissimilar triode used as CRT vertical deflection oscillator+amplifier, 985 mA heater, Novar base
6GH8, 6GH8A – Medium-μ triode + sharp-cutoff pentode used as CRT horizontal deflection oscillator, 450 mA heater, Noval base
6GJ5, 6GJ5A (Evacuation tip at bottom of shorter envelope) – 17.5 W Beam power pentode used as CRT horizontal deflection amplifier, 1.2 A heater, Novar base with anode on top cap
6GJ7/ECF801 – VHF Frame-grid triode/pentode oscillator/mixer used in analog TV tuners, 410 mA heater, Noval base
6GJ8 – Triode + pentode used as CRT horizontal deflection oscillator, 600 mA heater, Noval base
6GU7 – Medium-μ dual triode used as CRT vertical/horizontal oscillator or chroma amplifier, 600 mA heater, Noval base
6GV5 – 17.5 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 1.2 A heater, anode on top cap
6GV7/ECF805 – VHF Frame-grid triode/remote-cutoff pentode oscillator/mixer used in analog TV tuners, Noval base; 7GV7/PCF805 with a 6.3 V/350 mA heater
6GV8/ECL85 = 6Ф5П↦6F5P – Triode + 7-watts power pentode used as CRT vertical deflection oscillator+amplifier, 900 mA heater, Noval base
6GW5 – Frame-grid VHF triode, 190 mA heater, Miniature 7-pin base
6GW8/ECL86 – AF Triode + 9-watts power pentode used as audio or CRT vertical deflection oscillator+amplifier, 700 mA heater, Noval base
6GX6 – Dual-control, sharp-cutoff pentode used as FM quadrature demodulator, 450 mA heater, Miniature 7-pin base
6GX7 – Medium-μ triode + sharp-cutoff pentode used as VHF oscillator/mixer, 400 mA heater, Noval base
6GY5 – 18 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 1.5 A heater
6GY6 – Dual-control, sharp-cutoff pentode used as gated AGC amplifier/keyer/noise inverter, 450 mA heater, Miniature 7-pin base
6GY8 – Triple high-μ VHF triode used as Autodyne or AFC reactance[66] circuit in FM tuners, 450 mA heater, Noval base, cathode 3, control grid 1 and one side of the heater share pin 4
6GZ5 – 4.8 W AF Power pentode, 380 mA heater, Miniature 7-pin base
6HA5/6HM5/EC900 (6HA5S) – Shielded, frame-grid, vari-μ VHF triode, Miniature 7-pin base; 3HM5/3HA5/LC900, 4HM5/4HA5/PC900 or 2HM5/2HA5/XC900 with a 6.3 V/185 mA heater
6HA6 – 8 W Power pentode used as CRT cathode driver, 710 mA heater, Noval base
6HB5 – 18 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 1.5 A heater
6HB6 – 10 W Power pentode used as CRT vertical deflection amplifier, 760 mA heater, Noval base
6HB7 – Medium-μ triode + sharp-cutoff pentode used as VHF oscillator/mixer, 450 mA heater, Noval base
6HC8 – Triode + 11-watts power pentode, 1.2 A heater, Noval base
6HD5 – 24 W Compactron Beam power tetrode used as CRT horizontal deflection amplifier, 2.25 A heater
6HD7 – Medium-μ triode + sharp-cutoff pentode used as VHF oscillator/mixer, 450 mA heater, Noval base
6HE5/6JB5/6JC5 – 12 W Compactron Beam power tetrode used as CRT vertical deflection amplifier, 800 mA heater
6HE7 – Compactron High-perveance CRT horizontal deflection output booster/damper/efficiency diode + 10-watts beam power pentode used as CRT horizontal deflection amplifier, 2.7 A heater
6HF5 – 28 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 2.25 A heater, anode on top cap
6HF8 – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and video amplifier, 750 mA heater, Noval base
6HG8/ECF86 – VHF Frame-grid, medium-μ triode/sharp-cutoff pentode oscillator/mixer, 340 mA heater, Noval base
6HJ5 – 24 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 2.25 A heater
6HJ8 – High-perveance diode + sharp-cutoff pentode used as audio/video detector or gated AGC amplifier/keyer/noise inverter or DC restorer, and IF or video amplifier, 450 mA heater, Noval base
6HK5 – Frame-grid, vari-μ VHF triode, 190 mA heater, Miniature 7-pin base
6HK8 – Dual VHF triode, 400 mA heater, Noval base
6HL5 – 12 W AF Beam power tetrode, 950 mA heater, Noval base
6HL8 – Medium-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and video or IF amplifier, 600 mA heater, Noval base
6HZ5/6JD5/6JH5 – 3.5 kV, 35 W, 300 mApeakCompactron Beam power triode with a 2nd grid ("beam plate") connected to the cathode (technically a tetrode), used as EHV shunt regulator in analog color TV receivers, Uh-c=-200...+450 V, 2.4 A heater
6HZ6 – Dual-control, sharp-cutoff pentode used as FM quadrature demodulator, 450 mA heater, Miniature 7-pin base
6HZ8 – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and video amplifier, 1.125 A heater, Noval base
6JA5 – Compactron Beam power pentode used as CRT vertical deflection amplifier, 1 A heater
6JA8 – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or phase inverter/splitter/comparator, and CRT cathode driver, 750 mA heater, Noval base
6JB6, 6JB6A – 17.5 W Beam power pentode used as CRT horizontal deflection amplifier, 1.2 A heater, Novar base with anode on top cap
6JC5 – See 6HE5/6JB5/6JC5
6JC6, 6JC6A – Sharp-cutoff IF pentode, 300 mA heater, Noval base
6JC8 – Medium-μ triode + sharp-cutoff pentode used as VHF oscillator/mixer, 450 mA heater, Noval base
6JD5 – See 6HZ5/6JD5/6JH5
6JD6 – Sharp-cutoff IF pentode, 300 mA heater, Noval base
6JE6 (24 W), 6JE6A (30 W), 6JE6C/6LQ6/6MJ6 (30 W) – Beam power pentode used as CRT horizontal deflection amplifier, 2.5 A heater, Novar base with anode on top cap
6JE8 – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and video amplifier, 780 mA heater, Noval base
6JF6 – 17 W Beam power pentode used as CRT horizontal deflection amplifier, 1.6 A heater, Novar base with anode on top cap
6JG5 – Sharp-cutoff pentode used as video amplifier, 525 mA heater, Noval base
6JG6, 6JG6A – 17 W Beam power pentode used as CRT horizontal deflection amplifier, 1.6 A heater, Novar base
6JH5 – See 6HZ5/6JD5/6JH5
6JH6 – Semiremote-cutoff IF pentode, 300 mA heater, Miniature 7-pin base
6JK5 – 5.5 kV, 35 W, 325 mApeakCompactron Beam power triode used as EHV shunt regulator in analog color TV receivers, 1.8 A heater, anode on top cap
6JK6 – Sharp-cutoff IF pentode, 350 mA heater, Miniature 7-pin base
6JK8 – Dual dissimilar triode used as frame-grid, high-μ VHF preamplifier and medium-μ oscillator/mixer in FM tuners, 400 mA heater, Noval base
6JL6 – Semiremote-cutoff IF pentode, 350 mA heater, Miniature 7-pin base
6JL8 – Medium-μ triode + 5-watts power pentode, 750 mA heater, Noval base
6JM6, 6JM6A – 17.5 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 1.2 A heater, anode on top cap
6JN6, 6JN6A – 17.5 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 1.2 A heater
6JN8 – Medium-μ triode + sharp-cutoff pentode, 450 mA heater, Noval base
6JQ6 – 10 W Beam power tetrode used as CRT vertical deflection amplifier, integral diode internally connected to the suppressor grid to prevent it from becoming positive, 1.2 A heater, Noval base
6JR6 – 17 W Beam power tetrode used as CRT horizontal deflection amplifier, 1.6 A heater, Novar base
6JS6 (28 W), 6JS6A (28 W), 6JS6C (30 W) – Compactron Beam power pentode used as CRT horizontal deflection amplifier, 2.25 A heater
6JT6, 6JT6A – 17.5 W Beam power pentode used as CRT horizontal deflection amplifier, 1.2 A heater, Novar base
6JT8 – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and video amplifier, 725 mA heater, Noval base
6JU8, 6JU8A – 9 mA Quad diode used in FM-stereo demuxers or as color killer phase detector, units 1&2 and 3&4 internally series-connected, 600 mA heater, Noval base
6JV8 – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and video amplifier, 600 mA heater, Noval base
6JW6 – 11.5 W Frame-grid power pentode used as CRT cathode driver, 600 mA heater, Noval base
6JW8/ECF802 – Triode + sharp-cutoff pentode used as CRT horizontal deflection oscillator and reactance tube, 430 mA heater, Noval base
6JZ6 – 18 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 1.5 A heater
6JZ8 – Compactron Medium-μ triode + 7-watts beam power pentode used as CRT vertical deflection oscillator+amplifier, 1.2 A heater
6KA8 – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, 600 mA heater, Noval base
6KD6 – 33 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 2.85 A heater
6KD8 – Medium-μ triode + sharp-cutoff pentode used as VHF oscillator/mixer, 400 mA heater, Noval base
6KE8 – Medium-μ triode + sharp-cutoff pentode used as VHF oscillator/mixer, 400 mA heater, Noval base
6KG6, 6KG6A/EL509 – 40 W Beam power pentode used as CRT horizontal deflection amplifier, 2 A heater, Magnoval base
6KM6 – 20 W Beam power pentode used as CRT horizontal deflection amplifier, 1.6 A heater, Novar base with anode on top cap
6KM8 – Diode + triple-anode sharp-cutoff tetrode used in musical instruments, frequency dividers and complex wave generators, 300 mA heater, Noval base
6KN6 – 30 W Compactron Dual beam power pentode with both sections in parallel used as CRT horizontal deflection amplifier, 3 A heater
6KN8 – Dual VHF triode used as cascode amplifier, 400 mA heater, Noval base
6KR8, 6KR8A – Medium-μ triode + sharp-cutoff pentode used as video amplifier, 750 mA heater, Noval base
6KS8 – High-μ triode + semiremote-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector, and video amplifier, 600 mA heater, Noval base
6KT6 – Semiremote-cutoff pentode used as IF amplifier in analog TV receivers, 300 mA heater, Noval base
6KT8 – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and IF amplifier, 600 mA heater, Noval base
6KU8 – Dual diode + sharp-cutoff pentode used as horizontal phase detector and video amplifier, 725 mA heater, Noval base
6KV6, 6KV6A – 6.5 kV, 20 W, 580 mApeak Beam power pentode used as EHV shunt regulator in analog color TV receivers, 1.6 A heater, Novar base
6KV8 – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and audio-IF or video amplifier, 775 mA heater, Noval base
6KY6 – 9 W Frame-grid power pentode used as CRT cathode driver, 520 mA heater, Noval base
6KY8, 6KY8A – High-μ triode + 12-watts beam power pentode used as CRT vertical deflection oscillator+amplifier, 1.1 A heater, Novar base
6KZ8 – Medium-μ triode + sharp-cutoff pentode used as VHF oscillator/mixer, 450 mA heater, Noval base
6LB6 – 30 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 2.25 A heater
6LB8 – Medium-μ triode + sharp-cutoff pentode used as DC voltage amplifier and video amplifier, 725 mA heater, Noval base
6LC6 – Beam power triode used as EHV shunt regulator in analog color TV receivers, 200 mA heater, Octal base with anode on top cap
6LC8 – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector and gated AGC amplifier/keyer/noise inverter, 600 mA heater, Noval base
6LD6/EL802 – 6 W Power pentode used as CRT cathode driver in analog color TV receivers, 800 mA heater, Noval base
6LF6/6LX6 – 40 W Compactron Beam power tetrode used in CRT horizontal deflection amplifiers, 2 A heater, anode on top cap
6LF8 – High-μ triode + sharp-cutoff pentode used as video amplifier, 600 mA heater, Noval base
6LG6 – 28 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 2 A heater
6LH6A/6LJ6A – 27 kV, 40 W, 1.5 mA Beam power triode used as EHV shunt regulator in analog color TV receivers, 200 mA heater, Octal base with anode on top cap
6LJ8 – Medium-μ triode + sharp-cutoff pentode used as VHF oscillator/mixer, 400 mA heater, Noval base
6LM8, 6LM8A – Medium-μ triode + semiremote-cutoff pentode used as color burst amplifier, 450 mA heater, Noval base
6LQ8 – Medium-μ triode + sharp-cutoff pentode used as audio-IF amplifier or combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and CRT cathode drive, 775 mA heater, Noval base
6LR6 – 30 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 2.5 A heater
6LR8 – High-μ triode + 14-watts beam power pentode used as CRT vertical deflection oscillator+amplifier, 1.5 A heater, Novar base
6LT8 – Dual diode + pentode used as horizontal oscillator and AFC, 600 mA heater, Noval base
6LU6 – Pentode, 400 mA heater, Miniature 7-pin base
6LU8 – Compactron High-μ triode + 14-watts beam power pentode used as CRT vertical deflection oscillator+amplifier, 1.5 A heater
6LW6 – Beam power pentode used as CRT horizontal deflection amplifier, 2.65 A heater, Octal base with anode on top cap
6LX6 – See 6LF6/6LX6
6LX8/LCF802 – Medium-μ triode + sharp-cutoff pentode used as horizontal oscillator and reactance tube, 450 mA heater, Noval base
6LY8 – High-μ triode + sharp-cutoff pentode used as video amplifier, 750 mA heater, Noval base
6LZ6 – 30 W Beam power pentode used as CRT horizontal deflection amplifier, 2.3 A heater, Novar base with anode on top cap
6MA6 – 30 kV, 40 W, 1.5 mA Beam power triode used as EHV shunt regulator in analog color TV receivers, 200 mA heater, Octal base with anode on top cap
6MB6 – Compactron Beam power pentode used as CRT horizontal deflection amplifier, 2.25 A heater
6MB8 – Medium-μ triode + sharp-cutoff pentode used as burst amplifier and video amplifier, 400 mA heater, Noval base
6MC6 – 33 W Beam power pentode used as CRT horizontal deflection amplifier, 2.85 A heater, Novar base with anode on top cap
6MD8 – Triple medium-μ triode used as NTSC chroma signal demodulator matrix in analog color TV receivers, 900 mA heater, Novar base
6ME6 – 30 W Beam power pentode used as CRT horizontal deflection amplifier, 2.3 A heater, Novar base with anode on top cap
6MF8 – Compactron High-μ triode + 12-watts beam power pentode used as CRT vertical deflection oscillator+amplifier, 1.4 A heater
6MG8 – Medium-μ triode + sharp-cutoff pentode used as CRT horizontal deflection oscillator, and combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, 450 mA heater, Noval base
6MH6 – 38.5 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 2.65 A heater
6MN8 – Compactron Triple high-μ triode used as NTSC chroma signal demodulator matrix in analog color TV receivers, 900 mA heater
6MQ8 – Medium-μ triode + sharp-cutoff pentode, 535 mA heater, Noval base
6MU8 – Medium-μ triode + semiremote-cutoff pentode used as color burst amplifier, 600 mA heater, Noval base
6MV8 – High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and IF amplifier, 600 mA heater, Noval base
6MY8 – Compactron Triode + beam power pentode, 1.45 A heater
6SA7, 6SA7-G, 6SA7-GT – First commercially available heptode pentagrid converter with American grid topology, 300 mA heater, Octal base; derived from 6A7 via 6A8, with the control (#3) grid on pin 8 instead of discarded top cap; Miniature 7-pin version: 6BE6/EK90
6SB7Y (Octal Micanol base), 6BA7 (Noval base) – VHF heptode pentagrid converters with American grid topology, 300 mA heater, 1946
6SC7, 6SC7-GT – Common cathode dual high-μ triode, 300 mA heater, Octal base
6SD7-GT – Semiremote-cutoff RF/IF pentode, 300 mA heater, Octal base
6SE7-GT – Sharp-cutoff pentode, 300 mA heater, Octal base
6SF5, 6SF5-GT – High-μ triode, 300 mA heater, Octal base; derived from 6F5, with the grid on pin 3 instead of discarded top cap
6SF7, 6SF7-GT – Diode + remote-cutoff RF/IF pentode, 300 mA heater, Octal base
6SG7, 6SG7-GT – Semiremote-cutoff RF/IF pentode, 300 mA heater, Octal base
6SH7, 6SH7-GT, 6SH7L – Sharp-cutoff RF/IF pentode, 300 mA heater, Octal base
6SJ7, 6SJ7-GT (Bakelite base), 6SJ7Y (Micanol base) – Dual-control, sharp-cutoff RF pentode, 300 mA heater, Octal base, control grid on pin 4; derived from 6J7, with the control grid on pin 4 instead of discarded top cap, and the screen grid on pin 6; similar to types 1603, 77 and U6A-based type 6C6 (control grid on top cap)
6SK7 = 6К3↦6K3, 6SK7-G, 6SK7-GT – Remote-cutoff pentode used in IF amplifiers of North American radios, 300 mA heater, Octal base; derived from 6K7, with the control grid on pin 4 instead of discarded top cap, and the screen grid on pin 6; Miniature 7-pin version: 6BD6
6SL7-G/ECC35, 6SL7-GT – General purpose dual triode, 300 mA heater, Octal base; similar to 6Н9С↦6N9S; ruggedized version: 6SL7-WGT
6SN7-G/ECC32, 6SN7-GT = Brimar 13D2, 6SN7-GTA, 6SN7-GTB – Dual medium-μ triode used in audio amplifiers, Hammond organs, television, and extensively in World War II radar and in the ENIAC computer, each section is equivalent to a 6J5, 600 mA heater, Octal base; derived from 6N7-G, 6F8-G discarding the control grid top cap; Noval version: 6CG7/6FQ7, later 12AU7; ruggedized versions: 6SN7-WGT, 6SN7-WGTA, 5692, 6042, 6180, CV1986; similar to 6Н8С↦6N8S, M-OV/GEC B65
6SQ7, 6SQ7-G, 6SQ7-GT/PBC3 – Dual diode + high-μ triode, 300 mA heater, Octal base; derived from 6Q7, with revised pinout, discarding its control grid top cap
6SR7, 6SR7-GT – Dual diode + medium-μ triode, Octal base; derived from 6R7, with revised pinout, discarding its control grid top cap; 12SR7 with a 6.3 V/300 mA heater
6SS7, 6SS7-GT – 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; derived from 6S7, with the control grid on pin 4 instead of discarded top cap; 6SK7 with a 6.3 V/150 mA heater
6ST7 – Dual diode + high-μ triode, 300 mA heater, Octal base; derived from 6T7, with revised pinout, discarding its control grid top cap
6SU7-GTY – 6SL7-GT with a Micanol base; avionics version: 6SU7-WGT/6188
6SV7 – Diode + sharp-cutoff pentode, 300 mA heater, Octal base
6SZ7 – Dual diode + high-μ triode, 150 mA heater, Octal base
6ZY5-G – 1.25 kV, 2×120 mA Full-wave rectifier, 300 mA heater, 6-pin Octal base
More of these tubes are listed as equivalents under M-P E - 6.3 V heater
These tubes all have a Loctal base and, unless otherwise noted, a 6.3 V heater, despite the 7-prefix; actual 7-volts series heater tubes are listed below
7A4 = Philco XXL – 6J5 Medium-μ triode, 300 mA heater, with a Loctal base
7A5 – 5.5 W Beam power pentode, 7 V/800 mA (Sylvania) or 6.3 V/750 mA (Tung-Sol) heater; similar to 6U6-GT
7A6 – Dual diode, 150 mA heater; similar to 6H6
7A7, 7A7-LM – 6SK7-GT Remote-cutoff pentode, 300 mA heater, with a Loctal base
7A8 – The only American-made, commercially available octode pentagrid converter used mostly in Philco radios, produced in 1939 by Sylvania; 7B8 with a suppressor grid and a 150 mA heater
7B4 – 6SF5-GT High-μ triode, 300 mA heater, with a Loctal base
7B5, 7B5-LT – 8.5 W AF Power pentode, 400 mA heater; types 41, 6K6-GT with a Loctal base
7B6, 7B6-LM – Dual diode + high-μ triode, 300 mA heater; type 75 with a Loctal base; similar to 6AV6/EBC91, 6SQ7
7B7 – Remote-cutoff pentode, 150 mA heater
7B8, 7B8-LM – Heptode pentagrid converter, 300 mA heater; 6A7, 6A8 with a Loctal base
7C4 – Detector diode, 150 mA heater
7C5, 7C5-LT – 6V6-GT 12 W Beam power pentode, 450 mA heater, with a Loctal base
7C6 – Dual diode + high-μ triode, 150 mA heater
7C7 – Sharp-cutoff pentode, 7 V/160 mA (Sylvania) or 6.3 V/300 mA (Tung-Sol) heater
7D7 – Triode/heptode oscillator/mixer, 7 V/480 mA heater
7E5 – Medium-μ RF triode, 150 mA heater
7E6 – 6SR7 Dual diode + medium-μ triode, 300 mA heater, with a Loctal base; Miniature 7-pin version: 6BF6
7E7 – Dual diode + semiremote-cutoff pentode, 300 mA heater; similar to 6B8-GT
7F7 – 6SL7-GT Dual high-μ triode, 300 mA heater, with a Loctal base
7F8 – 400 MHz Dual medium-μ triode used as amplifier or converter, 300 mA heater; ruggedized version: 7F8-W
7G7 – Dual-control, sharp-cutoff pentode, 450 mA heater
7G8 – Dual sharp-cutoff tetrode, 7 V/320 mA heater
7H7 – Semiremote-cutoff pentode, 300 mA heater
7J7 – Triode/heptode oscillator/mixer, 300 mA heater; similar to 6J8-G
7K7 – Dual diode + high-μ triode, 300 mA heater; similar to 6AT6/EBC90, 6Q7
7L7 – Dual-control, sharp-cutoff pentode, 300 mA heater
7N7 – 6SN7-GT Dual medium-μ triode, 600 mA heater, with a Loctal base
7Q7 – Heptode pentagrid converter, 7 V/320 mA heater; similar to 6SA7
7R7 – Dual diode + remote-cutoff pentode, 300 mA heater
7S7 – Triode/heptode oscillator/mixer, 300 mA heater
7T7 – Sharp-cutoff pentode, 300 mA heater
7V7 – Dual-control, sharp-cutoff pentode, 450 mA heater; 7W7 but with the suppressor grid on pin 4, an internal shield on pin 5, and the cathode on pin 7
7W7 – Sharp-cutoff pentode; 7V7 but with the suppressor grid and internal shield on pin 5, and the cathode on pins 4 and 7Note: When substituting a 7V7 for a 7W7 or vice-versa, verify connections on socket pins 4 and 7; pin 5 is usually connected to the chassis
7X6 – Dual 700 V, 450 mA rectifier with separate cathodes used as a voltage doubler, 1.2 A heater
7X7 = Philco XXFM – High-μ triode + common-cathode diode + separate-cathode diode used as FM ratio detector and AF amplifier, 300 mA heater
7Y4 – 1.25 kV, 2×210 mA Full-wave rectifier, 500 mA heater
7Z4 – 1.25 kV, 2×300 mA Full-wave rectifier, 450 mA heater
7AB7 – Sharp-cutoff RF pentode, 7 V/160 mA heater
7AD7 – 10 W Power pentode used as wideband IF amplifier or as CRT cathode driver, 600 mA heater
7AF7 – Dual medium-μ triode, 7 V/320 mA heater
7AG7 – Sharp-cutoff pentode, 7 V/160 mA heater
7AH7 – Remote-cutoff pentode, 150 mA heater
7AJ7 – Sharp-cutoff pentode, 7 V/320 mA heater
7AK7 – Dual-control, sharp-cutoff pentode used in computer equipment, 800 mA heater. Perhaps the first tube specifically designed for computer use
Many of their heaters are rated 150 mA and so were popular in AA5 radio receivers; others are rated 300, 450 or 600 mA for use also in analog TV receivers
—with a straight heater:
12A6, 12A6-GT – 7.5 W Avionics AF Beam power tetrode, 150 mA heater, Octal base[116]: 45 – not related to 2A6 nor 6A6
12A7 – 125 VRMS, 30 mA Half-wave rectifier + power pentode used in one-tube portable phonographs and a few two- and three-tube radios, 300 mA heater, U7A base with top cap; pentode section is similar to type 38; forerunner of such types as 32L7-GT, 70L7-GT and 117L7-GT – not related to 2A7 and 6A7 pentagrid
12A8-G, 12A8-GT – Remote-cutoff heptode pentagrid converter with British grid topology and control (#4) grid on top cap, 150 mA heater, Octal base
12B3 – CRT horizontal deflection output booster/damper/efficiency diode, 600 mA heater, Noval base with cathode on top cap
12B6-GM – Diode + high-μ triode, 150 mA heater, Octal base with control grid on top cap
12B7 = 14A7 (Commonly branded 14A7/12B7), 12B7-ML – Remote-cutoff pentode, 150 mA heater, Loctal base
12B8-GT – Triode + remote-cutoff pentode, 300 mA heater, Octal base with pentode control grid on top cap
12C5/12CU5 – 6 W AF Beam power pentode, 600 mA heater, Miniature 7-pin base
12C8, 12C8-G, 12C8-GT – Dual diode + semiremote-cutoff pentode, Octal base with control grid on top cap; 6B8 with a 150 mA heater
12D4, 12D4A – CRT horizontal deflection output booster/damper/efficiency diode, 600 mA heater, 6-pin Octal base
12E5-GT – Triode, 150 mA heater, 6-pin Octal base
12F5-GT – High-μ triode, 150 mA heater, 7-pin Octal base with grid on top cap
12F8 – Dual diode + remote-cutoff pentode used as detector and AF amplifier, 150 mA heater, Noval base
12G4 – Medium-μ triode, 150 mA heater; 12J5 with a Miniature 7-pin base
12G11 – Compactron Dual-control, sharp-cutoff pentode + 6.5-watts beam power pentode used as FM quadrature demodulator and AF power amplifier, 600 mA heater
12H6 – Dual diode, 150 mA heater, 7-pin Octal base
12J5, 12J5-GT – Medium-μ triode, 6-pin Octal base; 6J5-GT with a 12.6 V/150 mA heater; avionics version: 12J5-WGT
12J7-GT – Sharp-cutoff pentode, 150 mA heater, 7-pin Octal base with control grid on top cap
12K7-G, 12K7-GT – Remote-cutoff pentode, 150 mA heater, 7-pin Octal base with control grid on top cap
12K8, 12K8-GT – Triode/hexode oscillator/mixer, 150 mA heater, Octal base with hexode control grid #1 on top cap
12L6-GT – 10 W Beam power tetrode, Octal base; 6W6-GT, 25L6-GT or 50L6-GT with a 12.6 V/600 mA heater
12L8-GT – 2×2.5 W Common cathode dual power pentode used as a parallel-connected or push-pull output amplifier, 150 mA heater, Octal base
12Q7-G, 12Q7-GT – Dual diode + high-μ triode, 150 mA heater, 7-pin Octal base with grid on top cap
12R5 – 4.5 W Beam power pentode used as CRT vertical deflection amplifier, 600 mA heater, Miniature 7-pin base
12S7/UAF42 – Diode + remote-cutoff RF/IF/AF pentode, 100 mA heater, Rimlock base
12S8-GT – Triple diode + high-μ triode, 150 mA heater, Octal base with grid on top cap
12T10 – CompactronDual-control, sharp-cutoff pentode + 10-watts beam power pentode used as FM quadrature demodulator and AF power amplifier, 450 mA heater
12U5-G – Tuning indicator; 6U5-G with a 12.6 V/150 mA heater
12V6-GT – 12 W Beam power pentode used as audio power amplifier or CRT vertical deflection amplifier, 6- or 7-pin Octal base; 5V6 or 6V6 with a 12.6 V/225 mA heater
12W6-GT – 12 W Beam power pentode used as audio power amplifier or CRT vertical deflection amplifier, 600 mA heater, 6- or 7-pin Octal base
12X3 – 7 kV, 10 mA Half-wave rectifier, 650 mA heater, UX4 base
12X4 – 1.25 kV, 2×210 mA Full-wave rectifier, Miniature 7-pin base; 6X4/6BX4/EZ90 with a 12.6 V/300 mA heater
12Y4 – 420 V, 2×8 mA Full-wave rectifier, 150 mA heater, O5A European 5-pin base
12Z3 – Half-wave rectifier, 300 mA heater, UX4 base
12AB5 – 12 W Beam power tetrode, 200 mA heater, Noval base[117]
12AC5/UF41 – Remote-cutoff RF pentode, 100 mA heater, Rimlock base
12AD5 – Remote-cutoff RF pentode, 100 mA heater, Noval base
12AE6, 12AE6A – Dual diode + medium-μ triode used as detector and AF amplifier, 150 mA heater, Miniature 7-pin base
12AE10 – Compactron Sharp-cutoff pentode + 6-watts beam power tetrode, 450 mA heater[117]
12AF3 – CRT horizontal deflection output booster/damper/efficiency diode, 600 mA heater, Noval base with cathode on top cap
12AF6 – Remote-cutoff RF/IF pentode, 150 mA heater, Miniature 7-pin base
12AF11 – Compactron High-μ triode + medium-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and video amplifier, 450 mA heater
12AH7-GT = 12Н11С↦12N11S – Dual medium-μ triode, 150 mA heater, Octal base
12AJ6 – Dual diode + medium-μ triode, 150 mA heater, Miniature 7-pin base
12AJ7/HCH81 – Triode/remote-cutoff heptode oscillator/mixer, 150 mA heater, Noval base; 19D8/UCH81 with a 12.6 V/150 mA heater
12AL5/HAA91 – Dual diode with separate cathodes, Miniature 7-pin base; 6AL5/EAA91, UAA91 or 3AL5/XAA91 with a 12.6 V/150 mA heater
12AL11 – Compactron Dual-control, sharp-cutoff pentode + 10-watts beam power pentode used as FM quadrature demodulator and AF power amplifier, 450 mA heater
12AQ5 (HL90) – 12 W Beam power pentode used as audio power amplifier or CRT vertical deflection amplifier, 225 mA heater, Miniature 7-pin base
12AS5 – 5.5 W AF Beam power pentode, 400 mA heater, Miniature 7-pin base
12AT6/HBC90 – Dual diode + triode, 150 mA heater, Miniature 7-pin base; superseded by 12AV6/HBC91 in consumer radios
12AU6/HF94, 12AU6A – Sharp-cutoff RF pentode, 150 mA heater, Miniature 7-pin base
12AU8 – Medium-μ triode + sharp-cutoff pentode, 300 mA heater, Noval base
12AV5-GA – 11 W Beam power pentode used as CRT horizontal deflection amplifier, 600 mA heater, Octal base
12AV6/HBC91, 12AV6A – Dual diode + high-μ triode, Miniature 7-pin base; 6AV6/EBC91 with a 12.6 V/150 mA heater
12AW6 – Sharp-cutoff pentode, 150 mA heater, Miniature 7-pin base
12BE6/HK90, 12BE6A – Heptode pentagrid converter with American grid topology, Miniature 7-pin base; 6BE6/EK90 with a 12.6 V/150 mA heater
12BF6 – Dual diode + medium-μ triode, 150 mA heater, Miniature 7-pin base
12BF11 – Compactron Dual-control, sharp-cutoff pentode + 6.5-watts beam power pentode used as FM quadrature demodulator and AF power amplifier, 600 mA heater
12BK5 – 9 W AF Beam power pentode, 600 mA heater, Noval base
12BK6 – Common cathode dual diode + high-μ AF triode, Miniature 7-pin base; 6BK6 or 26BK6 with a 12.6 V/150 mA heater
12BL6 – Semiremote-cutoff RF/IF pentode, 150 mA heater, Miniature 7-pin base
12BN6, 12BN6A – Gated-beam discriminator pentode used as FM quadrature demodulator, Miniature 7-pin base; 3BN6, 4BN6, 6BN6 with a 12.6 V/150 mA heater
12BQ6-GT, 12BQ6-GA, 12BQ6-GTB/12CU6 – 11 W Beam power pentode used as CRT horizontal deflection amplifier, 600 mA heater, Octal base
12BR3 – CRT horizontal deflection output booster/damper/efficiency diode, 600 mA heater, Noval base
12BS3, 12BS3A/12DW4A – CRT horizontal deflection output booster/damper/efficiency diode, 600 mA heater, Novar base
12DW5 – Beam power pentode used as CRT vertical deflection amplifier, 600 mA heater, Noval base
12DZ8 – High-μ AF triode + 6.5-watts AF power pentode, 12.0 V/450 mA heater, Noval base
12ED5 – 6.25 W AF Beam power pentode, 450 mA heater, Miniature 7-pin base
12EF6 – 10 W Beam power pentode used as CRT vertical deflection amplifier, 450 mA heater, Octal base
12EH5 – 5.5 W AF Beam power pentode, 600 mA heater, Miniature 7-pin base
12EN6 – 7 W Beam power pentode used as CRT vertical deflection amplifier, 600 mA heater, 7-pin Octal base
12EQ7 – Diode + sharp-cutoff pentode used as detector and IF amplifier, 150 mA heater, Noval base
12FB5 – Power pentode used as CRT vertical deflection amplifier, 300 mA heater, Noval base
12FQ7 – Medium-μ dual triode used as CRT horizontal and vertical deflection oscillator, Noval base; 6CG7/6FQ7, 8CG7/8FQ7 with a 12.6 V/300 mA heater
12FQ8 – Common cathode, dual split-anode triode used in musical instruments, frequency dividers and complex wave generators, 150 mA heater, Noval base[118]
12FX5 – 5.5 W AF Beam power pentode, Miniature 7-pin base; 19FX5 or 60FX5 with a 12.6 V/450 mA heater
12GC6 – 17.5 W Beam power tetrode used as CRT horizontal deflection amplifier, 600 mA heater, 6-pin Octal base
12GE5 – 17.5 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 600 mA heater
12GJ5, 12GJ5A – 17.5 W Beam power pentode used as CRT horizontal deflection amplifier, 600 mA heater, Novar base
12GN6 – Remote-cutoff RF/IF pentode, 150 mA heater, Miniature 7-pin base
12GT5, 12GT5A – 17.5 W Beam power pentode used as CRT horizontal deflection amplifier, 600 mA heater, Novar base
12GW6 – 17.5 W Beam power pentode used as CRT horizontal deflection amplifier, 600 mA heater, 6-pin Octal base
12HE7 – Compactron High-perveance CRT horizontal deflection output booster/damper/efficiency diode + 10-watts beam power pentode used as CRT horizontal deflection amplifier, 1.35 A heater
12HL5 – 12 W AF Beam power tetrode, 450 mA heater, Noval base
12HU8/PLL80 – 2×6 W Dual AF power pentode, 300 mA heater, Noval base
12JB6, 12JB6A – 17.5 W Beam power pentode used as CRT horizontal deflection amplifier, 600 mA heater, Novar base
12JF5 – 17.5 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 600 mA heater
12JN6, 12JN6A – 17.5 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 600 mA heater
12JN8 – Medium-μ triode + sharp-cutoff pentode, 225 mA heater, Noval base
12JQ6 – 10 W Beam power tetrode with integral diode used as CRT vertical deflection amplifier, 600 mA heater, Noval base
12JS6 – 28 W Compactron Beam power pentode used as CRT horizontal deflection amplifier, 1.125 A heater
12JT6, 12JT6A – 17.5 W Beam power pentode used as CRT horizontal deflection amplifier, 600 mA heater, Novar base
12KL8 – Diode + sharp-cutoff pentode, 150 mA heater, Noval base
12MD8 – Triple medium-μ triode used as NTSC chroma signal demodulator matrix in analog color TV receivers, 450 mA heater, Novar base
12MN8 – Compactron Triple high-μ triode used as NTSC chroma signal demodulator matrix in analog color TV receivers, 450 mA heater
12SA7, 12SA7-GT – Heptode pentagrid converter with American grid topology, 150 mA heater; 12BE6/HK90 with an Octal base
12SC7 = 12Н10С↦12N10S – Dual high-μ AF triode used as amplifier or phase inverter, 150 mA heater, Octal base
12SF5, 12SF5-GT – High-μ triode, 150 mA heater, Octal base; derived from 12F5, with the grid on pin 3 instead of discarded top cap
12SF7, 12SF7-GT – Diode + remote-cutoff RF/IF pentode, 150 mA heater, Octal base
12SG7 – Remote-cutoff RF/IF pentode, 150 mA heater, Octal base
12SJ7, 12SJ7-GT – Sharp-cutoff RF/AF pentode, 150 mA heater, Octal base; derived from 12J7, with the control grid on pin 4 instead of discarded top cap, and the screen grid on pin 6
12SK7, 12SK7-GT – Remote-cutoff pentode, 150 mA heater; 12BA6/HF93 with an Octal base; derived from 12K7 with the control grid on pin 4 instead of top cap, and the screen grid on pin 6
12SL7-GT – High-μ dual triode used as AF or DC voltage amplifier, 150 mA heater, Octal base
12SN7-GT, 12SN7-GTA – Medium-μ dual triode used as phase inverter or CRT horizontal or vertical oscillator, 300 mA heater, Octal base; ruggedized version: 12SN7-WGT
12SQ7, 12SQ7-GT – Dual diode + triode, 150 mA heater; 12AV6/HBC91 with an Octal base; derived from 12Q7, with revised pinout, discarding its control grid top cap
12SR7, 12SR7-GT – Dual diode + triode used as detector and AF amplifier, Octal base; 6SR7 with a 12.6 V/150 mA heater
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 used as CRT vertical deflection amplifier, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base
12A5 – 8.25 W Power pentode mostly used in pre-war car radios, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, U7A base
12B4A – 5.5 W Power triode, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base[117]
12H4 – Triode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater, Miniature 7-pin base
12Z5 = 6Z5 – Full-wave rectifier used as renewal type for Majestic receivers, U6A base, marketed as "6Z5/12Z5"; similar to types 6Z4/84 and 6X5, but with a center-tapped 12.6 V/400 mA resp. 6.3 V/800 mA heater
12AD7 – Dual high-μ, low-microphonics triode, center-tapped 12.6 V/225 mA resp. 6.3 V/450 mA heater, Noval base
12AH8 – Triode/heptode oscillator/mixer, center-tapped 12.6 V/150mA resp. 6.3 V/300 mA heater, Noval base
12AT7/ECC81 = M-OV/GEC B309 (12AT7-WA, 6060, 6201, M8162) – Dual high-μ triode used as amplifier/mixer in VHF tuners, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater[117]
12AU7/ECC82 = M-OV/GEC B329 (12AU7-WA, 6067, 6189, M8136) – Dual medium-μ AF triode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater.[117] Two 6C4/EC90s in one envelope;[119] however, it is only specified as an audio frequency tube
12AV7 (5965) – Dual medium-μ VHF triode used as amplifier or mixer, center-tapped 12.6 V/225 mA resp. 6.3 V/450 mA heater[120]
12AX7/ECC83 = M-OV/GEC B339 (12AX7S, 12AX7-WA, 6057, 6681, M8137) – Dual high-μ AF triode used in high-gain audio amplifiers, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater; very similar to triode section of 6AV6/EBC91;[117] similar to 6Н2П↦6N2P
12AY7 – Dual low-noise, medium-μ triode used as preamplifier, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater[117]
12AZ7, 12AZ7A – Dual medium-μ triode used as AF amplifier or combined oscillator/mixer, center-tapped 12.6 V/225 mA resp. 6.3 V/450 mA heater, Noval base[121][117]
12BH7, 12BH7A – 2×3.5 W Dual medium-μ power triode, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater[122][117]
12BR7, 12BR7A – Dual diode + triode, center-tapped 12.6 V/225 mA resp. 6.3 V/450 mA heater; 9BR7 with a different heater – not related to 6BR7 pentode
12BV7, 12BY7/EL180, 12DQ7 – Power pentodes used as CRT cathode driver, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base[123]
12BZ7 – Dual high-μ triode used as combined sync sep/clipper/amplifier/phase detector, 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 used as a voltage doubler, center-tapped 12.6 V/450 mA resp. 6.3 V/900 mA heater, Noval base
12DF7 – Dual triode, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater, Noval base; low-microphonics variant of 12AX7/ECC83
12DM7 – Dual high-μ triode, low hum, center-tapped 12.6 V/130 mA resp. 6.3 V/260 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, center-tapped 12.6 V/150 mA resp. 6.3 V/300 mA heater, Noval base; one half 12AU7/ECC82-type triode, other half 12AX7/ECC83-type triode
12GN7/12HG7 – Sharp-cutoff pentode used as video amplifier, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base
12HL7 – Sharp-cutoff pentode used as video amplifier, center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater, Noval base
12J8 – Dual diode + low (12.6-30 V) anode voltage power tetrode, 325 mA heater, Noval base
12K5 – Low (12.6-30 V) anode voltage power tetrode with a space charge grid, 400 mA heater, Miniature 7-pin 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
12AC6 – Low (12.6-30 V) anode voltage remote-cutoff pentode, 150 mA heater, Miniature 7-pin base
12AD6 – Low (10.0-15.9 V) anode voltage sharp-cutoff heptode pentagrid converter with American grid topology, 150 mA heater, Miniature 7-pin base
12AE7 – Dual dissimilar (medium-μ + low-μ), low (12.6-16 V) anode voltage AF triode for use in semi-transistorized car radios, 450 mA heater, Noval base
12AG6 – Low (12.6-16 V) anode voltage heptode pentagrid converter with American grid topology, 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, 550 mA heater, Noval base
12CN5 – Low (12.6-16 V) anode voltage sharp-cutoff IF pentode, 450 mA heater, Miniature 7-pin base
12CX6 – Low (12.6-33 V) anode voltage sharp-cutoff pentode, 150 mA heater, Miniature 7-pin base
12CY6 – Low (12.6-16 V) anode voltage sharp-cutoff RF pentode, 200 mA heater, Miniature 7-pin base
12DE8 – Diode + low (12.6-30 V) anode voltage, remote-cutoff pentode, 200 mA heater, Noval base
12DK5 – Low (12.6-16 V) anode voltage sharp-cutoff RF/IF pentode, 300 mA heater, Noval base
12DK7 – Dual diode + low (12.6-30 V) anode voltage power tetrode, 500 mA heater, Noval base
12DL8 – Dual diode + low (12.6-30 V) anode voltage power tetrode with a space charge grid, 550 mA heater, Noval base
12DS7, 12DS7A – Dual diode + low (12.6-16 V) anode voltage power tetrode, 400 mA heater, Noval base
12DU7 – Dual diode + low (12.6-16 V) anode voltage power tetrode, 250 mA heater, Noval base
12DV7 – Dual diode + low (12.6-16 V) anode voltage triode, 150 mA heater, Noval base
12DV8 – Dual diode + low (12.6-16 V) anode voltage power tetrode with a space charge grid, 375 mA heater, Noval base
12DW8 – Diode + dual dissimilar (medium-μ + low-μ), low (12.6-16 V) anode voltage AF triode for use in semi-transistorized car radios, 450 mA heater, Noval base
12DY8 – Low (12.6-16 V) anode voltage medium-μ triode + remote-cutoff pentode, 350 mA heater, Noval base
12DZ6 – Low (12.6-16 V) anode voltage RF pentode, 190 mA heater, Miniature 7-pin base
12EA6 – Low (12.6-16 V) anode voltage IF pentode, 175 mA heater, Miniature 7-pin base
12EC8 – Low (12.6-16 V) anode voltage medium-μ triode + semiremote-cutoff pentode, 225 mA heater, Noval base
12EG6 – Low (12.6-30 V) anode voltage heptode pentagrid converter with American grid topology, both control grids #1 and #3 are sharp-cutoff, 150 mA heater, Miniature 7-pin base
12EK6 – Low (12.6-16 V) anode voltage sharp-cutoff RF/IF pentode, 200 mA heater, Miniature 7-pin base
12EL6 – Dual diode + low (12.6-30 V) anode voltage, high-μ triode, 150 mA heater, Miniature 7-pin base
12EM6 – Diode + low (12.6-30 V) anode voltage power tetrode, 500 mA heater, Noval base
12EZ6 – Low (12.6-30 V) anode voltage sharp-cutoff RF/IF pentode, 175 mA heater, Miniature 7-pin base
12FA6 – Low (12.6-30 V) anode voltage heptode pentagrid converter with American grid topology, 150 mA heater, Miniature 7-pin base; car radio variant of 12BE6/HK90
12FK6 – Low (12.6-16 V) anode voltage dual diode + low-μ triode used as detector, AVC rectifier and AF amplifier, 150 mA heater, Miniature 7-pin base
12FM6 – Dual diode + low (12.6-30 V) anode voltage, medium-μ triode, 150 mA heater, Miniature 7-pin base
12FR8 – Diode + low (12.6-16 V) anode voltage triode + pentode used as IF/AF amplifier and detector, 320 mA heater, Noval base
12FT6 – Dual diode + low (12.6-30 V) anode voltage triode used as detector and AF Amplifier, 150 mA heater, Miniature 7-pin base
12FX8, 12FX8A – Low (12.6-16 V) anode voltage triode/heptode oscillator/mixer, 270 mA heater, Noval base
12GA6 – Low (12.6-16 V) anode voltage heptode pentagrid converter with American grid topology, 150 mA heater, Miniature 7-pin base; similar to 12FA6, but with lower conversion transconductance
12SW7 – Dual diode + low (26.5-250 V) anode voltage triode, 150 mA heater, Octal base
12SX7-GT – Dual low (26.5-300 V) anode voltage triode, 300 mA heater, Octal base
12SY7, 12SY7-GT – Low (26.5-300 V) anode voltage pentagrid converter, 150 mA heater, Octal base
These tubes 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 14-volts series heater tubes are listed below
14A4 – 7A4 Medium-μ triode with a 12.6 V/150 mA heater; 12J5 with a Loctal base
14A5 – 7.5 W Beam power pentode, 150 mA heater
14A7 = 12B7 (Commonly branded 14A7/12B7) – 7A7 Remote-cutoff pentode with a 12.6 V/150 mA heater; 12SK7-GT with a Loctal base
14B6 – 7B6 Dual diode + high-μ triode with a 12.6 V/150 mA heater; similar to 12AV6/HBC91, 12SQ7
14B8 – 7B8 Heptode pentagrid converter with a 12.6 V/150 mA heater; 12A8 with a Loctal base
14C5 – 7C5 Beam power pentode with a 12.6 V/225 mA heater; 12V6-GT with a Loctal base
14C7 – 7C7 Sharp-cutoff pentode with a 12.6 V/150 mA heater
14E6 – 7E6 Dual diode + medium-μ triode with a 12.6 V/150 mA heater; 12SR7 with a Loctal base
14E7 – 7E7 Dual diode + semiremote-cutoff pentode with a 12.6 V/150 mA heater; similar to 12C8
14F7 – 7F7 Dual high-μ triode with a 12.6 V/150 mA heater; 12SL7-GT with a Loctal base
14F8 – 7F8 Medium-μ VHF triode with a 12.6 V/150 mA heater, used as amplifier or converter
14H7 – 7H7 Semiremote-cutoff pentode with a 12.6 V/160 mA heater
14J7 – 7J7 Triode/heptode oscillator/mixer with a 12.6 V/150 mA heater
14N7 – 7N7 Dual medium-μ triode with a 12.6 V/300 mA heater; 12SN7-GT with a Loctal base
14Q7 – 7Q7 Heptode pentagrid converter with a 12.6 V/150 mA heater; similar to 12SA7
14R7 – 7R7 Dual diode + remote-cutoff pentode with a 12.6 V/150 mA heater
14S7 – 7S7 Triode/heptode oscillator/mixer with a 12.6 V/150 mA heater
14W7 – 7W7 Sharp-cutoff pentode with a 14 V/240 mA heater
14X7 – 7X7/XXFM Dual diode + high-μ triode on separate cathodes with a 14 V/160 mA heater, used as FM ratio detector and AF amplifier
14Y4 – 7Y4 1.25 kV, 2×210 mA Full-wave rectifier with a 14 V/320 mA heater
14AF7 = Philco XXD – 7AF7 Dual medium-μ triode with a 12.6 V/150 mA heater
25F5 – 50C5 Beam power pentode with half the heater power, allowing for push-pull output amplifiers with the heater spec of a single 50C5
For AA5 radio receivers with 300 mA series heater strings
25A6, 25A6-G – AF Power pentode; type 43 with an Octal base
25B5 (U6A base), 25N6-G (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. 6N6-G with a 25 volt heater
25B6-G (5824) – AF Power pentode, Octal base
25C5 – 50C5 Beam power pentode with a 25 volt heater
25L6 – 12L6 or 50L6 Beam power pentode with a 25 volt heaterBesides 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 25L6-GT 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
25Z4, 25Z4-GT – 125 Vrms, 125 mA Half-wave rectifier, Octal base
25Z5 (U6A base), 25Z6 (Octal base) – Dual 700 V, 450 mA rectifier with separate cathodes used 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 (Miniature 7-pin base), 117Z4-GT (Octal base) – 330 V, 540 mA Half-wave rectifier, 40 mA heater
117Z6-GT – Dual, separate cathodes 700 V, 60 mA rectifier used as a voltage doubler, 75 mA heater, Octal base; some versions have a heater center-tap on pin 1 for 150 mA/58.5 V operation
14GT8/7724, 14JG8 – Dual diode + high-μ triode used as FM demodulator and AF amplifier in fixed, series-heated, or mobile, parallel-heated equipment, 14 V heater, Noval base
17EW8/HCC85 – 6AQ8/ECC85, 9AQ8/PCC85 or UCC85 Dual triode with a 17.5 V heater
19HV8 – AF triode + IF pentode, 18.9 V heater, Noval base
19T8 – 6T8 Triple diode + triode with an 18.9 V heater; HABC80 with a shorter glass envelope
40B2 – 20 to 60 V Barretter, Octal base, to stabilize against mains voltage fluctuations
50JY6 – Horizontal deflection beam power pentode, 50 V heater, Octal base
56R9 – Compactron AF triode + beam power pentode, separate heaters for triode (14 V) and pentode (42 V) for flexibility with the series string order
70A7GT (With heater tap for a pilot lamp), 70L7GT – Half-wave rectifier + beam power pentode, 70 V heater, Octal base
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 analog TV receivers with series heater strings
4HK5 – 2HK5, 3HK5 or 6HK5 VHF triode with a 4.0 V heater
6AU7 – 12AU7/ECC82 Dual AF triode with a center-tapped 300 mA/6.3 V resp. 600 mA/3.15 V heater, Noval base
6AX7 – 12AX7/ECC83 Dual AF triode with a center-tapped 300 mA/6.3 V resp. 600 mA/3.15 V heater
6CN7 – 8CN7 Dual common cathode diode + high-μ triode used as reactance tube or combined sync sep/clipper/amplifier/phase detector, center-tapped 300 mA/6.3 V resp. 600 mA/3.15 V heater, Noval base
7AN7/PCC84 – 6CW7/ECC84 Dual VHF triode with a 7.2 V heater – not related to 6AN7/ECH80 triode/hexode
7AU7/XCC82 – 6AU7 Dual triode with a center-tapped 300 mA/7.0 V resp. 600 mA/3.5 V heater
7DJ8 – 6DJ8 Dual VHF triode with a 7 V heater
7FC7/PCC89 – 6FC7/ECC89 Dual VHF triode with a 7.2 V heater
7GS7 – 6GS7 Triode + pentode with a 7.6 V heater
7GV7/PCF805 – 6GV7/ECF805 Triode + pentode with a 7.4 V heater
7HG8/PCF86 – 4HG8/XCF86, 5HG8/LCF86, 6HG8/ECF86 or 8HG8 VHF Triode/pentode oscillator/mixer with a 7.2 V heater
9AK8/PABC80 – 6AK8/EABC80 Triple diode + triode with a 9.5 V heater
16Y9 – Pentode + power pentode used as audio-IF amplifier or combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and CRT cathode driver, Decal base; 17Y9/PFL200 with a 16.5 V heater
18A5 – Beam power pentode used as CRT horizontal deflection amplifier, 18.5 V heater, Octal base
42A1 (141 Ω), 49A1 (162 Ω), 55A1 (183 Ω), 80A1 (266 Ω), 86A1 (287 Ω), 92A1 (308 Ω) – Straight ballast resistors used in areas with a stable power grid, Octal base
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, UX4 base, to stabilize against mains voltage fluctuations
58HE7 – 6HE7, 12HE7 or 38HE7 Compactron Booster/damper/efficiency diode + beam power pentode with a 58 V heater
More of these tubes are listed as equivalents under M-P P - 300 mA heater
7KZ6 – Power pentode used as CRT cathode driver, 7.3 V heater, Noval base
8AC10 – 6AC10, 12AC10A Triple triode with an 8.4 V heater
8B10 – 6B10 Dual diode + dual triode with an 8.5 V heater
8CG7/8FQ7 – 6CG7/6FQ7, 12FQ7 Dual triode with an 8.4 V heater
8CN7 – 6CN7 Dual common cathode diode + triode used as reactance tube or combined sync sep/clipper/amplifier/phase detector, center-tapped 225 mA/8.4 V resp. 450 mA/4.2 V heater
9AU7 – 7AU7/XCC82 Dual triode with a center-tapped 225 mA/9.4 V resp. 450 mA/4.7 V heater
10JA8/10LZ8 – 6JA8 High-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase inverter, and CRT cathode driver, 10.5 V heater, Noval base
10JY8 – Medium-μ triode + sharp-cutoff pentode used as combined sync sep/clipper/amplifier/phase inverter, and CRT cathode driver, 10.5 V heater, Noval base
11DS5 – 50B5 or 35B5 Beam power tetrode with an 11.2 V heater
13J10/13Z10 – 6J10/6Z10, 10Z10 Pentode + power pentode with a 13.2 V heater
14BL11 – Compactron Medium-μ triode + high-μ triode + sharp-cutoff video pentode, 14.2 V heater
14BR11 – Compactron Medium-μ triode + high-μ triode + frame-grid, sharp-cutoff video pentode, 14.2 V heater
17D4 – 6DA4/6DM4 Booster/damper/efficiency diode with a 16.8 V heater
17LD8 – Medium-μ triode + power pentode used as CRT vertical deflection oscillator+amplifier, 16.8 V heater, Neonoval base
33GY7 – Compactron Booster/damper/efficiency diode + beam power pentode, 33.6 V heater
38HE7, 38HK7 – 6HE7, 12HE7, 53HK7 or 58HE7 Compactron Booster/damper/efficiency diode + beam power pentode with a 37.8 V heater
42KN6 – 6KN6 Beam power pentode with a 42 V heater
More of these tubes are listed as equivalents under M-P L - 450 mA heater
26A6 – Remote-cutoff RF pentode, 26.5 V/70 mA heater, Miniature 7-pin base
26A7-GT – 2×2 W Dual low (26.5-50 V) anode voltage AF beam power pentode used as a push–pull audio amplifier, designed for both anode and 26.5 V/600 mA heater to run directly off the standard avionics 28-volts DC bus, Octal base; cf. 13П1С, Shuguang 13P1P
26BK6, 26C6 – Common cathode dual diode + high-μ AF triode, Miniature 7-pin base; 6BK6 or 12BK6 with a 26.5 V/70 mA heater
26D6 – Heptode pentagrid converter with American grid topology, Miniature 7-pin base; 6BE6/EK90 with a 26.5 V/70 mA heater and reduced-specs minimum anode voltage 26.5 V
26E6-G = 26E6-WG – 12.5 W Avionics AF beam power pentode, 26.5 V/300 mA heater, Octal base
26Z5-W – Avionics dual 1.375 kV, 300 mA rectifier with separate cathodes used as a voltage doubler, 26.5 V/200 mA heater, Noval base
28D7-W – 2×3 W Dual low (28-100 V) anode voltage AF beam power pentode used 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, both anode and 28 V/400 mA heater run off the avionics 28-volts DC bus, shock resistant up to 350 g, Loctal base
40A1, 40B2 (Octal base), 50A1 (Noval base) – Barretters used as cathode resistors of horizontal-deflection output tubes in early TV receivers to stabilize the picture width against mains voltage fluctuations
45Z3 – Half-wave rectifier used in Three-way portable (AC or DC mains, or batteries) radio receivers, 45 V/75 mA heater, Miniature 7-pin base
315 mA series heater tubes
16BQ11 – Compactron Remote-cutoff pentode + sharp-cutoff IF pentode, 16 V heater
16BX11 – Compactron Medium-μ triode + high-μ triode + sharp-cutoff video pentode, 16 V heater
18AJ10 – Compactron Dual-control pentode + AF power pentode, 18 V heater
24BF11 – Compactron Dual-control, sharp-cutoff pentode + beam power pentode, 24.2 V heater
24JZ8 – Compactron Medium-μ triode + beam power tetrode used as CRT horizontal deflection amplifier, 24.2 V heater
31AL10 – Compactron High-μ triode + medium-μ triode + beam power tetrode used as combined sync sep/clipper/amplifier/phase detector or gated AGC amplifier/keyer/noise inverter, and CRT vertical deflection oscillator+amplifier, 31.5 V heater
32HQ7 – Compactron High-perveance CRT horizontal deflection output booster/damper/efficiency diode + beam power pentode, 32.6 V heater
53HK7 – Compactron Booster/damper/efficiency diode + beam power pentode, 53.2 V heater
1S22 – 10 kV, 20 A Vacuum SPDT switch actuated by a lever extending through a flexible Kovar diaphragm
2A21 (6.5-9.5 V/1 A), 2A22 (3-8 V/1.7 A) – Ballast tubes, Octal base
2B22 – 1.5 GHz Lighthouse-type Disk-seal diode, 6.3 V/750 mA heater, Octal base
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), 6.3 V/300 mA heater, Octal base[129]
2B25 – 2.8 kV, 1.5 mA Directly heated half-wave rectifier, 1.4 V/110 mA filament, Miniature 7-pin base
2B35/EA50 – Subminiature video detector diode, 6.3 V/150 mA heater, 3+1-pin all-glass with anode on top pin
2C21 = 1642 – Separate cathodes dual RF triode, 6.3 V/600 mA heater, Micanol U7A base, one grid on top cap
2C22 = 7193 – 3.3 W VHF Triode, 6.3 V/300 mA heater, Octal base, grid and anode on separate top caps
2C26, 2C26A (Pulse-rated) – 10 W, 300 MHz Triode, 6.3 V/1.1 A heater, Octal base, grid and anode on separate top caps
2C33 – 1.25 kV, 25 mAavg, 1.5 Apeak Argon-filled tetrode thyratron, negative starter voltage, 2.5 V/2.5 A filament, Octal base
2C34 – 2×5 W, 80 MHz Dual power triode, 6.3 V/600 mA heater, Octal base with two anode top caps
2C36 – 1.75 GHz Rocket-type Disk-seal triode with an internal feedback circuit between cathode and anode used as UHF oscillator, 6.3 V/400 mA heater
2C37 – 3.3 GHz Rocket triode used as SHF oscillator, 6.3 V/400 mA heater
2C40, 2C40A – 6.5 W, 3.37 GHz Lighthouse-type Disk-seal power triode for CW operation, 6.3 V/750 mA heater, Octal base
2C41 – 2.2 kWpeak, 3 GHz Oil can-type Pulse-rated power triode, 6.3 V/1.03 A heater
2C42 – 1750 Wpeak, 1050 MHz Lighthouse-type Pulse-rated power triode, 6.3 V/900 mA heater, 6-pin Octal base; upgraded 446
2C43 – 12 W, 1.5 GHz Lighthouse-type Pulse-rated power triode, 6.3 V/800 mA heater, 6-pin Octal base
2C46 – 12 W, 1.3 GHz Lighthouse-type Power triode, 6.3 V/750 mA heater, 6-pin Octal base
2C50 – Separate cathodes dual triode used in servo amplifiers, 12.6 V/300 mA heater, Octal base
2C51 – Dual separate cathodes, shielded, medium-μ VHF triode, 6.3 V/300 mA heater, Noval base
2C52 – Separate cathodes, low-drift, dual triode used as precision DC amplifier, 12.6 V/300 mA heater, Octal base
2C53 – 12 W, 8 kV Power triode used as 5 mA shunt regulator, 6.3 V/300 mA heater, Octal base with anode on top cap
2D21/EN91 = Philips PL21 = PL2D21 = STC 4G/280K – 650 V, 100 mAavg, 500 mApeak, 10 Asurge, Xenon-filled tetrode thyratron used as relay driver or grid-controlled rectifier, mostly in jukeboxes and computer equipment, negative starter voltage, 6.3 V/600 mA heater, Miniature 7-pin base; ruggedized versions: 2D21-W/5727/E91N, CV797
2E22 – 30 W RF Power pentode, 6.3 V/1.5 A heater, UY5 base with anode on top cap
2E24 – 10 W, 125 MHz Beam power tetrode, center-tapped 6.3 V/650 mA filament, Micanol Octal base
2E25 – 15 W, 100 MHz Beam power tetrode, 6.3 V/1 A thoriated Tungsten quickstart filament, Octal base
2E26 – 5.3 W, 175 MHz Beam power tetrode, 6.3 V/800 mA heater, Octal base, popular among radio amateurs
2E30 – 10 W, 165 MHz Beam power tetrode with deflection screens available on separate pin, direct 6.3 V/650 mA quickstart filament, Miniature 7-pin base
2E31 (Long wire-ends), 2E32 (short wire-ends for use with a socket) – Subminiature, directly heated, low (22.5-45 V) anode voltage, fully shielded sharp-cutoff RF/IF pentode, 1.25 V/50 mA filament, all-glass elliptical cross-section envelope with 5 inline wire-ends
2E35 (Long wire-ends), 2E36 (short wire-ends) – 6 mW Subminiature, directly heated, low (22.5-45 V) anode voltage power pentode, 1.25 V/30 mA filament, all-glass elliptical cross-section envelope with 5 inline wire-ends
2E41 (Long wire-ends), 2E42 (short wire-ends) – Subminiature, directly heated, low (22.5-45 V) anode voltage diode + pentode, 1.25 V/30 mA filament, all-glass elliptical cross-section envelope with 5 inline wire-ends
2G21 (Long wire-ends), 2G22 (short wire-ends) – Subminiature, directly heated, low (22.5-45 V) anode voltage triode/heptode oscillator/mixer, 1.25 V/50 mA filament, all-glass elliptical cross-section envelope with 7 inline wire-ends
2H21 – Phasitron, a magnetically controlled beam deflection phase modulator tube used in early FM broadcast transmitters, 6.3 V/300 mA heater, Magnal 11-pin base;[130] superseded by 5593[131][132][133]
2K40 – 30 mW, 5-10 GHz Reflex Klystron, 6.3 V/330-390 mA heater, 3-pin PeeWee base
2K45 – 30 mW, 8.5-9.66 GHz Reflex Klystron with thermal tuning - one wall of the cavity is also the anode of a triode, so increasing the triode current results in thermal expansion of that wall, altering the cavity geometry, 6.3 V/760 mA heater
2K50 – 15 mW, 23.5-24.5 GHz Reflex Klystron, 6.3 V/705...805 mA heater, Octal base
2K51 (2.7-3.3 GHz), 2K52 (2.9-3.7 GHz), 2K53 (3.2-4 GHz) – 2-Cavity Klystrons, 6.3 V/1.4 A heater, Octal base
2K56 – 3.84-4.46 GHz Reflex Klystron, 6.3 V/440 mA heater, Octal base
2K57 – 4.82-5.12 GHz Reflex Klystron, 6.3 V/1.5 A heater, Octal base
3B23 – 3.5 kV, 2×600 mA Full-wave rectifier, half-indirect 2.5 V/8 A heater, UX4 Bayonet base with dual anode top cap
3B24 = Western Electric 732A – 20 kV, 60 mAavg, 300 mApeak Half-wave rectifier, center-tapped 2.5 V/6 A resp. 5 V/3 A filament, UX4 Bayonet base with anode on top cap; ruggedized versions: 3B24-W, 3B24-WA
3B25 – 4.5 kV, 500 mAavg, 2 Apeak Gas-filled half-wave rectifier, 2.5 V/5 A filament, UX4 Bayonet base with anode on top cap
3B26 – 15 kV, 20 mAavg, 8 Apeak Ruggedized, Nonex hard glass clipper diode, half-indirect 2.5 V/4.75 A heater, Octal base with anode on top cap
3B27 – 8.5 kV, 150 mAavg, 600 mApeak Half-wave rectifier, split-cathode half-indirect 2.5 V/5 A heater, UX4 Bayonet base with anode on top cap
3B28 – 10 kV, 250 mAavg, 1 Apeak Xenon-filled half-wave rectifier, 2.5 V/5 A filament, UX4 Bayonet base with anode on top cap; ruggedized replacement for Mercury-vapor type 866
3B29 – 16 kV, 64 mAavg, 250 mApeak Ruggedized, Nonex hard glass clipper diode, half-indirect 2.5 V/4.9 A heater, UX4 Bayonet base with anode on top cap
3C22 – 125 W, 1.4 GHz Forced-air cooled, disk-seal power triode, 6.3 V/2 A heater, Octal base
3C23 – 1.25 kV, 1.5 Aavg, 6 Apeak Argon/Mercury-vapor triode thyratron, 2.5 V/7 A filament, UX4 Bayonet base with anode on top cap
3C24 (Grid on side pin), 3C28 (grid on dual side pin), 3C34 (grid on base pin) – 25 W, 60 MHz Power triodes, 6.3 V/3 A filament, ceramic UX4 Bayonet base with anode on top pin
3C33 – ±2 kV, 2×15 W Common cathode dual power triode used in burst- or phase-fired controllers, 12.6 V/1.125 A heater, Septar base
3C36 – 500 W, 1.5 GHz Water-cooled disk-seal power triode, 6.3 V/2.8 A heater
3C45 = 6130 – 3 kV, 45 mAavg, 1.5 ARMS, 35 Apeak Hydrogen triode thyratron, positive control characteristic, half-indirect 6.3 V/2-2.5 A heater, Micanol UX4 base with anode on top cap; ruggedized version: 3C45-W
3D21, 3D21A, 3D21B – 5 kV, 15 W Pulse-rated beam power tetrode, center-tapped 12.6 V/850 mA resp. 6.3 V/1.7 A indirect heater, Octal base with anode on top cap; ruggedized version: 3D21-WB
3K23 (5 W, 950-1150 MHz), 3K27 (3 W, 750-960 MHz) – Reflex Klystrons, 6.3 V/1.5 A heater, Octal base
4A21 – 11-15 V/1.59-1.65 A Ballast tube, Octal base
4B22 = EL5B – 340 V, 5 A Argon-filled full-wave rectifier, 2.5 V/11-13 A filament, E39 MogulEdison screw lamp base with Graphite anodes on top pins
4B23 = EL5BHD – 425 V, 5 A Heavy-duty Argon-filled full-wave rectifier, 2.5 V/16-18 A filament, E39 Mogul Edison screw lamp base with Graphite anodes on top pins
4B24 = EL3C – 725 V, 2.5 A Argon-filled full-wave rectifier with Graphite anodes, 2.5 V/10.5-12.5 A filament, 4-pin base
4B25 = EL6CF – 725 V, 6.4 A Argon-filled full-wave rectifier with Graphite anodes, 2.5 V/16-18 A filament, 4-pin base
4B26 = 2000 – 375 V, 6 A Gas-filled half-wave rectifier, 2.2 V/18 A filament, E39 Mogul Edison screw lamp base with anode on top pin
4B27 – 1 kV, 2 A Gas-filled full-wave rectifier, 2.5 V/10 A filament, 4-pin base
4B28 – 300 V, 6 A Gas-filled half-wave rectifier, 2.2 V/17 A filament, E39 Mogul Edison screw lamp base with anode on top pin
4B31 – 15 kV, 60 mA Half-wave rectifier, half-indirect 5 VAC/5 A heater, B4D Superjumbo base with anode on top cap
4B32 = STC 2G/472B – 10 kV, 1.25 Aavg, 5 Apeak Xenon-filled half-wave rectifier, 5 V/7.25 A filament, B4F/U4J Jumbo base with anode on top cap
4B35 (90 V, 3 A), 4B36 (275 V, 2 A) – Tungar-type Gas-filled half-wave rectifier, 2 V/12 A filament, E39 Mogul Edison screw lamp base
4C21 – 100 W, 1 MHz Power triode, 10 V/3.25 A filament, B4F/U4J Jumbo base
4C25 – 50 W, 30 MHz Power triode, 5 V/5 A filament, UX4 base
4C27 = 8026 – 150 W, 600 MHz Coaxial power triode, 6 V/6.5 A filament
4C28 – 7.5 kV, 2 A Pulse modulator power triode used in small LORAN and SHORAN transmitters, 6 V/6.5 A filament
4C29 – 150 W Pulse-rated UHF power triode, 6 V/6.5 A filament
4C32 – 200 W, 60 MHz Power triode used in shortwave diathermy generators, 10 V/4.5 A filament
4C33 – 250 W, 625 MHz Forced-air cooled, pulse-rated power triode, 5 V/9.1 A heater
4C34 – 250 W, 60 MHz Power triode, 11 V/4 A filament
4C35 = Philips PL435 = Toshiba 1G35P, 4C35A – 8 kV, 100 mAavg, 90 Apeak Hydrogen thyratron, 6.3 V/5.5-6.7 A heater, B4D Superjumbo base with anode on top cap
4C36 – 125 W, 60 MHz Power triode, 5 V/7.5 A filament, B4F/U4J Jumbo base
4D21 = 6155 = Eimac 4-125A – 125 W Glass VHF beam power tetrode, 5 V/6.5 A filament, B5E Giant 5-pin UY base with metal shell and anode on top cap
4D22 (Center-tapped 25.2 V/800 mA resp. 12.6 V/1.6 A heater), 4D32 (6.3 V/3.75 A heater) – 50 W, 60 MHz Beam power tetrodes, Septar base with anode on top cap
4D23 – 150 W, 120 MHz Beam power tetrode, 5 V/7.5 A filament, B5D/U5G Giant 5-pin UY base
4E27/8001 (75 W), 4E27A/5-125B (85 W) – Glass radial-beam power pentode, 5 V/7.5 A filament, B7D/U7G Giant 7-pin base with anode on top pin
5B21 – 225 V, 15 A Gas-filled half-wave rectifier, 2.5 V/25 A filament, E39 Mogul Edison screw lamp base
5B24 – 1 kV Full-wave, Mercury-vapor Tungar bulb, a low-voltage rectifier for charging 60-cell lead-acid batteries at 6 A, 2.5 V/18 A filament[136]
5C21 = C6J – 750 V, 6.4 A Xenon-filled triode thyratron with negative control voltage, 2.5 V/21 A heater, B4D Superjumbo base
5C22/6279, 5C22A – 16 kV, 200 mAavg, 325 Apeak Hydrogen triode thyratron used in radar modulators, half-indirect 6.3 V/9.6-11.6 A heater, B4D Superjumbo base with anode on top cap
5C30 – 750 V, 5 A Triode thyratron with negative control voltage, 2.5 V/23 A heater, E39 Mogul Edison screw lamp base
5D21 – 60 W Beam power tetrode, 26 V/2.1 A heater, B4A Ventilated 4-pin base with anode on top terminal
5D22/6156/4-250A – 250 W, 110 MHz Glass beam power tetrode, 5 V/14.5 A filament, B5E Giant 5-pin UY base with anode on top cap
5D23 – 140 W, 45 MHz Power tetrode, 5 V/14.5 A filament, B4F/U4J Jumbo base
7C23 – 17.5 kV, 120 kWpeak, 1.2 kWavg, 5 MHz Pulse power triode, center-tapped 11 V/29 A filament
7C24/5762 = RCA 4654 – 4 kW, 30 MHz Forced-air cooled power triode, center-tapped 12.6 V/29 A filament
7C25 – 2.5 kW, 30 MHz Power triode, center-tapped 11 V/28 A filament
7C26 – 1 kW, 150 MHz Power triode, center-tapped 9 V/28 A filament
7C27 – 3 kW, 110 MHz Power triode, center-tapped 16 V/28.5 A filament
7C30 – 3 kW, 1.6 MHz Power triode, center-tapped 16 V/28.5 A filament
8C22 – 1 kW, 400 MHz Forced-air cooled, pulse-rated power triode, 4.1 V/296...344 A filament
8C23 – 1 kW, 600 MHz Forced-air cooled, pulse-rated power triode, 4.1 V/296...344 A filament
8D21 – 2×3 kW, 216 MHz Internally water-cooled dual power tetrode used in early VHF TV transmitters, 3.2 V/125 A filament
9C21 (Water+forced-air-cooled, 40 kW), 9C22 (Forced-air cooled, 20 kW) – Power triodes, 19.5 V/415 A filament, 4-pin base and flanged-header grid terminal around the tube
9C24 – 5 kW, 220 MHz Water-cooled, ceramic/metal VHF power triode used in grounded-grid amplifiers, 6.3 V/240 A filament; superseded by 6039
9C25 – 11.5 kW, 30 MHz Forced-air cooled beam power tetrode, 6.0 V/285 A filament, 2-pin base and flanged-header grid terminal
9C26 – 7.5 kW Forced-air cooled power triode, 6.0 V/285 A filament, 2-pin base and flanged-header grid terminal
9C27 – 25 kW, 30 MHz Water+forced-air cooled power triode, 6.0 V/285 A filament, 2-pin base and flanged-header grid terminal
Many of these are special quality versions of the equivalents given. Some manufacturers preceded the EIA number with a manufacturer's code, as explained above
5512 – 25 kW, 110 MHz Water-cooled, coaxial power triode with integral water jacket, 6.2 V/435 A filament
5513 – 1.2 kW, 220 MHz Forced-air cooled, glass/metal, coaxial power triode, 6.3 V/30 A filament
5514 – 65 W RF Power triode with a Zirconium-coated Graphite anode on top cap, 7.5 V/3 A filament, UX4 base
5516 – 15 W, 80 MHz Directly heated VHF beam power pentode, Zirconium-coated anode on top cap, Gold-coated control grid, "carbonized" screen grid, center-tapped 6 V/700 mA oxide-coated quickstart filament, Micanol Octal base
5517 – 2.8 kV, 12 mA Gas-filled, cold-cathode, triggerable half-wave rectifier used in photoflash power supplies, Miniature 7-pin base with anode on top cap
5518 – 4 kW, 110 MHz Forced-air cooled, glass/metal, coaxial power triode, 6.3 V/235 A filament
5556 – 10 W, 6 MHz Directly heated power triode, 4.5 V/1.1 A filament, UX4 Bayonet base
5557 – 2 kV, 500 mA Mercury-vapor triode thyratron, negative control characteristic, 2.5 V/5 A filament, UX4 Bayonet base with anode on top cap
5558 – 5 kV, 2.5 A Mercury-vapor half-wave rectifier, half-indirect 5 V/4.5 A heater, UX4 Bayonet base with anode on top cap
5559 – 1 kV, 2.5 A Mercury-vapor triode thyratron, half-indirect 5 V/4.5 A heater, UX4 Bayonet base with anode on top cap
5560 – 1 kV, 2.5 A Mercury-vapor tetrode thyratron, half-indirect 5 V/4.5 A heater, UX4 Bayonet base with anode on top cap
5561 – 3 kV, 6.4 A Mercury-vapor, half-wave rectifier, 5 V/10 A heater, B4D Superjumbo base with anode on top cap
5563 (10 kV), 5563A (15 kV) – 1.8 A Mercury-vapor triode thyratron with a negative control characteristic, 5 V/10 A heater, B4F/U4J Jumbo base with anode on top cap
5575/100 (20 V/24 A filament, 1 A anode current), 5576/200 (20 V/32 A filament, 2.5 A) – 150 kV Radiation-cooled half-wave rectifier
5588 – 200 W, 1 GHz Forced-air cooled, coaxial power triode, half-indirect 6.3 V/2.5 A heater; superseded by 6161
5589 = Western Electric 376B – 275 V, 20 mA (10000h lifespan) or 35 mA (1000h lifespan) Gas-filled cold-cathode trigger triode, 6-pin Octal base
5590 = Western Electric 401A (Long-life 6AK5/EF95), 5591 = 403B – VHF Pentodes, 6.3 V/150 mA heater, Miniature 7-pin base
5592 – Forced-air cooled power triode, 11 V/412 A heater, special 4-pin base
5593 – Phasitron, a magnetically controlled beam deflection phase modulator tube used in early FM broadcast transmitters, 6.3 V/300 mA heater, Magnal 11-pin base;[137] derived from the 2H21[131][132][133]
5594 – 5 kV, 500 mA Gas-filled triode thyratron, 2.5 V/5 A filament, UX4 Bayonet base
5603 = Western Electric 398A – Power pentode, 6.3 V/500 mA filament, Octal base
5604, 5604A (Forced-air cooled, 10 kW), 5619 (water-cooled, 20 kW) – 25 MHz Power triode, 11 V/176 A filament
5618 – VHF Power pentode, center-tapped 6 V/230 mA resp. 3 V/460 mA heater, Miniature 7-pin base
5632 = EEV C3J = ELC3J – 1.25 kV, 2.5 A Xenon-filled triode thyratron with negative control characteristic, center-tapped 2.5 V/9 A heater, UX4 Bayonet base with anode on top cap
5643 – Subminiature Xenon-filled tetrode thyratron with negative control characteristic, 6.3 V/150 mA heater, all-glass round cross-section E8-10 envelope, circular 8-pin/wire-ends; similar to 5696/EN92, 546
5652 (For AC use with balancing capacitor), 5653 (for DC use) – High-vacuum, side-on, S4 phototubes, 5-pin Octal base
5654/6096/6AK5-W/E95F, CV4010 – Avionics version of 6AK5/EF95 sharp-cutoff pentode, popular in vintage radar IF amplifiers; 20 V/50 mA heater version: Western Electric 6028/408A
5655 – 1.6" Image Orthicon, magnetic focus and deflection, 6.3 V/600 mA heater, Diheptal 14-pin base
5656 – 2×3 W, 400 MHz Dual power tetrode, 6.3 V/400 mA heater, Noval base
5658 – Upgraded drop-in replacement for the 880 power triode used for industrial, RF dielectric heating
5659 – Ruggedized 12A6 beam power tetrode
5660 – Ruggedized 12C8 dual diode + pentode
5661 – Ruggedized 12SK7 pentode
5662 – 2.25 A Triode thyratron for electric blanket controllers, 6.3 V/150 mA heater, Miniature 7-pin base
5663 – Tetrode thyratron, 6.3 V/150 mA heater, Miniature 7-pin base; similar to 5696/EN92, 546
5664 = EEV ELC1B/A – 1.25 kV, 1 A Xenon-filled triode thyratron with a Tantalum anode, 2.5 V/6.3 A filament, UX4 Bayonet base with anode on top cap
5665 = EEV C16J – 1.25 kV, 16 A Xenon-filled triode thyratron with negative control characteristic, 2.5 V/31 A filament
5666 (Water-cooled, 12.5 kW), 5667 (forced-air cooled, 7.5 kW) – Upgraded replacements for the 889A, 889RA power triodes used for industrial, RF dielectric heating
5668 (Water-cooled, 20 kW), 5669 (forced-air cooled, 10 kW) – Upgraded replacements for the 892, 892R power triodes used for industrial, RF dielectric heating
5670 – 800 MHz Dual medium-μ triode with separate cathodes, 6.3 V/350 mA heater, Noval base; avionics version: 5670-WA; similar to 2C51 or 6385
5671 – 25 kW, 10 MHz Forced-air cooled power triode, 11 V/285 A filament
5672 – Subminiature, directly heated power pentode, 1.25 V/50 mA filament, all-glass elliptical cross-section envelope with 5 inline wire-ends
5674 – Directly heated dual, compensating electrometerspace charge grid tetrode for use in the 2 branches of a differential-in, differential-out bridge circuit, 3.8 V/90 mA filament, U6A base
5675 – Pencil-type Glass/metal medium-μ triode, 6.3 V/135 mA heater
5676 – Subminiature VHF triode, 1.25 V/120 mA filament, all-glass elliptical cross-section envelope with 5 inline wire-ends
5677 – Subminiature UHF triode, 1.25 V/60 mA filament, all-glass elliptical cross-section envelope with 4 inline wire-ends
5678/DF60 – Subminiature, directly heated, shielded RF pentode with a split suppressor grid, its halves tied to the positive resp. negative 1.25 V/50 mA filament end, all-glass elliptical cross-section envelope with 5 long inline wire-ends
5679 – Dual diode, 6.3 V/150 mA heater, Loctal base
5680 – 2.5 kW, 30 MHz Forced-air cooled power triode, 13 V/36 A filament
5681 – 75 kW, 30 MHz Water-cooled power triode with coaxial terminals, 12 V/220 A filament
5682 – 140 kW, 30 MHz Water-cooled power triode with coaxial terminals, 16.5 V/325 A filament
5683 – 1.25 kV, 1 A Gas-filled triode thyratron, 2.5 V/6.3 A filament, UX4 Bayonet base
5684 = EEV C3J/A = ELC3J/A – 1.25 kV, 2.5 A Xenon-filled triode thyratron with negative control characteristic, center-tapped 2.5 V/9 A filament, UX4 Bayonet base with anode on top cap
5685 = EEV C6J/A = ELC6J/A – 1.25 kV, 6.4 A Xenon-filled triode thyratron with negative control characteristic, 2.5 V/21 A filament, B4D Superjumbo base with anode on top cap
5686 – 8.25 W, 160 MHz Ruggedized beam power tetrode, 6.3 V/350 mA heater, Noval base
5687 – Dual medium-μ triode with separate cathodes, center-tapped 12.6 V/450 mA resp. 6.3 V/900 mA heater, Noval base; avionics version: 5687-WA
5690 – 1.12 kV, 2×375 mA Dual rectifier with separate cathodes and separate 6.3 V/1.2 A (each) heaters, Octal base
5691 – Special Red ruggedized, long-life version of 6SL7-GT dual high-μ triode
5692 – Special Red ruggedized, long-life version of 6SN7-GT dual medium-μ triode, extensively used in the SAGE computer systems
5693 – Special Red ruggedized, long-life version of 6SJ7 sharp-cutoff pentode
5694 – Pre-aged 6N7-G dual high-μ triode, Octal base
5695 – 5 kV, 150 mA Mercury-vapor half-wave rectifier, 2.5 V/3 A filament, UX4 Bayonet base
5696/EN92 (5663, 546) – 500 V, 25 mAavg, 100 mApeak, 2 Asurge Xenon-filled tetrode thyratron for industrial control systems, negative starter voltage, 6.3 V/150 mA heater, Miniature 7-pin base
5697 – Subminiature triode, 625 mV/20 mA filament, all-glass elliptical cross-section envelope with 4 inline wire-ends
5702 – Subminiature, dual-control pentode, 6.3 V/200 mA heater, all-glass round cross-section envelope but 7 long inline wire-ends; ruggedized versions: 5702-WA, 5702-WB = 6148
5703 – Subminiature UHF triode, 6.3 V/200 mA heater, all-glass round cross-section envelope with 5 long wire-ends; ruggedized versions: 5703-WA, 5703-WB = 6149
5704 – Subminiature diode, 6.3 V/150 mA heater, all-glass round cross-section envelope, but 4 long inline wire-ends; ruggedized version: 5704-WA
5705 – 10 kW, 30 MHz Water-cooled power triode, 22 V/60 A filament
5710 – 5 kW, 20 MHz Forced-air cooled power triode, 10 V/420 A filament
5725/6187/6AS6-W, 7752 (Different pinout) – Avionics version of 6AS6 sharp-cutoff pentode
5726 = 6097, 6AL5-W = E91AA/EAA901S – Ruggedized dual RF diode, Silicon-free 6.3 V/300 mA heater, Miniature 7-pin base
5727/E91N = 2D21-W – Up to 750 g shock resistant 2D21
5728 = FG-67 – 1 kV, 2.5 A Mercury-vapor triode thyratron, half-indirect 5 V/4.5 A heater, UX4 Bayonet base with anode on top cap
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, 6.3 V/450 mA heater, 42-pin base;[138] cf. 5738, 6090, 6091, 6170, 6324
5730 – Cyclophon, a beam deflection, 30-channel analog demultiplexer for telecomms receiving channel banks, internal electrostatic focusing and deflection to determine which one out of 30 anodes receives the electron beam controlled by a common grid, 6.3 V/450 mA heater, 42-pin base
5731 – Narrow-tolerance selected 955Acorn triode used in Radiosonde weather balloon transmitters
5732 – Ruggedized 6K7 pentode
5734, 5734A – 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, 6.3 V/150 mA heater, metal envelope, circular 4-pin/wire-ends[139][140][98]
5736 – 2.5 kW, 60 MHz Forced-air cooled power triode, 6 V/60 A filament
5737 – 150 kW, 20 MHz Water-cooled power triode, 25 V/650 A filament
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, 6.3 V/600 mA heater, 12-pin Diheptal (electron gun) plus JEDEC B26-53 26-pin (dynodes) bases;[141] cf. 5729, 6090, 6091, 6170, 6324
5741 – 20 kV, 20 mA Radiation-cooled half-wave rectifier, 10 V/5 A filament, UX4 Bayonet base with anode on top cap
5750 – Ruggedized 6BE6/EK90 heptode pentagrid converter, shock resistant up to 450 g
5751 – Dual low-noise, high-μ triode with separate cathodes, center-tapped 12.6 V/175 mA resp. 6.3 V/350 mA heater, Noval base; avionics version: 5751-WA
5755 – Ruggedized, low microphonics, low-drift, separate cathodes dual triode used as precision DC amplifier in stabilized DC power supplies and analog computers, center-tapped 12.6 V/180 mA resp. 6.3 V/360 mA heater, Noval base
5759 – 1 kW, 150 MHz Forced-air cooled power triode, center-tapped 7.5 V/24 A filament
5760 (Water-cooled), 5761 (Forced-air cooled) – 1.5 kW, 150 MHz power triode, center-tapped 7.5 V/24 A filament
5762/7C24 = RCA 4654, 5762A – 4 kW, 30 MHz Forced-air cooled power triode, center-tapped 12.6 V/29 A filament
5763 (6.0 V/750 mA heater), 6417 (12.6 V/375 mA heater) – 12 W, 175 MHz Beam power tetrode, Noval base
5794, 5794A/6562 – 600 mW, 1.68 GHz Pencil-type power triode fixed-tuned oscillator assembly with integral cathode and anode cavity resonators used in Radiosonde weather balloon transmitters, 5.2-6.6 V/160 mA heater
5812 – 10 W, 165 MHz Beam power pentode, center-tapped 6 V/650 mA oxide-coated quickstart filament, Miniature 7-pin base
5813 – 1.8" Slow scan video camera tube, 6.3 V/600 mA heater
5814, 5814A – Ruggedized, industrial/computer-rated version of 12AU7/ECC82 dual medium-μ triode with a Silicon-free, center-tapped 12.6 V/175 mA resp. 6.3 V/350 mA heater; avionics versions: 5814-WA, 5814-WB
5817 (4.8-5 GHz), 5818 (5-5.2 GHz) – 1.6 W Forced-air cooled Reflex Klystrons used in microwave radio relais, 6.3 V/1.5 A heater
5819 – 10-Stage, head-on S9 photomultiplier, Diheptal 14-pin base
5820, 5820A, 5820A/L (Longer-life, non-deteriorating glass target) – 1.8" Image Orthicon, 6.3 V/600 mA heater, Diheptal 14-pin base
5821 – 1.2 kV, 9 A Water-cooled Ignitron
5822, 5822A – 1.2 kV, 20 A Water-cooled Ignitron
5823/Z900T – 200 V, 25 mAavg, 100 mApeak Gas-filled, cold-cathode AC trigger triode, Miniature 7-pin base
5824 – Premium version of 25B6-G power pentode
5825 – 60 kV, 2 mA Half-wave rectifier, 1.6 V/1.25 A heater, UX4 base with anode on top cap
5826 – 1.6" Image Orthicon, magnetic focus and deflection, 6.3 V/600 mA heater, Diheptal 14-pin base
5828 – Subminiature medium-μ triode, 1.25 V/10 mA filament
5829-WA – Ruggedized, subminiature avionics separate cathodes dual diode, 6.3 V/150 mA heater, all-glass round cross-section envelope with 7 long wire-ends
5831 – 150 kW Water-cooled beam power tetrode, 6 V/2.22 kA heater
5833 – 35 kW, 6 MHz Forced-air cooled power triode, 3-phase filaments internally star-connected with center/neutral available, 20 V/143 AY each
5834 = 649 (2.5 V/7 A filament, 2 A anode), 5835 = 653 (2.5 V/9.5 A filament, 3 A anode) – 900 V Half-wave Mercury-vapor rectifiers, UX4 Bayonet base
5836Raytheon RK5836 – 250 mW, 1.6-6.5 GHz Reflex Klystron, 6.3 V/750 mA heater, 4-pin PeeWee base with external-cavity contact rings and top cap; pulse-rated variant of type 6BL6
5837 – 150 mW, 0.55-3.8 GHz Reflex Klystron, 6.3 V/675 mA heater, 4-pin PeeWee base with external-cavity contact rings and top cap; pulse-rated variant of type 6BM6
5838 (12.6 V/600 mA heater), 5839 (26.5 V/255 mA heater), 5852 (6.3 V/1.2 A heater) – Ruggedized, pre-aged 6X5/EZ35 full-wave rectifier
5841 – 900 V Subminiature Corona voltage-regulator tube
5842 = Western Electric 417A = CSF F7004 – Medium-μ triode used in grounded-grid amplifiers, 6.3 V/300 mA heater, Noval base (not to be confused with the 7004=TBL2/300 RF power triode)
5844 – Dual medium-μ triode, 6.3 V/300 mA heater, Miniature 7-pin base
5845 – Directly heated, dual 300 V, 1 mA thermally-limited (=saturated) emission diode used as a heating current-controlled, variable series resistor in voltage/current stabilizer circuits, or as an RMS heating current-to-DC anode current converter, or as a noise diode, center-tapped 5 V/435 mAmax uncoated Tungsten filament, Miniature 7-pin base; cf. Tesla RA0007, YA1000
5846 – 9.28 GHz Reference microwave cavity
5847 = Western Electric 404A, 5847A – Frame-grid sharp-cutoff pentode, 6.3 V/300 mA heater, Noval base
5851 – Ruggedized, subminiature 400 MHz beam power pentode, center-tapped 2.5 V/55 mA resp. 1.25 V/110 mA filament, all-glass round cross-section envelope, circular 8-pin/wire-ends
5875 – Subminiature sharp-cutoff pentode used in Radiosonde weather balloon transmitters, 1.25 V/100 mA filament, all-glass elliptical cross-section envelope with 5 inline wire-ends
5876, 5876A – 6.25 W, 1.7 GHz Ruggedized, Pencil-type, glass/metal, disk-seal, high-μ UHF power triode, 6.3 V/135 mA heater
5877 (2.5 V/10.8 A filament, 3.2 A anode), 5878 (2.5 V/21 A filament, 6.4 A) – 1.5 kV Gas-filled triode thyratrons with negative control characteristic, 4-pin base with anode on top cap
5879 – Low microphony, low-noise, low-hum, sharp-cutoff AF pentode, 6.3 V/150 mA heater, Noval base
5881 – Ruggedized 6L6 AF beam power tetrode with 20% higher anode and screen grid dissipation
5889 – Subminiature electrometer pentode, 12 V anode voltage, 1.25 V/7.5 mA filament, 4+1-pin/wire-ends
5890 – 10 kV, 10 W Remote-cutoff beam power pentode used as 500 µA shunt regulator, 6.3 V/600 mA heater, 7-pin Duodecal base with anode on top cap
5891 – 25 kW, 10 MHz Forced-air cooled power triode, 3-phase filaments internally star-connected with center/neutral available, 11 V/95 AY each
5892 = EL6B – 920 V, 6.4 A Xenon-filled, half-wave rectifier with a Tantalum anode on top cap, 2.5 V/21 A filament, 4-pin base
5893 – Pencil-type, glass/metal, medium-μ triode, 6.0 V/280 mA heater
5894, 5894B = 8738 – 2×20 W, 250 MHz Dual beam power tetrode, center-tapped 12.6 V/900 mA resp. 6.3 V/1.8 A heater, Septar base with anodes on top pins
5895 – 2×8 W, 186 MHz Dual RF power tetrode, 6.3 V/680 mA heater, Loctal base
5896 (6.3 V/300 mA heater), 5903 (26.5 V/75 mA heater) – Subminiature separate cathodes dual diode, all-glass round cross-section envelope, circular 8-pin/wire-ends
5902/EL71 – Ruggedized, subminiature AF beam power pentode, 6.3 V/450 mA heater, all-glass round cross-section envelope with 8 long circular wire-ends; avionics version: 5902-WA
5908 – Ruggedized, subminiature, low (26.5-55 V) anode voltage, dual-control, sharp-cutoff VHF pentode used as a gated or gain-controlled amplifier, designed for both heater and anode to run directly off the standard avionics 28-volts DC bus, 26.5 V/150 mA heater, all-glass round cross-section envelope, circular 8-pin/wire-ends base; similar to 5784
5910 – Sharp-cutoff pentode used in Radiosonde weather balloon transmitters, 1.4 V/50 mA filament, Miniature 7-pin base
5913/6007/DL67 – Subminiature power pentode, 1.25 V/13.3 mA filament, all-glass round cross-section envelope, inline 5-pin/wire-ends
5915/EH960/EH900S, 5915A – Sharp-cutoff switching heptode used in high speed digital computer equipment, Silicon-free 6.3 V/300 mA heater, Miniature 7-pin base
5916 – 5636 Ruggedized, subminiature pentode with a 26.5 V/45 mA heater
5917 – 5 kW, 110 MHz Water-cooled power triode, 7.5 V/48 A filament
5920/E90CC – Common cathode dual triode used as a flip-flop in computers, Silicon-free 6.3 V/400 mA heater, Miniature 7-pin base
5921, 5922 – ATR cells
5923 = TBW6/6000 – 6 kW, 75 MHz Water-cooled power triode, center-tapped 12.6 V/33 A filament
5924, 5924A – 5 kW, 75 MHz Forced-air cooled power triode, center-tapped 12.6 V/33 A filament
5927 – TR cell
5929 – 4.4-5 GHz Power Traveling-wave tube, 6.3 V/2 A heater
5930 – 15 W Ruggedized, directly heated AF power triode, 2.5 V/2.5 A filament, 4-pin base
5931/5U4-WG – Ruggedized full-wave rectifier, 5 V/3 A heater, 5-pin Octal base
5932/6L6-WGA – Ruggedized beam power tetrode, 6.3 V/900 mA heater, 7-pin Octal base
5933/807-W – Ruggedized beam power tetrode, 6.3 V/900 mA heater, 5-pin Octal base
5934 – 20 kV, 25 mA Half-wave rectifier, 2.5 V/6 A filament, 4-pin base with anode on top cap
5935 – Subminiature diode used in VHF voltmeters, 6.3 V/150 mA heater, all-glass wire-ended
5936 – 70 kW, 15 MHz Water-cooled power triode, 20 V/143 A filament
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) – Industrial/computer-rated versions of 12AV7 dual medium-μ triode with a high zero-bias anode current and a Silicon-free, center-tapped (except 5964) 12.6 V/225 mA resp. 6.3 V/450 mA heater
6039 – 7 kW, 220 MHz Water-cooled, ceramic/metal, coaxial VHF power triode used in grounded-grid amplifiers, 5 V/78 A filament; 9C24 with a thoriated Tungsten filament consuming 74.2% less power
6042 (25 V/150 mA heater), 6180 (6.3 V/600 mA heater) – Ruggedized 6SN7-GT dual triodes
6043 = Raytheon QK159 – 2.95-3.275 GHz Reflex Klystron, 6.3 V/650 mA heater, Octal base
6044 – 500 V, 6.4 A Gas-filled triode thyratron, negative control characteristic, 2.5 V/17 A filament
6045 – Ruggedized, dual low-μ triode, 6.3 V/350 mA heater, Miniature 7-pin base
6046 – 25L6-GT Beam power tetrode with a Silicon-free heater and a low-secondary emission control grid
6047 – Additron, a triple-control grid, split-anode tetrode for use as a single-bit digital full adder, 6.3 V/150 mA heater, Noval base[142] (technically a hexode)
6049 – Ruggedized, subminiature remote-cutoff UHF pentode, 6.3 V/150 mA heater, all-glass round cross-section envelope, circular 8-pin/wire-ends base
6050 – Subminiature, directly heated triode, 1.25 V/120 mA filament, all-glass elliptical cross-section envelope with 4 inline wire-ends
6051 – Subminiature power pentode, 1.25 V/100 mA filament, all-glass elliptical cross-section envelope with 5 inline wire-ends
6080 (6.3 V/2.5 A heater), 6082, 6082A (26.5 V/600 mA heater) – Ruggedized 6AS7-G/ECC230 very-low impedance dual power triode, now popular for output transformerless audio amplifiers, shock resistant up to 450 g; avionics versions: 6080-WA, 6080-WB, 6080S
6081 – ATR cell
6083 = PE1/100 = YL1200 – 45 W, 60 MHz Radiation-cooled power pentode, 12.6 V/1.35 A heater, Septar base
6084/E80F – Ruggedized RF/IF/AF pentode, 6.3 V/300 mA heater, Noval base
6085/E80CC – Ruggedized, separate cathodes dual triode used as DC or AF amplifier, center-tapped 6.3 V/600 mA resp. 12.6 V/300 mA heater, Noval base
6086 = Philips 18042 – Pentode used in telephone equipment, 18 V/100 mA heater, Noval base
6087 (Half-indirect 2 A heater), 6106 (half-indirect 1.7 A heater), 6853 = Bendix TE-45 (pre-aged, hard glass, half-indirect 5 V/1.7 A heater) – Ruggedized 5Y3-GB full-wave rectifier
6088 – Subminiature pentode, 1.25 V/20 mA filament, all-glass elliptical cross-section envelope with 5 inline wire-ends
6089 – 9.28 GHz Reference microwave cavity
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, 6.3 V/670 mA heater, 30-pin base;[143] 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, 6.3 V/670 mA heater, 30-pin base;[144] cf. 5729, 5738, 6090, 6170, 6324
6092 – Subminiature power pentode, 1.25 V/50 mA filament, all-glass elliptical cross-section envelope with 5 inline wire-ends
6094 – 12,5 W Ruggedized, hard glass 6005/6AQ5-W beam power tetrode with a 6.3 V/600 mA heater and a Noval base with Gold-plated pins
6130/3C45 – 3 kV, 45 mAavg, 1.5 ARMS, 35 Apeak Hydrogen triode thyratron, positive control characteristic, half-indirect 6.3 V/2-2.5 A heater, Micanol UX4 base with anode on top cap
6132 – Ruggedized 6CH6/EL821 power pentode
6133 – 1.2-3.75 GHz Reflex Klystron, 6.3 V/650 mA heater, Octal base
6134 – Ruggedized 6AC7 sharp-cutoff pentode
6135 – Ruggedized 6C4/EC90 VHF triode with a 6.3 V/175 mA heater
6136 – Ruggedized 6AU6/EF94 sharp-cutoff pentode
6137 – Ruggedized 6SK7 remote-cutoff pentode
6140 – 100 V, 4 to 8 mA Voltage-regulator tube, Noval base
6141 = Western Electric 427A – 100 V, 5 to 40 mA Voltage-regulator tube with a keep-alive (primer) electrode, Noval base
6142 – 150 V, 75 to 400 µA Voltage-regulator tube with 2 axial leads like a r
H3A European 3-pin
A4A Transcontinental European 4-pin
O5A Transcontinental European 5-pin
B6H Continental European 6-pin "Hexode"
C7H Continental European 7-pin "Hexode"
M7A British 7-pin
B9H British 9-pin
UX4 American 4-pin, optionally with Bayonet (=side locating key pin)
UY5 American 5-pin
U6A American 6-pin
U7A/B American 7-pin with pin circle diameters A: 0.75in, B: 0.855in, optionally with Bayonet
P8A Transcontinental European side-contact 8-pin
V5A Transcontinental European side-contact 5-pin
Y8A German steel tube 8-pin, a.k.a. "German Metal Octal"![K8A [International] Octal ("IO"; IEC 67-I-5a) 8-pin](https://upload.wikimedia.org/wikipedia/commons/thumb/a/a1/Roehre-Oktalsockel.jpg/120px-Roehre-Oktalsockel.jpg)
K8A [International] Octal ("IO"; IEC 67-I-5a) 8-pin
K8B MazdaOctal 8-pin with one missing
B12A Duodecal (IEC 67-I-17a) 12-pin
B8G Loctal (IEC 67-I-9a) 8-pin, a.k.a. Loktal, Lock-in, Octalox
B9G Loctal (IEC 67-I-6a) 9-pin, a.k.a. Enneal
B7A Septar (IEC 67-I-20a, JEDEC E7-2) 7-pin
B7G Miniature 7-pin (IEC 67-I-10a, JEDEC E7-1), a.k.a. Heptal, Small-Button 7, Pico-7
B8A Rimlock (IEC 67-I-11a, JEDEC E8-30) 8-pin, a.k.a. Rimlok, Pico-8
B9A Noval (T6½ env., IEC 67-I-12a, JEDEC E9-1)/Neonoval (T9 env., JEDEC E9-68) 9-pin, a.k.a. Small-Button 9, Pico-9
B9D Magnoval (IEC 67-I-36a, JEDEC E9-23 - not B9E Novar) 9-pin
B10B Decal (IEC 67-I-41a, JEDEC E10-61) 10-pin
B12C Duodecar (IEC 67-I-34a for T9 env. resp. 67-I-35a for T12 env., JEDEC E12-70 resp. E12-74 – Compactron) 12-pin
B4F/U4J Jumbo (IEC 67-I-23, JEDEC A4-29) 4-pin, Bayonet between pins 2, 3
B4D Superjumbo (IEC 67-I-28a, JEDEC A4-81) 4-pin, Bayonet between pins 2, 3
![K8A [International] Octal ("IO"; IEC 67-I-5a) 8-pin](https://commons.wikimedia.org/wiki/File:Roehre-Oktalsockel.jpg)
Media related to Vacuum tube bases at Wikimedia Commons
Globe tube
Baloon tube
Metal tube, this one with a top cap
ST – Shouldered tube, a.k.a. domed baloon tube![GT – Glass Tubular cylindrical tube, a.k.a. Bantam tube, Dwarf tube, "Tom Thumb"[16]](https://upload.wikimedia.org/wikipedia/commons/thumb/3/31/Fender_vacuum_tube.jpg/53px-Fender_vacuum_tube.jpg)
All-glass miniature, a.k.a. Button tube (mostly Heptal, Noval, Duodecar base)
Subminiature all-glass wire-ended (fly-leads in place of pins), low-frequency Pencil tubes
Steel tube(de)
_Svetlana_1969_01.jpg)
![GT – Glass Tubular cylindrical tube, a.k.a. Bantam tube, Dwarf tube, "Tom Thumb"[16]](https://commons.wikimedia.org/wiki/File:Fender_vacuum_tube.jpg)
