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This is a list of vacuum tubes or thermionic valves, and low-pressure gas-filled tubes, or discharge tubes. Before the advent of semiconductordevices, thousands of tube types were used in consumer electronics. Many industrial, military or otherwise professional tubes were also produced. Only a few types are still used today, mainly in high-power, high-frequency applications.
Vintage General Electric 6CS7 vacuum tube marked 'Tassa Radiofonica'
Receiving tubes have heaters or filaments intended for direct battery operation, parallel operation off a dedicated winding on a supply transformer, or series string operation on transformer-less sets. High-power RF power tubes are directly heated; the heater voltage must be much smaller than the signal voltage on the grid and is therefore in the 5...25 V range, drawing up to hundreds of amperes from a suitable heater transformer. In some valve part number series, the voltage class of the heater is given in the part number, and a similar valve might be available with several different heater voltage ratings.
FL – Subminiature all-glass elliptical body and flat bases with long, inline "flying leads" (wire-ends) that are soldered into the circuit
SL – Subminiature all-glass elliptical body and flat bases with short inline leads that can be soldered or can be mated with a special socket. (Flying leads can be cut short to fit into inline sockets.)
R8 – Subminiature all-glass round body and base with 8 flying leads or stiff pins arranged in a circle
RETMA is the acronym for the Radio Electronic Television Manufacturers Association formed in 1953 - however the standard itself had already been in use since 1933, when RCA/Cunningham introduced the 1A6, 2A3, 2A5, etc.
The first character group is a number representing the heater voltage rounded to the nearest whole number; 0 indicates a cold-cathode tube.
One or two letters assigned to the devices in order of development.
A single numeral that represents the number of active elements in the tube.
Lastly, manufacturers may decide to combine two type numbers into a single name, which their one device can replace, such as: 6DX8/ECL84 (6DX8 and ECL84 being identical devices under different naming schemes) or 6BC5/6CE5 (sufficiently identical devices within the RETMA naming system) and even 3A3/3B2, or 6AC5-GT/6AC5-G (where the single type number, 6AC5-GT/6AC5-G, supersedes both the 6AC5-G and the 6AC5-GT).
Often designations that differed only in their initial numerals would be identical except for heater characteristics.
The system was used in 1942–44 and assigned numbers with the base form "1A21", and is therefore also referred to as the "1A21 system".
The first numeric character indicated the filament/heater power rating, the second alphabetic character was a code for the function, and the last 2 digits were sequentially assigned, beginning with 21
A four-digit system was maintained by JETEC since 1944, then by EIA since 1957 for special industrial, military and professional vacuum and gas-filled tubes, and all sorts of other devices requiring to be sealed off against the external atmosphere.
Some manufacturers preceded the EIA number with a manufacturer's code:
Eitel/McCullough and other manufacturers of high power RF tubes use the following code since 1945:
An initial digit denoting the number of electrodes:
2 – Diode
3 – Triode
4 – Tetrode
5 – Pentode
Up to 2 letters denoting the construction type and the cooling method:
R or a dash ("-") – Glass envelope, radiation cooling
C – Ceramic envelope
K – (Reflex-)Klystron
P – Primarily for pulse applications
L – External anode, liquid convection cooling
N – External anode, natural convection air cooling
S – External anode, conduction cooling
V – Vapor cooled (anode is immersed in boiling water, and the steam is collected, condensed and recycled)
W – Water cooled (water is pumped through an outer metal jacket thermically connected to the anode)
X – Forced-air cooled (air is blown through cooling fins thermally connected to the anode)
A number to indicate the maximum anode dissipation in watts. This can be exceeded for a short time, as long as the average is not exceeded over the anode's thermal time constant (typically 0.1 sec). In Class-C applications, the amplifier output power delivered to the load may be higher than the device dissipation
One or more manufacturer-proprietary letters denoting the construction variant
4-1000A (8166) – 1 kW Glass beam tetrode popular in broadcast and amateur transmitters.
4CX250B – 250 W Ceramic tetrode, forced-air cooled, version 'B', favored by radio amateurs as a final amplifier.
4CX250BC – 250 W Ceramic tetrode, forced-air cooled, version 'BC'
4CX35000 – Ceramic tetrode used in numerous 50-kW broadcast transmitters, forced-air cooled, often in a Doherty configuration as in the Continental Electronics 317C series.
This system is very descriptive of what type of device (triode, diode, pentode etc.) it is applied to, as well as the heater/filament type and the base type (octal, noval, etc.). Adhering manufacturers include AEG (de), Amperex (us), CdL (1921, French Mazda brand), CIFTE (fr, Mazda-Belvu brand), EdiSwan (uk, British Mazda brand), Radiotechnique (fr, Coprim, Miniwatt-Dario and RTC brands), Lorenz (de), MBLE (be, Adzam brand), Mullard (uk), Philips (nl, Miniwatt brand), RCA (us), RFT (de), Siemens (de), Telefunken (de), Tesla (cz), Toshiba (ja), Tungsram (hu), Unitra (pl, Dolam, Polam and Telam brands) and Valvo (de).
Standard tubes
This part dates back to the joint valve code key (German: Röhren-Gemeinschaftsschlüssel) negotiated between Philips and Telefunken in 1933–34. Like the North American system the first symbol describes the heater voltage, in this case, a Roman letter rather than a number. Further Roman letters, up to three, describe the device followed by one to four numerals assigned in a semi-chronological order of type development within number ranges assigned to different base types.
If two devices share the same type designation other than the first letter (e.g. ECL82, PCL82, UCL82) they will usually be identical except for heater specifications; however there are exceptions, particularly with output types (for example, both the PL84 and UL84 differ significantly from the EL84 in certain major characteristics, although they have the same pinout and similar power rating). However, device numbers do not reveal any similarity between different type families; e.g. the triode section of an ECL82 is not related to either triode of an ECC82, whereas the triode section of an ECL86 does happen to be similar to those of an ECC83.
Pro Electron maintained a subset of the M-P system after their establishment in 1966, with only the first letters E, P for the heater, only the second letters A, B, C, D, E, F, H, K, L, M, Y, Z for the type, and issuing only three-digit numbers starting with 1, 2, 3, 5, 8, 9 for the base.
Notes:Tungsram preceded the M-P designation with the letter T, as in TAD1 for AD1; VATEA Rádiótechnikai és Villamossági Rt.-t. (VATEA Radio Technology and Electric Co. Ltd., Budapest, Hungary) preceded the M-P designation with the letter V, as in VEL5 for EL5.
First letter: heater/filament type
Heater ratings for series-string, AC/DC tubes are given in milliamperes; heater ratings for parallel-string tubes are given in volts
D – 1.4 V DC filament for Leclanché cells, later low-voltage/low power filament/heater:
0.625 V DC directly heated for NiCd battery, series-heated two-tube designs such as hearing aids. If either filament breaks, further draining of all batteries stops
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
Until at least 1938: 4 V battery (as opposed to A for "4 V AC"; no known examples assigned)
I – 20 V heater
K – 2.0 V filament for 1-cell lead-acid batteries, later for AC transformers
L – 450 mA AC/DC series heater; was shifted here from Y
Z – Vacuum full-wave rectifier (dual power diode with common cathode)
Following digits: model number and base type
For signal pentodes, an odd model number most often identified a variable-mu (remote-cutoff) tube, whereas an even number identified a 'high slope' (sharp-cutoff) tube
For power pentodes and triode-pentode combinations, even numbers usually indicate linear (audio power amplifier) devices while odd numbers were more suited to video signals or situations where more distortion could be tolerated.
1–9 – Pinch-type construction tubes, mostly P8A side-contact 8-pin bases (P base) or V5A side-contact 5-pin (V base) and various other European pre-octal designs
50–59 – "Special construction types fitted with bases applicable to design features used"; mostly locking bases: "9-pin Loctal" (B9G) or 8-pin Loctal (B8G); but also used for Octal and others (3-pin glass; Disk-seal incl. Lighthouse tubes; German 10-pin with spigot; min. 4-pin; B26A; Magnoval B9D)
60–69 – Pencil tubes – sub-miniature all-glass tubes, wire-ended (inline fly-leads in place of pins)
—Before the 1950s:
60–64 – All-glass tubes fitted with 9-pin Loctal (B9G) bases
70–79 – Pencil tubes with circular pins or fly-leads
Vacuum tubes which had special qualities of some sort, very often long-life designs, particularly for computer and telecommunications use, had the numeric part of the designation placed immediately after the first letter. They were usually special-quality versions of standard types. Thus the E82CC was a long-life version of the ECC82 intended for computer and general signal use, and the E88CC a high quality version of the ECC88/6DJ8. While the E80F pentode was a high quality development of the EF80, they were not pin-compatible and could not be interchanged without rewiring the socket (the E80F is commonly sought after as a high quality replacement for the similar EF86 type in guitar amplifiers). The letters "CC" indicated the two triodes and the "F", the single pentode inside these types.
A few special-quality tubes did not have a standard equivalent, e.g. the E55L, a broadband power pentode used as the output stage of oscilloscope amplifiers and the E90CC, a dual triode with a common cathode connection and seven pin base for use in cathode-coupled Flip-flops in early computers. The E91H is a special heptode with a passivated third grid designed to reduce secondary emission; this device was used as a "gate", allowing or blocking pulses applied to the first, (control) grid by changing the voltage on the third grid, in early computer circuits (similar in function to the U.S. 6AS6).
Many of these types had gold-plated base pins and special heater configurations inside the nickel cathode tube designed to reduce hum pickup from the A.C. heater supply, and also had improved oxide insulation between the heater and cathode so the cathode could be elevated to a greater voltage above the heater supply. (Note that elevating the cathode voltage above the average heater voltage, which in well-designed equipment was supplied from a transformer with an earthed center-tapped secondary, was less detrimental to the oxide insulation between heater and cathode than lowering the cathode voltage below the heater voltage, helping to prevent pyrometallurgical electrolytic chemical reactions where the oxide touched the nickel cathode that could form conductive aluminium tungstate and which could ultimately develop into a heater-cathode short circuit.)
Better, often dual, getters were implemented to maintain a better vacuum, and more-rigid electrode supports introduced to reduce microphonics and improve vibration and shock resistance. The mica spacers used in "SQ" and "PQ" types did not possess sharp protrusions which could flake off and become loose inside the bulb, possibly lodging between the grids and thus changing the characteristics of the device. Some types, particularly the E80F, E88CC and E90CC, had a constricted section of bulb to firmly hold specially shaped flakeless mica spacers.
Later special-quality tubes had not base and function swapped but were assigned a 4-digit number, such as ECC2000 or ED8000, the first digit of which again denoting the base:
S – Separate-cathode Counter/Selector Dekatron that makes all cathodes available on individual pins for displaying, divide-by-n counter/timer/prescalers, etc.
T – Relay triode, a low-power triode thyratron, one starter electrode, may need illumination for proper operation if not radioactively primed
U – Low-power tetrode thyratron, may mean:
Trigger tetrode, one starter electrode and a primer (keep-alive) electrode for ion availability to keep the ignition voltage constant, for analog RC timers, voltage triggers, etc.
Relay tetrode, two starter electrodes to make counters bidirectional or resettable
W – Trigger pentode, two starter electrodes and a primer electrode
X – Shielded Trigger pentode, two starter electrodes, a primer electrode and a conductive coating of the glass envelope inside connected to a separate pin
X – Large thyratron (including all hydrogen thyratrons and high-current types)
The following letter indicates the filament or cathode type, or the fill gas or other construction detail. The coding for vacuum devices differs between Philips (and other Continental European manufacturers) on the one hand and its Mullard subsidiary on the other.
The second digit is a sequentially assigned number.
The following letter indicates the photocathode type:
A – Caesium-activated antimony cathode. Used for reflective-mode photocathodes. Response range from ultraviolet to visible. Widely used.
C – Caesium-on-oxidated-silver cathode, also called S1. Transmission-mode, sensitive from 300...1200 nm. High dark current; used mainly in near-infrared, with the photocathode cooled.
T – Trialkalisodium-potassium-antimony-caesium cathode, wide spectral response from ultraviolet to near-infrared; special cathode processing can extend range to 930 nm. Used in broadband spectrophotometers.
75B1 – Voltage reference tube, miniature 7-pin base
75C1 – Voltage reference tube, miniature 7-pin base
83A1 – Voltage reference tube, miniature 7-pin base
85A1/0E3 – Voltage reference tube, B8G Loctal base
85A2/0G3 – Voltage reference tube, miniature 7-pin base
90C1 – Voltage reference tube, miniature 7-pin base
95A1 – Voltage reference tube, miniature 7-pin base
100E1 – Voltage reference tube, A4A European 4-pin Base
108C1/0B2 – Voltage reference tube, miniature 7-pin base
150A1 – Voltage reference tube, P8A side-contact 8 base
150B2 – Voltage reference tube, miniature 7-pin base
150B3 – Voltage reference tube, miniature 7-pin base
150C1 – Voltage reference tube, P8A side-contact 8 base
150C2/0A2 – Voltage reference tube, miniature 7-pin base
150C4 – Voltage reference tube, miniature 7-pin base
Compagnie des Lampes (1888, "Métal") system
The first (1888) incarnation of La Compagnie des Lampes produced the TM tube since 1915 and defined one of the first French systems; not to be confused with Compagnie des Lampes (1921, "French Mazda", see below).
B142 – 400 W RF power triode up to 50 MHz similar to 833A
B1109 = 3C24 – 25 W VHF power triode up to 60 MHz
B1135 = 5867 = CV1350 – VHF power triode up to 100 MHz
B1152 – 500W RF power triode up to 50 MHz
QT1257 – Touch button tube, an illuminated capacitance touch switch; a cold-cathode DC relay tube, external (capacitive) starter activated by touching; then the cathode glow is visible. 6-pin octal base
XL601, XL602, XL603, XL627, XL628, XL631 and XL632 – Cold-cathode, linear light source (glow modulator tube), gas diode with a blue-violet glow, modulation up to 1 MHz, 2-pin Octal base, for rotating-drum FAX receivers, etc.
The British GEC–Marconi–Osram designation from the 1920s uses one or two letter(s) followed by two numerals and sometimes by a second letter identifying different versions of a particular type.
The letter(s) generally denote the type or use:
Note: A preceding letter M indicates a 4-volts AC indirectly heated tube
Older Mullard tubes were mostly designated PM, followed by a number containing the filament voltage.
Many later tubes were designated one to three semi-intuitive letters, followed by a number containing the heater voltage. This was phased out after 1934 when Mullard adopted the Mullard–Philips scheme.
Examples:
2D4 – Dual Diode with a 4 V/650 mA heater and a British 5-pin base
AP4 = 4676 – Acorn UHF pentode up to 430 MHz, 4 Volts heater
AT4 = 4675 – Acorn UHF triode up to 430 MHz, 4 Volts heater
FC4 – Octode Frequency Converter with a 4 V/650 mA heater and a British 7-pin base; similar to the M-OV/GEC MX40 heptode
Pen20 – Power Pentode with a 20 V/180 mA heater and a British 5- or 7-pin base
PM254 = P425 – "Super Power" triode with a 4 V/200 mA battery heater and a British 4-pin base
TDD4 = MHD4 = AC/HLDD – Triode, dual Diode with a 4 V/550 mA heater and a British 7-pin base
TH21C – Triode/Hexode frequency converter with a 21 V/200 mA series heater and a British 7-pin base
TP4 = AC/TP – Triode, Pentode with a 4 V/1.25 A heater and a British 9-pin base
VP2 = VP21 = VP215 – Variable-mu Pentode with a 2 V/180 mA heater and a British 7-pin base
Philips system before 1934
The system consisted of one letter followed by 3 or 4 digits. It was phased out after 1934 when Philips adopted the Mullard–Philips scheme.
20D4 – Indirectly heated, triode/heptode frequency mixer, Noval base
Valvo system before 1934
Valvo 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.
L496D = E443H = RES964 = PP4101 – Power pentode, 4 V heater
L2318D = B2043 = RENS1823D = PP2018D – Power pentode, 180 mA heater
East European systems
Lamina transmitting tubes system
Polish Lamina transmitting tube designations consist of one or two letters, a group of digits and an optional letter and/or two digits preceded by a "/" sign.
The first letter indicates the tube type, two equal letters denoting a dual tube:
P – Pentode
Q – Tetrode
T – Triode
A group of digits represents the maximum anode power dissipation in kW
An optional letter specifies the cooling method:
<none> – Radiation
P – Forced air
W – Water
The first of the two digits after the "/" sign means:
1 – Tube for radio broadcasting and radiocommunication equipment
2 – Tube for industrial equipment
3 – Tube used in TV broadcasting equipment
4 – Tube for radiocommunication equipment with unbalanced modulation
5 – Modulator or pulse tube
The second digit after the "/" is sequentially assigned.
Examples:
Q01 – Power tetrode up to 125 MHz, 0.1 kW (=100 W)
Q3.5 – Power tetrode up to 220 MHz, 3.5 kW
QQ-004/11 – Dual beam power tetrode up to 500 MHz, 0.04 kW (=40 W)
T01 – Power triode up to 200 MHz, 135 W
T015/21 – Power triode up to 150 MHz, 150 W
T02 – Power triode up to 60 MHz, 200 W
T05P/31 – Forced air cooled power triode up to 1 GHz, 1 kW
T2/22 – Power triode up to 60 MHz, 3 kW
T6 – Power triode up to 30 MHz, 6 kW
T8P/21 – Forced air cooled power triode up to 120 MHz, 8 kW
T10P/22 – Power triode up to 30 MHz, 10 kW
T-25P – Forced air cooled power triode up to 30 MHz, 25 kW
T60W/21 – Water cooled power triode up to 30 MHz, 6 kW
RFT transmitting tubes system
Rundfunk- und Fernmelde-Technik was the brand of a group of telecommunications manufacturers in the German Democratic Republic. The designation consists of a group of three letters and a group of three or four digits.
The first two letters determine the tube type:
GR – Rectifier tube
SR – Transmitter tube
VR – Amplifier tube
The third letter specifies the cooling method:
L – Forced air
S – Radiation
V – Vapor (the anode is immersed in evaporating water, and the steam is collected, condensed and recycled)
W – Water
The first digit (or the first two digits in double tubes) indicates the number of electrodes:
2 – Diode
3 – Triode
4 – Tetrode
5 – Pentode
The last two digits are sequentially assigned.
Examples:
SRS301 – Radiation-cooled triode up to 40 MHz, 900 W
SRS464 – Radiation-cooled, vibration-resistant pulse tetrode up to 300 kW
SRS4451 – Radiation-cooled dual tetrode up to 500 MHz, 60 W
SRS4452 = QQE03/20 = 6252 – Radiation-cooled dual tetrode up to 600 MHz, 20 W
SRS4452 – Radiation-cooled dual tetrode up to 600 MHz, 20 W
SRS501 – Radiation-cooled pentode up to 50 MHz, 100 W
SRS552N = ГУ-50 – Radiation-cooled pentode up to 120 MHz, 50 W
Next number: Anode dissipation in W (if radiation cooled) or kW (otherwise)
The next letter specifies the cooling method:
<none> – Radiation
V – Vapor
X – Forced air
Y – Water
Examples:
RA0007B – Directly heated saturated-emission ballast diode. Acts as a heating current-controlled, variable series resistor in voltage/current stabilizer circuits; UAmax 600 V IAmax 700 μA, noval base
RA100A – 40 kV, 100 mA Half-wave rectifier with an E40 Goliath Edison screw lamp base and an anode top cap
RC5B – Bowl-type UHF power triode up to 5 W
RD27AS – Radiation-cooled power triode up to 25 MHz, 27 W
RD200B – Radiation-cooled power triode up to 60 MHz, 200 W
RD300S – Radiation-cooled power triode up to 200 MHz, 300 W
RD150YA – Water-cooled power triode up to 3 MHz, 150 kW
RE65A – Radiation-cooled beam tetrode up to 260 MHz, 65 W
RE125C – Radiation-cooled beam tetrode up to 235 MHz, 125 W
RE400C – Radiation-cooled beam tetrode up to 235 MHz, 400 W
RE20XL – Air-cooled beam tetrode up to 220 MHz, 20 kW
REE30A – Radiation-cooled dual beam tetrode up to 250 MHz, 20 W
RL15A – Radiation-cooled power pentode up to 60 MHz, 20 W
RL40A – Radiation-cooled power pentode up to 120 MHz, 40 W
RL65A – Radiation-cooled power pentode up to 15 MHz, 65 W
UA025A – 10 kV, 250 mA Argon-filled, half-wave rectifier with an E27 Edison screw lamp base and an anode screw top cap
UA5A – 11 kV, 5 A Half-wave mercury-vapor rectifier with a 2-pin base and an anode screw top cap
ZD1000F – Radiation-cooled power triode up to 60 MHz, 1 kW
ZD1XB – Air-cooled AF power triode up to 1.2 kW
ZD3XH – Air-cooled power triode up to 60 MHz, 3 kW
ZD8XA – Air-cooled power triode up to 20 MHz, 8 kW
ZD12YA – Air-cooled AF power triode up to 20 MHz, 12 kW
ZE025XS – Air-cooled beam tetrode up to 400 MHz, 250 W
Tungsram receiving tubes system before 1934
The Tungsram system was composed of a maximum of three letters and three or four digits. It was phased out after 1934 when Tungsram adopted the Mullard–Philips scheme, frequently preceding it with the letter T, as in TAD1 for AD1.
Letter: System type:
Note: A preceding letter A indicates an indirectly heated tube
D – Detector diode
DD – Dual diode
DG – Tetrode with a space charge grid (the 2nd grid is the control grid)
Vacuum tubes produced in the former Soviet Union and in present-day Russia are designated in Cyrillic. Some confusion has been created in transliterating these designations to Latin.
The first system was introduced in 1929. It consisted of one or two letters (designating system type and, optionally, type of cathode), a dash, then a sequentially assigned number with up to 3 digits.
In 1937, the Soviet Union purchased a tube assembly line from RCA (who at the time had difficulties raising funds for their basic operations), including production licenses and initial staff training, and installed it on the Svetlana/Светлана plant in St. Petersburg, Russia. US-licensed tubes were produced since then under an adapted RETMA scheme.
In the 1950s a 5-element system (Russian: Государственный Стандарт "State standard" ГОСТ/GOST 5461–59, later 13393–76) was adopted in the (then) Soviet Union for designating receiver vacuum tubes.
The first element is a number specifying filament voltage. The second element is a Cyrillic letter specifying the type of device. The third element is a sequentially assigned number that distinguishes between different devices of the same type.
The fourth element denotes the type of envelope. An optional fifth element consists of a dash followed by one or more characters to designate special characteristics of the tube. This usually implies construction differences, not just selection from regular quality production.
Professional tubes system
There is another designation system for professional tubes such as transmitter ones.
The first element designates function. The next elements varies in interpretation. For ignitrons, rectifiers, and thyratrons, there is a digit, then a dash, then the anode current in amperes, a slash, anode voltage in kV. A letter may be attached to designate water cooling (no letter designates a radiation cooled device). For transmitting tubes in this system, the second element starts with a dash, a sequentially assigned number, then an optional letter specifying cooling method. For phototubes and photomultipliers, the second element is a sequential number and then a letter code identifying vacuum or gas fill and the type of cathode.
6M-E10 – "Magic Eye"-type tuning indicator, miniature 7-pin base
6N-H10 – Nuvistor
6R-A8 – Power triode
6R-B10 – Beam power tube
6R-B11 – Beam power tube
Military naming systems
British CV and M8000s naming systems
This system prefixes a three- or four-digit number with the letters "CV", meaning "civilian valve" i.e. common to all three armed services. It was introduced during the Second World War to rationalise the previous nomenclatures maintained separately by the War Office/Ministry of Supply, Admiralty and Air Ministry/Ministry of Aircraft Production on behalf of the three armed services (e.g. "ACR~", "AR~", "AT~", etc. for CRTs, receiving and transmitting valves used in army equipments, "NC~", "NR~" and "NT~" similarly for navy equipments and "VCR~", "VR~" and "VT~" etc. for air force equipments), in which three separate designations could in principle apply to the same valve (which often had at least one prototype commercial designation as well). These numbers generally have identical equivalents in both the North American, RETMA, and West European, Mullard–Philips, systems but they bear no resemblance to the assigned "CV" number.
Examples:
CV1988 = 6SN7GT = ECC32 (not a direct equivalent as heater current is different and bulb is larger)
CV2729 = E80F – An SQ version of EF80 but with revised pin-out and a base screen substituted for the RF screen
The "CV4000" numbers identify special-quality valves though SQ valves CV numbered before that rule came in retain their original CV number:
The "M8" in the part number denotes that it was developed by the military:
M8083 – Sharp-cutoff pentode, miniature 7-pin base (SQ version of EF91 = 6AM6 = Z77)
M8162 = 6060 – High-mu dual triode, for use as RF amplifier/mixer in VHF circuits, Noval base (SQ versions of ECC81 = 12AT7 = B309)
The principle behind the CV numbering scheme was also adopted by the US Joint Army-Navy JAN numbering scheme which was later considerably expanded into the US Federal and then NATO Stock Number system used by all NATO countries. This part-identification system ensures that every particular spare part (not merely thermionic valves) receives a unique stock number across the whole of NATO irrespective of the source, and hence is not held inefficiently as separate stores. In the case of CV valves, the stock number is always of the format 5960-99-000-XXXX where XXXX is the CV number (with a leading 0 if the CV number only has 3 digits).
U.S. naming systems
One system prefixes a three-digit number with the letters "VT", presumably meaning "Vacuum Tube". Other systems prefix the number with the letters "JHS" or "JAN". The numbers following these prefixes can be "special" four-digit numbers, or domestic two- or three-digit numbers or simply the domestic North American "RETMA" numbering system. Like the British military system, these have many direct equivalents in the civilian types.
Confusingly, the British also had two entirely different "VT" nomenclatures, one used by the Royal Air Force (see the preceding section) and the other used by the General Post Office, responsible for post and telecommunications at the time, where it may have stood for "valve, telephone"; none of these schemes corresponded in any way with each other.
Various numeral-only systems exist. These tend to be used for devices used in commercial or industrial equipment. The oldest numbering systems date back to the early 1920s, such as a two-digit numbering system, starting with the UV-201A, which was considered as "type 01", and extended almost continuously up into the 1980s. Three- and four-digit numeral-only systems were maintained by R.C.A., but also adopted by many other manufacturers, and typically encompassed rectifiers and radio transmitter output devices. Devices in the low 800s tend to be transmitter output types, those in the higher 800s are not vacuum tubes, but gas-filled rectifiers and thyratrons, and those in the 900s tend to be special-purpose and high-frequency devices. Use was not rigorously systematic: the 807 had variants 1624, 1625, and 807W.
Other letter followed by numerals
There are quite a number of these systems from different geographical realms, such as those used on devices from contemporary Russian and Chinese production. Other compound numbering systems were used to mark higher-reliability types used in industrial or commercial applications. Computers and telecommunication equipment also required tubes of greater quality and reliability than for domestic and consumer equipment.
Some designations are derived from the behavior of devices considered to be exceptional.
Mazda/EdiSwan sold their first tubes for 4-volts AC mains transformer (as opposed to home storage battery) heating with the prefix AC/ (for examplessee below).
The first beam tetrodes manufactured in the UK in the late 1930s by M-OV, carried a "KT" prefix meaning Kinkless Tetrode (for examplessee above).
Function in a similar way to a Zener diode, at higher voltages. Letter order (A-B-C) indicates increasing voltage ratings on octal-based regulators and decreasing voltage ratings on miniature-based regulators.
0A2 – 150 volt regulator, 7-pin miniature base
0A3 – 75 volt regulator, octal base, aka VR75
0B2 – 105 volt regulator, 7-pin miniature base
0B3 – 90 volt regulator, octal base, aka VR90
0C2 – 75 volt regulator, 7-pin miniature base
0C3 – 105 volt regulator, octal base, aka VR105
0D3 – 150 volt regulator, octal base, aka VR150
Other cold-cathode tubes
0A4G – 25 mAavg, 100mApeak Gas triode designed for use as a ripple control receiver; with the cathode tied to the midpoint of a series-resonance LC circuit across live mains, it would activate a relay in its anode circuit while fres is present
0Y4 – 40 ≤ I ≤ 75 mA Half-wave gas rectifier with a starter anode, 5-pin octal base
0Z4 – 30 ≤ I ≤ 90 mA Argon-filled, full-wave gas rectifier, octal base. Widely used in vibrator power supplies in early automobile radio receivers.
1 volt heater/filament tubes
1.25 volt DC filament subminiature tubes
The following tubes were used in post-World War II walkie-talkies and pocket-sized portable radios. All have 1.25 volt DC filaments and directly heated cathodes. Some specify which end of the filament is to be powered by the positive side of the filament power supply (usually a battery). All have glass bodies that measure from 0.285 to 0.400 inches (7.2 to 10.2 millimetres) wide, and from 1.25 to 2.00 inches (32 to 51 millimetres) in overall length.
1A3 – High frequency diode with indirectly heated cathode. Used as a detector in some portable AM/FM receivers.
1A7GT/DK32 – Pentagrid converter, re-engineered version of types 1A6 and 1D7-G, designed for use in portable AC/DC/Dry-cell battery radios introduced in 1938. Has 1.4 V/50 mA filament.
1B7-GT – Re-engineered version of types 1C6 and 1C7-G, designed for use in dry-cell battery radios with shortwave bands. Has 1.4 V/100 mA filament
1G6-G – Dual power triode. "GT" version also available.
1L6 – Pentagrid frequency changer for battery radios with 50 mA filament
1LA6 (Loctal) and later 1L6 (7-pin miniature) – Battery pentagrid converter for Zenith Trans-Oceanic shortwave radio, 50 mA filament
1LB6 – Superheterodyne mixer for battery-operated radios
1LC6 – Similar to type 1LA6, but with higher conversion transconductance
1S4 – Power output pentode Class-A amplifier, anode voltage in the 45...90 volt range.
1S5 – Sharp-cutoff pentode Class-A amplifier, and diode, used as detector and first A.F. stage in battery radio receivers. Anode voltage in the 67...90 volt range.
1T4/DF91 – Remote-cutoff R.F. Pentode Class-A amplifier, Miniature 7-pin base, used as R.F. and I.F. amplifier in battery radio receivers.
1U4 – Sharp-cutoff R.F. Pentode Class-A amplifier, Miniature 7-pin base, used as R.F. and I.F. amplifier in battery radio receivers, similar characteristics to 6BA6.
1U6 – Nearly identical to type 1L6, but with a 1.4 V/25 mA filament
"1" prefix for home receivers
These tubes were made for home storage battery receivers manufactured during the early to mid-1930s; all have 2.0 volt DC filaments despite the 1-prefix, intended to distinguish them from the 2.5 volt AC heated tubes listed below
1A4-p – Remote-cutoff pentode
1A4-t – Remote-cutoff tetrode
1A6 – Pentagrid converter up to only 10 MHz due to low heater power (2 V/60 mA) and consequent low emission in the oscillator section; also occasionally used as a grid-leak detector
1B4-p – Sharp-cutoff pentode
1B4-t – Sharp-cutoff tetrode
1B5 – Dual detector diode, medium-mu triode. Usually numbered 1B5/25S
1C5 – Power pentode (similar to 3Q5 except for filament)
1C6 – Pentagrid converter; 1A6, with double the heater power and double the frequency range
1C7-G – Octal version of type 1C6.
1D5-Gp – Octal version of type 1A4-p.
1D5-Gt – Octal version of type 1A4-t. (Note: This is a shouldered "G" octal, not a cylindrical "GT" octal.)
1D7-G – Octal version of type 1A6.
1E5-Gp – Octal version of type 1B4-p.
1E5-Gt – Octal version of type 1B4-t. (Note: This is a shouldered "G" octal, not a cylindrical "GT" octal.)
1E7-G – Dual power pentode for use as a driver when parallel-connected, or as a push-pull output. "GT" version also available
1F4 – Power pentode
1F5-G – Octal version of 1F4.
1F6 – Duplex diode, sharp-cutoff pentode
1F7-G – Octal version of type 1F6
1G4-GT/G – Octal triode, mu 8.8
1G5-G – Power pentode
1H4-G – Medium-mu triode, can be used as a power triode. Octal version of type 30, which is an upgraded version of type 01-A. "GT" version also available.
1H6-G – Octal version of type 1B5/25S. "GT" version also available.
1J5-G (950) – AF Power pentode
1J6-G – Dual power triode, octal version of type 19. "GT" version also available.
CRT anode rectifiers
1G3GT – Octal High-voltage rectifier. Same Characteristics as 1B3GT. Many listed and labeled as 1B3GT/1G3GT.
1H2 – Noval High-voltage rectifier with 1.4 V/550 mA filament
1J3GT – Octal High-voltage rectifier. Same Characteristics as 1B3GT. Has filament-plate shorting protection. Many listed and labeled as 1J3GT/1K3GT.
1K3GT – Octal High-voltage rectifier. Same Characteristics as 1B3GT. Has filament-plate shorting protection. Many listed and labeled as 1J3GT/1K3GT.
1S2A – Noval High-voltage rectifier with 1.4 V/550 mA filament. Similar to DY86, DY87, DY802, 1R10, and 1R12.
1T2 = R16 – Subminiature High-voltage rectifier with 1.4 V/140 mA filament. Has flexible leads.
1V2 – High-voltage rectifier with 0.625 V/300 mA filament, Miniature 7-pin base
1X2 – Noval High-voltage rectifier with 1.25 V/200 mA filament. 1X2A, 1X2B and 1X2C have X-Radiation Shielding. Similar to DY80 and R19.
1Y2 – 4 pin High-voltage rectifier with 1.5 V/290 mA filament. 50KV max PIV, 10mA peak, 2mA average. Usable up to 1 MHz.
1Z1 – Octal High-voltage rectifier with 0.7 V/180 mA filament.
1Z2 – Noval High-voltage rectifier with 1.25 V/265 mA filament.
1AD2 – Compactron High-voltage rectifier with 1.25 V/200 mA filament. Type 1AD2A has X-Radiation Shielding.
1AJ2 – Compactron High-voltage rectifier with 1.25 V/200 mA filament
1AY2 – 2-pin "Duopin" base High-voltage rectifier. Has similar electrical characteristics as 1B3GT.
1B3GT – Octal High-voltage rectifier diode with 1.25 V filament common in monochrome TV receivers of the 1950s and early 1960s. Peak inverse voltage of 30 kV. Anode current 2 mA average, 17 mA peak. Derived from the earlier industrial type 8016. Many listed and labeled as 1B3GT/1G3GT.
1BC2 – Noval High-voltage rectifier with 1.25 V/200 mA filament. Types 1BC2A and 1BC2B have X-Radiation Shielding.
1BG2 – Subminiature High-voltage rectifier with 1.4 V/575 mA filament. Has flexible leads.
1BQ2 – Noval High-voltage rectifier with 1.4 V/600 mA filament
1BY2 – Compactron High-voltage rectifier with 1.25 V/200 mA filament. Type 1BY2A has X-Radiation Shielding.
2 volt heater/filament tubes
2.5 volt AC heater tubes
Tubes used in AC-powered radio receivers of the early 1930s
2A3 – Directly heated power triode, used for AF output stages in 1930s–1940s audio amplifiers and radios.
2A5 – Power Pentode (Except for heater, electronically identical to types 42 and 6F6)
2A6 – Dual diode, high-mu triode (Except for heater, electronically identical to type 75)
2A7 – Dual-tetrode-style pentagrid converter (Except for heater, electronically identical to types 6A7, 6A8 and 12A8)
2B7 – Dual diode and remote-cutoff pentode (Except for heater, electronically identical to type 6B7)
2E5 and 2G5 – Electron-ray indicators ("Eye tube") with integrated control triode. (Except for heater, electronically identical to types 6E5 and 6G5)
CRT anode rectifiers
2X2 – High Vacuum High Peak inverse voltage diode, used as rectifier in CRT EHT supplies. Similar to 1B3 and 1S2 except for heater voltage.
3 volt heater/filament tubes
3A3/3B2/3AW3 - High Voltage rectifier. An octal type used in color television sets. The heater power is 3.15 volts and 0.22 amps.
3CA3 - High Voltage rectifier. An octal type used in color television sets. The heater power is 3.6 volts and 0.225 amps.
3CN3 - High Voltage rectifier. An octal type used in color television sets. The heater power is 3.15 volts and 0.48 amps. The large current is for the advantage of fast warm-up.
3CU3 - High Voltage rectifier. An octal type used in color television sets. The heater power is 3.15 volts and 0.28 amps.
3CZ3 - High Voltage rectifier. An octal type used in color television sets. The heater power is 3.15 volts and 0.48 amps. The large current is for the advantage of fast warm-up.
3AT2 - High Voltage rectifier. A compactron used in television sets to supply power to the anode of the picture tube. It comes in the variation as the 3AT2B, mainly for color television sets with a large picture tube. The 3AT2B comes with X-radiation shielding on the inside. The heater power is 3.15 volts and 0.22 amps.
3AW2 - High Voltage rectifier. A compactron used for color and black and white television sets. It comes in the variation as the 3AW2A as a replacement for the 3AW2 after the 1967 General Electric X-radiation scandal. The 3AW2A comes with X-radiation shielding on the inside. The heater power is 3.15 volts and 0.22 amps.
3BF2 - High Voltage rectifier. A compactron used in television sets to supply power to the anode of the picture tube. This tube is very rare, and very special, because it implements an indirectly heated cathode, not connected to the filament. No data is found on this tube, except for the filament power (which is 3.6 volts, 0.225 amps) and the base (which is the 12GQ type). The only reason why we know it is a high voltage rectifier is that the base tells us so.
3BL2 - High Voltage rectifier. A compactron used in television sets to supply power to the anode of the picture tube. It comes in the variation as the 3BL2A as a replacement for the 3BL2 after the 1967 General Electric X-radiation scandal. The 3BL2A comes with X-radiation shielding on the inside. The heater power is 3.3 volts and 0.285 amps.
3BM2 - High Voltage rectifier. A compactron used in television sets to supply power to the anode of the picture tube. It comes in the variation as the 3BM2A as a replacement for the 3BM2 after the 1967 General Electric X-radiation scandal. The 3BM2A comes with X-radiation shielding on the inside. The heater power is 3 volts and 0.3 amps.
3BN2 - High Voltage rectifier. A compactron used for color television sets. It comes in the variation as the 3BN2A as a replacement for the 3BN2 after the 1967 General Electric X-radiation scandal. The 3BN2A comes with X-radiation shielding on the inside. The heater power is 3.15 volts and 0.22 amps.
3BS2 - High Voltage rectifier. A compactron used for color television sets. It comes in the variation as the 3BS2A and 3BS2B as a replacement for the 3BN2 after the 1967 General Electric X-radiation scandal. The 3BS2A and 3BS2B tubes are identical, maybe a small difference in ratings and characteristics. We do not know these differences as the 3BS2B tube data is not available. The 3BS2A and 3BS2B comes with X-radiation shielding on the inside. The heater power is 3.15 volts and 0.48 amps. The large current is for the advantage of fast warm-up.
3BT2 - High Voltage rectifier. A compactron used for color television sets. It comes in the variation as the 3BT2A as a replacement for the 3BT2 after the 1967 General Electric X-radiation scandal. The 3BT2A comes with X-radiation shielding on the inside. The heater power is 3.15 volts and 0.48 amps. The large current is for the advantage of fast warm-up.
3BW2 - High Voltage rectifier. A compactron used for color and black and white television sets. The 3BW2 comes with X-radiation shielding on the inside. It also comes with diffusion bonded cathode (a type of cathode that prevents the back-emission of the anode). This tube was designed in December 1970, after the 1967 General Electric X-radiation scandal. All high voltage rectifier tube types that were designed before 1967 had no X-radiation protection internally. That is why all these tubes made during and after 1967 have a suffix showing they had internal X-radiation protection. This is why there is no '3BW2A' type since it was made after 1967. The heater power is 3.15 volts and 0.22 amps.
5 volt heater/filament tubes
5R4 – Full wave rectifier
5U4 – Full wave rectifier
5V4, GZ32 – Full wave rectifier
5Y3 – Full-wave rectifier, octal base version of type 80
5AR4, GZ34 – Full wave rectifier
5AS4 – Full wave rectifier
6 volt heater tubes
6A6 – Dual Power Triode, used as a Class-A audio driver or a Class-B audio output. U7B base. 6.3 volt heater version of type 53 which had a 2.5 volt heater. Octal version – 6N7.
6A7 and 6A8 (PH4, X63) – Pentagrid converter – dual tetrode style. Based on type 2A7, which had a 2.5 volt heater. 6A7 has a UX7 base with top cap connection for control grid (grid 4). 6A8 is octal version with top cap connection for control grid. Loctal version: type 7B8.
6B6-G – Dual Diode, High-mu Triode. Octal version of type 75. Has top-cap connection for triode grid. Later octal version, type 6SQ7, has under-chassis connection for triode grid. Miniature version: 6AV6.
6B7 (UX7 base), 6B8 (EBF32, Octal base) – Dual Diode, Semiremote-cutoff Pentodes with control grid on top cap. Based on type 2B7 which had a 2.5 volt heater. The diode anodes are most commonly used as (second) detectors and AVC rectification in superheterodyne receivers. Because their control grids have both sharp-cutoff and remote-cutoff characteristics, these types were used as I.F. amplifiers with AVC bias to the control grid, and as A.F. amplifiers. These types were also used in reflex radios. In a typical 2B7/6B7/6B8 reflex circuit, the I.F. signal from the converter is injected into the pentode and is amplified. The diodes then act as detectors, separating the A.F. signal from the R.F. signal. The A.F. signal is then re-injected into the pentode, amplified, and sent to the audio output tube.
6C4/EC90 – 3.6 W small-power V.H.F. triode up to 150 MHz; single 12AU7/ECC82 system
6C6 – Sharp-cutoff R.F. Pentode. Most common commercial uses were as a tuned R.F. amplifier, a detector, and an A.F. amplifier. Also used in test equipment. Has UX6 base with top cap. Based on type 57, which had a 2.5 volt heater. Similar to types 1603, 77 and octal types 6J7 and 6SJ7
6C10 – Compactron High-mu triple triode, 12-pin base – not related to the Mazda/EdiSwan 6C10 triode-hexode
6D4 – 25 mAavg, 100 mApeak Indirectly heated, argon triode thyratron, negative starter voltage, miniature 7-pin base; found an additional use as a 0 to 10 MHz noise source, when operated as a diode (starter tied to cathode) in a transverse 375 G magnetic field. Sufficiently filtered for "flatness" ("white noise") in a band of interest, such noise was used for testing radio receivers, servo systems and occasionally in analog computing as a random value source.
6D6 – Remote-Cutoff R.F. Pentode. Most common commercial uses were as an I.F. amplifier or as a superheterodyne mixer, aka 1st detector. Also used in test equipment. Has UX6 base with top cap. Based on type 58, which had a 2.5 volt heater. Similar to type 78. Octal version: 6U7-G.
6D8-G – Pentagrid converter, similar to type 6A8. Octal base with top cap. Has 150 mA heater. Used in pre-war 6-volt farm radios.
6D10 – High-mu triple triode for use as oscillator, mixer, amplifier or AFC tube, 12-pin base
6E5 – "Magic Eye" Tuning indicator. Has incorporated driver triode with sharp-cutoff grid which makes it extremely sensitive to any changes in signal strength. Has UX6 base. Based on type 2E5, which had a 2.5 volt heater.
6F4 – Acorn UHF triode up to 1.2 GHz, for use as an oscillator
6F5 – High-mu triode, equal to triode section of type 6Q7
6F6 (KT63) – Power Pentode. Octal base version of type 42. Moderate power output rating – 9 watts max. (Single-ended Class-A circuit); 11 watts max. (Push-pull Class-A circuit); 19 watts max. (push-pull Class-AB2 circuit). Available in metal (numbered "6F6"), shouldered glass ("6F6-G"), and cylindrical glass ("6F6-GT"). Sometimes used as a transformer-coupled audio driver for types 6L6-GC and 807 when those tubes were used in Class-AB2 or Class-B amplifiers. Also used as a Class-C oscillator/amplifier in transmitters.
6F7 – Remote-cutoff Pentode, Medium-mu Triode. Has UX7 base with top-cap connection for the pentode's control grid (grid 1). Most common uses were as superheterodyne mixer ("first detector") and local oscillator, or as a combination I.F. amplifier (pentode) and (second) detector or A.F. amplifier (triode). Octal version: 6P7-G.
6G5 – "Magic Eye" Tuning indicator. Has incorporated triode with remote-cutoff grid, which makes it less reactive to low-level changes in signal strength. Has UX6 base. Electronically identical to type 6U5 except for indicator. Both types had "pie wedge" shadow indicators. At first, the shadow indicator for type 6G5 was fully closed at zero signal and opened as signal strength increased. For type 6U5, the shadow indicator was fully open at zero signal and closed as signal strength increased. After World War II, type 6G5 was discontinued as a unique tube and all 6U5s were double-branded either as 6G5/6U5 or 6U5/6G5.
6G6-G – Power pentode. Octal base. Low power output – 1.1 watt max. output. Has 150 mA heater. Used in pre-war 6-volt farm radios. Miniature version – 6AK6.
6G8-G – Dual Diode, Sharp-cutoff Pentode (Used as Detector and first A.F. stage in Australian 1940s radios)
6H6, D63, EB34, OSW3109 – Dual diode. Octal base. Most commonly found as a "stubby" metal envelope tube. Glass versions 6H6-G and 6H6-GT are also found.
6J5WGT – Premium version of 6J5GT, identical to 12J5WGT except heater characteristics
6J6 – Dual general purpose VHF triode with common cathodes, operates over much of the UHF band (up to 600 MHz), equivalent to ECC91
6J7, EF37 – Sharp-cutoff Pentode. Most common commercial uses were as a tuned R.F. amplifier, a (second) detector, or an A.F. amplifier. Octal version of type 77. This type included a top-cap connection for the control grid. Later version, type 6SJ7, had its control grid connection on pin 4.
6J8-G – Triode-Heptode (radio local oscillator/mixer)
6K6-G – Power Pentode, octal version of type 41. Low-to-moderate power output rating – 0.35 to 4.5 watts (single-ended Class-A circuit); 10.5 watts max. (push-pull Class-A circuit).
6K7, EF39 – Remote-cutoff R.F. pentode. Most common commercial uses were as an I.F. amplifier or as a superheterodyne mixer, aka 1st detector. Also used in test equipment. Octal version of type 78. This type included a top-cap connection for the control grid. Later version, type 6SK7, had its control grid connection on pin 4.
There are several variations. Except for types 6L6-GC and 6L6-GX, all have the same maximum output ratings:
11.5 watts (single-ended Class-A circuit)
14.5 watts (push-pull Class-A circuit)
34 watts (push-pull Class-AB1 circuit)
60 watts (push-pull Class-AB2 circuit)
6L6 (metal envelope) and 6L6-G (shouldered glass envelope) were used in pre-World War II radios and Public Address amplifiers.
6L6 and 25L6 were introduced in 1935 as the first beam tetrodes. Both types were branded with the L6 ending to signify their (then) uniqueness among audio output tubes. However, this is the only similarity between the two tubes. (Type 6W6-GT is the 6.3 volt heater version of types 25L6-GT and 50L6-GT.)
6L6GA – Post-war version of type 6L6-G, in smaller ST-14 shape with Shouldered Tubular, (ST), shaped bulb, revision A.
6L6GB – Post-war improved version in a cylindrical glass envelope. Similar to type 5881.
6L6GTB – 6L6 with Tubular, (T), shaped bulb, revision B, (higher power rating, as it happens. The 6L6GTB can always replace the 6L6, 6L6G, and 6L6GT, but a 6L6GTB running at maximum rating should not be replaced with another subtype).
6L6-WGB – "Industrial" version of type 6L6GB.
6L6GC – Final and highest-powered audio version of the tube. Max. outputs:
17.5 watts (single-ended Class-A circuit)
32 watts (push-pull Class-A circuit)
55 watts (push-pull Class-AB1 circuit)
60 watts (push-pull Class-AB2 circuit)
6L6-GX – Class-C oscillator/amplifier used in transmitters. Max. output 30 watts. (All versions may be used as a Class-C oscillator/amplifier, but this version is specifically designed for this purpose, has a special ceramic base.)
6L7 – Pentagrid converter often used in console radios of the late 1930s. Similar in structure to pentode-triode pentagrid converters 6SA7 and 6BE6, except that a separate oscillator – usually type 6C5 – is required. Also, grid 1 is remote-cutoff control grid, grid 3 is oscillator input grid. (In types 6SA7 and 6BE6, grid 1 is the internal oscillator grid, grid 3 is the control grid.) Because of low conversion transconductance, radios using type 6L7 typically have either a tuned RF pre-amplifier stage, or at least two stages of I.F. amplification. (A few models have both.)
6M5 – Audio Output Pentode (Used as Class-A or C output stages of 1950s Australian radiograms) similar to 6BQ5
6M11 – Compactron Dual triode and pentode
6N3, EY82 – Half-Wave Rectifier
6N5 – Tuning indicator
6N7 – Dual Power Triode, used as Class-A audio driver or as Class-B power output (also 6N7-G and 6N7-GT). Max. output (Class-B) – 10 watts. Octal version of type 6A6.
6N8, EBF80 – Remote-cutoff pentode, dual diode. (detector plus RF or AF amplifier in radios)
6P5-G/GT – Medium-mu triode, Octal version of type 76, often used as driver for type 6AC5-G.
6P7-G – Rarely seen octal version of type 6F7.
6Q5-G – Triode gas thyratron used in DuMont oscilloscopes as a sweep generator. Identical to type 884.
6Q11 – Medium-mu triple triode, 12-pin base, for use as a sync clipper and gated AGC amplifier in TV receivers
6R3, EY81 – TV "Damper/Efficiency" Diode
6R7 – Dual Diode, Medium-mu Triode (also 6R7-G and 6R7-GT). Octal base with top cap. Miniature version – 6BF6. Amplification factor: 16.
6S7-G – Remote-cutoff RF Pentode, similar to type 6K7. Octal base with top cap. Has 150 mA heater. Used in pre-war 6-volt farm radios.
6S8-GT – Triple Diode, High-mu Triode. Octal tube with top-cap connection to triode grid. Has three identical diodes – two diodes share a cathode with the triode, one has a separate cathode. Used as a combined AM detector/AVC rectifier/FM ratio detector/A.F. amplifier in AM/FM radios. Typically, all sections of this tube are arranged around a single heater.
6T5 – "Magic Eye" Tuning indicator. Has incorporated driver triode with remote-cutoff grid. Has UX6 base. Shadow indicator is fully closed at zero signal. As signal increases, shadow grows outward from the center, covering the entire circumference of the indicator. Electronically identical to types 6G5 and 6U5, which may be used as substitutes.
6T7-G – Dual diode, high-mu triode, similar to type 6Q7. Octal base with top cap. Has 150 mA heater. Used in pre-war farm radios.
6T8 – Triple Diode, High-mu Triode. Has three identical diodes – two have cathodes connected to the triode's cathode, one has a separate cathode. Triode amplification factor: 70. Used as an AM detector/AVC rectifier/FM ratio detector/A.F. amplifier in North American AM/FM radios. Identical to type 6AK8/EABC80, but with a shorter glass envelope.
6U5 (UX6 base), 6U5G (Octal base) – "Magic Eye" Tuning indicator. Has incorporated driver triode with remote-cutoff grid. Has "pie wedge" shadow indicator that is open at zero signal and closes as signal increases. Electronically identical to types 6G5 and 6T5 and may be used as a substitute for those types. After World War II, most new 6U5s were double-branded as either 6G5/6U5 or 6U5/6G5.
6U7-G – Remote-cutoff R.F. Pentode. Most common commercial uses were as an I.F. amplifier or as a superheterodyne mixer, aka 1st detector. Also used in test equipment. Octal version of type 6D6. Most direct substitute: 6K7. Similar to types 58, 78 and 6SK7.
6V4 (EZ80) – Noval-base, indirectly heated, full-wave rectifier. EZ80 rated at 90mA, but 6V4 only rated for 70. Some brands were identical.
6V6 – Beam power tetrode, used in single-ended Class-A audio output stages of radios and sometimes seen in Class-B audio amplifiers (see also: 5V6 and 12V6). Electrically similar to 6AQ5/EL90.
6V6G – 6V6 with Shouldered Tubular, (ST), shaped bulb.
6V6GT – 6V6 with Tubular, (T), shaped bulb.
6V7-G – Dual diode, Medium-mu Triode. Octal version of type 85. Amplification factor: 8.3. Similar to type 6R7.
6W6-GT – Beam power pentode, used most often as a Vertical Deflection Output tube in monochrome TV receivers of the 1950s. Can also be used as an Audio Output tube. This is the 6.3 volt heater version of types 25L6-GT and 50L6-GT.
6X4 (EZ90) and 6X5 (EZ35) – Full-wave rectifiers with indirectly heated common cathode. Type 6X4 has a 7-pin miniature base, the 6X5 has an octal base. Based on type 84/6Z4. No longer in production.
6AB4/EC92 – High-mu triode (Pinout same as 6C4 except for pin 5 not having a connection)
6AD6-G and 6AF6-G – "Magic Eye" tuning indicators. Both have two "pie wedge" shadow indicators, one each on opposite sides of a single circular indicator target. Both shadows may be used in tandem or may be driven by two different signal sources. Type 6AE6-G is specifically made to drive each indicator with different signals. May also be driven by separate pentodes with different characteristics. E.g., a sharp-cutoff pentode like a 6J7 – which would be hyper-sensitive to any signal change – would drive one shadow, while a remote-cutoff pentode like a 6K7 – which would only react to stronger signals – would drive the other shadow. Both tubes have octal bases. Type 6AD6-G, with a target voltage rated from 100 to 150 volt, is designed for AC/DC radios. Type 6AF6-G, with a target voltage rated at 250 volt, is designed for larger AC radios.
6AE6-G – A driver triode specially designed for "Magic Eye" tuning indicator types 6AD6-G and 6AF6-G. Has a common heater and indirectly heated cathode, two internally connected triode grids – one with sharp-cutoff characteristics, one with remote-cutoff characteristics – and two anodes, one for each grid. The sharp-cutoff grid reacts to any signal change, while the remote-cutoff grid reacts only to stronger signal changes.
6AE7-GT – Dual Triode with a common, single anode, for use as a power triode driver
6AF4 – UHF Medium-mu Triode, commonly found in TV UHF tuners and converters.
6AF11 – Compactron High-mu dual triode and sharp-cutoff pentode
6AG11 – Compactron High-mu dual triode and dual diode
6AH5-G – Beam power tube for early TV use. Same as type 6L6-G, but with scrambled pinout. Used in some Philco receivers.
6AK5, EF95, 5654, CV4010, 6J1P (6Ж1П) – Miniature V.H.F. Sharp-cutoff pentode (Used in old Radiosonde weather balloon transmitters, receiver front ends and contemporary audio equipment), Miniature 7-pin base
6AK6 – Power pentode. 7-pin miniature version of type 6G6-G. Unusual low-power consumption output tube with 150 mA heater.
6AK8/EABC80 – Triple Diode, High-mu Triode. Diodes have identical characteristics – two have cathodes connected to the triode's cathode, one has a separate cathode. Used as a combination AM detector/AVC rectifier/FM ratio detector/A.F. amplifier in AM/FM radios manufactured outside of North America. Triode amplification factor: 70. North American type 6T8 is identical (but for a shorter glass envelope) and may be used as a substitute.
6AK9 – Compactron 1x high-mu + 1x medium-mu dual triode and beam power pentode, 12-pin base
6AK10 – Compactron High-mu triple triode for use as NTSC chroma signal demodulator matrix in analog color TV receivers, 12-pin base
6AL6-G – Beam power tube for early TV use. Same as type 6L6-G, but with scrambled pinout and anode connected to top cap.
6AL7-GT – Tuning indicator used in many early AM/FM Hi-Fi radios. Similar in function to "Magic Eye" tubes. Has two bar-shaped shadows; one grows to indicate signal strength, the other moves to indicate center tuning on FM.
6AM6, EF91, Z77 – Sharp-cutoff R.F. pentode used in receiver front ends and test gear such as VTVMs and TV broadcast modulation monitors.
6AN7, – Triode-Hexode Oscillator/Mixer (radio)
6AN8, – Triode-Pentode used in frame timebase circuits for television. Electrically fairly similar to ECL80 but with a different pinout.
6AQ5 – Beam-power pentode, 7-pin miniature similar of type 6V6.
6AQ8/ECC85 – Dual triode with internal shield. Designed for use as oscillator and mixer in FM receivers. The heater to cathode insulation is inadequate for use in cascode operation
6AS6 – Pentode with a fine-pitched suppressor grid which could serve as a second control grid. Used in radar phantastron circuits.
6AS7, 6080 – Dual low-mu Triode, low impedance, mostly used for voltage regulation circuits.
6AS11 – Compactron 1x high-mu + 1x medium-mu dual triode and sharp-cutoff pentode, 12-pin base
6AT6 – Dual Diode, High-mu Triode, miniature version of type 6Q7. Triode amplification factor: 70.
6AU4 – TV "Damper/Efficiency" Diode
6AU6, EF94, 6AU6A – Sharp-cutoff pentode
6AV6 – Dual Diode, High-mu Triode, miniature version of type 75. Triode amplification factor: 100. (Triode section similar in characteristics to one half of a 12AX7.)
6AV11 – Compactron Medium-mu triple triode, 12-pin base
6AX4 – TV "Damper/Efficiency" Diode
6AX5 – Full-wave rectifier. Octal base. Similar in structure to type 6X5, but with higher voltage and current ratings which are comparable to those of types 5Y3 and 80.
6BA6, EF93, W727, 5790 – Semiremote-cutoff R.F. Pentode (Often encountered in car radios)
6BD11 – Compactron 1x high-mu + 1x medium-mu dual triode and sharp-cutoff pentode, 12-pin base
6BE6, EK90, 5750, X727 – Pentagrid Converter (Often encountered in car radios)
6BF6 – Dual Diode, Medium-mu triode. Miniature version of octal type 6R7.
6BF8 – Sextuple diode with a common cathode
6BG6 – Beam tetrode, anode cap. Used in early TV magnetic-deflection horizontal-output stage.
6BH11 – Compactron Medium-mu dual triode and sharp-cutoff pentode
6BK4 – High Voltage beam Triode (30 kV anode voltage). Used as shunt regulator in color TV receivers and measurement equipment such as high voltage meters
6BK7 – Dual Triode with Internal shield between each section, used in RF circuits (Similar to 6BQ7)
6BK11 – Compactron 2x High-mu + 1x medium-mu triple triode preamplifier, 12-pin base; used in some guitar amps made by Ampeg.
6BL6 (5836) – Sutton tube, a reflex klystron used as a 250 mW CW microwave source, 1.6 to 6.5 GHz depending upon an external cavity. 4-pin peewee base with cavity contact rings and top cap
6BL8, ECF80 – General-purpose Triode pentode used in TV, audio and test gear
6BM6 (5837) – Sutton tube used as a 150 mW CW microwave source, 550 MHz to 3.8 GHz depending upon an external cavity. 4-pin peewee base with cavity contact rings and top cap
6BM8, ECL82 – Triode pentode used as the driver and output stages in audio amplifiers, audio output and vertical output stages in TV receivers and has even been seen in an electronic nerve stimulator.
6BN6 – Gated-beam discriminator pentode, used in radar, dual channel oscilloscopes and F.M. quadrature detectors (cf. 6DT6, nonode).
6BQ5, EL84,(N709) – 5.7 Watts AF Power pentode, noval base
6BQ6-GT – Beam Power Pentode, used as a Horizontal Deflection Output tube in monochrome TV receivers of the 1950s. Most commonly used in receivers with diagonal screen sizes less than 19 inches (48 cm). (However, may be found in some larger models.) Larger receivers often used similar type 6DQ6. Later versions of this tube branded as 6BQ6-GTB/6CU6.
6BQ7 – Dual RF/VHF triode with internal screen. The two sections can be used independently or in a cascode stage
6BQ7A – Improved 6BQ7 capable of operation at UHF frequencies
6BU8 – Split Anode TV Sync Separator
6BX6, EF80 – Sharp-cutoff RF/IF/Video pentode, noval base
6BY6 – Similar to type 6CS6, but with higher transconductance. 3BY6 with a different heater
6CW4 – Nuvistor high-mu VHF triode, most common one in consumer electronics
6CZ5 – Beam pentode for use in vertical deflection or audio amplifier. In certain applications, it can be used in place of a 6973.
6DA6, EF89 – R.F. Pentode used in AM/FM radios manufactured outside North America.
6DJ8, ECC88, E88CC, 6922, 6N23P, 6N11 – Dual Audio and R.F. Triode (often used in TV broadcast equipment, test gear, oscilloscopes and audiophile gear) similar to 6ES8
6DQ6 – Beam Power Pentode, used as a Horizontal Deflection Output tube in monochrome TV receivers of the 1950s. Most often found in receivers with diagonal screen measurements larger than 17 inches (43 cm). Smaller receivers often used similar type 6BQ6-GT. Also used as Audio Output tubes in Standel guitar amplifiers. Later versions branded as 6DQ6-B/6GW6.
6DR8, EBF83 – R.F. pentode which will operate with 12 V anode supply, used as I.F. amplifier in car radios which run directly off the 13.5 volt supply.
6DS4 – Nuvistor VHF triode used in TV tuners immediately prior to the introduction of solid state tuning circuits. (RCA TVs equipped with a 6DS4 tuner bore the trademark "Nu-Vista Vision"); successor of the 6CW4.
6DS8, ECH83 – Triode-heptode Local oscillator-Mixer which will operate with 12 V anode supply, used in car radios which run directly off the 13.5 volt supply.
6DT6 – Quadrature detector used in TV audio circuits of the 1950s and early 1960s; cf. 6BN6, nonode.
6DV4 – Medium-mu Nuvistor triode for UHF oscillators; some versions had a gold-plated envelope
6DX8 – Triode pentode
6EM5 – TV Vertical Output Pentode
6ES6, EF98 – R.F. pentode which will operate with 12 V anode supply, used as tuned R.F. amplifier in car radios which run directly off the 13.5 volt supply.
6ES8, ECC89, E89CC – Dual Triode used as cascode R.F. amplifier in TV tuners and V.H.F. receiver front ends, also used as general-purpose dual triode in test gear, similar to 6DJ8
6EZ8 – High-mu triple triode, Noval base
6FH8 – Medium-mu triode and three-anode sharp-cutoff tetrode for use in TV receivers and complex wave generators
6GK5 – Miniature V.H.F. triode (Used as V.H.F. local oscillator in some T.V. Turret Tuners)
6GM5 – Beam power pentode, identical to 7591 and 7868 with a Noval base
6GV8, ECL85 – Triode Pentode (TV vertical output)
6GW8, ECL86 – Audio Triode Pentode (audio, TV vertical output)
6GY8 – High-mu triple triode for use as oscillator, mixer, RF amplifier or AFC tube, Noval base
6HS8 – Dual-anode pentode for TV receiver sync separation service or as a two-channel VCA
6JU8A – 9 mA, Quad diode, units 1&2 and 3&4 internally series-connected
6KM8 – Diode and three-anode sharp-cutoff tetrode for use in musical instruments, frequency dividers and complex wave generators
6LF6 – Beam power tetrode with a duodecar Compactron base and anode cap, for CRT horizontal-deflection amplifiers
6SB7Y (octal), 6BA7 and 12BA7 (Noval) – VHF pentagrids, 1946
6SC7 – High-mu dual triode (Both sections share a single cathode)
6SK7 – Remote-cutoff pentode (Used in I.F. stages of North American radios) Miniature version: 6BD6
6SL7, ECC35 – Dual triode (Used in TV and general electronics)
6SN7, ECC32, B65, 13D2, CV1986, 6042 – Medium-mu dual triode (Used in Audio Amplifiers, Hammond Organs and Television; extensive use in World War II radar) Each section is equivalent to a 6J5. Miniature version: 12AU7
6SS7 – Remote-cutoff pentode (150 mA heater version of the 6SK7, found in some AA6 radios as both the RF amplifier and first IF). This is the only tube to have a same-letter repetition
"7" prefix Loctal tubes
These tubes all have 6.3 volt AC/DC heaters.
7A4 – Medium-mu triode, Loctal version of type 6J5, often numbered 7A4/XXL
7A5 – Beam power pentode, Loctal version of type 6U6GT
7A6 – Dual detector diode, similar to type 6H6
7A7 – Remote-cutoff pentode, Loctal version of type 6SK7
7C5 – Beam power pentode, Loctal version of type 6V6
7C6 – High-mu triode, dual detector diode
7C7 – Sharp-cutoff pentode
7E5 – Medium-mu high-frequency triode
7E6 – Medium-mu triode, dual detector diode, Loctal version of types 6R7 and 6SR7, electronically identical to miniature type 6BF6.
7E7 – Semiremote-cutoff pentode, dual detector diode, similar to types 6B7 and 6B8
7F7 – High-mu dual triode, Loctal version of type 6SL7-GT
7F8 – Medium-mu VHF triode, used as amplifier or converter
7G7 – Sharp-cutoff pentode
7G8 – Sharp-cutoff dual tetrode
7H7 – Semiremote-cutoff pentode
7J7 – Triode-heptode converter, similar to type 6J8-G
7K7 – High-mu triode, dual detector diode, similar to types 6AT6 and 6Q7
7L7 – Sharp-cutoff pentode
7N7 – Dual medium-mu triode, Loctal version of type 6SN7-GT
7Q7 – Pentagrid converter, similar to type 6SA7
7R7 – Remote-cutoff pentode, dual detector diode
7S7 – Triode-heptode converter
7T7 – Sharp-cutoff pentode
7V7 – Sharp-cutoff pentode; 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 7
Note: 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 rectifier diode
7X7 – High-mu triode, dual detector diodes on separate cathodes, used as FM discriminator and AF amplifier, often numbered 7X7/XXFM
7Y4 – Full-wave rectifier
7Z4 – Full-wave rectifier
7AB7 – Sharp-cutoff pentode
7AD7 – Power pentode
7AF7 – Dual medium-mu triode
7AG7 – Sharp-cutoff pentode
7AH7 – Remote-cutoff pentode
7AJ7 – Sharp-cutoff pentode
7AK7 – Sharp-cutoff, dual control pentode for computer service. Perhaps the first active device specifically designed for computer use.
12 volt heater tubes
12A5 – Power pentode. UX7 base. Center-tapped 12.6 V/300 mA resp. 6.3 V/600 mA heater. Mostly used in pre-war car radios.
12A7 – Power pentode, rectifier diode. Pentode section is similar to type 38. Diode has a low power rating – 120 volt, 30 mA – that limits the number of tubes that can be tied to its B+ circuit. Used in one-tube portable phonographs and a few two- and three-tube radios. Forerunner of such types as 32L7-GT, 70L7-GT and 117L7-GT. UX7 base with top cap. Not related to types 2A7 and 6A7.
12AE10 – Compactron Beam power tube and sharp-cutoff pentode
12AL5 – Dual diode (similar to 6AL5 except for heater)
12AT6 – Dual diode/triode (Commonly replaced by 12AV6 in consumer radios)
12AT7, ECC81, 6060, B309, M8162 – High-mu dual triode. Commonly used as R.F. amplifier/mixer in VHF circuits.
12AU7, ECC82, 6067, B329, M8136 – Medium-mu dual triode. Two 6C4/EC90s in one envelope; however, it is only specified as an audio frequency device. Commonly used in audio applications and TV receivers.
12AV6 – Dual diode/High-mu triode (see also: 6AV6)
12AV7, 5965 – Medium-mu dual triode. Principally designed for VHF amplifier/mixer operation.
12AX7, ECC83, 6057, B327, M8137 – High-mu dual triode. Very similar to triode section of 6AV6. Commonly used in high-gain audio stages and as power inverters in class A/B amplifiers.
12AW7 – See 12DW7 below. Called AW by some, but proper name is DW.
12AY7 – Dual Triode. Medium gain but low noise, intended for low-level/preamplifier use.
12AZ7 – Dual Triode. Medium-mu, AF Amplifier, or combined oscillator and mixer, Noval base.
12BA6 – Remote-cutoff pentode, 6BA6/EF93 with a different heater
50X6 – Dual Diode (Loctal, commonly used as a rectifier-doubler)
50DC4 – Rectifier diode (Similar to 35W4 except for heater)
50EH5 – Beam Power tube, (Similar to 50C5 but with higher gain, some radios that use this tube do not have an audio amplifier section.)
50HK6 – Power pentode (Filament is tapped for use with a dial lamp)
117 volt heater tubes
All of the following tubes are designed to operate with their heaters connected directly to the 117 volt (now 120 volt) electrical mains of North America. All of them use indirectly heated cathodes. All of them incorporate at least one rectifier diode.
Rectifier diode – Beam power pentode combinations
117L7GT
117M7GT
117N7GT
117P7GT
Rectifier tubes
117Z3 – Single diode, 7-pin miniature version of 117Z4GT
117Z4GT
117Z6GT – Dual diode, can be used as a voltage doubler
Other tubes with nonstandard heater voltages
The tubes in this list are most commonly used in series-wired circuits.
5J6 – General purpose RF dual triode with common cathodes, a 6J6 with a 4.7 volt/600 mA controlled warm-up heater
8B10 – Compactron Dual triode and dual diode
2AF4 – UHF triode oscillator
2BN4 – VHF triode
2CW4 – Nuvistor high-mu VHF triode, 6CW4 with a 2.1 volt/450 mA heater; used in TV receivers with series heater strings
6C21 – Triode radar modulator for "hard tube" pulsers.
7C23 – 120 kW Power triode for high voltage pulse operation.
8D21 – Internally water cooled dual tetrode used in early VHF TV transmitters.
9C21 – 100 kW Water-cooled power triode, directly heated, 4-pin base with dual top caps for grid and anode
List of EIA professional tubes
Note: Most of these are special quality versions of the equivalents given. Some manufacturers preceded the EIA number with a manufacturer's code, as explained above.
5000s
5651
5331, 5332, 5514 – Directly heated power triodes, 4-pin base with anode top cap
5556 – Directly heated power triode, 4-pin base
5593 – Phasitron, a magnetically controlled beam-deflection phase modulator tube similar to the 2H21, used in early FM broadcast transmitters
5608 – Dual power triode, designed for use with AC anode voltage and critical grid leak requirements
5651 – 86-volts, cold-cathode, glow-discharge voltage reference, 7-pin miniature base
5654, CV4010, 408A – VHF pentode; common in vintage radar IF amplifiers; premium version of 6AK5, EF95, 6J1P (6Ж1П)
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. Cf. 5738, 6090, 6091, 6170, 6324
5731 – Narrow-tolerance selected 955Acorn triode for use in Radiosonde weather balloon transmitters
5734 – 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
5738 – 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. Cf. 5729, 6090, 6091, 6170, 6324
5749– RF pentode; premium version of 6BA6, EF93, W727
5750 – Heptode mixer; premium version of 6BE6, EK90, X727
5751 – Low-noise avionics dual triode with separate cathodes
5814A – Industrial, computer-rated version of 12AU7/ECC82
5836, 6BL6Raytheon RK5836 – Sutton tube, a reflex klystron used as a 250 mW CW microwave source, 1.6 to 6.5 GHz depending upon an external cavity. 4-pin peewee base with cavity contact rings and top cap
5837, 6BM6 – Sutton tube used as a 150 mW CW microwave source, 550 MHz to 3.8 GHz depending upon an external cavity. 4-pin peewee base with cavity contact rings and top cap
5845 – Dual directly heated saturated-emission diode. Acts as a heating current-controlled, variable series resistor in voltage/current stabilizer circuits.
5876A – Glass pencil-type disk-seal UHF power triode up to 2 GHz
5963, 5964, 5965 – Dual triode, designed for high speed digital computers, has a high zero-bias anode current, industrial/computer-rated versions of 12AV7
5998, 6336A, 6394, 6520, 6528, 7802 – Dual power triodes, designed for series voltage regulator applications
6000s
6047 – Additron, a triple-control grid, split-anode tetrode for use as a single-bit digital full adder (technically a hexode)
6057, M8137 – High-mu dual triode; premium version of 12AX7, ECC83, B339
6059 – Low-microphonics pentode; premium version of 6BR7
6060, M8162 – High-mu dual triode; premium version of 12AT7, ECC81, B309
6064, M8083 – R.F. pentode; premium version of 6AM6, EF91, Z77
6067, M8136 – Medium-mu dual triode; premium version of 12AU7, ECC82, B329
6080 – Very-low impedance dual power triode, designed for series voltage regulator applications, now popular for output transformerless audio amplifiers; premium version of 6AS7
6082 – Ruggedized, indirectly heated power triode, octal base
6090 – 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. 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. Cf. 5729, 5738, 6090, 6170, 6324
6146 – 60 MHz, 120 W AF/RF/VHF beam power pentode
6146B (8298A) – Improved version of 6146, 6146A and 8298.
6170 and 6324 – Beam-deflection, 25-channel analog multiplexer for telecomms transmitting channel banks, external focusing and deflection by a multiphase, rotating magnetic field to determine through which one out of 25 grids the electron beam passes to the common anode. Cf. 5729, 5738, 6090, 6091
6173 – Pencil-type disk-seal UHF diode up to 3.3 GHz
6196 – Directly heated dual, compensating electrometer tetrode with space charge grids for use in the 2 branches of a differential-in, differential-out bridge circuit
6218/E80T (CV5724) – Modulated, single-anode beam deflection tube for pulse generation up to 375 MHz; shock resistant up to 500 g
6263 – Pencil-type disk-seal UHF power triode up to 500 MHz, Panode = 8 W
6351 – Secondary emission pentode for wide band RF amplifiers
6361 – Convectron, an inclinometer tube that senses tilt from the vertical by means of different gas convections around a heating wire in a glass envelope, of two 6361s aligned in a 90° V-shaped position to each other and the heating wires connected in a bridge circuit
6441 – 650 V, 100 mAavg, 300 mAsurgeTacitron, a grid turn-off hydrogen thyratron with a grid that forms a shield around both the cathode and anode and separates the two by a wire mesh, so the arc discharge can be extinguished by a negative grid that surrounds the positive anode with a field of opposing polarity and inhibits conduction, taking over part of the anode current during deionisation – similar to today's GTOs; Octal base
6462 – Magnetic pickup tube, a 1-axis beam-deflectionmagnetometer with approx. 1 G (100 μT) resolution; an electron beam is electrostatically centered between two anodes while no magnetic field is present; the magnetic field to be detected will then deflect the beam more towards one of the anodes, resulting in an imbalance between the two anode currents
6762 – Wamoscope, a TWT/CRT combination used to directly visualize an incoming microwave signal by electron velocity-sorting
6835, 7570, 7571 – Single-electron gunrecording storage tube, an analog videoframe freezer tube. This was achieved by a CRT that writes the video image onto a thin, dielectric target and subsequently can read the generated charge pattern up to 30000 times from that target, producing a video signal containing a static shot that resembles a still photograph
6846 – Gas-filled, three-cathode 1-bit binary counter or switching tube, Miniature 7-pin base
6877, 7233 – Power triodes, designed for series voltage regulator applications
6900 – Dual power triode for pulse applications in missiles, avionics and industrial systems; noval base
6922 (E88CC, industrial version of 6DJ8/ECC88)
6973 – Power pentode similar in shape, size, and base to the EL84/6BQ5, but with a high gain for more than double the output range. Popular in some makes of 1960s era guitar amplifiers, though rarely implemented in modern times.
7000s
7025 – Low-hum, noise and microphonics version of 12AX7
7027 – AF Power pentode, improved 6L6 with a 25 Watt anode and different pinout
7199 – Triode-pentode, noval base. Similar to 6U8.
7229, 7230, 7231, 7232, 7439, 7440, 7441, 7595, 7596, 7597, 7598, 7599, 7600, 7602 – Krytrons, cold-cathode gas-filled trigger tubes with a primer electrode for use as a very high-speed, high-surge current switch – second source to EG&G
7236 – Dual power triode for use as long-life power amplifier in computer applications
7241, 7242 – Triple-cathode power triodes, designed for hi-rel cathode follower series voltage regulator applications where the cathode is split into 3 sections connected together via balancing resistors to equalize the emission along the cathode
7414 – Time Totalizer, a metal-vapor coulometer, a cold-cathode gas-discharge tube where metal is constantly sputtered off the cathode and deposited on a collector element whose resistance therefore decreases with elapsed time
7430 – Flat-envelope version of the 6AK5/EF95 sharp-cutoff pentode for use on PCBs in Radiosonde weather balloon transmitters
7548 – Secondary emission hexode for pulse generator and pulse amplifier applications
7551 – Noval-base beam power pentode with 12-15 volt heater. 6.3 volt heater version was 7558. Used in telephony, RF amplification, and more rarely AF amplification.
7554 – Ceramic/metal pencil-type disk-seal SHF power triode up to 5 GHz
7572, 7575, 7702 – Dual-electron gunrecording storage tube, a realtime analog videoframe freezer tube with simultaneous R/W, and storing capability. This was achieved by a CRT/camera tube combination; the CRT part writes the video signal onto a thin, dielectric target, which can hold the generated charge pattern for many hours; the camera part reads the charge pattern from the back side of this target, producing a video signal containing a static shot that resembles a still photograph
7586 – First Nuvistor available on the market, medium-mu triode
7587 – Nuvistor Sharp cutoff tetrode
7591 – Beam power pentode, octal base. Found in many guitar amps made by Gibson and Ampeg.
7763 – Beam deflection tube, used as IF amplifier/limiter where a constant phase shift over a wide range of input signal amplitudes is required
7768 – Miniature ceramic/metal disk-seal planar SHF triode up to 4 GHz
7868 – Beam power pentode, B9E Novar base version of 7591. Found in many of the once popular Challenger series PA amps made by Bogen Communications, also found in some guitar amplifiers made by Ampeg.
8514 – 1 kV/10...800 μA Corona voltage reference, 7-pin with anode top cap
8515 – 1.6 kV/20...950 μA Corona voltage reference, 7-pin with anode top cap
8526 – Nuvistor-type medium-mu dual triode
8873 – 500 MHz, 200 W anode dissipation power triode
8874 – 500 MHz, 400 W anode dissipation power triode
8875 – 500 MHz, 300 W anode dissipation power triode
8877 = 3CX1500A7 – Ceramic, forced air cooled, 1.5 kW power triode
8974 (X-2159) – Giant water-cooled megawatt-class tetrode used for very high-power broadcast and industrial service; possibly the most powerful tube ever commercially produced
XP1010 – 10-stage photomultiplier for r-ray and gamma ray scintillation spectrometry, selected 150AVP for low noise and resolution, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, duodecal (12-pin) base
XP1011 – 10-stage photomultiplier, blue-sensitive Sb-Cs cathode, Ag-Mg-O-Cs dynodes, shock and vibration-proof, duodecal base
XP1120 – 17-stage photomultiplier for x-ray (λ > 200 pm) or UV (λ < 150 nm) photon counting in a high-vacuum environment, Nickel cathode, Cu-Be-O dynodes, coaxial outputs, built-in resistor ladder
XP1121 – 17-stage photomultiplier for ion (> 10 keV) or electron (0.1...10 keV) photon counting in a high-vacuum environment, Cu-Be-O cathode and dynodes, coaxial outputs, built-in resistor ladder
XP1122 – 17-stage photomultiplier for x-ray (λ > 200 pm) or UV (λ < 150 nm) photon counting in a high-vacuum environment, Nickel cathode, Cu-Be-O dynodes, coaxial outputs, built-in resistor ladder
XP1123 – 17-stage photomultiplier for ion (> 10 keV) or electron (0.1...10 keV) photon counting in a high-vacuum environment, Cu-Be-O cathode and dynodes, coaxial outputs, built-in resistor ladder
XP1130 – 17-stage photomultiplier for x-ray (λ > 200 pm) or UV (λ < 150 nm) photon counting in a high-vacuum environment, Nickel cathode, Cu-Be-O dynodes, coaxial outputs, built-in resistor ladder
XP1131 – 17-stage photomultiplier for ion (> 10 keV) or electron (0.1...10 keV) photon counting in a high-vacuum environment, Cu-Be-O cathode and dynodes, coaxial outputs, built-in resistor ladder
XX1190 – 1. Gen. inverter, 1-stage image intensifier
XX1192 – 1. Gen. inverter, 1-stage image intensifier
XX1200 – 1. Gen. inverter, 1-stage image intensifier
XX1211 – 1. Gen. inverter, 3-stage image intensifier
XX1270 – 1. Gen. inverter, 2-stage image intensifier
XX1400 – 2. Gen. inverter, 1-stage image intensifier
XX1430 – 1. Gen. inverter, 1-stage image intensifier
XX1510 – 1. Gen. 3-stage image intensifier
XX1610 – 2. Gen. image intensifier
XX1800 – 2. Gen. proximity focused, 1-stage image intensifier
Y - Vacuum tubes
YA
YA1000 – 5 kV, 5mA, Directly heated saturated-emission diode with pure-metal cathode for use in RMS converters of AC voltage/current stabilizer circuits, noval base
YD
YD1000 – 45 kW, Water-cooled RF power triode
YD1001 – 35 kW, Air-cooled RF power triode
YD1012 – 360 kW, Vapor-cooled RF power triode
YD1130 – 400 W, Air-cooled, linear RF/AF power triode
YD1342 – 30 MHz, 530 kW, Water-cooled RF power triode
YD1352S (8867, DX334) – 5 MHz, 2 kW, Water-cooled Neotron, a gridless field-effect tube where a magnetically focused electron beam is modulated by varying the voltage of a gate electrode surrounding it. Used as RF power amplifier or oscillator
YG
YG1000 – Directly heated electrometer tetrode with an oxide cathode and a space charge grid, grid current ≤600 fA, magnoval base with input grid on top cap
ZA1001 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode with traces of heavy gas (krypton/xenon) for slow de-ionization, e.g. for low-frequency relaxation oscillators; meshed cylinder anode, all-glass wire-ended
ZA1002 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode, large difference between burning and ignition voltage, meshed cylinder anode, 3-pin all-glass wire-ended
ZA1003 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode for use as indicator tube in transistorized circuits, meshed cylinder anode, 3-pin all-glass wire-ended
ZA1004 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode, small difference between burning and ignition voltage, for use as indicator tube in transistorized circuits or as 86.4 V Voltage reference, meshed cylinder anode, 3-pin all-glass wire-ended
ZA1005 – Neon-filled, coaxial, tritium-primed, sputtered-molybdenum cold-cathode switching diode for use like a DIAC in thyristor circuits, meshed cylinder anode, 2-pin all-glass wire-ended
ZC
ZC1010 (Z661W) – 8 mAavg, 50 mApeak, Gas-filled, cold-cathode AC trigger pentode, two starters and a primer electrode, positive starter voltage, 5-pin all-glass wire-ended, envelope inside radioactively coated for a constant ignition voltage, for use in bidirectional counters
ZC1040 – 25 mA, Gas-filled, cold-cathode AC trigger tetrode, one starter and a primer electrode, positive starter voltage, noval base
ZC1050 – 2 mA, Gas-filled, cold-cathode, luminescent trigger tetrode, one starter and a primer, 300 mlm light output for use as self-displaying shift register cells in large-format, crawling-text dot-matrix displays; all-glass wire-ended
ZC1060 – 20 mAavg, 5 kApeak, Gas-filled, cold-cathode, high-current trigger triode for e.g. capacitor discharge circuits. One external (capacitive) starter electrode
ZM1020 (Z520M) – ZM1022 with a red contrast filter coating
ZM1021 (Z521M) – ZM1023 with a red contrast filter coating, for use with ZM1020
ZM1022 – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, 15.5mmCH top-viewing, no decimal point
ZM1023 – A V Ω % + - ~ Neon-filled digital indicator tube, 15.5mmCH top-viewing, for use with ZM1022 in digital multimeters
ZM1024 – ZM1025 with a red contrast filter coating, for use with ZM1020
ZM1025 – c/s Kc/s Mc/s μs ms ns s Neon-filled digital indicator tube, 15.5mmCH top-viewing, for use with ZM1022 in digital frequency counters
ZM1030 – ZM1032 with a red contrast filter coating
ZM1031 – ZM1031/01 without the ~
ZM1031/01 – ZM1033/01 with a red contrast filter coating, for use with ZM1030
ZM1032 – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, 15.5mmCH side-viewing, no decimal point, 5 dual cathodes and separate odd/even anode compartments for biquinary multiplexing
ZM1033/01 – + - ~ Neon-filled digital indicator tube, 15.5mmCH side-viewing, separate anode compartment for + , for use with ZM1032
ZM1040 (Z522M) – ZM1042 with a red contrast filter coating
ZM1041 – ZM1043 with a red contrast filter coating, for use with ZM1040
ZM1041S – ZM1043S with a red contrast filter coating, for use with ZM1040
ZM1042 (Z5220M) – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, 30mmCH side-viewing, no decimal point
ZM1043 – + - Neon-filled digital indicator tube, 30mmCH side-viewing, for use with ZM1042
ZM1043S – Y X + W U Z - Neon-filled digital indicator tube, 30mmCH side-viewing, for use with ZM1042
ZM1047 – ZM1049 with a red contrast filter coating, for use with ZM1040
ZM1049 – T F S N Z Y G H M X Neon-filled digital indicator tube, side-viewing, for use with ZM1042 in numerical control systems
ZM1050ZM1070 (Z550M, 8453) – Neon-filled digital indicator tube, top-viewing, dekatron-type readout with common anode and common cathodes, pulsating anode voltage, controlled by 5-volts sensitive starter electrodes, for transistorized circuits
ZM1130 – ZM1132 with a red contrast filter coating
ZM1131 – ZM1133 with a red contrast filter coating, for use with ZM1080
ZM1132 – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, side-viewing, left and right decimal point
ZM1133 – + - ~ Neon-filled digital indicator tube, side-viewing, for use with ZM1132
ZM1136L/R – ZM1138L/R with a red contrast filter coating
ZM1137 – ZM1139 with a red contrast filter coating, for use with ZM1136L/R
ZM1138L/R – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, 13mmCH side-viewing, left or right decimal points (specify)
ZM1139 – + - ~ Ω Neon-filled digital indicator tube, 13mmCH side-viewing, for use with ZM1138 in digital multimeters
ZM1162 – 0 1 2 3 4 5 6 7 8 9 Long-life neon-filled digital indicator tube, 15.5mmCH top-viewing, no decimal point, rectangular envelope for close stacking in both axes
ZM1170 – ZM1172 with a red contrast filter coating
ZM1172 – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, 15.5mmCH side-viewing, no decimal point
ZM1174 – ZM1175 with a red contrast filter coating
ZM1175 – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, 15.5mmCH side-viewing, left decimal point
ZM1176 – ZM1177 with a red contrast filter coating
ZM1177 – ZM1175, but right decimal point
ZM1180 – ZM1182 with a red contrast filter coating
ZM1181 – ZM1183 with a red contrast filter coating, for use with ZM1180
ZM1182 – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, 16mmCH top-viewing, no decimal point, semi-rectangular envelope for close horizontal stacking
ZM1183 – + - ~ Ω Neon-filled digital indicator tube, top-viewing, 13mmCH for use with ZM1182 in digital multimeters
ZM1184D – ZM1185D with a red contrast filter coating
ZM1185A (GR1420) – 1 2 3 4 5 6 U K E R Neon-filled digital indicator tube, 16mmCH top-viewing
ZM1185D (GR1430) – ∇ Δ Neon-filled digital indicator tube, 16mmCH top-viewing, for use in elevators
ZM1185E (GR1472) – 0 1 2 3 4 5 - t kg + Neon-filled digital indicator tube, 16mmCH top-viewing
ZM1200 – Pandicon, multiplexed 14-digit display tube with decimal points and punctuation marks, pin connections on both ends
ZM1202 – 12-Digit Pandicon
ZM1204 – 10-Digit Pandicon
ZM1206 – 8-Digit Pandicon
ZM1210ZM1212 – ZM1212 with a red contrast filter coating
ZM1212 – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, 15.5mmCH side-viewing, left decimal point, all-glass wire-ended
ZM1220 – ZM1222 with a red contrast filter coating
ZM1222 – 0 1 2 3 4 5 6 7 8 9 Large neon-filled digital indicator tube, 40mmCH side-viewing
ZM1230 – ZM1232 with a red contrast filter coating
ZM1232 – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, 15.5mmCH upside-down side-viewing, no decimal point
ZM1240 – ZM1242 with a red contrast filter coating
ZM1241 – ZM1243 with a red contrast filter coating, for use with ZM1240
ZM1242 – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, 16mmCH side-viewing, right decimal point
ZM1243 – + - ~ Ω Neon-filled digital indicator tube, 16mmCH side-viewing, for use with ZM1242 in digital multimeters
ZM1330 – ZM1332 with a red contrast filter coating
ZM1331 – ZM1333 with a red contrast filter coating, for use with ZM1330
ZM1332 – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, 13.1mmCH side-viewing, left and right decimal points, all-glass wire-ended
ZM1333 – + - ~ Ω Neon-filled digital indicator tube, 13.1mmCH side-viewing, all-glass wire-ended, for use with ZM1332 in digital multimeters
ZM1334 – ZM1336 with a red contrast filter coating
ZM1335 – ZM1337 with a red contrast filter coating, for use with ZM1334
ZM1336 – 0 1 2 3 4 5 6 7 8 9 Neon-filled digital indicator tube, 13.1mmCH side-viewing, left and right decimal points, multiplex-capable
ZM1337 – + - ~ Ω Neon-filled digital indicator tube, 13.0mmCH side-viewing, right decimal point (!), all-glass wire-ended, red contrast filter coating, for use with ZM1336 in digital multimeters
ZP1600 – Halogen-quenched Geiger-Müller tube, 19.8 mm diameter mica window, X-rays, 6.0 to 20 keV energy, 60 to 200 pm wavelength range
ZP1610 – Side window, organically quenched Geiger-Müller tube. 7 x 18 mm mica window; X-rays, 2.5 to 40 keV energy, 30 to 500 pm wavelength range
ZP1700 – Halogen-quenched, cosmic-ray guard counter tube for low-background measurements; to be used with another radiation counter tube in an anticoincidence circuit
ZP1800 – Halogen-quenched Geiger-Müller tube for use at temperatures up to 200 °C, γ
ZP1810 – Halogen-quenched Geiger-Müller tube for use at temperatures up to 200 °C, γ, low sensitivity, up to 40 mGy/h
ZP1860 – Halogen-quenched Geiger-Müller tube, β and γ
QE05/40 (6146) – 40 W Radiation-cooled output beam-tetrode, popular amongst radio amateurs as a final RF amplifier
QE08/200 – 200 W Beam-tetrode
QEL
QEL1/150 – Air-cooled 150 W beam-tetrode
QEL1/250 – Air-cooled 250 W beam-tetrode
QEP
QEP20/18 – 18 W Beam-tetrode for use as a pulse modulator
QQC
QQC03/14 – 14 W Dual beam-tetrode
QQE
QQE02/5 (6939) – 5 W Dual beam-tetrode
QQE03/12 (6360) – 12 W Dual beam-tetrode
QQE03/20 (6252) – 20 W Dual beam-tetrode
QQE04/5 (7377) – 5 W Dual beam-tetrode
QQE06/40 (5894, YL1060) – 40 W dual beam-tetrode, internally neutralized, Septar base with dual anode top cap
QQV
QQV02/6 – 6 W dual beam-tetrode
QQV03/20A – 20 W Radiation-cooled split-anode tetrode made by Mullard and used in the 1940s, 1950s and 1960s as a VHF frequency-doubling output stage with balanced output.
QQV07/50 – 50 W Dual beam-tetrode
QQZ
QQZ03/20 (8118, YL1020) – 20 W Dual beam-tetrode
QQZ06/40 (YL1030) – 40 W Dual beam-tetrode
QV
QV04/7 – 7 W Beam-tetrode
QV05/25 (807) – 25 W Radiation-cooled output beam-tetrode made by Mullard.
QV2/250C – 250 W Beam-tetrode
QY
QY3/65 – 65 W Beam-tetrode
QY5/3000A – 3 kW Beam-tetrode
QY5/3000W – Water-cooled version of QY5-3000A
QYS
QYS50/P40 – Pulsed power tetrode, Silica envelope, 50 kV anode voltage, considerable x-radiation, 810 °C anode temperature at 700 W anode dissipation, 40 A anode current at duty factor 0.0005, Vg1Cut-off (IA=1 mA@VA=55 kV): > -3.4 kV, gm: 38 mS
TD03/5 – Indirectly heated disk-seal UHF power triode up to 2 GHz
TD03/10 – Indirectly heated disk-seal UHF power triode up to 2.8 W, 3.75 GHz
TD03/10F – TD03/10 with internal feedback for use as an oscillator
TD04/20 – Indirectly heated disk-seal UHF power triode up to 13.5 W, 1 GHz
TD1/100C = 2C39BA – Indirectly heated, ceramic disk-seal UHF power triode up to 24 W, 3.5 GHz
TD2/400 – Directly heated, ceramic disk-seal UHF power triode up to 600 W, 900 MHz
TD2/500 – Directly heated, ceramic disk-seal UHF power triode up to 500 W, 940 MHz
TE
TE05/10 – RF power triode up to 150 MHz
TX
TX12/12W – Water-cooled RF power triode
TX12/20W – Water-cooled RF power triode
TX10/4000 – Power triode, Silica envelope, 12 kV anode voltage, 4 kW anode dissipation, 1.6 A cathode current, gm: 4.5 mS, for use as self-excited high-power oscillator in induction heating equipment.
TY
TY2/125 – 135 W VHF power triode up to 200 MHz
TY12/50A – Forced-air cooled 45 kW RF power triode up to 30 MHz
TY12/50W – Water-cooled 50 kW RF power triode up to 30 MHz
TYS
TYS2/250 – Power triode, Silica envelope, 2.5 kV anode voltage, 250 W anode dissipation
TYS4/500 – Power triode, Silica envelope
TYS5/1000 – Power triode, Silica envelope
TYS5/2000 – Power triode, Silica envelope
TYS5/3000 – Power triode, Silica envelope, 6 kV anode voltage, 950 °C anode temperature at 3.5 kW anode dissipation, 2.8 A cathode current, gm: 15 mS. Used in RF generators for induction hardening.
X - Thyratron
XGQ
XGQ2/6400 – 2 kV, 6.4 kW Mercury-vapor tetrode thyratron with anode and grid1 top caps
XR
XR1/1600 (5545) – 1 kV, 1.6 kW Inert gas-filled triode thyratron with anode top cap
XR1/6400 – 1 kV, 6.4 kW Inert gas-filled triode thyratron with anode top cap
Compagnie des Lampes (1921, "French Mazda") and Mazda-Belvu
Not to be confused with Compagnie des Lampes (1888, see above) nor with British Mazda (see above).
TGI1-270/12 ТГИ1-270/12 – 12 kV, 270 A Hydrogen thyratron
Indicator tubes
IN-33 ИН-33 – Neon-filled, planar, dual 105-segment linear glow-transfer plasma bar graph display with three cathode strings, for use in VU meters etc.; similar to BG16101
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ITM2-M ИТМ2-М – Four-color phosphored-thyratronlatchingpixel; 4x4 array of 4 subminiature dual-starter luminescent thyratrons each for the colors red, yellow, green and blue (thus, 5 intensities per color yields 5 = 625 colors), 4x4 matrix of 10-volts sensitive starter electrodes, cubic envelope for easy stacking in both axes, 12-pin all-glass wire-ended, similar to today's RGBA LEDs
ITS1 ИТС1 – Green phosphored-thyratron latching seven-segment display, no decimal point, 5-volts sensitive starter electrodes, all-glass wire-ended, rectangular envelope for easy stacking in both axes
MTX-90 МТХ-90 – Small neon-filled thyratron for use as a latching single-dot indicator, top-viewing, top of envelope acts as a magnifier, all-glass wire-ended, comes with a blob of solder on the end of each wire for rapid installing, like today's ball grid arrays
1602 – Directly heated power triode used for A.F. amplification with low microphonics. 7.5 volt filament. 12 watts of A.F. operating in Class-A. 15 watts of low R.F. operating in Class-C. Similar to type 10.
1603 – Indirectly heated pentode used for A.F. amplification with low microphonics. Similar to types 6U7, 57, 6D6 and 6C6. UX6 Base.
1608 – Directly heated triode giving 20 watts at up to 45 MHz. 2.5 volt heater/filament. UX base.
1609 – Directly heated pentode used for A.F. amplification with low microphonics. American 5-Pin(UY)base.
1610 – Directly heated pentode specially designed for use as a crystal oscillator. 2.5 volt heater/filament, American 5-Pin base.
1612 – Pentagrid converter; low-microphonics version of type 6L7. Both control grids (1 and 3) are sharp-cutoff.
1619 – Beam Power Tetrode, similar to 6L6 with directly heated filament, common in World War II battle tank transmitters.
1624, 1625 – Very similar to the 807, but with different heater voltage
1626 – RF triode, very similar to 6J5 but with 12.6 volt filament
29C1 – Directly heated saturated-emission diode; acts as a heating current-controlled, variable series resistor in voltage/current stabilizer circuits.
200s
203A – 100 W, Directly heated RF transmitter power triode, 4-pin base, anode on top cap
204A – 250 W, Directly heated RF transmitter power triode, 3-pin base, anode on top cap
205D – 14 W, Directly heated AF or modulator power triode, 4-pin base
4598, 7539, 7828, 8087, 8098 – Graphechon dual-electron gun scan conversion tubes, analog video transcoders with simultaneous R/W capability for realtime resolution and frame rate transcoding between different analog video standards. This was achieved by a CRT/camera tube combination; the CRT part writes onto a thin, dielectric target; the camera part reads the generated charge pattern at a different scan rate from the back side of this target. The setup could also be used as a genlock
4205E = 205E – Directly heated power triode, 4-pin bayonet base with offset pin
4270A = 270A = 3C/350E – Directly heated power triode, 3-pin base
4275A = 275A – Directly heated power triode, 4-pin base
4300A = 300A – Directly heated power triode, 4-pin base
4307A = 307A – Power pentode similar to the output beam-tetrode type 807. It differs from an 807 by being a directly heated pentode rather than an indirectly heated beam-tetrode. Both types are contained in an ST-16 bulb with an anode cap and 5-pin "American" UY base
The SY4307A is historically notable because a pair of them in parallel Class-C was used as the output stage in a transmitter built in secret by Australian soldiers in Japanese-occupied Portuguese Timor during World War II in 1942. This transmitter, now reconstructed and on display at the Australian War Memorial in Canberra, was called "Winnie the War Winner".
7JP4 – Monochrome cathode ray tube common in early postwar TV receivers. Electrostatic deflection, P4 white, medium-persistence phosphor, 7-inch (180 mm) screen.
7JP7 – Monochrome cathode ray tube for use in early postwar radar displays. Electrostatic deflection, P7 blue-white, long-persistence phosphor, 5+1⁄2-inch (140 mm) screen.
700s
703A – Directly heated Doorknob UHF power triode up to 1.5 GHz
713A – Indirectly heated Little Doorknob UHF pentode, Bakelite Octal base
800 – Directly heated V.H.F. power triode, giving 35 watts up to 60 MHz and 18 watts at 180 MHz. American 4-Pin(UX)base with side locating pin.
801 – Directly heated power triode, used in pairs in Class-B in A.M. modulation sections of transmitters giving up to 45 watts of power at 60 MHz and 22 watts at 120 MHz.
802 – Indirectly heated H.F. power pentode, giving 8 watts up to 30 MHz and 4 watts at 110 MHz.
803 – Directly heated H.F. power pentode, giving 50 watts up to 20 MHz and 25 watts at 70 MHz.
804 – Directly heated H.F. power pentode, giving 20 watts up to 15 MHz and 10 watts at 10 MHz.
805 – Directly heated H.F. high-mu triode, giving 140 watts up to 30 MHz and 70 watts at 85 MHz.
806 – Directly heated H.F. high-mu triode, giving 390 watts up to 30 MHz 195 watts at 100 MHz.
807 – Indirectly heated H.F. beam power tetrode, giving 25 watts up to 30 MHz and 12 watts at 125 MHz. A variation of type 6L6 originally designed as a Class-C transmitter tube. Later used in pairs as push-pull outputs for high-wattage Class-AB2 audio amplifiers. Also used as a horizontal output tube in early TV receivers. One of the first commercial tubes that used the top cap to connect the anode (instead of the control grid) to the circuit.
808 – Directly heated H.F. high-mu triode, giving 140 watts up to 30 MHz and 70 watts at 130 MHz.
809 – Directly heated H.F. high-mu triode, giving 55 watts up to 27 MHz and 30 watts at 100 MHz.
810 – Directly heated H.F. triode, 10 volt filament and Zirconium Carbide anode. Base fits R.C.A. UT-541A Socket.
813 – Beam Power Tetrode possessing about 5 times the Anode dissipation of an 807.
814 – A directly heated Beam Power Tetrode giving about 130 watts at 30 MHz and 65 watts at 100 MHz operating in Class-C.
815 – An indirectly heated dual beam power pentode. Octal base.
825 – First commercially available klystrode, a VHF/UHF linear-beam transmitting tube, similar to a klystron
829 – A dual indirectly heated beam power tetrode. Two 6.3 volt heaters sharing a common tap.
830 – A directly heated triode giving about 50 watts at 15 MHz and 7.5 watts at 60 MHz operating in Class-C.
831 – A directly heated triode giving about 400 watts at 20 MHz and 200 watts at 60 MHz operating in Class-C. 11 volt heater/filament.
833 – A larger directly heated high-mu triode giving about 1 kW at 30 MHz and 500 watts at 45 MHz operating in Class-C. Usable up to 100 MHz at reduced power, (400 W). 10 volt heater/filament drawing 10 A. The anode of this device is fabricated from tantalum. Anode current of 800 mA with an anode voltage of 3 kV and grid voltage of zero. Anode current of 4.3 A at a voltage of 750 with 350 volt on the grid. Uses two-part R.C.A socket assembly UT-103.
834 – A directly heated triode giving 58 watts at 100 MHz and 25 watts at 350 MHz operating in Class-C. 7.5 volt heater/filament. Fitted with an American 4-Pin, (UX4), base with side locating pin.
836 – An indirectly heated high vacuum rectifier with a peak inverse voltage of 5 kV and peak anode current of 1 ampere. 2.5 volt heater.
837 – An indirectly heated pentode giving 11 watts at 20 MHz and 5 watts at 80 MHz. operating in Class-C. 12.6 volt heater.
838 – A directly heated triode giving about 100 watts at 30 MHz operating in Class-C. 10 volt heater/filament.
841 – A directly heated high-mu triode giving about 10 watts at 6 MHz and 5 watts at 170 MHz operating in Class-C. 7.5 volt heater/filament.
842 – A directly heated triode giving about 3 watts at 6 MHz operating in Class-C. 7.5 volt heater/filament.
843 – An indirectly heated tetrode giving gain at 6 MHz and usable up to 200 MHz operating in Class-C. 2.5 volt heater/filament.
844 – A directly heated triode giving gain at 6 MHz and usable up to 155 MHz operating in Class-C. 2.5 volt heater/filament.
845 – A directly heated triode giving up to 24 watts of undistorted power in Class-A at audio frequency with an anode voltage of 1250. 10 volt heater/filament.
849 – A directly heated triode giving gain at 3 MHz operating in Class-C. Two 849s, working in push-pull Class-B are capable of delivering 1.1 kW of audio output with an anode voltage of 3 kV. Usable up to 30 MHz. 11 volt filament/heater.
850 – A directly heated tetrode giving 120 watts of power gain up to 13 MHz and 50 watts at 100 MHz, operating in Class-C. 10 volt heater/filament.
851 – A directly heated triode giving 1.5 kW of power up to 3 MHz operating in Class-C. 11 volt heater/filament.
852 – A directly heated triode giving 75 W of power up to 30 MHz operating in Class-C. 10 volt heater/filament.
857B – Large mercury-vapor rectifier used in 50 kW class broadcast transmitters. 22 kV anode voltage, 10 A anode current. Filament 5 V @ 30 A
860 – A directly heated tetrode giving 105 W of power up to 30 MHz and 50 watts at 120 MHz operating in Class-C. 10 volt heater/filament.
861 – A directly heated triode giving 400 W of power up to 20 MHz and 200 watts at 60 MHz operating in Class-C. 11 volt heater/filament.
862 – Large water-cooled triode for broadcast/industrial applications. Used in experimental 500 kW transmitter at WLW.
864 – A directly heated general-purpose, low-microphonics triode with a maximum anode voltage of 135 volts and anode current of 3.5 mA. 1.1 volt heater/filament.
865 – A directly heated tetrode giving 30 W of power up to 15 MHz 15 watts at 70 MHz operating in Class-C. 7.5 volt heater/filament.
866866A – A mercury-vapor rectifier with a peak inverse voltage of 5 kV and peak anode current of 1 ampere. Average anode current, 250 mA, forward drop, 15 volt. Heater voltage and current, 2.5 at 5 A. American 4-Pin(UX) base.
866A – Improved 866 with a peak inverse voltage of 10 kV and a forward drop of 10 volt.
872 – A mercury-vapor rectifier with a peak inverse voltage of 5 kV and peak anode current of 5 amperes. Average anode current, 1250 mA, forward drop, 15 volt. Heater voltage, 5.0 at 10 A. Base fits R.C.A. UT-541A Socket.
872A – Improved 872 with a peak inverse voltage of 10 kV, a forward drop of 10 volt and a heater current of 6.25 A.
879 – A high vacuum rectifier with a peak inverse voltage of ca. 15 kV and peak anode current of ca. 5 mA. 2.5 volt heater and American 4-Pin, (UX) base. Used as half wave rectifier for high voltage cathode ray tube supplies. Similar to type 2X2.
884 – An indirectly heated triode thyratron. 6.3 volt heater/filament, Octal base. Electrically similar to type 885. Once commonly used as a sawtooth horizontal sweep waveform generator in recurrent-sweep oscilloscopes. Marketed by DuMont under the type number 6Q5.
885 – An indirectly heated triode thyratron. 2.5 volt heater/filament, American 5-Pin (UY) base. Otherwise similar to type 884.
898 – Large water-cooled triode for broadcast/industrial applications. Updated version of 862, with 3-phase filament structure.
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900s
934 – Vacuum Phototube, spectral S4 response (maximum sensitivity at 400±50 nm), 3-pin Small-Shell Peewee base
935 – Vacuum Phototube, spectral S5 response (maximum sensitivity at 340±50 nm), 4-pin octal base
950 – Power pentode with directly heated cathode, used in storage battery home radios with 2.0 volt filament supply. Similar to types 1F4 and 1J5G
951 – Sharp-cutoff pentode with directly heated cathode, used in storage battery home radios with 2.0 volt filament supply. Similar to type 1B4P
954 (4672/E1F) – Indirectly heated Acorn-type sharp-cutoff pentode giving gains of 2...3 up to 300 MHz operating in Class-A and usable up to 600 MHz with careful stage design; 6.3 V heater
955 (4671/E1C) – Indirectly heated Acorn-type triode giving a power of 135 mW up to 600 MHz operating in Class-A and 500 mW in Class-C with careful stage design; 6.3 V heater
956 (4695/E2F) – Indirectly heated Acorn-type remote-cutoff pentode giving gains of 3...4 up to 600 MHz operating in Class-A with careful stage design; 6.3 V heater
957 (D1C) – Directly heated Acorn-type UHF receiving triode; 1.25 V filament for portable equipment
958 (D2C) – Directly heated Acorn-type UHF transmitting triode with dual, paralleled 1.25 V filaments for increased emission, for portable equipment
958A – 958 with tightened emission specs
959 (D3F) – Directly heated Acorn-type sharp-cutoff UHF pentode; 1.25 V filament for portable equipment
BG08220-K – 120-Segment circular with five cathode strings plus a Reset cathode, 1-in-5 major/minor graduation, for use e.g. in direction-finding equipment
BG12201 = DalePBG12201 – Dual 201-segment linear with three cathode strings plus a Reset cathode, for use in VU meters etc.
BG12203 = PBG12203 – Dual 203-segment linear bidirectional with three cathode strings plus two Reset cathodes
BG12205 = PBG12205 – Dual 201-segment linear with five cathode strings plus a Reset cathode, for use in VU meters etc.
BG16101 = PBG16101 – Dual 101-segment linear with three cathode strings plus a Reset cathode, for use in VU meters etc.; cf. ИН-33
CH1027 – Curristor – Four types of nitrogen-filled, radioactive constant-current tubes with a current plateau from 25 to 500 V, all-glass wire-ended, active material is Ra with a half-life of 1601 years, for linear capacitor charging and draining in missile and ordnance mine timing circuits, instrumentation biasing, as current reference, etc.:
CK1366, CK1367, CK1368, CK1369 – CRTs with an unphosphored front glass but with fine wires embedded in it for use as electrostatic print heads; the wires would pass the electron beam current through the glass onto a sheet of paper where the desired content was therefore deposited as an electrical charge pattern. The paper was then passed near a pool of liquid ink with the opposite charge. The charged areas of the paper attract the ink and thus form the image.
CK1383 – Dual-electron gunrecording storage tube, a realtime polar, radar PPI-to-rectangular, TV-type analog videotranscoder similar to the 7702, with simultaneous R/W, and storing capability. This was achieved by a CRT/camera tube combination; the CRT part writes the PPI-format image onto a thin, dielectric target; the camera part reads the generated charge pattern in TV format from the back side of this target.
CL40 and CL41 – Indirectly heated, linear light source (glow modulator tube), mercury/argon-filled gas diode with primer electrode, Octal base, for rotating-drum FAX receivers, film soundtrack recording, etc.
CL42 and CL43 – Indirectly heated, low-noise linear light source, helium-filled gas diode with primer electrode, Octal base, for film soundtrack recording, interferometers, etc.
CL44 – Indirectly heated, low-noise linear light source, neon-filled gas diode with primer electrode, Octal base
CL50 and CL52 – Indirectly heated, linear light source, gas-filled diode with primer electrode, Miniature 7-pin base, for rotating-drum FAX receivers, film soundtrack recording, etc.
CL55 – Indirectly heated, spectrally pure light source, helium-filled gas diode with primer electrode, Miniature 7-pin base with anode top cap
CL56 – Indirectly heated, spectrally pure light source, krypton-filled gas diode with primer electrode, Miniature 7-pin base with anode top cap
CL57 – Indirectly heated, spectrally pure light source, neon-filled gas diode with primer electrode, Miniature 7-pin base with anode top cap
CL58 – Indirectly heated, spectrally pure light source, xenon-filled gas diode with primer electrode, Miniature 7-pin base with anode top cap
EN10 – Neostron, 400 Apk Gas-filled, cold-cathode tetrode thyratron, differential trigger electrodes, Octal base, for use as a relay or as a reddish 700 Cdstroboscope lamp
EN15 – 80 Aavg Neon-filled, cold-cathode tetrode thyratron, differential trigger electrodes, Noval base, for use as a stroboscope lamp
EN30 – 250 Apk Gas-filled, arc-discharge cold-cathode tetrode thyratron, differential trigger electrodes, miniature 7-pin base with anode cap, for use as a relay or as a stroboscope lamp
EN40 – 250 Apk Gas-filled, cold-cathode tetrode thyratron, differential trigger electrodes, Octal base, for use as a whitish stroboscope lamp with a high actinism for photographic film
EN55 (Single), EDN10 (dual) – Xenon-filled, arc-discharge cold-cathode tetrode thyratron, external (capacitive) trigger, 12-pin base, for use as a white 140 kCd stroboscope lamp
EN60 – Gas-filled, arc-discharge cold-cathode tetrode thyratron, external (capacitive) trigger, Edison screw lamp base with anode cap, for use as a white 900 klm@10μF@800V stroboscope lamp
GE10 – Directly heated saturated-emission diode. Acts as a heating current-controlled, variable series resistor in voltage/current stabilizer circuits. It has two shorted pins that can be used to disable the circuit if the tube is removed from its socket
GK
Cerberus:
GK11 – Touch button tube, an illuminated capacitance touch switch; a cold-cathode DC relay tube, external (capacitive) starter activated by touching; then the cathode glow is visible as an orange ring. 2-pin all-glass wire-ended
GN10 – 250 Amps pulse-current, cold-cathode tetrode thyratron. Octal base
GR
Cerberus:
GR15 – 15 mA Gas-filled cold-cathode DC tetrode, one starter and one electrical primer and tritium-primed (half-life: 12.32 years), noval base, for voltage triggers, RC timers etc.
GR16 – 20 mA Gas-filled, cold-cathode, tritium-primed AC/DC triode, one starter and an EM shield, noval base, for voltage triggers, RC timers etc.
GR17 – 15 mA Gas-filled cold-cathode AC triode, one starter and an EM shield, noval base, for voltage triggers, RC timers etc.
GR31 – 15 mA Gas-filled cold-cathode DC tetrode, one starter and one electrical primer plus a tritium primer, noval base
GR44 – 12 mA Subminiature gas-filled cold-cathode DC pentode, two starters and one primer electrode plus a tritium primer, 5-pin all-glass wire-ended
GR46 – 12 mA Subminiature gas-filled cold-cathode DC tetrode, one starter and one primer electrode, 4-pin all-glass wire-ended
KN2 – 4 kV, 500 AsurgeKrytron, a cold-cathode gas-filled tube with a primer electrode, for use as a very high-speed, high-surge current switch; similar to a thyratron, lifespan 10 shots, 4-pin all-glass wire-ended
KN4 – 5 kV, 2.5 kAsurge Krytron with a primer electrode, lifespan 25000 shots, 4-pin all-glass wire-ended
KN6 – 5 kV, 3 kAsurge Krytron with a primer electrode, lifespan 35000 shots, 4-pin all-glass wire-ended
KN6B – 8 kV, 3 kAsurge Krytron with a primer electrode, lifespan 35000 shots, 4-pin all-glass wire-ended
KN9 – 4 kV, 500 Asurge Krytron with a primer electrode, lifespan 1.5×10 shots, 4-pin all-glass wire-ended
KN22 – 5 kV, 100 Asurge Krytron with a primer electrode, lifespan 2×10 shots, 4-pin all-glass wire-ended, for laser pumping, to drive Pockels cells, also for educational purposes
KN26 – 5 kV, 3 kAsurge Krytron with a primer electrode, lifespan 75000 shots, 4-pin all-glass wire-ended
RK61 – Miniature, gas-filled, directly heated thyratron designed specifically to operate like a vacuum triode below its ignition voltage, allowing it to both amplify analog signals and work as a relaxation oscillator, for use as a self-quenching superregenreative detector up tp 100 MHz in radio control receivers, activating a relay in its anode circuit when a carrier wave is received; 4-pin all-glass wire-ended, 1.4 V, 45 mA filament, Ua=45 V, Ia=1.5 mA.
RK62 – RK61's predecessor, marketed since 1938; this was the major technical development which led to the wartime development of radio-controlled weapons and the parallel development of radio controlled modelling as a hobby.
TuneOn – Early neon-filled bar graph tuning indicator, a glass tube with a short wire anode and a long wire cathode that glows partially; the glow length is proportional to the tube current
TuneOn Button – Early glow modulator used as a budget-priced tuning indicator – a neon lamp whose brightness is proportional to the tube current
Tunograph – Precursor of the "Magic Eye" tuning indicator first introduced in 1933; a tiny CRT with 1-axis electrostatic deflection and a phosphored target at 45° to the electron beam, so the projected green dot can be observed from the side
TH9503 – Scripticon, a character generatormonoscope for text mode video rendering in early computer monitors, with a square target having letters, digits and symbols patterned on it in an (optionally customer-supplied) 8x8 array. An electron beam selects and scans a character, both by appropriate magnetic deflection, and generates an analog video signal; cf. 4560, CK1414
TM – Vacuum triode for amplification and detection of radio signals, developed in France and made since 1915. It became the standard receiving and amplifying tube of the Entente countries during World War I, and the first mass-produced radio tube. TM's production volume in France alone is estimated at 1.1 million units; in addition, the production of TM and/or improved versions was started in the UK (Marconi–OsramR tube), the Netherlands (PhilipsE tube), the United States and the Soviet Union (R-5, Russian: Р-5).
The TM was developed in 1914–15 by the French military telecommunications service Télégraphie Militaire on the initiative of their technical director Gustave-Auguste Ferrié. He and his assistant, physicist Henri Abraham, visited the American laboratories on a number of occasions and were aware of the works of Lee de Forest, Reginald A. Fessenden and Irving Langmuir. They knew that de Forest's Audion and Henry Round's British tube were unreliable and imperfect, and Langmuir's Pliotron was too complex for mass production. They also knew about the latest German developments: Soon after the outbreak of the war, Ferrié received extensive information from a former Telefunken employee, the Frenchman Paul Pichon, who, upon return from a mission from his German employer to gather samples of the latest triodes from the USA, had to surrender himself and the samples to the French. The samples Pichon brought performed poorly due to insufficient vacuum. Following the ideas of Langmuir, Ferrié required the industry to guarantee a high vacuum in series production.
In October 1914, Ferrié, Abraham and François Péri from the radiotelegraph centre in Lyon/La-Doua went to the light bulb department of Société des Téléphones E.C.&Alexandre Grammont in Lyon to develop with them a triode suitable for mass production. The first prototypes, mere copies of de Forest's Audion, proved to be unreliable and unstable; the next ones were rejected for being too complex. Only the fourth prototype developed in December 1914, with a vertical coaxial system, an Edison screw lamp base for the filament and additional side terminals for anode and grid, was deemed suitable for series production, which started in February 1915 and stopped in October 1915 when it became clear that the vertical structure of "Abraham's Lamp" was too fragile and too many tubes were damaged during transport. Ferrié asked Péri to resolve the problem, and two days later Péri and Jacques Biguet came up with a horizontal coaxial system on the latest four-pin type European 4-pin base. The series production of the Péri/Biguet tubes, named TM after Ferrié's service unit, began in November 1915 under Grammont's Radio Fotos brand; this variant became highly successful, and when demand started to exceed Grammont's production capacity, Compagnie des Lampes (1888) in Ivry-sur-Seine also started production under their Métal brand. Ferrié and Abraham were nominated for the 1916 Nobel Prize in Physics for their work in the field of radio communications.
The TM is a cylindrical/coaxial triode; the directly-heated cathode is a filament made of pure tungsten with a diameter of 60 μm, the anode is a nickel cylinder with a diameter of 10 mm and a length of 15 mm. The dimensions and material of the grid depend on the place of production – the Grammont plant in Lyon used molybdenum wire, the CdL plant in Ivry-sur-Seine used nickel. The diameter of the grid spiral is 4 resp. 4.5 mm. The filament required 4 V and 700 mA to bring it up to white heat; the bright glow prompted Grammont in 1923 to start producing TM tubes with dark blue glass envelopes to protect the eyes of radio operators from the blinding glare, and hide the harmless, but unsightly plaque of metal particles inevitably deposited on the inner wall of the bulb while evacuating during production – but also prevented the triodes' previous, secondary use as light sources, which had earned them their nickname Loupiote ("little lamp").
The TM could be used for their intended purpose, amplifying and detecting signals in radio receivers, or as power oscillators in low-power radio transmitters, and also, by paralleling of several tubes, as AF power amplifiers. The Soviet analogue of the TM, the triode R-5, could withstand anode voltages of up to 500...800 V, and was able to deliver a power of up to 1 W in Class-C mode, but only 40 mW in Class-A mode. A typical single-TM radio receiver of World War I ran at Ua=40 V, Ug=0 V, Ia≈2 mA, gm=400 μS, Ri=25 kΩ, μ=10. With an anode voltage of 160 V and a grid bias of -2 V, the anode current was 3...6 mA, while the reverse grid current reached 1 μA.
The problem of TM tubes was their short service life of 100 hours maximum – if the tube was manufactured in strict accordance with the specifications. In wartime, this was not always possible; due to raw materials supply problems, plants sometimes had to use substandard materials. Such tubes were marked with a cross; they differed from the standard by a higher noise level and were prone to catastrophic failures due to cracks in the glass envelope.
FM1000 – Unusual pentagrid for use as oscillator and coincidence-type phase detector in a PLL FM quadrature detector. The anode signal is loosely coupled into the oscillator tank and pulls it to stay quadrature-phase-locked with the IF; manufactured by Sylvania and used in Philco AM/FM radios of the late 1940s and early 1950s. Predecessor of the nonode approach
XXB – Medium-mu twin triode, also numbered 3C6/XXB
XXD – Medium-mu twin triode, also numbered 14AF7/XXD
XXFM – High-mu triode, twin diode (one shares its cathode with the triode, one with separate cathode), also numbered 7X7/XXFM
XXL – Medium-mu triode, also numbered 7A4/XXL
List of tubes used in 1920s and 1930s radio receivers
Directly heated
Used with AC, DC or home-based storage battery power supplies (1927–31)
1.1 Volt DC filament
Used in 1920s home radios. Filaments powered by 1.5 volt dry cells, anodes powered by storage batteries.
Used in 1930s home radios powered by storage batteries.
19 – Dual power triode – also used in farm radios with 6-volt vibrator power supplies. Early version of octal type 1J6G.
20 – Power triode – Early versions numbered UX-120.
22 – Sharp-cutoff tetrode – Early versions numbered UX-222 or CX-322.
25S – Dual detector diode, medium-mu triode. Identical to type 1B5. Usually numbered 1B5/25S.
30 – Medium-mu triode, An upgraded version of type 01-A – Early versions numbered RCA-230 or CX-330. Can also be used as a power triode. The type 30 was popular amongst amateurs of the day. Early UX4 based version of octal type 1H4G.
31 – Power triode, UX4 based – Early versions numbered RCA-231 or CX-331.
32 – Sharp-cutoff tetrode – Early versions numbered RCA-232 or CX-332.
33 – Power pentode – Early versions numbered RCA-233 or C-333.
34 – Remote-cutoff tetrode – Early versions numbered RCA-234 or CX-334.
49 – Dual-grid power triode, similar to type 46
3.3 Volts DC filament
Used in 1920s home radios powered by dry cells (filaments) and storage batteries (B-plus voltage).
V99 – Low-mu triode. Except for stub-pin bayonet base and pinout, electronically similar to X99
X99 – Similar to V99, but with standard pins and different basing arrangement (pinout).
4 Volts DC filament
3NF – Tube-based "integrated circuit" with 3 triodes and passive components in the same envelope. 4V heater
5 Volts DC filament
Used in 1920s home radios powered by storage batteries.
00-A – Detector triode with a trace of argon. "00-A" is the number used in most tube manuals. Numbers for earlier versions include UX-200-A and CX-300-A (long pins, push-in socket) and UV-200-A (stub pins, bayonet socket).
01-A – All-purpose low-mu triode, used as RF amplifier, detector, AF amplifier and power triode. The most popular tube of the 1920s. "01-A" is the number used for replacements manufactured after 1930 and in tube manuals. Numbers for early versions include UX-201-A and CX-301-A (long pins, push in socket) and UV-201-A (stub pins, bayonet socket).
Note: There were four tubes in the "01" series, each with different current ratings for their filaments. Type 01-A was the most commonly used.
Types UV 201 and UX 201 – 1.0 ampere
Type 01-A (UV 201-A, UX 201-A, etc.) – 250 milliampere
Type UX 201-B – 125 milliampere
Type UX 201-C – 60 milliampere
12-A – Medium-mu triode, often used as detector, audio driver or audio output, but not as an RF amplifier. This type is listed in tube manuals after 1930 for replacements purposes. Also referred to as type 112-A. Many early versions are marked UX-112-A or CX-112-A.
40 – Medium-mu triode – Early versions numbered UX-240. Introduced in 1927, this was an upgraded version of the "01" series. The "01" series had an amplification factor of 8, while type 40 had an amplification factor of 30. (By comparison, the two AC triodes introduced in the same time period – types 26 and 27 – had amplification factors of 8.3 and 9, respectively.) Because this was the highest-amplification triode available, advertising literature of the time lists it as a high-mu triode, although it is now classified as a medium-mu triode. Type 40 had the highest amplification factor of any triode until the introduction in 1932 of diode/triode complex type 2A6, which had an amplification factor of 100. It also had the highest amplification factor of any DC filament triode until the introduction in 1939 of complementary diode/triode complex types 1H5GT (octal) and 1LH4 (Loctal), which both had amplification factors of 65.
Directly AC-heated power tubes
10 – Power triode – Early versions numbered UX-210 or CX-310.
26 – Medium-mu triode, used in early AC radio receivers manufactured in the late 1920s. Used as an RF or AF amplifier, but not as a detector or power output tube – Early versions numbered UX-226 or CX-326.
45 – Power triode – Early versions numbered UX-245 or CX-345.
46 – Dual grid power triode – Grids 1 and 2 connected together for use as push-pull Class-B outputs, Grid 2 and anode connected together for use as single-tube audio driver.
47 – Power pentode – Early versions numbered RCA-247 or C-347.
50 – Power triode – Early versions numbered UX-250 or CX-350.
71-A – Power triode – This type listed in tube manuals after 1930 for replacements purposes. Also referred to as 171-A. Many early versions numbered as UX-171-A or CX-371-A.
Directly AC-heated rectifier tubes
80 – Full-wave rectifier used in early power supplies or battery eliminators (electronically similar to 5Y3G) – Early versions numbered UX-280 or CX-380; derived from the 13 (UX-213)
81 – Half-wave rectifier – Early versions numbered UX-281 or CX-381; derived from the 16-B (UX-216-B)
83-V – High-vacuum version of type 83, Early UX4 based version of octal type 5V4G.
Indirectly heated
DC heater
15 – Sharp-cutoff pentode, used in farm radios, in autodyne circuits requiring a separate cathode.
48 – Power tetrode, used in 32-volt farm radios. When two are parallel-connected, they can operate with anode and screen voltages as low as 28 volt.
2.5 Volts heater
Powered by an AC transformer
24 – Sharp-cutoff tetrode, UX5 based, Early versions numbered UY-224 and C-324
24-A – an upgraded version of type 24, see type 24 above. Early versions numbered UY-224A and C-324A
27 – Medium-mu triode, UX5 based, Early versions numbered UY-227 and C-327. The first North American tube with an indirectly heated cathode, which is necessary for detector circuits in AC powered tube radios.
35 – Remote-cutoff tetrode, UX5 based, (Commonly branded as 35/51). Early versions numbered UY-235 or C-335
51 – Similar to 35, see type 35 above. (Commonly branded as 35/51)
53 – Dual power triodes, Class-B, UX7 based, (Except for heater, electronically similar to 6A6 and octal based 6N7)
55 – Dual diode, medium-mu triode, UX6 based, (Except for heater, electronically similar to type 85, and octal based 6V7G, but not to 75)
56 – Medium-mu triode, UX5 based, (Except for heater, electronically similar to 76, and octal based 6P5G)
57 – Sharp-cutoff pentode used in cabinet and mantel radio receivers, UX6 based, (Except for heater, electronically similar to 6C6 and octal based 6J7G, and somewhat similar to type 77)
58 – Remote-cutoff pentode, UX6 based, (Except for heater, electronically similar to 6D6 and octal based 6U7G, but not to 78)
59 – Power pentode, UX7 based.
90 – Wunderlich detector
95 – Original number of type 2A5
4 Volts heater
2HF – Tube-based "integrated circuit" with 2 tetrodes and passive components in the same envelope
6.3 Volts heater
Powered by an AC transformer or a vehicle crank battery
1-V – Half-wave rectifier, UX4 based, (often branded as type 1V/6Z3). Early version was KR-1.
36 – Sharp-cutoff tetrode, UX5 based. Early versions numbered RCA-236 or C-336
37 – Medium-mu triode, UX5 based. Early versions numbered RCA-237 or C-337
38 – Power pentode, UX5 based. Early versions numbered RCA-238
39 – Remote-cutoff pentode, UX5 based (Commonly branded as 39/44).
41 – Power pentode, Early UX6 based version of octal type 6K6G, and Loctal type 7B5.
42 – Power pentode, Early UX6 based version of octal type 6F6G, Except for heater, similar to types 2A5 and 18.
44 – Similar to type 39, see type 39 above. (Commonly branded as 39/44).
64 – Sharp-cutoff tetrode (Except for 400 milliampere heater, similar to 36)
65 – Remote-cutoff pentode (Except for 400 milliampere heater, similar to 39)
67 – Medium-mu triode (Except for 400 milliampere heater, similar 37)
68 – Power pentode (Except for 400 milliampere heater, similar to 38)
69 – Wunderlich detector
70 – Wunderlich detector used in Mission Bell model 19 car radio. Listed in early Philco tube lists.
75 – Dual diode, high-mu triode. Early UX6 based version of octal types 6B6G & 6SQ7GT, and Loctal type 7B6, and 7-pin miniature type 6AV6. Also except for heater, electronically similar to 2A6.
76 – Medium-mu triode, Early UX5 based version of octal type 6P5G.
77 – Sharp-cutoff pentode, Early UX6 based version of octal type 6J7G.
78 – Remote-cutoff pentode, Early UX6 based version of octal type 6K7G.
79 – Dual power triode, Early UX6 based version of octal type 6Y7G.
84 – Full-wave rectifier, often branded as type 84/6Z4. Early UX5 based version of octal type 6X5GT, and Loctal 7Y4, and 7-pin miniature 6X4.
85 – Dual diode, medium-mu triode. Early UX6 based version of octal type 6V7G, except for heater voltage similar to type 55. Also somewhat similar to octal type 6SR7GT and 7-pin miniature types 6BF6.
89 – Power pentode, UX6 based.
92 – Wunderlich detector
AC/DC series heater
14 – Similar to 24-A but with a 14 volt, 300 milliampere heater. Used in Philco models 46 and 46E
17 – Similar to 27 but with a 14 volt, 300 milliampere heater. Used in Philco models 46 and 46E
18 – Similar to 2A5 and 42 but with a 14 volt, 300 milliampere heater. No known commercial use.
43 – Power pentode, Early UX6 based version of octal type 25A6G
WG38 – Tube-based "integrated circuit" with 2 pentodes, a triode and passive components in the same envelope
Shielded tubes for Majestic radios
In the early 1930s, the Grigsby-Grunow Company – makers of Majestic brand radios – introduced the first American-made tubes to incorporate metal shields. These tubes had metal particles sprayed onto the glass envelope, copying a design common to European tubes of the time. Early types were shielded versions of tube types already in use. (The shield was connected to the cathode.) The Majestic numbers of these tube types, which are usually etched on the tube's base, have a "G" prefix (for Grigsby-Grunow) and an "S" suffix (for shielded). Later types incorporated an extra pin in the base so that the shield could be connected directly to the chassis.
Replacement versions from other manufacturers, such as Sylvania or General Electric, tend to incorporate the less expensive, form-fitting Goat brand shields that are cemented to the glass envelope.
Grigsby-Grunow did not shield rectifier tubes (except for type 6Y5 listed below) or power output tubes.
Early types based on existing tubes. (Non-shielded versions may be used, but add-on shielding is recommended.)
G-25-S – Medium-mu triode, dual detector diode for 2.0 volt storage battery radios. Glass type 1B5/25S used for replacement.
G-51-S – Remote-cutoff tetrode
G-55-S – Medium-mu triode, dual detector diode
G-56-S – Medium-mu triode
G-56A-S – Medium-mu triode, original version of type 76, but with 400 milliampere heater. (Not to be confused with types 56 or G-56-S, which has a 2.5 volt, 1.0 ampere heater.)
G-57-S – Sharp-cutoff pentode
G-57A-S – Sharp-cutoff pentode, original version of type 6C6, but with 400 milliampere heater. (Not to be confused with types 57 or G-57-S, which has a 2.5 volt, 1.0 ampere heater.)
G-58-S – Remote-cutoff pentode
G-58A-S – Remote-cutoff pentode, original version of type 6D6, but with 400 milliampere heater. (Not to be confused with types 58 or G-58-S, which has a 2.5 volt, 1.0 ampere heater.)
G-85-S – Similar to G-55-S, but with 6.3 volt heater.
Later types
6C7 – Medium-mu triode, dual detector diode, similar to later octal types 6R7 and 6SR7. Seven pin base. (Shield to pin 3.)
6D7 – Sharp-cutoff pentode, identical to type 6C6, but with 7-pin base. (Shield to pin 5.)
6E7 – Remote-cutoff pentode, identical to type 6D6, but with 7-pin base. (Shield to pin 5.)
6Y5 – Dual rectifier diode, similar to type 84/6Z4, but with 6-pin base. (Shield to pin 2.)
Other tubes unique to Majestic radios
G-2-S and G-4-S – Dual detector diodes with common cathodes. The first detector diodes packaged in a separate tube. Forerunners of octal type 6H6. Spray-shielded. Both tubes have 2.5 volt heaters. G-2-S is larger and has a 1.75 ampere heater. Type G-4-S has a 1.0 ampere heater. Later Sylvania replacement type 2S/4S has a 1.35 ampere heater.
2Z2/G-84 – Half-wave rectifier diode with 2.5 volt indirectly heated cathode. A lower-voltage version of type 81. Not interchangeable with type 6Z4/84.
6Z5 – Full-wave rectifier, similar to types 6Z4/84 and 6X5, but with 12.6 volt center-tapped heater.
Rarely used tubes
52 – Dual grid power triode similar to types 46 and 49. Has 6.3 volt filament. Most commonly used in early car radios
181 – Power triode
182-B – Similar to 482-B below.
183 – Similar to 483 below.
482-B – Power triode with directly heated cathode. Used in Sparton AC radios, circa 1929. Replacements often numbered 182-B/482-B. Similar to type 71-A, but with higher anode voltage.
483 – Power triode with directly heated cathode. Used in Sparton AC radios, circa 1929. Replacements often numbered 183/483. Similar to type 45, but with a 5.0 volt, 1.25 ampere heater.
485 – Medium-mu triode with indirectly heated cathode. Used in Sparton AC radios, circa 1929. Similar to types 56 and 76, but with a 3.0 volt, 1.25 ampere heater, and lower anode voltage.
Miniwatt Technical Data, 6th Edition; 1958; Published by the "Miniwatt" Electronics Division of Philips Electrical Industries Pty. Limited, 20 Herbert Street, Artarmon, N,S,W., Australia
"Miniwatt" Premium Quality and Special Purpose Tubes, Philips Electrical Industries Pty. Ltd., Australia, November 1957.
5J6 data sheet - this particular Tung-Sol datasheet contains a copy/paste error in the description where it cites 6J6's 450 mA heater current when it should read 5J6's 600 mA.
^ Rider, John. F.; Seymour D. Uslan (1948). "FM Transmission and Reception" (PDF). John F. Rider Publisher, Inc. pp. 130–135. Retrieved 25 December 2016.
This tube's designation is inconsistent with the scheme
Wechselspannungs- und Wechselstrom-Stabilisierungsschaltungen mit der Diode YA1000. Telefunken Laborbuch (in German). Vol. IV. Ulm: AEG-Telefunken. 1967. pp. 189–195.
