Frank's Electron tube Pages
	Tube Number Systems

European system after 1934 Philips system before 1934 Mazda numbering system Russian numbering system Brimar type designation code Tesla numbering system

European system after 1934 (pro-electron)

See also: Type Designation Code from "Preferred Types of Electron Tubes 1967".

1st letter heater indication 0 tubes without filament A 4 V AC parallel connection B 180 mA DC C 200 mA AC/DC series or parallel connection D <= 1.4 V DC dry-battery, parallel connection E 6.3 V AC or carbattery, parallel connection F 13 V carbattery G 5V AC parallel connection H early: 4V DC battery. later: 150mA AC/DC series connection I 20V AC/DC parallel connection K 2 V battery O 150 mA AC/DC series connection P 300 mA AC/DC series connection U 100 mA AC/DC series connection V 50mA AC/DC series connection X 600 mA AC/DC series connection Y 450 mA AC/DC series connection 2nd+next letters tube systems A single detection diode B double detection diode C small-signal triode D power triode E small-signal tetrode (or 2nd emmission tube EE1) F small-signal pentode H hexode or heptode K octode L power pentode or power tetrode M indicator tube N thyratron Q enneode W single gasfilled rectifier diode X double gasfilled rectifier diode Y single vacuum rectifier diode Z double vacuum rectifier diode digits socket & order x P (some are V) (except U-series (e.g.UBL1), those are octal) 1x Y8A 2x W8A, Loctal (except D-series (e.g. DL21), those are octal) 3x K8A, A08, octal 4x A8A, B8A, Rimlock 5x T9A, B9G, Enne-al and C2R and some special bases 6x Subminiature 7x Subminor8p 8x, 18x, 8xx B9A, noval 9x, 19x, 9xx B7G, miniature-7p (Exception: The ECC99 is a poorly chosen tube type number, as it comes with a noval base.) 2xx, 2xxx decal 5xx B9D, magnoval Examples Description CBL1 output pentode with dual detection diode, heater 200mA, P base EABC80 tripple signal diode with triode, heater 6.3V, noval base ECC83 dual triode, heater 6.3V, noval base GZ34 dual vacuum rectifier, heater 5V, octal base PFL200 pentode and power pentode, heater 300mA, decal base UCH21 triode and heptode, heater 100mA, base loctal

Philips system before 1934

1st letter heater current A 0.06 to 0.10 A B 0.10 to 0.20 A C 0.20 to 0.40 A D 0.40 to 0.70 A E 0.70 to 1.25 A F > 1.25 A 2nd digit or 2nd+3rd digits heater voltage x heater voltage < 10 V xx heater voltage >= 10V last 2 digits description xx amplification factor for triodes 41, 51 etc tetrode with spacecharge grid (2nd grid is control grid) 42, 52 etc tetrode with screen grid (1st grid is control grid) 43, 53 etc power pentode 44, 54 etc triode with diode or tetrode with diode 45, 55 etc hf tetrode with variable gain 46, 56 etc hf pentode 47, 57 etc hf pentode with variable gain 48, 58 etc hexode frequency changer 49, 59 etc hexode with variable gain Suffix letter Description H ? N ? New, later version S ? Series connection allowed T ? Examples Bases usually: A or O E499 triode, If=1A , Vf=4V, gain=99 F443N power pentode, If=2A, Vf=4V B2046 hf pentode, If=0.18A, Vf=20V

MAZDA NUMBERING SYSTEM Signal valves

First number indicates heater or filament rating 1 1.4V (parallel or series) 6 6.3V (parallel or series) 10 0.1A (series) 20 0.2A (series) 30 0.3A (series) Following letter or letter sequence indicates class of valve C Frequency changer with special oscillator section D Signal diode(s) F Voltage amplifier tetrode or pentode FD Voltage amplifier tetrode or pentode with diode(s) FL Voltage amplifier tetrode or pentode with voltage amplifier triode K Small gas triode or tetrode L Voltage amplifier triode or double triode including oscillator triode LD Voltage amplifier triode with diode(s) M Tuning indicator P Power amplifier valve, tetrode or pentode PL Power amplifier valve, tetrode or pentode with voltage amplifier triode Final number distinguishes between different valves in the same class MAZDA NUMBERING SYSTEM Power rectifier valves Letters indicates heater or filament rating U High vacuum half-wave UU High vacuum full-wave Final number distinguishes between different valves in the same class

RUSSIAN NUMBERING SYSTEM

The regulation GOST 5461-59 applies to tubes manufactured from 1959 and semiconductors manufactured from 1959 to 1963. Every symbol consists of four elements. If an element is absent, a dash should be written at its place. Note: There are exceptions. Not all Russian tubes are numbered according this system. First element Generator (transmitting) tubes up to 25 MHz UKF generator (transmitting) tubes 25-600 MHz Centimeter range generation (transmitting) tubes Modulator tubes High power rectifiers Voltage stabilizers Current stabilizers Thyratrons Gas-discharge rectifiers Mercury gas-discharge rectifiers , Photocells and photomultipliers Approximate (usually full volts) heater voltage Receiving tubes Screen diameter in cm Picture tubes Semiconductor diodes Transistors Second element Diodes Double diodes Triodes Tetrodes Power pentodes and tetrodes Remote cut-off pentodes Sharp cut-off pentodes Secondary emission pentodes Mixing tubes with two signal grids Pentodes with one or two diodes Triodes with one or more diodes Tuning indicators Triodes with hexode, heptode or octode Double triodes Double tetrodes and pentodes Triode - pentodes Rectifiers Type sequence number Gas-discharge tubes, power rectifiers Gas thyratrons Mercury thyratrons Cold cathode thyratrons Oscillograph tubes with electrostatic deflection Oscillograph tubes with electromagnetic deflection TV picture tubes Type sequence number Semiconductors Third element Receiving, picture, generator and modulator tubes voltage and current stabilizers photocells and photomultipliers cold cathode thyratrons Type sequence number Semiconductors Subtype, group (letter) Fourth element none Metal Receiving tubes; voltage and current stabilizers Glass HF glass, side leads Ceramic Miniature glass 19 and 22.5 mm Subminiature > 10 mm Subminiature 10mm Subminiature 4 mm Subminiature 6 mm lock-in-key Disc leads Water cooled Generator (transmitting) and modulator tubes Air cooled letter Luminophor color code Picture tubes X/Y X = average current in A Y = reverse voltage amplitude in kV Thyratrons (non cold cathode), Gas-discharge, power rectifiers After symbol dash and postfix of one or more letters may be added: high reliability tube (military) long life tube (military) designed for impulse operation vibration resistant Current Regulators [A][V1-V2] [A] is the current (in amperes) and [V1-V2] is voltage range

Brimar type designation code for Receiving Valves

First Number Indicates the Construction 1 Half Wave Rectifiers 2 Diodes. Single 3 Triodes, Output 4 Triodes, High-mu 5 Tetrodes, Straight 6 Tetrodes, Vari-mu 7 Pentodes, Power and Video 8 Pentodes, R.F. Straight 9 Pentodes, R.F. Vari-mu 10 Diodes, Double 11 Triodes with Double Diode 12 Pentodes, A.F. with Double Diode 13 Triodes Double, High-mu 14 Triodes Double, Class B Output 15 Heptodes 16 Triodes Output, D.C. Coupled 17 Pentodes R.F. with Double Diode 18 Pentodes with Triode 19   20 Hexode/Heptode with Triode Letter Indicates the heater rating A 3.6 to 4.4V Indirectly Heated B 2V Directly Heated C Directly Heated other then 2 or 4V D All other heater ratings Indirectly Heated other then 4V Number Serial number Serial Numbers are allocated in chronological order as new valve types are introduced

TESLA NUMBERING SYSTEM

leading digits heater indication   Approximate (usually full volts) heater voltage middle letters tube systems (a subset of European system) A single detection diode B double detection diode C small-signal triode F small-signal pentode H hexode or heptode L power pentode or power tetrode M indicator tube Y single vacuum rectifier diode Z double vacuum rectifier diode trailing digits socket and order 1x octal K8A, A08 2x loctal W8A 3x heptal B7G 4x noval B9A 5x special; mostly, 9 out of 10 pins 1.25mm on a circle diameter 25mm 6x submagnal B11A (no actual tube in this system known) 7x duodecal B12A (no actual tube in this system known) 8x diheptal B14A (no actual tube in this system known) 9x free wires Examples Description 35Y31 Single rectifier, heptal (7pin miniature) socket; 35V/150mA series heater; otherwise, European UY1N in heptal format 4L20 HF power pentode; filament 2x2.4V / 325mA, Soviet 4П1Л; German RL4,2P6 in loctal format 6CC42 VHF double triode; 6.3V/350mA heater, noval; equivalent to 2C51 6F24 Telecom pentode, 6.3V/450mA heater, loctal; not similar to later Mazda's 6F24 1M90 Subminiature indicator tube, 1.4V/25 mA filament, European DM70 leading 2 digits screen specification   Approximate screen diameter or diagonal, in centimeters 3rd digit type order middle letters focusing and deflection QP magnetic focusing, magnetic deflection (early TV tubes) QQ electrostatic focusig, magnetic deflection (later TV tubes) QR electrostatic focusing and deflection (oscilloscope tubes) trailing digits screen color and persistence Examples Description 7QR20 Oscilloscope tube, 7cm diameter, green fluorescence, middle persistence 430QP44 TV tube, 43cm diagonal, magnetic focusing and deflection, white fluorescence, pentode system, 90 degrees deflection angle 430QQ44 TV tube, 43cm diagonal, electrostatic focusing, magnetic deflection, white fluorescence, tetrode system, 110 degrees deflection angle 431QQ44 Identical to 430QQ44, except with metal-backed screen 1st letter tube category R HF tube Z modulator tube U gas-filled power rectifier 2nd letter tube systems   see receiving tubes digits power level   Anode dissipation in watts or kilowatts trailing letters cooling system (optional 1st letter), tube order X air cooling Y water cooling Examples Description RA0007B Ballast diode controlled by filament current; max anode current 0.7mA RD1,5XA Air-cooled power triode up to 30MHz, 1.5kW anode dissipation RE40AK KT88 by Tesla Vršovive (in production)