Russian tube designations: Что?!

Ever wondered what the cycillic letters were in our alphabet?  Below is a list of the russian letters, their translation and the meaning. These definitions are mainly for receiver tubes.


position 1:  Denotes the whole number of the heater/filament voltage, i.e. 6 for 6.3V


position 2:

A     A      Pentagrid converter
B     Б     Combined pentode + diode
C     Ц     Rectifier
D     Д     Single diode
E     Э     Tetrode
F     Ф     Combined triode + pentode
G     Г     Combined triode + diode
H     X     Double diode
I      И     Combined triode+hep-/hex-/octode
J     Ж     Pentode (sharp cut-off)      * Also seen translated as Z or Zh
K     К     Pentode (remote cut-off)
L      Л     CRT (L is followed by a second letter)
N     Н     Double triode
P     П     Output pentode or beam-tetrode
R     P     Double pentode/tetrode
S     C     Triode
U     У     Power triode
V     B     Tube with secondary emission
Y     E     Magic eye


position 3: Unique number to identify the tube among similar types


position 4:

A     A      Sub-miniature (5-8mm) with wire leads
B     Б     Sub-miniature (8-10.2mm) with wire leads
D     Д     Glass-metal case with disc connections
G     Г     Glass (>10.2mm)
J     Ж     Acorn
K     К      Metal ceramic case
M    M     Glass (22,5mm) GT-shape
N     Н     Nuvistor
P     П     7-pin (19mm) or 9-pin (22.5mm)
R     P     Sub-miniature up to 5mm
S     C     Glass (>22.5mm) ST-shape


position 5:

D     Д     Extended Long-life (typically 10.000hrs)
I      И      For impulse or switch-mode
K     К     Vibration resistant
R     P     Increased reliability and mechanical ruggedness, low-noise, lower microphonics (better than V)
U     У     Gold pins, heavy burn-in (15% or rated life?), and possibly higher maximum operating frequency of 600MHz
V     B     Increased reliability and mechanical ruggedness, low-noise, lower microphonics (lower than R)
Y*    E     Long-life (typically 5.000hrs) 

* Typically not translated and E is used in western alphabets as well.

The I designation usually has a smaller glass envelope and is often not really recommended for audio. These tubes were optiomised for pulsed applications where constant plate dissipation like in audio was not intended. Although they are useable for audio, most people report worse sound quality than with the normale, non-I, versions.



6S45P-E    The -E is kept in western alphabets and is not translated to -Y for some reason
6 = 6.3V heater
S = triode
45 = unique number
P = 7-pin or 9-pin, ie noval
E = Long life


6 = 6.3V heater
P = output pentode
14 = unique number
P = noval
E = Long-life
V = low-noise, increased durability

6 = 6.3V heater
E = tetrode
6 = unique number
P = noval
D = extra long-life
R = low-noise, increased durability, better quality than V
U = gold pins, burned-in, 600MHz frequency