| 1st element |
  |
Generator tubes (TX) up
to 25MHz |
 |
Generator tubes (TX) 25
to 600MHz |
 |
Microwave TX tubes |
 |
Modulator tubes |
|
High power tubes |
|
Voltage stabilisers |
 |
Current stabilisers |
|
|
Thyratrons |
|
Gas discharge rectifiers |
 |
Mercury gas discharge
rectifiers |
|
Photocells/photomultipliers |
 |
Photocells/photomultipliers |
| Heater volts |
for receiving tubes |
| Screen diameter (cm) |
for picture tubes |
| 2nd element |
|
Diodes |
|
Double diodes |
|
|
Triodes |
|
Tetrodes |
|
Power tetrodes/pentodes |
|
|
Remote cutoff pentodes |
|
Sharp cutoff pentodes |
|
|
Secondary emission pentodes |
 |
Mixing tubes with signal
grids |
|
Pentodes with diode(s) |
|
|
Triodes with diode(s) |
|
Tuning indicators |
 |
Triodes with hexode, heptode
or octode |
|
Double triodes |
|
|
Double tetrodes/pentodes |
|
|
Triode/pentodes |
|
Rectifiers |
| Sequence number |
Gas discharge tubes, power
rectifiers |
|
|
Gas thyratrons |
|
|
Mercury thyratrons |
|
|
Cold cathode thyratrons |
  |
Electrostatic deflection
CRTs |
|
Electromagnetic deflection
CRTs |
|
TV CRTs |
| Third element |
Type sequence
number |
| Fourth element |
Receiving
and stabilisers |
|
|
Glass |
|
|
HF glass, side leads |
|
|
Ceramic |
|
|
Miniature glass, 19 &
22.5mm |
|
|
Submini > 10mm |
|
|
Submini 10mm |
|
|
Submini 4mm |
|
Submini 6mm |
|
|
Lock-in-key |
|
|
Disc leads |
| TX and modulator
tubes |
|
Water cooled |
|
|
Air cooled |
| |
Picture tubes |
| |
Letter |
Screen details, phosphor
etc. |
| |
'hot' Thyratrons,
gas discharge, power rectifiers |
| |
x/y |
x=average current in A;
y=reverse voltage in kV |
| |
|
|
| One or more
letters may be added |
| |
|
High reliability tube
(military) |
| |
|
Long life tube (military) |
| |
|
Designed for impulse operation |
| |
|
Vibration resistant |
| For current
regulators |
| |
[A][V1-V2] |
A=current in Amps, V1
- V2 is voltage range |
