405 Alive - Technical - Valve Numbers

This is an archived website which has not been updated since 2002.
Some information may be inaccurate or out of date.

Decoding Valve, Transistor and CRT Numbers
Voltage Stabilisers (Old System)

The type number consists of a number followed by a capital letter, a figure and in some cases by a second capital letter (e.g. 85A2, 150C1K).

Number (average burning voltage in volts)

First letter (current range)

A - max. 10 mA
B - max. 22mA
C - max. 40mA
D - max. 100mA
E - max. 200 mA

Figure (serial number)

Second letter (tube base)

E - Edison
K - Octal 8-pin base
P - P-base