Generators can be indentified by numbers with one or two suffix letters.  The first letter will signify the resistance (A to L used), whilst the additional suffix letter will signify that the generator is mounted in some way.

The resistance letters are:-

A = 500 ohms
B = 450 ohms
C = 400 ohms
D = 300 ohms
E = 200 ohms
F = 110 ohms
G = 60 ohms

Generator No. 4C
2 magnet (type 234 and 235) or 3 magnet (mark 236).

Includes Handles Generator No. 6.


Generator No. 4CN
Generator No. 8A


Generator No. 26A

Generator unit in general use from 1950 onwards.




BACK Home page BT/GPO Telephones Search the Site Glossary of Telecom Terminology Quick Find All Telephone Systems

Last revised: June 24, 2012