Combined, Bakelite cased, table telephone used by the BPO in CBS No's 1, 2, 3 & Magneto areas on private circuits without transmission feeds and in mobile vans.

This telephone had a tray for the subscribers personal directory but as from June 1940 the tray was not fitted and instead the telephone was supplied with a Tray, Dummy, D62099 (a blank plate).  This was probably a war time cost saving, as in late 1947 the tray was re-introduced.

Available in the colours - Jade green, Chinese red, Black and Ivory.

This phone would have been connected to a scrambler unit and the handset has been changed to a green variant to identify that the phone could be switched to make speech secret.

Supplied to the BPO by Ericsson, their Model N8440.

Pictures courtesy of Ian Nichol.
Adjustment of Magneto bells

Circuit diagram - N496.

Diagram for the Button labels  - N620.

Drawing - 63022.


History, Technical and General Information on 300 type telephones

Collectors information

General fault finding on your phone

How to restore Bakelite

Dismantling the Handset

Dismantling your Telephone No. 312

Keys for use in 300 type Wall and Table Telephones

Comparison chart of GPO 300 type telephones


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Last revised: November 20, 2021