TELEPHONE No. 321
This Bakelite cased wall telephone was introduced in 1955 and used by the BPO on shared service lines. Produced in Automatic or C.B. variants. The C.B. variant with fitted with a Dial, Automatic, Dummy No. 3.
It is fixed to the wall, on 4 rubber mounts, by wood screws.
It is fitted with an AC bell ringer and a single press button (no switch unit).
Produced in the colours; Black, Chinese Red, Ivory and Jade Green.
The telephone has provision for three press buttons and is used with Adaptors Shared Service No. 1 & 2.
The model with no press buttons was the Telephone No. 333.
Telephone No. 321F supplied by British Ericsson as their
Telephone No. 321CB supplied by British Ericsson as their
Circuit diagram - N421.
Diagram for Button labels - N620.
Drawing - 90509 (Mark 1).
Case and Adapter Shared-Service No. 1 removed
Case removed exposing Adapter Shared-Service No. 1 (centre)
Last revised: November 20, 2021