Bakelite cased handset wall telephone with DC trembler bell for use on extension plans in CBS No's 1, 2, 3 and Magneto exchange areas and on long lines in C.B. and Automatic exchange areas.

Fitted with a DC Trembler bell and has provision for three buttons.

All components and the case are mounted on a plate.  This plate is fixed to the wall, by means of 4 rubber mounts, using wood screws.

The case was fixed by a single screw next to the Handset cord entry.  The case had a strap that fixed to the back plate allowing the case to hang during maintenance work.

To remove the case, release the lower fixing screw adjacent t to the handset cord entry point.  Pull the bottom of the case outwards about one inch.  Lift the case upwards to release the top fixings.

Wall equivalent of Telephone No. 392.

Circuit diagram - N493.

Diagram for the Button labels  - N620.

History, Technical and General Information on 300 type telephones

Development of the Bakelite Wall Telephone

Collectors information

Keys for use in 300 type Wall and Table Telephones

How to restore Bakelite

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Last revised: February 07, 2023