TELEPHONE No. 331

Bakelite wall telephone for use in C.B. & Automatic exchange areas on PBX extensions, on certain extension plans and systems that require recall facilities.

This telephone had provision for one button in the case moulding.

There appears that there was no call for this telephone so it was not released, the Telephone No. 321 being used instead.

Diagram for telephone circuit - N431.

Diagram for Button labels - N620.

History, Technical and General Information on 300 type telephones
300 Type telephone circuit description
Development of the Bakelite Wall Telephone
Collectors information
Keys for use in 300 type Wall and Table Telephones
How to restore Bakelite
Comparison chart of GPO 300 type telephones