TELEPHONE No. 306


Introduced in 1939 this is a combined table handset telephone used by the BPO in both CB and Automatic areas.

This telephone has a DC Trembler bell, with one bell gong only and provision in the Bakelite case for three press buttons.

Detail as for Telephone No. 326, Black, minus Cord, except  the Cradle-switch action is 2M and lC, instead of 2M.

Used on extension plans that require an additional gravity switch hook springset.

Mark 1 - has a receiver, Inset No. 1L in the handset.
Mark 2 - has a receiver, Inset No. 2P in the handset.
Mark 2A - has a receiver, Inset No. 2P in the handset with a switch hook bracket and plungers of an improved design.

Early models may be found with a Filter, Suppression No. 6 and a Coil, Induction No. 22 fitted.

Spring 1 of the cradle switch is spring-set is adjacent to the mounting.

Diagram for telephone circuit - N406.

Diagram for Button labels - N620.

Drawing No. 63022 - Telephone components parts.
Drawing No. 63023 - Chassis components.
Drawing No. 63250 - Chassis components (improved switch hook buttons).
Drawing No. 90319 - Telephone parts (Mk 3A).
Drawing No. 90373 - Chassis components (improved switch hook buttons).
Drawing No. SBA12 - 300 type base plate.
Drawing No. SCA17 - 300 type complete case.
Drwaing No. SCA20 - 300 type case.
Drawing No. SCA47 - 300 type complete case (improved switch hook buttons).

How to wire your Telephone No. 306 to make it work on Plug and Socket

Dismantling the Telephone No. 306

Dismantling the Handset

History, Technical and General Information on 300 type telephones

Collectors information

Adjustment of Magneto bells

Keys for use in 300 type wall and table telephones

Lamp Fittings

Labels that fit in the sliding tray

General fault finding on your phone

How to restore Bakelite

Comparison chart of GPO 300 type telephones

 

Comparison chart of GPO 300 type telephones

 

 
 
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Last revised: April 22, 2022

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