Metal Central Battery wall telephone for outdoor use at cab ranks etc.

Comprises of a Transmitter No. 1 and Receiver Watch No. 1B.

The bell mechanism is a modified Bell No. 53A and is mounted, along with the gongs, inside the casing.

All the components are mounted on a separate chassis which includes two lightning protectors (they look like bulbs).

Telephone includes (1928):-
1 x Bell No. 53A (modified).
4 x Clips, Protector, G, No. 2.
1 x Condenser, M.C., No. 22.
2 x Cord, instrument, No. 116.
1 x Cord, instrument, No. 222, waterproof.
1 x Hook, Receiver, C.
2 x Protectors, G.
1 x Receiver, Watch, No. 1B.
1 x Transmitter No. 1.

Telephone (Mark 234) includes:-
2 x Bell-gong No. 7.
1 x Capacitor, Paper No. 22.
1 x Hook, Receiver, C.
1 x Bell, No. 53A (Modified).
1 x Receiver, Watch, No. 1B.
1 x Transmitter, No. 1.
2 x Protector, G.
4 x Clip, Protector, G, No. 2.
1 x Cord, Instrument, No. 222, Waterproof.
1 x Coil, Induction, No. 14.

Telephone (Mark 235) also includes:-
1 x Coil, Induction, No. 14.

The lock is a Key, Lock, A.

Supersedes Telephone No. 75.
Superseded by Telephone No. 145.

Circuit Diagram - N225.
Circuit Diagram - C.B. 943.
Circuit Diagram - C.B. 1394 (Mark 235)
Drawing No. 8727 (dated 1927) & 8822.

Pictures are dated March 1928


Chassis outside housing

Two different views of the internal chassis


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Last revised: February 05, 2020