TELEPHONE No. 103

A Fire telephone, used in Magneto telephone exchanges, with a high output generator.

On the right hand side of the telephone is a key with a special locking arm.  In the locked position the fire station line is switched to the exchange line and the telephone is disconnected from the circuit.  When the locking arm is released and the key operated the Fire Station line is connected to the telephone, but the exchange can monitor the conversation.

Batteries were required to power the transmitter.

Probably supplied by British Western Electric as it looks like a BTMC No. 2040.

Telephone includes :-
1 x Bell, Magneto 1,000ohms (N.R.B.).
1 x Coil, Induction N.T. 1001.
2 x Condensers, M.C. No. 1.
2 x Cord, Instrument No. 116.
1 x Cord, Instrument No. 222.
1 x Frame, Notice No. 1.
1 x Generator, N.T. No. 1001.
1 x Key No. 72 red.
1 x Key-mounting V.
1 x Transmitter, N.T., No. 13 or Transmitter No. 1.
1 x Receiver, Bell No. 1A.

Circuit diagram - N203.

Circuit diagram - TL 845 (Dated 1921).