GEC K7805

BATTERY CALL WALL TELEPHONE
(With Induction Coil)

Comprising a Manchester Shot Carbon Transmitter with Metal Mouthpiece, Watch Receiver and Flexible Cord, Automatic Switch, Call Push, 3in. Circular Call Bell and Induction Coil. Woodwork of solid well seasoned Polished Walnut and all external metal parts Nickel plated.

Price in 1908 was £0.18.0

Taken from the GEC Telephone Catalogue, K Section, 10th Edition, 1908

K7805

"BYNG"
Battery Call Telephone

Wall pattern battery call telephone (named Byng by GEC) comprising induction coil, inset transmitter with Electrose mouthpiece, `Stanley' receiver, trembler bell, ring key and automatic switch hooks.  Call button on side of case.

This instrument is constructed of polished walnut and the finish of all external metal work is oxidised.

Cost in 1916 was £0.19.3
Cost in 1926 was £2.7.6

Taken from the 1916 and 1926 GEC catalogues

Superseded by the Gecophone Junior telephone range

Additional Pictures

Circuit Diagram

Diagram KS 6340
 

Wiring two Telephones together

Each telephone requires three 1.5 volt batteries.  The phones are normally connected together by two wires, but if the ZE terminal is connected to a good earth then only the L terminals are connected together with one wire.  It is recommended to use two wires and dispense with the earth connection.

At each telephone connect the batteries as follows:-

1. Connect the three batteries in series.
2. Connect the free negative terminal of the battery set to terminal ZE on the phone.
3. Connect the free positive terminal of the battery set to terminal C on the phone.
4. Connect the positive terminal of the centre battery to terminal MC on the phone.

Connect the two phones together as follows:-

1. Connect terminal ZE of one phone to terminal ZE of the other.
2. Connect terminal L of one phone to terminal L of the other.

In the diagrams below the following abbreviations are:-

C = Carbon (Positive terminal of battery).
Z = Zinc (Casing and negative of battery).
MC = Microphone Carbon.
L = Line.
ZE = Zinc earth (this is connected to earth if only one line wire is used to connect the telephones together.  If two line wires are used then just connect the second wire to ZE and ZE).