GEC K8107

MINING TELEPHONE
CERTIFIED AS INTRINSICALLY SAFE

Table telephone with black Bakelite case and  generator box to be used on the surface.   The Generator box is made of Walnut and houses the bell and capacitor.

The Generator is a K9109.

Cost in 1935 was £7.10.0

 

Circuit Diagram

Conversion to the UK Plug and Socket system
As this is a Magneto telephone it cannot be wired to exactly emulate the UK plug and socket system.  The instructions below will work in most situations.

1. Remove any link between the EB terminals.
2. Remove the safety condenser from the bell terminals on the door.
3. Remove one of the bell wires from a bell terminal on the door and connect to a 3.3K ohm resistor to the wire removed.
4. Connect the other end of the resistor to the bell terminal you removed the bell wire from.
5. A 3 or 4.5 volt battery is required to operate this phone.  Connect the positive to C and the negative to Z.
6. Remove the permanently wired link between the right hand EB terminal and the L1 terminal.
7. Connect Red wire of the new line cord to L1 terminal.
8. Connect White wire of the new line cord to L2 terminal.
9. Connect Blue wire of the new line cord to the right hand EB terminal.
10. Insulate the Green wire of the new line cord as this is unused.
11. Wedge the hand generator so it cannot be operated.
    

Last revised: July 31, 2025