TMC produced this compact telephone for Telephone Rentals and probably other suppliers.  This base plate accommodates two capacitors (in the same casing), an induction coil and a bell on the base plate. 

In the body of the phone is an 8 way style terminal array with only 6 or 7 terminal connections and unlike Ericsson and GEC compacts, is the only terminal block within the phone.  The terminal block has screws instead of nuts.

The bell gongs are barrel shaped and the base plate also has five oblong slots covered with mesh, which stop insects and foreign objects entering the telephone.

The case is straight edged at the bottom and has two cable entry holes on the rear, which have ebonite grommets.

The handset will most probably have the TR logo in the centre of the handset.

Very similar to the S52597.

The cylindrical capacitor, which is the GPO Capacitor M.C. 97, was introduced circa 1947, whilst PVC insulated wire was first used in telphones in the late 1940's.

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Note the two cable entry holes




Standard GPO style Induction Coil


S52596 Diagram

How to convert this telephone to the UK PST System

7 terminal type
Using a standard UK line cord:-

  1. Remove and discard the old line cord.

  2. Feed the new line cord through the casing entry hole and tie it or knot it to the metal loop inside the phone.

  3. White wire of new line cord to terminal 4.

  4. Install a 3.3k resistor between 4 & 5.

  5. Red wire of new line cord to terminal 6.

  6. Green wire of new line cord - spare - insulate with tape.

  7. Disconnect the green wire on 2uf capacitor and insulate with tape.

  8. Blue wire of the new line cord to terminal 7.

  9. Check transmission and replace transmitter if bad and always fit a Rectifier element across the receiver on terminals 1 & 2.  Click here for more information.



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Last revised: November 11, 2023