Australian Post Office
Telephone No. 334MT & 334MP

This is a table telephone with Alnico hand generator projecting through the dummy dial plate.

These phones were fitted with an Induction Coil No. 21A (ASTIC), 1.7uf and 0.4uf capacitors and a 1000ohm bell ringer.

They also require three volts to power the transmitter and this is provided by two 1.5v batteries contained in an external battery box.

These telephones were developed in the UK and most were made by British Ericsson (ETL) with the 334MT from their N2120 range. Different variants of the N2120 were purchased.

The N2120H is shown on diagram CE456 sheet 1.

The N2120K (Circuit diagram N55548 which is dated 1939) is shown on diagram APO Diagram C1354 schedule C.

The N2120K1 (Mark 2) is shown on diagram APO Diagram CE1106 (334MT).

A later variant, the N2120K3, was also used and this is shown on the APO diagram CE456 sheet 2 (334MT). Introduced in 1949.

The 334MP is a portable telephone and has a plug ended line cord. This is shown in a diagram below although it is called a 334MT.

The generator is the C Type which is mounted on the chassis. Note that handle of the generator, on the 334MT, never protruded from the dead centre of the dummy dial cover, unlike the 300MT. The generator was moved slightly backwards to allow the inclusion of a capacitor fitted to the front of the base plate. The generator is pictured below.

Similar to 333MT and 300MT.

Training notes