TELEPHONE No. 131
The early type used a Transmitter No. 1 which could have Label No. 43A fitted between the speaking tube and the transmitter body. This label advised of the Exchange name and number.
The picture shows the Label No. 43A which has instructions of how to obtain trunk calls.
The Mark 234 Telephone includes:-
Circuit diagram - N231.
Circuit diagram - CB 1429.
Last revised: January 31, 2023