TELEPHONE No. 156
Automatic and CBS Pedestal Telephone
Similar to the Telephone No. 150 it was designed to use a local battery for connection to mainly C.B.S. type exchange systems. But it could also be used in Automatic exchange areas with a Bellset No. 21 on long lines where a normal instrument would give faint speech (Diagram AT1872). In this instance local batteries would still need to be provided and connected to the Bellset.
This telephone has no internal components except for switch hooks and the phone requires the correct Bellset to work properly. The switch hook springs in this telephone were totally insulated with no connection to the casing, which made the phone electrically safe.
The switch hook consists of two contact sets, one set has three contacts that all make together and the other has a changeover set.
Used on the following circuits:-
Early table telephones were connected to the internal wiring with a Strip, Flexible Cord Connection. Click here for more information.
Telephone includes (1928 and 1946):-
To be requisitioned separately as required:-
When fitted with a Transmitter No. 1 a Label No. 43C would be fitted between the speaking tube and the transmitter body. This label advised of the Exchange name and number. When fitted with a Transmitter No. 2 a Label No. 78E is fitted.
Two Transmitters were used on this telephone. Originally fitted with a 'Transmitter No. 2', this was superseded by the later style Bakelite 'Transmitter No. 22' which accepted the 'Transmitter Inset No. 10' which was itself superseded by the 'Transmitter Inset No. 13'.
Circuit diagram - N256.
Circuit diagram - AT 1872.
Drawing - 9543.
Specification - D788.
Last revised: October 17, 2023