TELEPHONE No. 3
CBS No. 1
telephone with no magneto generator.
It is a wooden Local Battery telephone with sloping writing shelf and paper clip. Two batteries were housed in the bottom of the case.
The set shown to the right was made by Ericsson. The Transmitter arm moved up and down.
A later version was produced, the Mark 238, which was oblong in shape (see pictures below).
This telephone was in the 1928 Rate book but not available in the 1946 Rate Book.
Fitted with a Transmitter No. 2 although earlier types had a Transmitter No. 6.
If a Transmitter No. 2 was fitted then a Label No. 78 was fitted between the speaking tube and the transmitter body. This label advised of the Exchange name and number.
This telephone could also work on CBS No. 2 & 3 exchanges by the addition of a capacitor.
In the 1909 GPO wiring book this phone can be on provincial party lines arranged for two and ten parties. In this system X subscribers 1, 2 ,3 ,4 and 5 would be called by ringing the A leg to earth, whilst the Y subscribers 1, 2, 3, 4 and 5 would be rung on the B leg to earth. In early directories a subscriber number on a party line would be described thus: 238Y5 - 238 being the line number, to be rung on the B wire, five times.
Mark 238 Telephone includes (1928):-
Frames, Notice No. 2 and Labels No. 53B were not maintained in the old type of these instruments.
Circuit diagram - N103.
Drawing for the desk - 7437.
Specification - D150.
Supplied by Ericsson, their Model N20141 (Mark 238 - Dated 1932).
GPO instructions state that this telephone should be fixed to
the wall with it's lower edge 36 inches from the floor.
Last revised: December 08, 2022