TELEPHONE No. 4
LB Pedestal Telephone
This telephone was also known as the "Telephone, Table, P.B., Transmitter Type".
CBS No. 1 - Table telephone if used with Bellset No. 5.
The Transmitter No. 2 would have Label No. 78 fitted between the speaking tube and the transmitter body. This label advised of the Exchange name and number.
The switch hook consists of two change-over type contact
This was the standard telephone instrument arranged for standing upon a table. Since this telephone is simply a transmitter, a receiver, and a gravity switch, the instrument is not complete, and a separate hand generator is provided, usually fixed to the desk or table in close proximity to the table telephone; the induction coil and magneto bell, with the condenser (should one be required), are fitted in a case and are known as a Bell Set.
The bell set for use with the telephone is Bell Set No. 5, if the condenser is not necessary, and Bell Set No. 15 if a condenser is required. The bell set need not be fitted close to the telephone so long as it is within audible distance of it. The primary battery is placed in a battery box and fitted close to the bell set to which it is connected.
The Gravity switch is a new design where the contact springs are operated by an Ebonite rod. This ensures that the receiver hook is insulated from the line, in case of a high voltage contact between external overhead cables.
There are a number of revisions to this telephone (Marks 234 to 236). The Mark 236 is fitted with a Transmitter No. 22.
Early table telephones were connected to the internal wiring with a Strip, Flexible Cord Connection. Click here for more information.
Superseded by the Telephone No. 156.
Telephone includes (1928):-
To be requisitioned separately if required:-
Telephone includes (1946):-
Circuit diagram - N104.
Diagram - CBS 265 (CBS 1 and Magneto - Non condensered).
Drawings - 10015, 9544 & 62901 (Mark 235 dated 1911).
Specification - D202.
Made obsolete in 1947 and superseded by Telephone No. 156LB.
When fitted with a Transmitter No. 2 the exchange number label is a Label No. 78.
Telephone No. 4 Mark 236
Last revised: October 27, 2023