SIEMENS BROTHERS No. Q3437

Q3437

This instrument is for use on C.B. systems in cases where two telephones - viz., a main and an extension - on one line are required to have intercommunication without calling the exchange.

The special switch, Q3437, is for fixing to a wall, and is for use where the main instrument is a wall-pattern telephone, but it can, of course, also be used in conjunction with a desk-pattern instrument. This switch comprises a 1000ohm magneto bell, hand generator, supervisory signal and switch, and provides the same facilities as described for the Q3573.

It should be noted that as these telephones are arranged for C.B. speaking, it is necessary to provide a small battery in the line circuit between the main and extension instruments to supply current for speaking when these two stations wish to carry on a conversation together. This extra battery may consist of two or more dry cells according to the length and resistance of the extension line.

Extension Switch, equipped with 1000ohm bell, hand generator, supervisory signal, etc. For use at a main station in conjunction with ordinary C.B. telephones.

Dimensions
9.5" x 7.5" x 7" / 238mm x 190mm x 178mm

Taken from the Siemens Brothers Catalogue 1928

Last revised: October 19, 2025

FM2