GEC K7820 & K7826

Battery Call Telephone

Similar to K7805 but fitted with Hunningscone-Deckert transmitter.

This instrument is constructed of polished walnut and the finish of all external metal work is oxidised.

Cost in 1916 was £1.10.0
Cost in 1928 was £3.1.9
Cost in 1935 was £2.7.6

Later version had a carbon granule transmitter and the terminals were internal.

Wall pattern battery call telephone, comprising K 7670 carbon granule transmitter, K 7630 “Watch” pattern double-pole receiver, K 7728 induction coil, automatic switch hook, ringing key and 25 ohm bell on tail piece.

Weight, 3 lbs. 8 ozs.

Dimensions, l0 x 7 x 5 ins.

In 1916 the telephone could be supplied mounted on a backboard.  See K7825.

BATTERY CALL TELEPHONES WITH INDUCTION COIL

Cabinet work of well seasoned walnut; external metal parts oxidised copper bronze.
The telephone instruments described here, along with K 7847, K 7851 & K 7855 can be used together for the following requirements:-

Connected up in pairs, to ring and speak both ways over approximately half a mile, a double line or single line with earth return.

To connect up three stations by the use of a K 8500 switch and a K 8313 bell,  to enable “A” station to ring and speak both ways to “B” and “C” stations only; the latter cannot communicate with each other.

To connect up three stations by the use of a K 8510 switch and a K 8313 bell to enable “A” station to ring and speak both ways to “ B” and “C” stations, and the later stations to speak together by “A” station placing the K 8510 switch in the through position.

Where a number of telephones are required in a building, these telephones can be installed to work in conjunction with Battery Call Switchboards K 8335, K 8350 and K 8360 with an operator in attendance.

K 7826
Backboard only, with battery box to accommodate three No. 3 G.E.C. dry cells, with space for mounting a K 7820 telephone.

Weight, 3 lbs. 4 ozs.
Dimensions, 20 x 9 x 4.5 ins.

Last revised: August 10, 2005