GEC K7820 & K7826
It consists of Hunningscone-Deckert Granular Transmitter, Induction Coil, Double Pole Watch Receiver, Call Bell, Ringing key and Automatic Switch Hook. Wood work of solid well seasoned Polished Walnut and all exterior Metal parts Nickel plated.
Can be used on lines up to half a mile in length.
Price in 1908 was £1.7.6.
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
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
of well seasoned walnut; external metal parts oxidised copper bronze.
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.
Found in the 1916, 1926, 1932 and 1935 Catalogues
Weight, 3 lbs. 4 ozs.
Wiring two Telephones together
Each telephone requires three 1.5 volt batteries. The phones are connected together by two wires.
At each telephone connect the batteries as follows:-
Connect the two phones as follows:-
Last revised: August 16, 2015