GEC INTERCOM TELEPHONES

None of these telephones have induction coils, except for K 7865, K7868 & K 7886.

K 7864
INTERPHONES
CONVERTIBLE TYPE

Converted for table use		For wall mounting

The Central Battery Domestic Interphone is intended for use under conditions in which a neat and simple telephone is required, such as in private residences, small suites of offices, etc., where it is unusual for more than one conversation to be necessary at one time. 

It consists of a hand combination, cradle support, selective ringing keys, call buzzer wound to 5 ohms, flexible cord, and connecting wall block.

This telephone is also supplied as table pattern as illustrated above. An ingenious feature of its design enables the set to be quickly converted into a wall set.

The cabinet work is of well-seasoned walnut; external metal parts are finished in oxidised copper bronze.

With each installation a K 7863 Battery Impedance Coil is necessary, comprising coil and terminals mounted on a brown Bakelite base, with cover.

The telephone is equipped for 5 lines; it can also be used as a central station set to work in conjunction with the instruments K 7735, K 7746, K 7750, K 7790 and 7796, as sub-stations, to ring and speak both ways to the central station only. In this instance the K 7863 is not required.

These instruments will not work with K 7887, K7888, K 7907, K 7913, K 7953 & K 7967.

Table or Wall Instrument.

Weight, 3 lbs. 6 ozs.

Dimensions, 6.5 x 10 ins.

Cost in 1935 was £3.7.6

K 7865
As K 7866 but fitted with induction coil.
Walnut with all external metal work in an oxidised finish.

K 7866
Wall pattern battery call intercom telephone comprising of `Manchester' shot transmitter, electro-magnetic watch receiver, automatic switchook, auto reset ring key, impedance coil and 25 ohm bell. Walnut with all external metal work in an oxidised finish.
Comes in 4 sizes:- 5 lines, 10 lines, 15 lines and 20 lines.

Cost in 1928 was £4.0.0 for the 20 line model.


A version similar to above was also made the only differences being the transmitter and receiver being replaced by a handset.

K 7867
Cabinet work of well-seasoned walnut.

Fitted with self-replacement device attached to the ringing key and switch hook Outward conversation finished, re ­ placing receiver or handset on switch hook or cradle automatically disconnects radial switch from instrument speaking circuit.

Only necessary to move radial switch when making outward call; calls received and answered whatever position of radial switch. Contact with more than one line at a time cannot be made. Receiver, or handset, should be removed from switch hook before making an outward call.

Switch contacts and line terminals fitted at back of instrument, well protected from dust and rough handling.

To facilitate wiring wall instrument provided with hinged fixing batten. Inductive cross-talk reduced to a minimum.

Pirelli-General anti-inductive intercommunication telephone cables, Class No. 992 braided, and No. 993 lead covered are recommended for use with these instruments. Two central batteries, one each for ringing and speaking, each comprising three No. 1 Carsak cells, L 4885, are all that are required, local batteries being dispensed with.

These instruments are suitable for working in conjunction with the Sterling "Primax" systems.

Instruments fitted with induction coil, and arranged for ordinary local or central battery circuits, can be obtained for extension to existing installations at extra charge.

Wall type telephone, comprising radial switch, K 7670 carbon granule transmitter, K 7631 “Watch” pattern electro-magnetic receiver, auto-reset ringing key, automatic switch hook, impedance coil and 25 ohm bell on tail piece. External metal parts oxidised copper bronze.

Weight:
6 lines, 5 lbs. 7 oz.
11 lines, 5 lbs. 8 oz
16 lines, 5 lbs. 11 oz.
21 lines, 5 lbs. 12 oz.
Dimensions, 14 x 8 x 6 ins.

Cost in 1935 for the 21 line model was £4.0.0

K 7868
As K 7869 except that this model has an induction coil.

K 7869
As K 7866 except that it has an electro-magnetic hand combination suspended from the switchook in place of the Manchester transmitter and receiver.

K 7886
As K 7887 except that this model has an induction coil.

K 7887
Table pattern battery call intercom telephone comprising electro-magnetic handset, automatic cradle switch, auto reset ring key, 25 ohm buzzer and flexible cord with rosette.
Comes in 4 sizes:- 5 lines, 10 lines, 15 lines and 20 lines.

Cost in 1928 was £6.18.0 for the 20 line model.

K 7888
Description as per K 7867 .
Table type telephone, comprising radial switch, automatic cradle, auto-reset ringing key, impedance coil, 25 ohm buzzer, brown Bakelite handset without speaking key in handle, fitted with receiver and inset transmitter which can be easily removed, flexible cord, and wall rosette. External metal parts coin bronze.

Cost in 1935 for the 21 line model was £6.15.0.

Weight:
6 lines, 5 lbs. 6 oz.
11 lines, 5 lbs. 10 oz.
16 lines, 6 lbs.
21 lines, 6 lbs. 4 oz.
Dimensions, 9.5 x 9 x 8 ins.

Extra charge when fitted with induction coil

K 7906
Wall pattern intercom telephone comprising if electro-magnetic handset, solid back transmitter with metal mouthpiece, automatic cradle switch, 25 ohm buzzer push button line selector and impedance coil.
Comes in 4 sizes:- 5 lines, 10 lines, 15 lines and 20 lines.

Cost in 1928 was £8.16.0 for the 20 line model.

K 7907
INTERCOMMUNICATION TELEPHONES WITHOUT INDUCTION COIL ELECTRO-MAGNETIC AUTO-RESET TYPE

Wall Pattern

These instruments are equipped with a combined line selector and ringing key in the a push button, which, when pressed, rings and selects the number required in ration. The buttons are held down during an outward conversation by an auto-vice, which restores the key to the normal position immediately the handset has been replaced on the cradle after a conversation has ceased. Before an outward call is made, it is necessary to remove the handset from the cradle. The button of any one line only be pressed when making an outward call; all incoming calls are answered y removing the handset from the cradle. Designation strips are fitted at the side row of buttons.

working parts are mounted on a strong steel frame with machine screws and fixed on a wood base, with a black stove-enamelled pressed steel cover overall. All instruments e to the same dimensions, irrespective of the number of lines, and are so arranged all capacity instruments can be extended on site by units of 5 lines, up to their capacity of 21 lines. Spare parts are obtainable for making extensions.

These instruments are suitable for working in conjunction with the Sterling “Primax”.

Wall type telephone, comprising automatic cradle switch, 25 ohm buzzer, impedance coil, and latest pattern black Bakelite handset without battery key in handle, fitted with a superior quality electro-magnetic receiver and improved type inset transmitter, which can be easily removed.

Dimensions, 10 x 9 x 7 ins.

K 7912
Table model intercom telephone similar to above, but fitted with flexible cord and rosette.
Comes in 4 sizes:- 5 lines, 10 lines, 15 lines and 20 lines.

Cost in 1928 was £9.11.0 for the 20 line model.

K7913

Table type telephone, similar to K7907 , but fitted with flexible cord and black Bakelite wall rosette.

Dimensions, 10 x 9 x 7 ins.

Last revised: August 10, 2005