GEC 75


GEC Wall Mounting Telephone

The GEC75 is a compact wall telephone suitable for use with any exchange. Its simple shape protrudes as little as possible into its surroundings. It is ideal for the person who likes, or needs a clear desk or draughting table. It can be used wherever a telephone is needed and working surfaces should be clear and clean - in workshops, canteens or kitchens, when a shelf or table would be inconvenient - in reception rooms, dining rooms, or corridors or by the bedside in hotel or nursing home.

There are many locations where the GEC75 proves more practical and more pleasing than the more usual table telephone.

The GEC75 is neat in appearance with no trailing wires; hygienic, easy to clean and attractively styled with simple, contemporary lines.

A feature of the GEC75 is the handset retention. The handset is placed, when not in use, into two case recesses, one above and one below the dial. Positive retention is by two nylon plungers which hold the earpiece firmly in its recess. This simple device makes the GEC75 particularly suitable for applications where vibration could accidentally dislodge the handset - ships and railway trains, for example.

G.E.C. telephones are renowned for their high-quality performance and the GEC75 is no exception.

It is built with many of the same reliable components that have proved themselves in hundreds of thousands of G.E.C. telephones throughout the world.

Case
The case is moulded in A.B.S., a scratch resistant, temperature-stabilized plastic that is easily cleaned and withstands rigorous use in climatic extremes. Designed specifically for use as a wall telephone there are no trailing wires and the case, having simple yet contemporary lines, is easy to clean, and therefore, hygienic in use. The case is retained on the baseplate by one screw located at the bottom of the instrument.

Handset
The handset, moulded in the same material as the case is light in weight and combines a high degree of user comfort with a maximum of transmitter efficiency. Its shape ensures that with the receiver held to the ear normally the transmitter is located in the most efficient position.

Handset location
In the rest position the handset is retained in the case recesses and is gripped firmly by two small spring-loaded nylon buttons in the receiver-bowl recess.

Transducers
The carbon-granule transmitter and the rocking-armature receiver provide clear speech reproduction with low distortion over a wide speech-frequency range.

Handset Cord
The handset cord is coiled for compactness and P.V.C. sheathed, affording protection to the conductors against wear and condensation. The cord ends are firmly secured so that the terminations are not subject to stress. The colour of the cord matches that of the handset.

Dial
The G.E.C. articulated-trigger dial is fitted to the instrument and has a self-compensating action that shows no appreciable variation in pulse ratio after 4.5 million impulses. The dial front is encased within a protective moulded ring which is supplied to match the handset colour. A wide range of number rings is available in various languages to suit the requirements of individual Administrations. The finger plate may be supplied in transparent or coloured plastic as required.

Cradle Switch
The cradle switch springset is operated by a p.t.f.e. gravity-triggered plunger located in the bowl for the handset receiver and is activated by removal of the handset.

Sensitivity
When the telephone is connected to a line of less than 400 ohms, an additional resistor is connected into the receiver circuit to reduce the received signal level. This is required principally on short lines when the sensitivity of the instrument is such that normal speech reproduction may be uncomfortable to the ear.

Buzzer
The single-coil buzzer has a pleasing and purposeful sound and will operate from all normal exchange ringing supplies. The tone of the buzzer can be adjusted to suit the subscriber at the time of the installation. An extension bell may be fitted.

Recall
Recall facilities may be fitted as an optional extra.

Tropicalization
Special insulation is included so that the telephone can be used in any climate. The design provides both adequate ventilation against humidity and protection against the ingress of insect and dust.

Abridged Specification

Catalogue Number
Drg. 97724

Exterior
Case and handset moulded in A.B.S. high-impact plastic. Three colours available : black, dual grey and ivory.

Cord
PVC-covered cadmium-tinsel-conductor coiled cord, colour to match handset. Held in position by grommets which relieve conductors of any stresses.
Length, 25 cm (10 in) un-extended; 170 cm (68 in) extended.

Dial
Articulated trigger type speed: 10 p.p.s.;
break-to-make ratio 2 to 1 - other ratios can be supplied
For C.B. Working, a dial-dummy disc replaces the dial.

Transducers
Receiver inset - Rocking armature, replaceable capsule: Sensitivity: +46 db relative to 1 dyne/cm2/mW available power.
Transmitter inset - Carbon granule, replaceable capsule: Sensitivity +30 db relative to 1 mV/dyne/cm2 at 20 dynes/cm2 input.

Buzzer
Single coil, d.c. resistance 1000 ohms, impedance 1500 ohms at 25 c/s, 15 k ohms at 1000 c/s. Accepts ringing currents of between 16 and 50 c/s.

Tropicalisation
Suitable for use in all climates. Protected against entry of insects.

Dimensions and Weight
Complete telephone:
height 280 mm (11 in)
width 105 mm (4 in)
depth 65 mm (2.5 in) over dial and 95 mm (3.75 in) over handset

Telephone - complete: weight 1.3 kg (2lb 14oz)
Handset: weight 280 gm (10oz)


Taken from the GEC Leaflet STL21B (1966) and DLT28C (1979)


ADDITIONAL INFORMATION

History
This telephone started life in 1962 as ships phone and was originally produced for the P&O liner Oriana.  This phone was very similar in design to the GEC75 except most noticeably was the bristle brush device mounted above the handset, which would hold it in place in rough seas.  The phone also had an elastic handset cord whilst the GEC75 had the standard 700 type plastic cord.

Pictures of the Ships phone

Retaining brushes can been seen at the top of the upper recess Handset in place

 

Case and dial removed exposing the base and components

 

Cover removed

Close up of retaining brushes

 

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Last revised: 30 November, 2008

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