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TEL/1P


In 1955 GEC decided to renumber all their telephones with the prefix TEL.  The ST33xx, ST34xx, ST35xx and ST36xx series, which were the original catalogue numbers for this telephone was part of this renumbering.  Please see the table below for more information.

GEC TABLE TELEPHONE

A table telephone of modern and distinctive appearance, supplied in either of two models: one for use with automatic exchanges and the other for manually-operated central battery systems.

The moulded plastic case combines a robust design with a pleasing simplicity of line and is of such a shape that it can easily be lifted and carried by one hand.

All components, except the dial when fitted, are mounted on a main assembly plate, which can be withdrawn from the case very easily as a complete unit.

The G.E.C. Trigger dial, adopted by the British Post Office as their standard, is fitted with a stainless steel finger-plate which retains its high polish indefinitely.

The C.B. telephone is the same as the automatic model except that a dial dummy replaces the dial. It can be installed even when a future changeover to automatic switching is anticipated since its conversion to automatic working is a simple operation - the baseplate, main assembly plate and dial dummy are removed, a dial is fixed in position and a dial cord is connected to the internal terminal strip, then the main assembly plate and baseplate are replaced.

The cradle-switch mechanism has been specially designed to eliminate any likelihood of sticking plungers. Twin contacts give maximum reliability. The handset is fitted with an inset type transmitter. The flexible handset cord will give exceedingly long service: the conductors are made from tinsel that withstands 200,000 reciprocations without breaking.

The four-way plastic terminal strip, connecting the incoming line wires to the telephone cord, has moulded separators between terminal plates to maintain long leakage paths. There are separate entrances for the line wires and the cord.

If required one, two or three keys can be fitted to the instrument for special circuit facilities such as executive right-of-way, etc. Facilities are provided for the operation of two telephones in parallel without bell tinkling during dialling.

The transmitter and receiver are British Post Office standards and the high efficiency speech circuit gives maximum volume with excellent frequency response and maximum side tone suppression.

The unfailing efficiency of the G.E.C. Trigger dial mechanism is well known and a special spark quenching circuit protects the impulsing contacts during dialling.

If required, a suppression circuit can be included to prevent interference with nearby radio receivers during dialling.

TROPICAL PATTERNS
G.E.C. telephones for service in tropical climates incorporate various special features, which are the result of long experience:-

A shunt may be connected across the transmitter to minimise the minute arcing that tends to occur at the granules and electrodes as the cradle switch operates ; the accelerated tendency towards frying often shown by transmitters in the tropics is thereby offset. The effect of any increase in transmitter resistance upon line circuit conditions is also minimised by the shunt. The loss in volume efficiency is very small and is partly cancelled by reduction of sidetone, the net result being a difference of only 1db. When required the shunt is connected by the simple transfer of one wire from one terminal to another.

Ventilation holes in top and bottom of the case allow air to circulate freely through the case to minimise internal condensation.
All apertures are covered with fine wire gauze to prevent the ingress of insects.

Metal parts are specially finished, and all wiring is specially made to resist the effects of high humidity and salt-laden atmospheres.

All coils are specially treated to render them impervious to damp, heat and sudden changes in temperature.

Cradle-switch springs have large insulators to ensure long leakage paths.

Flexible cord conductors are V.I.R. covered and braided overall. Since textile bindings are not in contact with conductors, moisture absorption cannot cause leakage.

For very dusty atmospheres, a transparent plastic cover can be fitted to the back of the dial to give complete enclosure to the mechanism.

Tray dummies are fitted in place of trays on tropical models, thus ensuring that no foreign bodies can enter the instrument.
Standard pattern telephones are supplied in black only.

Tropical pattern telephones are normally black, but can be supplied in ivory, jade green or Chinese red with cords and terminal strips finished to match. For ordering please quote the colour required after the Catalogue Number.

A magneto extension bell in the G.E.C. Cat. No. BE1100 series (Standard) or BE1200 series (Tropical) is recommended for use with this telephone, to provide calling signals at a distant point, indoors or out, or to augment calling signals in very noisy surroundings.

Dimensions
Length - 7.25 ins. (18.4 cms.)
Width - 9 ins. (22.9 cms.)
Height - 6 ins. (15.2 cms.)

Weight
5.5 lbs. (2.5 kgs.)

PART NUMBERS
(1955 PART NUMBERS SHOWN IN BRACKETS)

CATALOGUE NUMBER DESCRIPTION
STANDARD TROPICAL
ST 3301 (TEL/1P/CTS) ST 3403 (TEL/2P/CTT) 332 C.B. Manual
ST 3504 (TEL/1P/ATS) - 332 Automatic Non-Director areas
ST 3505 (TEL/1P/ATS/1) - 332 Automatic Director areas
ST 3509 (TEL/1P/ATS/1) - Automatic Director areas - minor variations
ST 3510 (TEL/1P/ATS/1) - Automatic Director areas - minor variations
- ST 3608 (TEL/2P/ATT) Automatic Dial Non-Director areas
ST 3521 (TEL/9P/ATS) ST 3621 (TEL/10P/ATT) Automatic for D.C. ringing.*
ST 3551 (TEL/3P/ATS) ST 3651 (TEL/4P/ATT) 312 Automatic two-party line, selective ringing, non-director areas
ST 3552 (TEL/3P/ATS/1) ST 3652 (TEL/4P/ATT/1) 312 Automatic, two-party line, selective ringing, director areas

Note : * For use with the 10-line All Relay P.A.X. Cat. No. PX1110 (Standard) and PX1210 (Tropical).


TEL/1P/ATS Circuit Diagram

 

TEL/1P/ATS insides

Note the heavy covered induction and bell coils

 
 
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Last revised: May 23, 2011

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