PYE/TMC TELEPHONE No. T102 (1741)

Catalogue No. T102

The wall mounting telephone set Type 1741 is manufactured to meet the stringent requirement of the British Post Office series of telephone instruments.  It is particularly suitable for use in work­shops, kitchens, passages and anywhere where wall or bulkhead mounting is desirable.

Provision is made for fitting up to two keys and two lamps, to give facilities for shared service, exchange recall, priority override and main/extension calling when used in parallel.

The design incorporates printed wiring boards and the use of modern miniaturised components which provide utmost mechanical and electronic reliability.  Ease of servicing is ensured by the simple internal layout.

Finished in non-scratch ABS plastics, the '1741' is supplied in three colours:- Black, Two-tone Grey, and Ivory.

Fully tropicalised versions are available, where all components are finished to better than BS.2011 Category 10/055/21, and the telephone meets the specification of Preece, Cardew and Rider.

Alternative Types

1. Apart from the normal direct line automatic instrument, versions with dial removed and a dummy dial substituted can be supplied for operation on central battery systems.

Other versions to supply the following facilities are available or can be produced from the basic instruments by use of conversion parts:-

2. Shared service line - auto­matic systems.

3. 2-wire PBX extensions with recall.

4. Hotel Telephone.  The wall telephone can also be fitted with 'message waiting' lamp and guest service symbols as incorporated in the standard hotel telephone - see Cat. No. T105.

Accessories

Recall Kit (for PABX working) Cat. No. A401.

Press-to-talk handset Cat. No. A434.

Handset retaining clip for use in maritime and other conditions of excessive vibrations.

Exterior
Case and handset moulded in ABS copolymer of acrylonitrile buta­diene and styrene.

Colours
Three colours available - ivory, two-tone grey and black (In dual-colour telephone, the handset and cord are the darker tone).

Cords
PVC - covered cadmium - tinsel conductor cords.  Held in position by grommets which relieve con­ductors of any stresses.  Handset cord, coiled: 250mm, uncoiled 1700mm.

Cradle Switch
Sealed microswitch.

Dial
Articulated-trigger type with self compensating action. Projects through self-centering ring on case.  Characters printed black on silver background beneath clear plastics finger plate.
Speed: 10pps nominal.
Inter train pause: 240ms minimum.
Break to make ratio: 66.6:33.3.
Other ratios available.

Transmitter
Carbon granule replaceable capsule type. The change in sensitivity over the input range 3-30 dynes per sq. cm. is less than 5db at a given frequency in the range 300-3400Hz.

Receiver
Rocking armature, replaceable capsule type.

Automatic Regulator
An automatic regulator is fitted to limit speech-signal amplitudes on lines shorter than 400 ohm; intro­duces virtually no attenuation on longer lines.

Ringer
Double coil, D.C. resistance 1000 ohms; impedance 2000 ohms at 25Hz, 20Kg at 1000Hz.  Accepts ringing currents of between 16 and 30Hz.

Bells, double gong, harmonizing tones. An extension bell can be connected if required.

Environment
Suitable for use in all temperate or tropical climates.

Dimensions/ Weight (unpacked)

Height - over handset 235mm
Width - over handset 255mm

Depth 108mm

Weight 1 .5kg