Some variants were made by Chesivale of Bristol and can be identified by the blue coloured plastic.  The yellow variants were all made by by A.P. Besson Ltd, now trading as Hosiden Besson Ltd.

This portable linesmans telephone features MF & LD signalling, LNR, Earth & TBR recall, microphone mute and Polarity check lights.

Approval No S/1501/GF/1981/PA

Connecting cords for the telephone No. 284A

Features and description of the Chesivale model (Pictured blue above)

An ideal low cost Test Telephone with all the essential features. Selected by many Network Operators and Customer Equipment Installers around the world for its reliability and ease of operation. Robust and durable, the model is equipped with a high impact case and belt clip. Features include unlimited line voltage protection, sounder and high impedance monitor.

The line cord is plug ended and a range of adaptors were available to enable connection to DP, terminals etc.

Chesivale called this telephone the DSTS 2.

Approval Number - S/1501/3/H/452744.

Key Features:

  • High impedance monitor
  • Ground start/earth calling
  • High impact case
  • Polarity check
  • Sounder
  • Time break recall
  • Tone/pulse operation
  • Unlimited line voltage protection

Operating instructions

In monitor made the phone has a high impedance and will affect data or digital transmission.  Talk position allows two way speech to take place.

TBR button - Timed break recall.

ER button - Earth recall - only will work if the correct connection lead is used and the green wire connected to earth/ground.

LNR - Last Number redial - dials the last number.  The phone will remember this for a about 5 minutes after disconnection from a working line.

Mute - In talk mode, this button mutes the transmitter.

Polarity test - Press the button and observe the LEDS:-
Red LED - Red wire connected to positive (UK plug pin - 2 positive, pin 5 negative / RJ11 - pin 4 positive, pin 3 negative).
Green LED - Red wire connected to negative.

Additional Pictures

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Last revised: June 15, 2023