STC TELEPHONE CAT No. 7706 and 7707

The 7006 was a basic low-cost version of the BPO Telephone No. 706 made by STC.  It is believed that these STC 7006 telephones were also resold by Modern Telephones Ltd.  Modern Telephones had a deal with STC to sell PO-approved PABXs made by STC.

Almost identical to the Tele. 706, it had a resistor network in place of the induction coil and a self contained microswitch/hookswitch.

Probably just used on PAX systems.

The CAT 7007 model had a recall switch and 4 wire line cord fitted.

Two-tone grey is the only colour seen.

Ericsson's N1900E244 was similar.

How to wire a 7006 to work on the UK's Plug and Socket system

  1. Remove existing line cord and replace with new style line cord.
  2. Connect red of new line cord to Terminal 11.
  3. Connect a 3.3k resistor between terminals 13 and 12.
  4. Connect white of new line cord to terminal 12.
  5. Locate the capacitor (Large silver cylinder) - and remove the brown wire.
  6. Connect blue of new line cord to brown wire that has just been disconnected and insulate.
  7. Connect a Rectifier element on Terminals 15 and 16.

Circuit Diagram

Additional Pictures

View of the self contained microswitch
Downward view of the terminations - note only row of terminals and the resistor network

Thanks to Dave Randall for the pictures


BACK Home page BT/GPO Telephones A - Z Index Glossary of Telecom Terminology Quick Find All Telephone Systems

Last revised March 05, 2011