Wall telephone, with integral bell, that's very much like the Siemens Brothers 366.  Bakelite cased with standard GPO style circuitry.  Generally fitted with an ATM dial No. 24.

When opening the case, release the two screws on the front cover and then pull them towards you are far as they will go.  They will not come out completely but if you do not pull them towards you then they will catch on the casing as the cover is swung open.  When closing the case it is also important to ensure the screws are pulled out.

Front view Internal view - with case hinged to left

Wiring a new style BT cord to a phone with diagram L530315A or L523602

  1. Remove the wire strap between terminal's 1 and E in the Bellset and replace with a 3.3k resistor .
  2. White of the line cord connects to terminal 1 of the Bellset.
  3. Red of the line cord connects to terminal 4 of the Bellset.
  4. Blue of the line cord connects to terminal 3 of the Bellset.
  5. Green of the line cord connects to terminal 2 of the Bellset.
  6. Disconnect the blue wire from the capacitor.


Additional Pictures

Earlier model shown above - identifiable by the square capacitor
(The dial cord shown is a modern plastic variant)


Straight from the skip - thanks to Dave Dockerill for the pictures

Case open


Circuit diagram for Telephone L1186B9 and L11186A9
Diagram L532602


BACK Home page BT/GPO Telephones Search the Site Glossary of Telecom Terminology Quick Find All Telephone Systems

Last revised: March 22, 2022