Last month we looked at the D Type field telephone. What you couldn’t tell from the photographs was that an important component of this set was missing, the four pin plug on the end of the telephone handset:

Since writing that post my good friend Bill Pozniak has kindly sent me a replacement plug and tonight I am going to show you how to refit one to restore a handset back to its original condition. The plug itself is made of Bakelite with four metal pins. Behind these are four terminals to attach the wires to, and a screw clamp is provided where the cable meets the plug to prevent a sharp tug from pulling the individual wires out of their connectors:

The first job is to get a flat bladed screw driver and loosen off the clamp:

This doesn’t need to be completely removed, but it does need to be loose enough that the wire can be threaded through. Also undo the four screws and washers for attaching the individual cables to:

Thread the wire through and place a wire on each terminal. The terminals are marked M for microphone and R for receiver. The Red and Green wires attach to the receiver and the white and blue ones to the microphone:

Finally tighten up all the screws so that the wiring is held firmly and will not work loose:

The handset is now repaired and ready to go back on the field telephone. A simple five minute job, but one that helps complete this piece of kit and makes it look “correct”.