A 680A transmitter from a 4A type speakerphone

Removing the cover

Squeeze the small section together and lift out
2 Gently pry large cover off with small screwdriver.
3 4

The underside of the cover

Notice the small rectangular dimples which capture the bumps on the rocker base which can be seen in the photo above or more clearly in photo 14 further down the page

The brass alignment key

This pin doesn't seem to be connected to anything inside the plug. On closer scrutiny, it appears that they used a standard 50 contact Amphenol connector and cut off all but the 10 contacts on one end. I am now speculating this is an early production model connector. Since the connector wouldn't have had the alignment key molded in, they had to jury rig something to form the alignment key, thus the brass pin. This may have been one of the earliest plugs made before the molded key connectors were developed.

A later model from 1980

Notice the brass pin has been replaced with a molded rib

Completely molded plug

Wiring is probably soldered to pins, then the entire assembly went through an injection molding process

Later connector

This connector can be disassembled for repair if neccessary. Probably easer to produce too.

Note compression ring holding pivot rod in place

Later models didn't have this ring.

Other end of pivot rod


Pivot rod being extracted


Note grove which holds compression ring


Removal of rocker switch mechanism

14 15

Top of circuit board exposed


Bottom of circuit board

Note only 8 wires in the cable

Microphone and volume control knob