RF-301P

Audio Connector:



OD is approx 0.575" - Single alignment lug.



Male pins seem to be about 0.039".

Contact arrangement is similar to British Clansman connectors, but the shell of the connector is quite different.

Info for the RF-301A connector believed to be the same one:
Harris Part# P-0400   
Manufacturer: The Deutsch Co.  
Manufacturer Part# DM9728-7P  
Cage code: 11139