COMMUNICATION PLUGS AND ADAPTERS
COMM SYSTEM-SIX POLE PLUG
Early Swiss AF leather, cloth and hardshell helmets were adapted to be compatible with British communication systems.
The "Six Pole Plug" ("MAAG Stecker") was the early standard configuration for aircraft and flight gear.
UK vs. US NATO PLUG
Following technical evolution, later version of SAF comm system were fitted with the so-called "UK (or European), NATO" plug - Type 671.
Other (and current) comm systems are fitted with another type of plug, the NEXUS U-174, sometime referred as the "US NATO" Plug.
The UK plug will not phisically mate with the US one, the mating shaft being 0.4 mm wider.
Due to this, helmet comm harnesses configured accordingly.
In case of system's mismatches, adapters provided.
Both "six poles" and UK NATO comm harnesses versions were installed on the ejection seats of DH-100 / DH-115 Vampire and DH-112 Venom, both connected to the aircraft's systems with a "Bell Connector" - See item "9" on LH drawing - same also on the RH one.
UK TO BELL PLUG EJECTION SEAT ADAPTER
Installed on early version of DH-100/ DH-115 and DH-112 ejection seats - See above.
H-3 (USN) to UK PLUG
(SE-015 COMM SYSTEM)
Fitted to H-3s during 1950 tests, in order to adapt US (PL-54/ JK-26 and PL 291/ JJ-048) comm system to UK Type 671 plug.
SE-015 was the Swiss designation of the British Standard Telephones & Cables Ltd. STR.9-X VHF communication system.
As mentioned above, over the years Swiss AF aircraft have been the subject of many improvement and upgrade programmes, between others, the implementation of UHF (Ultra High Frequency) radio equipment.
During the transition phase, there were problems with the impedance compatibility between flight gear, the comm systems in service and those in the implementation process.
Due to this, dedicated adapters were developed.
HAWKER HUNTER GROUND COMM
I could not find any documentation regarding this adapter. However, according to those who did their military service with Hunters, used to communicate with the pilot during the aircraft engine start-up procedure and before taxiing. If anyone could confirm this or have any information about it, I would be more than happy to be contacted.