Two pin SO-239 socket

[ppppenguin]

I amongst a batch of ordinary PL259/SO239 (aka UHF, aka F&E) connectors I found this odd 2 pin socket. Same outer as a SO-239 socket. Has anyone seen one of these before or know what it might have been used for?

Was there also a BNC with 2 pins?

[Mike Watterson]

IBM twinax was a coax like twisted pair.
The later normal plug looks a little like a two pin BNC without the bayonet lock.
https://en.wikipedia.org/wiki/Twinaxial_cabling

The socket you have looks like the early IBM twinax UG103 socket. The plug is the UG102
https://www.electronicsurplus.it/en/Conn...l,-Radiall

[ppppenguin]

Thanks for the info. Yes, definitely a UG103 socket.

According to this mammoth Amphenol catalogue the UHF connector was invented in the 1930s by the wonderfully named E. Clark Quackenbush. See p185.
http://www.farnell.com/datasheets/2362281.pdf