I've acquired an old Bell tube amplifier (model 3715-B) from the mid 1950s and it's got some rather...interesting input and output connections.
The inputs use some kind of modified UHF connector with no center pin hole:
https://i.imgur.com/8aegH4x.jpg
And the outputs use something that looks like a UX4 tube socket:
https://i.imgur.com/Rgp9s7B.jpg
Can anyone help me identify these connections so I can try and adapt them to something more standard?