Part ID on a Bruel & Kjaer conditioning amplifier 2690-0S2

[Jwalling]

Does anyone recognize what connector this is on the power input? The manual states it's a TNC connector, but the picture in the manual does not match what's on the unit I'm working on. The attached picture is what's on mine.
Thanks!

[xmo]

It looks like a Lemo connector.

[Jwalling]

It looks like a Lemo connector.

Thanks, that's it! Boy, there's a billion different ones. I opened up the unit and was able to see a part # ERA.00 After spending some time on Mouser and looking at the datasheet, I think I found it's mate:
https://www.mouser.com/ProductDetail/736-FFA00250CTAC27

Not cheap...

[xmo]

I have one of the Nexus conditioning amplifiers.  I was cheap and replaced the power connector with a round one I had on hand. 

Actually, I bought a couple of the Nexus units (used).  I wanted one to use as a mic pre-amp for a test setup to measure and compare communications headsets.  I did buy the Lemo connectors for the mic pre-amp inputs so I could make up the input cables.  One cable from Brüel & Kjær would cost as much as I paid for the unit.  Installing those Lemo connectors will test your soldering and mechanical skills

I did learn a few things.  You can't just mix & match parts from a couple of broken ones to make one good unit.  They do warn you in the brochure:  "To reduce the cost of the instrument and to ensure accuracy and reliability, modules must be replaced at Brüel & Kjær."

[b_force]

I think Brüel & Kjær is almost known of using awkward connectors.
I used to work with acceleration meters.
The pre-amplifiers had such weird COAX connectors