I have just acquired an old HP 3440A nixie tube rack mount DC
voltmeter. Although I have the service manual for the 3440A, the rack
mounted version is physically different from the one in the manual in
a few ways. For one - there are no inputs on the front panel, just on
the rear. There are 2 different BNC type jacks that I have never seen
before. The ground is isolated from the chassis so there are actually
2 internal connectors along with the usual outer ground connector.
Both jacks have these 2 internal contacts but both jacks are
different styles. I've tried to look these up (google images etc) and
have no idea what "type" they are so that I can get some kind of
adaptor to use a BNC terminated probe or even banana terminated test
leads.
Thanks
BL
