My new/old VIZ Voltohmyst

Resistance is Futile wrote:I believe it was an old style microphone connector. The one I'm thinking of is of the screw on type.

It certainly is. They are often seen as mike connectors on old PA systems. I have other equipment that uses the same connector for the probe, notably some EICO equipment. I keep a few on hand. If there is an electronic parts jobber in your area you could try them, or try a store that caters to musicians. Switchcraft still makes them, and Amphenol may still make them. Mouser has the Switchcraft connectors for just under $5.00 each in single quantities:

http://www.mouser.com/ProductDetail/Switchcraft/2501F/?qs=sGAEpiMZZMtAYTMy7wxAr2Jdw3UxKoXWQAin4vlzG44%3d

I get them on ebay new. Amphenol 80-75-MC1F is the female connector for most of these.

http://www.ebay.com/itm/NEW-Amphenol-80-75-MC1F-Single-Conductor-Mic-Connector-8075MC1F-/251431112958