On 28 Mar 2004 00:00:38 -0500, (DoN. Nichols) wrote:
There are some which *are* truly differential -- but they use
two BNCs for a single channel of differential input, and have a
long-range offset adjustment to allow you to tune out DC offsets.

Or in the case of the differential plugins I have, two banana
jacks per channel.

Unfortunately, one of the nicest has an interesting plastic
gear inside to couple a switch to the knob on the front panel, and the
plastic has gotten brittle over time. I've seen two of those with the
plastic disintergating. I own one of them. I would love to see a
drawing of the gear's dimensions, with the hopes that I could make a
replacement. The plug-in is too nice to consign to the trash bin.

It is a barrel (perhaps 3/4" long), with a hex hole through it,
and a set of gear teeth only about 1/8" long in the middle of it.

Dean Kidd is about the best source for obsolete Tek parts.

Gary