Maybe one of the network analyzer experts will jump in at this point --
I'm not one. If I were your client, I certainly wouldn't be satisfied
with your methodology. But I'm not your client, so what satisfies me
isn't important. Good luck.

Roy Lewallen, W7EL

wrote:
Well here's what I did: I treated it like a peice of coax. I made a
fixture to hold the "feedthru" with semi-rigid coax on one side and a
50 ohm chip resistor on the other. I dropped in a short peice of coax
and cal'ed to that. Then checked VSWR, was about 1.00something. Then I
took out the coax, dropped in a few feedthrus and got VSWRs about 1.04
- 1.06, which works out to about 53 - 55 ohms or so.
How's that sound?