On Tue, May 20, 2025 at 07:58 AM, W0LEV wrote:
the BNC connectors are part of the fixture and I can not eliminate
them.
Dave, the connector is part of the fixture, but since its impedance is 50 ohms, its capacitance does not contribute to the stray fixture capacitance. If you measure an uninstalled connector, you can subtract the capacitance reading from what you measure for the fixture, which includes connector capacitance.
I'm glad you posted about your new fixture. I think I've been overly concerned about shunt capacitance at HF. I see lots of evidence of it in the .s2p files the commercial L and C manufacturers provide, but that's in the GHz range where tiny strays do matter.
Brian
