I am looking to measure as accurately as possible the DC resistance of a number of types of RF loads - all around 50 Ohms. Types of interest include SMA, 3.5 mm, N, APC7, 7-16 & BNC. I want to see if the difference between the actual resistance at DC and 50 Ohms correlates with the performance at RF as measured on a vector network analyzer. I want to do both sexes, with the exception of the APC7.
I would expect RF performance to correlate well at low frequencies, but as the frequency is increased I would expect it not to correlate. I am looking for advice on the best way to do this. I have a HP 3457A (6.5 digit DVM with 4-wire resistance capability), but will consider purchasing a meter designed for low resistance measurements which I believe uses AC to avoid thermal EMF issues. But if possible I would rather use the 3457A. I was thinking of a plastic box with the RF connectors & 4 banana plugs. I suspect running the sense and drive wires back to the banana plugs would work. No signicant current would flow into the unterminated connectors as they would have just the dielectric. Ideally I would like to measure just the load and contact resistance and not the resistance of the plug or socket I connect it to. That might be next to impossible. Can anyone offer any recommendations of how to wire it up, type of connector (e.g. banana plug or similar) PS I once see someone selling a dummy load on eBay with an SO 239 socket and 47 Ohm wire wound resistor! Apparently the inductance made it 50 Ohms. Dave _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.