Hope someone can give me some insight on the TDR impedance measurement display. I have attached TDR impedance displays for two cable assemblies.
The first cable assembly was made up of a 0.3m length of RG-174, connected to a 1m length of RG-223 that was terminated in a 50 ohm load. The TDR impedance measurement display showed a 50 ohm impedance step for the RG-174 cable and then another slight impedance step for the terminated RG-223 cable. Pretty much what I was expecting.
The second cable assembly was made up of a 0.3m length of RG-174, connected to a 200 ohm coaxial feed-thru, connected to a 1m length of RG-223 that was terminated in a 50 ohm load. The TDR impedance measurement display showed a impedance step for the 200 ohm feed-thru but never stepped back down for the 50 ohm terminated RG-223 cable.
Am I misunderstanding how the second cable assembly should be shown on the TDR impedance measurement display?
BTW, really appreciate the capabilities Rune continues to add to NanoVNA-Saver. Just trying to wrap my head around the new TDR impedance measurement display.
- Herb
