On Fri, Jul 16, 2021 at 10:13 AM, Zack Widup wrote:
I kind of figured the carbon film resistors weren't as accurate at VHF/UHF
frequencies compared to carbon composition resistors. This verified it.
Probably a skin effect problem.
There is possibly even more important effect - nanoVNE does NOT measure impedance as an absolute value - it compares the current one with what you have declared as 50+j0 at the time of calibration. If what you used for calibration is not an ideal 50ohm, all the measures after that are invalid, or at least have inherited some "shift" in value.
If you used some of high quality (usually means expensive :)) 50ohm terminators, you are much closer to getting reliable results :)
