Hello, new to this group. I've learned a lot from reading here, but i seem to have run into some issues and could use some advice. I'm building a low pass filter, and trying to learn to measure inductance using the nanovna. I've built a test rig that I found on one of the threads here somewhere- three pieces of double sided pcb for OSL, and I'm soldering my air core inductors to that. I'm trying to use the S11 shunt method for a coil that needs to be 72.4nH.
Ive got a couple things I'm not understanding- should my coil be adjusted for the necessary inductance at the frequency for the filter of 50-55mhz? And does it need to be adjusted for impedance at that band as well? I've attached photos- my 90deg phase and 50 ohm mark is at 112mhz, but this inductor is for the 6m filter.
Another thing I'm not understanding is the 5khz self resonance dip seen at the beginning of the sweep, shouldn't it be reading capacitive since it's after the phase reversal?
Any help is appreciated
