Hi Mike-
This was a little unclear to me, but interesting. Are you saying that
you used the 51 ohm resistor held by the jaws of the alligator clips for calibration?
Exactly, IMO "calibration" should reflect actual measurement configuration
More specifically, SHORT was by clamping alligators together
and OPEN was by unclamping them.
I want nanoVNA "CAL" to automagically account for alligator clamps
and subsequent readings only about DUTs subsequently clamped.
More "ideal" might be SHORT using a length of wire clamped
between alligators approximately the length of resistor and coil.
Then the data you posted was for that inductor?
Yes, one that is very liable to stray pickup.
The attached image shows nanoVNA display for a frequency scan,
and hopefully visible is an approximating circular segment Smith plot,
as reactances should be.
While component RLC values at intended application wavelength[s] are
obviously of interest,
observing Smith plots over a wider range can reinforce credibility or
reveal anomalies.
Having not been otherwise informed,
nanoVNA reports 50 Ohms for that 51 Ohm resistor;
I can live with 2% errors...
IMO, 5 stored calibrations are none too many.
Oristo