dansawyeror wrote in
:

....

I think a summary is that at 3970KHz, the feedpoint Z looks like about 45
+j0 and you reckon the radiation resistance should be around 4+j0,
suggesting the earth system contributes around 40 ohms of resistance.
Observations at a single frequency provide a limited view of what might
be happening.

Elevated radials should exhibit a clear resonance, and will offer the
lowest impedance at resonance.

Buried radials will not exhibit such a clear resonance in lossy soil, and
using your wire to form more short radials might give better performance
than few longer radials.

Radials lying on the ground are likely to be somewhere in between. You
may observe resonance, and in that case the ground system impedance will
be optimised by "tuning" those radials (which will probably be a good bit
shorter than formula length for free space radials).

Owen