Mike Coslo wrote:
Most of my measurements have been at
the self-resonant frequency of a loading coil.

That isn't the design frequency though, is it?

No, so I changed my approach. My present approach is to
take a self-resonant coil and use only part of the coil
on the *same* frequency, e.g. use half the coil as a loading
coil on the *same* frequency. That way, the velocity factor
should be roughly the same in either case.

I'm not sure I have this straight. I think I understand Tom's info,
yet this has me completely baffled.

I accept his magnitude measurements as probably accurate
and reasonable. His phase measurements were meaningless
since standing wave current phase doesn't change relative
to the source and therefore cannot be used to measure phase
shift along a wire or through a coil.

The standing wave current phase is the same from end to
end in a 1/2WL thin-wire dipole. It cannot be used to
determine the phase shift through a wire or a dipole. EZNEC
reports the same thing. This is key to understanding the
misconceptions involved and why the phase measurements were
meaningless.

Would the short answer be that you do not find any correlation?

*Nobody* has made a valid measurement of the delay through
a coil. There's nothing to correlate. One cannot use a signal
with unchanging phase to measure that delay.
--
73, Cecil http://www.qsl.net/w5dxp