John Popelish wrote:
I also note that the opening statement:

"For closewound coils, with length to diameter ratios around 5:1, a
series of fairly careful measurements have been made with the coils
arranged vertically above a ground plane, fed at the base, with a
capacitive load on the other end, and the driving frequency arranged to
be at the resonant frequency of the whole assembly."

This definitely specifies only a single frequency for the test.

Yes, a 75m mobile base-loaded antenna is a single frequency
antenna. Why are you surprised? Those guys have figured out
something that I haven't, probably because they have better
tools at their disposal than I do. They seem to have a 1%
accurate model at frequencies other than the self-resonant
frequency. I, OTOH, am only sure of my accuracy at the
self-resonant frequency due to the limited tools at my
disposal.

So I don't see how this reference
supports your claim that measuring the delay at resonance tells you the
delay at other frequencies. It also contradicts your claim about how a
standing wave makes it difficult to measure the current delay through
the coil. What have I missed?

You missed the complete point, John. If one cannot eliminate
reflections from the measuring process, then use them to your
advantage in the measurements. Self-resonance means that the
forward wave is in phase with the reflected wave. The first
time that happens is when the wave has made a 180 degree round
trip to the tip of the antenna and back, i.e. it happens first
at self-resonance, when the coil is electrically 90 degrees
long. For a well-designed coil, like a well-designed transmission
line, it doesn't vary by much over HF frequencies. In short,
the self-resonance velocity factor should extend pretty well
to all HF frequencies below that self-resonance point. I need
to think about the frequencies above the self-resonance point,
but that doesn't apply to the present discussion.

I guess I should re-phrase my statement. Standing waves make
it difficult for *ME* and W8JI to measure the current delay
through the coil. I ran essentially the exact experiment that
W8JI ran with identical results. I even used the current pickups
that W8JI kindly furnished to me. The only difference between
W8JI and me is that I recognized the results to be bogus.
--
73, Cecil http://www.qsl.net/w5dxp