Cecil Moore wrote:

For more information, take a look at:

http://lists.contesting.com/archives.../msg00540.html

Very interesting, but not enough information to allow me to repeat
their measurements.

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. While
it is not the self resonant frequency of the coil alone, it is
definitely a resonant situation, where there will be a considerable
standing wave through the coil. 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?