Dave wrote:
In item 2 you make an unsupported statement: "Give that the coil is 90
degrees at the self-resonant frequency,..."

Self resonance only means that the capacitive and inductive reactances,
both distributed, are equal. That does not validate a 90 degree
assumption. Without that validation, IMO, the subsequent discussion is
questionable.

Quoting from the Corum paper concerning self resonance
of a coil:

"The forward and backward traveling waves have superposed
to give this voltage standing wave distribution along the
resonator. There is a voltage null at the base, a voltage
maximum at the top, and a sine wave envelope along the
structure." That defines 90 degrees of coil.

For the standing wave, there are 90 degrees between a voltage
null and a voltage maximum. The voltage maximum at the top
of the coil corresponds to the current null existing there
because the current has no place to go. The voltage null at
the base corresponds to the current maximum there which is
a necessary condition for self resonance. There's 90 degrees
between a voltage null and a voltage maximum. There's 90
degrees between a current null and a current maximum.
--
73, Cecil http://www.qsl.net/w5dxp