K7ITM wrote:
OK, so I suppose you are assuming that the current distribution will
follow a cosine along electrical degrees of your antenna, with a
maximum at the base/feedpoint.

This is a good assumption for horizontal 1/2WL thin-wire
dipoles as presented by Kraus. It doesn't seem to be valid
for loaded vertical antennas where there is an instantaneous
phase shift at the impedance discontinuities. There is a
definite change in the slope of the current profile at
such boundaries.

And there is the nagging current bulge in the loading coil
causing a rise in current in adjacent turns. Normally a
current maximum would indicate a purely resistive impedance
but that doesn't seem to be the case inside a loading coil.

Years ago, I gave up on the current cosine argument for
loaded mobile antenna current in favor of loading the
coil with its characteristic impedance and using traveling
wave current to measure the electrical length of the coil.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com