Cecil Moore wrote:
All I know is that every time there's a calculated or measured
current taper through a coil, according to some experts, it's
because the coil is not "physically small". :-) So where's the
model for "physically large" coils?

I've also noted the use of that qualifier on several occasions in the
discussion. There are apparently effects which become measureable as
the inductors physical size begins to approach significant fractions of
a wavelength. These affects appear to relate more to the impedance and
radiation pattern of the antenna - first order affects as far as most
here are concerned to be sure. On the other hand, if the coil is not
physically small, then its probably not electrically small either. In
other words it may comprise a significant fraction of the electrical
length of the antenna. For a given inductance, a longer coil will
require more turns than a shorter coil. The more turns, the greater the
length of wire, and the greater the phase delay through the coil. A
coil with shorter physical length, would require less wire and fewer
turns to give the same inductance, and would give a shorter phase delay.

73, Jim AC6XG