Tom Donaly wrote:
In actuality, there's a constant change in Z0 up
and down both the stinger and the coil so your idea is a
bust.

The gradual change in Z0 really doesn't matter. What matters
is the *abrupt* change in Z0's at the coil to stinger impedance
discontinuity. That's where the abrupt phase shift occurs.
--
73, Cecil http://www.qsl.net/w5dxp