K7ITM wrote:
For the "100 turn, 10 inch long, 2 inch diameter" coil wound
with 15AWG copper wire, using John's program, I see a variation of
about 2:1 in propagation velocity between 1MHz and 20MHz.

Now the question becomes, what was that propagation
velocity at 4 MHz? An EXCEL program that I have gives
a VF of around 0.03 for that coil making a 3 ns delay
through it impossible at 4 MHz.
--
73, Cecil http://www.w5dxp.com