Keith Dysart wrote:
So this means I could take an antenna element
which is longer than 90 physical degrees, i.e.
greater than 1/4WL, and with the appropriate
matching network make a system that was
90 "electrical degrees".

Of course, if you reverse the position of the
600 ohm line and 100 ohm line in the previous
open-stub example, you will *lose* 8.3 degrees
of phase shift at the impedance discontinuity.
The transmission line will have to be physically
98.3 degrees long to get an electrical 90 degree
phase shift.

In like manner, if you have a straight (Hustler)
base rod and make the rest of the antenna a
helical coil with no stinger, you will wind up
with a resonant mobile antenna that is more than
90 degrees long physically.

If the Z0 of the base rod is 400 ohms, the
Z0 of the loading coil is 4000 ohms, and the
length of the base rod is 10 degrees, you will
lose 9 degrees at the base rod-to-coil impedance
discontinuity. The coil will need to be 89 degrees
long, i.e. almost self-resonant. The antenna will
be 99 degrees long physically.
--
73, Cecil http://www.w5dxp.com