john doe wrote:
I'm trying to understand the shunt tapped inductor as a circuit.

How does it work??? As long as the inductor cancels out the reactance
of
the radiator you just need to find the 50 ohm point on the coil ...
or for
that matter any feedline impedance???

Pardon my lack of knowledge.

de ka2pbt

Hi John, Is the shunt tapped inductor you are refering to is a coil
with one end connected to the 5/8 radiator, the other end to the
radials, the coax shield to the radials, and the center conductor
tapped up the coil from the radials? If this is the case, according to
the Smith Chart, you can only get a perfect 50 ohm match if the real
part of the impedance you are trying to match less than 50 ohms. Our
models indicate this is not the case with a 5/8 radiator.
The shunt tapped inductor is actually a 2 element matching system,
with both elements being inductors. As you stated, the inductor in
series with the radiator cancels the reactance, and the tapped shunt
inductor provides a 50+j0 point. Works only if the real part of the
impedance is 50 ohms.
Gary N4AST