Many years ago when topbanders were looking for better efficiency and
something thart would radiate with limited space lots there was the "Z"
which was essentially a way of feeding a 1/2 wave sloper from a tapped
coil L/C circuit at the shack end by running the first 1/4 wave of wire
close to the ground (were it was claimed to do minimum radiation since
it was voltage rather than current fed) and then sloping it upward to a
tree or pole with the top portion doubled back horizontal to the ground
below. It has been many years since I heard of this antenna that was
supposed to minimize ground connection loss and provide some vertical
radiation (DX) component. Nor am I aware that anyone has model this
design as there were even some folded back version to save space.
Herb Schoenbohm, KV4FZ
I have modeled it and the results are predictable. About
half your power goes into likely useless horizontally
polarized radiation. If you instead make a top loaded
("T" type) vertical where the sum of the height and half
the top wire is a half wave, then you get a "voltage fed"
vertical that behaves pretty much like a half wave
vertical. Since the drive impedance is high, you MIGHT
get away with a much less extensive counterpoise.
There is some controversy about this.
Rick N6RK
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