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Topband: What ever happened to the 160 meter "Z" antenna?

To: topband@contesting.com
Subject: Topband: What ever happened to the 160 meter "Z" antenna?
From: Herbert Schoenbohm <herbert.schoenbohm@gmail.com>
Date: Sun, 15 Feb 2015 19:15:54 -0400
List-post: <topband@contesting.com">mailto:topband@contesting.com>
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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