On 160, I feed my 80m cage inverted vee (apex at 70' AGL) against ground. I use
a vacuum relay in a box just downstream from my ground bus to do the switching,
with a bias tee in the shack to feed DC to the relay coil. Of course, there is
no choke/balun at the apex. So far, I have a couple dozen radials in the
ground, and it seems to play well. My TS850SAT's ATU is able to tune it fine.
See http://tinyurl.com/wa7prc-80m-160m for more detail.
vy 73 es gl,Bryan WA7PRC
Date: Tue, 30 Jun 2015 21:32:12 -0400
From: Ed Sawyer
Subject: Re: [TowerTalk] Top Hat Vertical
Same here. My T vertical for 160 is 100 ft vertical and 82 ft horizontal.
That makes the antenna resonant below the band, with a feedpoint Z of 50
ohms plus some inductive reactance on 160M. I add series C to tune out the
L. The same idea will certainly work on 80M.
I believe that this antenna is functioning as a 3/8 wave vertical. Which is
nice, but not necessary for good performance.
I have a 70 ft high vertical portion with a total hat of about 45 ft (22.5
ft x 2). It resonates at 1.84Mhz with 20 Ohm impedance. It is fed against
a ground rod and 45 radials mostly long.
Works quite well.
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