The Unidilla trapped dipoles are hard to beat, AS LONG AS you don't run over
800-1000w PEP. I installed my 160/80/40 Unadilla trap dipole as an inverted
vee last fall. It worked great the first hour or so. Then I decided to turn on
the amp on 80m. Before I even made my first contact with 1000w pep, the coils
shorted in about 30 seconds.
Tried to ask the manufacturer why they blew so fast, even though they were
rated for legal limit pep. The owner proceeded to tell me I was doing something
wrong. I can't see why they just don't make them to handle the power they're
advertised for; I'd gladly pay a few dollars more for a higher rated cap
Anyway, down it came, and now I am using a parallel dipole. Basically, a full
length 80m dipole and full lenght 160m dipole, fed off the same balun, and both
legs tied off at the same points. I just let the 80m legs hang lower than the
160m legs, so that there is about a 2-3ft space between the wires towards the
end of the 80m legs. It works great, except that the bandwidth is about half
what a single 80m dipole would be. 160m is the same as a normal dipole. The
only downside is that on a windy day, the swr on 80m bounces around a little as
the 80 and 160 legs blow closer and further appart. But now I can run the amp
without worrying about it....
Date: Wed, 20 Apr 2011 17:35:41 -0400
From: "Dick Green WC1M" <firstname.lastname@example.org>
Subject: To: "'Mike Fatchett W0MU'"
Content-Type: text/plain; charset="us-ascii"
I've had good results on CW using a 80/160 trapped inverted vees made with a
pair of Unadilla/Reyco traps.
73, Dick WC1M
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