[TowerTalk] Inverted V for 160/80 on the same feedline

[Eric Dobrowansky K2WD]

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 inside. 



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.... 



Eric 

K2CB 







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Message: 5 
Date: Wed, 20 Apr 2011 17:35:41 -0400 
From: "Dick Green WC1M" <wc1m73 at gmail.com> 
Subject: To: "'Mike Fatchett W0MU'" <w0mu at w0mu.com>,        <towertalk at contesting.com> 
Message-ID: <002101cbffa2$e7362020$b5a26060$@com> 
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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