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Re: Topband: detuning shunt fed tower

To: N1BUG <paul@n1bug.com>
Subject: Re: Topband: detuning shunt fed tower
From: Jon Zaimes AA1K <jz73@verizon.net>
Date: Fri, 30 Nov 2012 07:51:38 -0500
List-post: <topband@contesting.com">mailto:topband@contesting.com>

On 11/29/2012 8:42 AM, N1BUG wrote:
Often, while listening to such a noise on one Beverage, switching from the vertical to a different transmit antenna (thus leaving the ~250 feet of coax feeding the vertical open at the shack end), there will be a dramatic change in noise on the Beverage, depending on the particular noise and Beverage selected. I take this as evidence the vertical is re-radiating noise and that detuning it should help. Is that a valid assumption?

73,
Paul N1BUG


Paul,

Sounds like you already have found the solution. I had a very similar shunt-fed tower back in the '80s and discovered quite by accident that by switching out the feedline in the shack I was detuning the tower and noise on a nearby Beverage was greatly reduced. I just did the switching manually but a relay keyed in sync with the TX would be a more elegant solution.

73/Jon AA1K
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