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Re: [TowerTalk] substandard aluminum?

To: "Michael Tope" <W4EF@dellroy.com>, <BobK8IA@aol.com>,<wa3gin@erols.com>, <jimjarvis@ieee.org>
Subject: Re: [TowerTalk] substandard aluminum?
From: "Tom Rauch" <w8ji@contesting.com>
Reply-to: Tom Rauch <w8ji@contesting.com>
Date: Tue, 1 Mar 2005 22:28:34 -0500
List-post: <mailto:towertalk@contesting.com>
> Dean had a pair of the 29 foot boom model - one at 90',
and the other
> at 180'. When I went up there, my expectation was that I
would be the
> loudest guy on the band (there weren't many 40 meter
stacks in
> those days). The real performance was a big
disappointment. I felt
> like I was running 100 watts to a dipole at 30 feet that
weekend.

Mine is the 47ft boom model Mike.

Something must have been seriously wrong with that setup.

While my antenna was better than a dipole, it was only about
3.5dB better and it had about 20dB peak F/R ratio.

After replacing the balun and retuning the elements (the
reflector was mainly the bad one) I got just under 7dBd gain
and the peak F/R was nearly 50dB. Of course the 50 dB null
depth only holds over a very narrow range, but all across
the band from 7 to 7.3MHz the F/R is substantially higher
than with the stock tuning lengths.

I don't think you would have noticed the change from 7dBd to
1 dBd without an antenna to compare it to. F/R shows up
easily but to notice low gain it has to be a dramatic drop.

73 Tom

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