That is correct. We used a Force-12 1:1 bead balun (i.e. common-mode choke)
on all of the other antennas, including the reference dipole, except for the
KT-34XA which came with a 4:1 balun/transformer.
There are a number of stations with good signals, using Mosley beams. Most
notably, K4RO has a pair of them and does quite well. He also has an
extraordinary ridge-top location and has taken great pains to locate the
antennas and towers to take advantage of that location. As in real estate -
location, location, location. I used a Mosley Classic 36 at W0EEE for
years, myself, with pretty good results.
The Mosley manual we had with the loaned PRO-57B (I think it was a B model)
gave specific instructions how to construct the coax pigtail and said
specifically not to use any additional devices at the feed point. It has
been a long time since we did the tests (11 years, I think) and it is quite
likely that the manual has been changed to recommend a common-mode choke. I
would applaud that change as good practice. Feed line interaction could
have certainly affected the results on one or more bands. We followed the
rule of doing what the manufacturer said to do.
73, Ward N0AX
Date: Tue, 16 Oct 2012 10:14:21 -0400
From: john@kk9a.com
To: towertalk@contesting.com
Subject: Re: [TowerTalk] If you had a choice
Message-ID: <4ef571bb19327019e3bfc21e35f9638a.squirrel@www11.qth.com>
Content-Type: text/plain;charset=iso-8859-1
Was this test run with no choke at the feed point of the Mosley and the
other antennas in your test had one?
To: "Towertalk Reflector" <towertalk@contesting.com>
Subject: Re: [TowerTalk] If you had a choice
From: "Ward Silver" <hwardsil@gmail.com>
Date: Tue, 16 Oct 2012 08:09:51 -0500
A cautious word of defense on Mosley...the PRO series was definitely not
the top performing tribander in the tests (www.championradio.com) but they
are built like tanks (that also means they are very heavy antennas) and do
stand up to the elements, particularly ice loading. The Mosleys would
probably also benefit from decoupling the feedline shield with common-mode
chokes (ferrite or
coiled-coax) although the manual I saw during the test said not to use a
balun for some reason - that may have changed.
I agree with whoever said to avoid quads in Alaska - unless you like
rebuilding antennas :-)
Check with other KL7s in your area as to what they have put up that makes
it through the storms and gives adequate performance on the air. In
extreme weather environments, there are more requirements than just gain
to worry about.
73, Ward N0AX
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