[TowerTalk] If you had a choice

[Ward Silver]

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 at kk9a.com
To: towertalk at contesting.com
Subject: Re: [TowerTalk] If you had a choice
Message-ID: <4ef571bb19327019e3bfc21e35f9638a.squirrel at 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 at contesting.com>
Subject: Re: [TowerTalk] If you had a choice
From: "Ward Silver" <hwardsil at 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