[TowerTalk] If you had a choice

[john at kk9a.com]

It would be interesting to know how the antenna would have performed without 
feedline distortion by using with a choke-balun, however you did the test 
correctly following the manufacture's instructions. You were testing and not 
optimizing the antennas.  I wonder if the stations that claim to be doing 
well with these antennas are isolating their feedlines.  Mosley's PRO-57B 
claim of 8.5dBd gain on 20m with only a 24' boom is incredible

John KK9A


To:<towertalk at contesting.com>
Subject:Re: [TowerTalk] If you had a choice
From:"Ward Silver" <hwardsil at gmail.com>
Date:Tue, 16 Oct 2012 11:13:31 -0500

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?