We pull the boom up to where it attaches to the PVRC cross boom and mount it
pointed straight up (that is 30 feet of boom above the top of the tower),
attach elements one at a time, working from the center out, out paying
careful attention to keeping the antenna as balanced as possible. We use a
come along to pull the boom from pointing up to pointing at the ground. On a
bigger multi-element antenna, the boom may swap back and forth 3 or 4 times.
In the case of the 40 meter, the driven element is the last one attached,
the boom is pulled to the horizontal position and then rotated so the
elements are parallel to the ground. It actually works very well and does
not require the upper body strength of a gorilla. The old 40 meter beam had
2 inch OD tubing for the center of the elements, the version up now uses
trussed M2 elements. I have helped with this twice on Lew's 40 meter beam
and more recently the 6 element 20 meter beam, both were on that nasty AB105
tower.
NG9R
Message: 4
Date: Sat, 12 Nov 2011 08:38:39 -0500
From: "Larry" <lknain@nc.rr.com>
Subject: Re: [TowerTalk] Dropping guys
To: "TowerTalk" <towertalk@contesting.com>
Message-ID: <288EFD16E2B04098B71E2C1CF5BA7171@LarryKnainPC>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I have heard of a couple of people assemble antennas on the tower
over the years. I would have think about that some because it
seems like that could be very awkward to build it on the tower. The
antenna would be unbalanced for a good part of the assembly. I had
to pull down my 2 el 40M yagi a year ago that had lost one element
and that was quite awkward (the yagi was relatively light - only about
45 lbs when complete). But assembling on the tower is a thought.
73, Larry W6NWS
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