Date: Thu, 26 Feb 2015 16:14:52 -0600
From: "john@kk9a.com" <john@kk9a.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Mosley Antenna Question
Interesting information Jim. If I were in the market for a tribander I
would definitely buy the K7LXC report. One potential problem with
interlaced beans is that there appears to be little room for side mounting
them on a tower. I also wonder what happens when they are used in a windy
environment and the closely spaced element move around.
John KK9A
## Old f12..and the new \f12 will spec how much clearance u have in the
middle,
to mount the yagi on say a tic ring, or clamped to the face of a rotating tower.
IE: 41 inchs etc. That’s part of the yagi design. A wide faced tower like
65 g or
the bigger 1032 tic rings is where u require some space..and is factored in.
## Local buddy had a f12 5BA. The real short els would get smacked by the
immediately adjacent eles. His fix was to use some scrap pvc sheeting, and
attach
it towards the outer ends of the shorter ele..which bridges across to the
longer ele.
Problem solved, and no more ele smacking. He mentioned the fix to n6bt, who
said
it was a great idea. Its described in detail in n6bts book, array of light.
Just a small piece
of sheet abs..with 2 x slots cut into each side. A SS hose clamp is fully
opened up, and
inserted through the pair of slots..and around the ele itself. Ditto with
adjacent ele.
Tighten up both clamps and end of problem. On the 5ba it only had to be done
with
2 of the eles I believe. Simple, easy fix...and weighs nothing.
## A lot of other excellent ideas, and pix of em in the same book ( available
from K7LXC)
IE: the easy on boom to mast double plate concept. One of those brilliant
ideas, that is so obvious
when u 1st see it, and wonder why u didn’t cook it up urself 35 yrs ago. The
single plate, used by
everybody else is fubar. I built several HB versions, but using .375 thick
plates..and the DX eng
super jumbo mast clamps. By offsetting the Horz boom plate down a bit, I
could also get 2 of the
jumbo dx engineering mast clamps above the boom plane...and a 3rd one below
the boom plane,
without having to resort to using a bigger Horz boom plate. 3 of those clamps
will hold an insane amount
of weight. I did that since I also use the same plate as a mast step. The
other yagis just have 2 jumbo
mast clamps. The double plate concept has been adapted to several yagis here
in town, on a lot of
other brands of yagis. Nobody uses the concept since f12 has a copyright
/patent on it. Its
simple to hb with just a drill press or punch. I had the plates cut at the
local shop in a few minutes.
## On the 40m plates, I made the Hor plate a little wider, 17 inchs vs 12
inches, that F12 used. Then used
3 X dx eng standard SS u bolts + solid saddles on each end of the Horz plate.
The 140 lb ant is not going
anywhere.
later.... Jim VE7RF
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