One of my towers is 102 feet of Rohn 25 with a Wilson 6 el 15 right at the tip
top and a Wilson 5 el 10 10 feet above the top on a 2 inch mast. originally,
I did not break up the guys. There are four sets three directions. I noticed
that the 15 meter beam which was about 6 feet above the top set of b? guys
seemed to have several very sharp nulls that are not on the standard patterns
for yagis. It also seemed to have a different pattern depending on which
direction it was pointed. I assumed all of this was due to the up?? unbroken
guys and that the pattern actually changed as I rotated the beam and its
position chanbged relative to the guys. I later broke the fuys ?? guys
every 20 feet and right at the tower. I did this to all 12 guys at one time
so I cannot say what the impact might have been if I had done only the top
set as some guys do?? . Anyway, after breakinbg up the guys, the pattern
seem like it came from the text book. The question really is this: were
those deep narrow nulls a "problem"? If you are aware of them, you could
use them to notch out QRM. I believe they could be an advantage as often
as a disadvantage so there doesn't seem to be much point in botherieng to
insulate the guys. If your questions is "does breaking up guys change things?":
I believe it does, but does it really matter? Who knows.
On another subject: Phillystan?? Phillystran. The first piece I ever saw
was a very early sample that W7RM showed me. I took a piece about 10 feet long
which was about 1/4 inch in diameter and ran it at a 45 degree angle from
the ceiling of my garage to the floor. I then took an ordinary paper book
match and proceded to ih?? light it on fire! I lit it at the bottom and
it sustained a flame as it climed up the Phillystran with gobs of flaming
black goo that used to be the outer covering dripping on my garge floor
where they continued to burn. I thought how lucky I was that the flaming goo
was not dropping on my roof! Right then I decided not to use Phillystran.
I heard later that they fixed that problem and it is no longer flammable,
but I have never had the occasion to test it again.
Another ham in the area decided to use Phillystran in spite of my experience
but he used steel cable for the first 20 feet or so at the bottom so the local
vandals could not light his guys on fire in an attempt to bring down his
195 foot rotating Rohn 65 with 7 KLM's on it. It has been up not for ??? now
for about 15 years with no problems.
W7NI@delphi.com "If you can't work'em, it doesn't matter if you
can hear 'em."
>From Peter G. Smith" <n4zr@netcom.com Fri Sep 2 11:25:00 1994
From: Peter G. Smith" <n4zr@netcom.com (Peter G. Smith)
Subject: AG6K Mods
Message-ID: <Pine.3.89.9409020311.A26752-0100000@netcom3>
Well, your praise for the Measures mods makes me wonder all the more what
the story is behind the QST article. Anybody from ARRL care to clarify that?
73, Pete
N4ZR@netcom.com
"Better, faster,cheaper -- choose any two"
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