I had a 160 foot Rohn 65G tower with a number of large (up to 60 foot boom)
antennas at various heights and the tower did twist. The tower had a pier
pin base and was guyed on three levels. I changed the top set to a star
configuration and there was noticeable less twisting. You may wish to try
this at one level and if you are not happy add additional star guys. It
sound like you are putting a lot of antenna load on your Rohn 55G tower,
hopefully it can handle it.
John KK9A
To: towertalk@contesting.com
Subject: [TowerTalk] Star guying
From: Arliss <w7xu@iw.net>
Date: Fri, 30 Nov 2007 07:04:41 -0600
List-post: <mailto:towertalk@contesting.com>
I have a question about star guying.
This fall I erected 170 feet of Rohn 55. The tower is mounted on a pier
pin with a tapered base section. I have another 20 feet to go, but due
to weather, that will have to wait until next spring. The only antenna
on the tower at this point is my full size 3-el 30 meter beam at 100 ft.
After completing the tower, I plan to put long boom (50') yagis for
other bands at 160 and 190 ft.
Even with just the 30 m beam on the tower, the tower exhibits a modest
amount of twisting at the 100 ft. level. when the wind blows (which is
most of the time here on the Great Plains). I'm thinking that star
guying at one or more levels would help reduce the torque. However,
since I haven't used star guying before, I don't know if I should just
do this at the 100' level, the 190' level, or both. Suggestions?
Thanks and 73,
Arliss, W7XU
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