If you double the guys can't you half the tension to present the same amount
of tension on the tower legs. The star configuration would prevent twist
movement in the horizontal plan...I don't see a need to double the guy
tension on the star connection. Any experts out there that can provide
"standard" practices for star guying?
73,
dave
wa3gin
----- Original Message -----
From: <K7LXC@aol.com>
To: <towertalk@contesting.com>; <w7xu@iw.net>
Sent: Saturday, December 01, 2007 10:47 AM
Subject: Re: [TowerTalk] Star guying
>
> In a message dated 11/30/2007 9:05:18 A.M. Pacific Standard Time,
> towertalk-request@contesting.com writes:
>
>> 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.
>
> While I agree with Frank, W3LPL, about the stress issues on the legs
> due
> to increased guy tension, 55G is good to at least 300 feet so the
> additional
> stresses introduced by the 6-way guying at 190' should be well within the
> design limits. (I'm not an engineer but I've worked on several towers.)
>
> Using a star bracket will certainly lock down the tower and prevent it
> from twisting but I've never heard of a properly installed Rohn tower
> failing
> because of too much wind induced torque. They'll take a fair amount of
> abuse
> even when overstressed so either way I'd say you're okay.
>
> One thing you can do is to have the guy wires mounted as close to the
> rotator plate as possible. That way the torque is transmitted directly to
> the
> guy wires without as much influence on the tower itself.
>
> Cheers & GL,
> Steve K7LXC
> TOWER TECH
>
>
>
>
>
>
>
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