> I'm thinking of putting up about 60' of Rohn 25...I'd like it to be
Free-standing if possible...I'd like a few ideas.
I'm no expert. I've only done two tower projects, but here's what I
noticed...
I put up 80 feet of 25G a couple of months ago. I rented an excavator to
dig the holes and it was my first time using one. The holes ended up coming
out significantly larger than I intended. The hole for the tower base was
nearly 5 x 5 x 5 and took around 4.5 cubic of concrete yards to fill.
I was using a 5' base section embedded in the concrete, so it was safe to
start stacking on sections without guys attached. Even with that base,
there was noticeable sway in the tower at only 30 feet. Once the first set
of guys were attached (at 27'), it was rock solid again. By the 60 foot
level, before the guys at 54' were attached, once again there was a lot of
sway until the guys were attached. Same thing at the 80 foot level.
My other tower project was helping a friend who wanted to cut every corner
possible. He put up 37' (40' with 3' in the ground) of 25G into about
1000lbs of hand-mixed concrete. There are no guys. There is only a 5/8
wave vertical for 10 meters up there along with a small UHF yagi (not much
wind load). The tower sways when a fly lands on it.
In other words, I really don't think you want 60 feet of unguyed 25G. Thats
way outside Rohn's specifications. And, from my experience, I really don't
think it matter how large the base it; unguyed 25G is going to sway
significantly.
Tom, NI1N
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Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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