>Roger, N1RJ, writes:
>
>>Any opinions or
>>experience on using [Rohn 20G] sections at 120-130 ft with no load on
>top?
>
>Even a well guyed Rohn 25G tower feels pretty limber at 130 feet. (The
>tallest 25G tower I've climbed personally is 160 feet.) Irrespective
>of Rohn's specs., I would not be comfortable in working on a 130-foot
>Rohn 20G tower, even with no load on it. And I'm a risk taker, at that!
>
>73 de Bob, K0KR and K7KU
Unless the above messages are in reference only to un-guyed towers, I
disagree! I have a 130 foot Rohn 25G tower in my yard with a TH7DXX at
132 feet and a 402CD at 140 feet on the 20 foot mast (7 down, 13 up). In
the past, it has also held a TIC RotorRing at 68 feet with a Classic 33 on
it. In addition, it has 3 each 13B2s at the 120 foot level. It is guyed
with quarter inch Seimens-Marten (sp?) galvanized steel cable that is
anchored at 3 points, 120 degrees apart, with 4,000 lbs (1 yard) of
concrete at each anchor point. The guys are at 32, 64, 96, and 128 ft
on the tower. The tower only has a half yard of concrete at the base.
The 4,000 lb rated guys (I'm sure they are derated by Seimens-Martin)
are tensioned to 10% of their ratings - 400 lbs. I defy you to climb it
and do anything at the top that would make it feel "pretty limber". It
is as solid as a rock.
Rod, W5HVV
Roderick M. Fitz-Randolph
w5hvv@aeneas.net
79 Highland Hills Cove,
Jackson, TN 38305
(901) 661-9278 (Phone - after 10 AM and prior to 9 PM)
(901) 664-7539 (FAX - any time of day or night)
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