Can anyone tell me what the length is for the Rohn TB25 torque bars that go
with the
GA25GD guy bracket? They are not shown in the catalog and I am wondering if
they
create a larger or smaller cross section than the TA25 torque arm stabilizer
assembly.
I am trying to rebuild a large HF stack (300 lbs/20 sqft) and am concerned
about
rotational inertia and wind induced torque being transmitted from the antennas
thru
the rotator and into the tower. I have seen some broken welds on the current
installation,
but this appears to be due to a faulty rotator installation (the rotator was
attached to the
rungs instead of the tower legs as a quick "get on for the contest" kludge and
was never
fixed). Is it better to let the tower twist with the load, or stiffen the tower
with the torque
bars? And if I install the torque bars, how close should the rotator mounting
point be to one
of the torque bar augmented guy points?
BTW, this brings up another question, do Rohn specs quantify allowed torque
loads on
25/45/55G anywhere in a manner similar to overturning moment? In other words, I
know
how to design Rohn tower for side load, but I do I quantify design margin for
torque?
Thanks,
Mike, W4EF..........................
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|