Actually, all the back and forth on this caused me to go back and look at MY
copy of the Rohn Ham Tower Catalog which shows a number of different
scenarios:
1.) 110 MPH Basic wind speed ratings for everything from 40 to 170 ft.
of 45G. (60 ft. will support 9.6 sf of antenna...guyed at 25 ft.
with
3/16 EHS tensioned to 400# and 55 ft. with 1/4 EHS tensioned to 660#
The same tower height, with a single 3/16 EHS 400# set of guys will
support 16.7 sf at 70 MPH).
2.) 70, 80 and 90 MPH ratings for everything from 40 to 100 ft. of
bracketed 45G
(60 ft. will support 33.3 sf at 70 MPH, 24.7 sf at 80 MPH and
17.0 sf
at 90 MPH...bracketed at 23 and 46 ft. levels).
What it does NOT show is any ratings for bracketed towers in excess of 90
MPH
wind speed ratings. My guess is they don't recommend it. That's not to say
that
it "can't" be done...just that if you want to be sure that it is done
safely, you'll get
someone who is qualified to 'run the numbers' to check the installation.
ARRL
has a Volunteer Engineer program, similar to the Volunteer Counsel program
for
legal issues, and I'd wager you could find someone to take a look at your
proposed
installation for a LOT less than $1800/hr.
73/Be Safe, Gerald W5BA
w5ba@compuserve.com
<snip>
> It seems that the tower specs provided by the manufacturers are not
adequate
> for many areas of the country. Why they choose not to give us the specs
we
> need, I will not venture to guess, but they are the only ones that can do
it
> properly.
<snip>
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