In a message dated 2/5/2008 4:51:47 P.M. Pacific Standard Time,
towertalk-request@contesting.com writes:
> I am having difficulty finding 100 feet of Rohn 45 or larger tower in
the neighborhood of Walla Walla, Washington, but I can find heaps of
Rohn 25 tower. I am considering putting a shorty 40 and a 4 element
Steppir on top. The wind loading specs of 25G and 45G are not that
different if you believe Rohn. The big thing is that I would like to
use my prop pitch to turn the antennas, and I'm afraid I can't fit it.
There are three top sections available for Rohn 25G.
Actually you need to read the General Notes to see a difference in the
windload rating. For 45G and up, there is 8 sq. ft. already taken out of the
loading for what Rohn calls a "symmetrical mount" which is pretty common in
commercial installations. So add the 8 sq.ft. back into the 45G windload
rating
and you'll be in business.
As far as the PP in 25G, I'm not sure it'll fit. If it will, you'll need
to cut out a brace to get it in. The other problem with 25G is that the
rotator shelf only goes in a taper top section or at the junction of two
sections.
Cheers,
Steve K7LXC
TOWER TECH -
Professional tower services for hams
**************Biggest Grammy Award surprises of all time on AOL Music.
(http://music.aol.com/grammys/pictures/never-won-a-grammy?NCID=aolcmp003000000025
48)
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|