In a message dated 98-02-11 23:33:43 EST, ke4rna@Traveller.COM writes:
> Will a properly installed Rhon 25G, 50-70 ft. high, with stabilizing
> arms, handle a 149 pound beam antenna with a 36 foot boom. The ant
> has 18 sq. ft. wind surface area, Wind load at 80 MPH is 450 lbs. The
> ant is a Mosley "PRO-95". I will use a Tailtwister rotator. Any
> thoughts???
First of all, Morgan County is a 70 MPH wind speed zone which is the
lowest rating they give.
Looking in the Rohn catalog (I take it you don't have one - five bucks
from TOWER TECH) 70 feet of 25G is rated at 16.2 sq.ft. It looks like you'll
be about 10% overloaded. 25G @ 50 feet is rated at 17.5 sq.ft. so you might
want to consider the lower height.
Is this a big concern? Well, while you should ALWAYS do what the
manufacturer recommends, this wouldn't be a fatal problem. A much better
solution would be 45G which is rated at 23.9 sq.ft. at 70 feet. And it should
be like you said - properly installed.
When you say 'stabilizing arms', do you mean the TA25 torque arm
stabilizing assembly or just the GA25GD guy bracket? The TA25 adds a
significant amount of torque resistance with its bigger width and double
guying system.
My more basic question is - why are you putting up a big Mosley antenna?
Have you already purchased it or are contemplating it?Just about any other
antenna out there will be a better performer.
73 and GL, Steve K7LXC
TOWER TECH -- professional tower supplies and services for amateurs
--
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
|