I want to thank the many who responded directly to my request for information
concerning the use of aluminum mast for my particular situation as described in
my request. To summarize the responses, 1/3 said use only steel mast !!. 1/3
provided history of successful performance in the past with aluminum mast and
1/3 provided technical information that also helped me make a decision. Several
included help and assistance in finding a source and their assistance is
appreciated. The process was a learning experience and a good one. For the 1/3
who were so adamant about using a steel mast I am sure they will think I did
not learn much.
I have purchased a new 2" X .25 6061-T6 mast to use as a 16 foot mast. 12
feet above the thrust bearing. The computer program winmarc says my
configuration needs more than 15878 in-lbs.in bending moment at 70mph and this
mast provides 18800 in.lbs. The difficult part was determining the force
required to bend this particular mast. Not a large safety factor but enough
considering that I don't think my guyed Rohn 25 tower with hazer will stand
much more than 70 MPH winds. Weight was important to me so as to not overload
the hazer and this drove my decision to an aluminum mast. I look forward to
getting up a 4 El Steppir at 70 feet and the rotatable dipole for 40 at 80
feet. The new antenna arrangement will be less total weight, and less total
square footage than I now have up on a 10 foot steel mast. It has been up for
10 years. Not a world class instillation but one I think will be competitive
when hooked to a PRO II and Alpha. My thanks to towertalk for providing this
great venue for assistance. 73 Van W4GIW
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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