40M Beam and Mast
Tue, 4 Feb 1997 11:33:29 -0500 (EST)
In a message dated 97-02-04 09:56:06 EST, firstname.lastname@example.org (Pete Soper)
>> If you're in Marion County, it's only a 70 MPH wind zone. With that as
>> the wind pressure and 6 sq.ft. of windload, the total bending force for
>> antenna and mast is less than 25,000 psi. In this case, a 4130 cold
>Could you share the formula(s) for this calculation?
Inquiring minds want to know, eh?
The calculations were taken primarily from Dave Leeson's (W6NL, ex-W6QHS)
book Physical Design of Yagi Antennas with some help from Stan Griffith's
(W7NI) NCJ article on masts. I have reprints of Stan's landmark article
available for an SASE. Send it to TOWER TECH, Box 572, Woodinville, WA,
The actual number crunching is from a new product that is just about
ready for announcement. It is the MARC Program (c) from TOWER TECH. MARC
stands for Mast, Antenna and Rotator Calculator. It'll handle wind speeds
from 70 MPH to 120 MPH and up to 5 antennas on the mast. It'll even make
rotator recommendations based on the Effective Moment of the antennas. It'll
be $9.95 and I expect it'll be available soon.
73 and tnx for your interest, Steve K7LXC
TOWER TECH -- professional tower supplies and services for amateurs
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Administrative requests: towertalk-REQUEST@contesting.com
Sponsored by Akorn Access, Inc & N4VJ / K4AAA