[Elecraft] 60 foot fiberglass pole (Pole Strength)

Ron D'Eau Claire rondec at easystreet.com
Thu Aug 10 14:03:16 EDT 2006


I've used 50 foot steel push-up masts which are arguably much stiffer than
the fiberglass. Even so, I'd never consider using one as a center or end
support without lots of guys. 

If the mast is used at the center of an inverted V, I might leave the top 5
or 10 feet free-standing (except for the support the antenna wire itself
provides) with at least two sets of three guys below that, spaced at
120-degree intervals. For an end support, I'd use the same guy sets plus two
additional guys attached to the very top spaced 120 degrees relative to the
antenna wire to handle the horizontal load of the antenna itself. 

It's not just wind loading on the pole or the weight of the wire. The system
must handle the shock loads of the weight of the antenna and feedline
dancing in the wind as well. If it's a permanent or semi-permanent
installation, remember you must design for the worst-case winds, not what
you typically see. 

If you don't have room all the way around the pole for those guys, you're
probably much too close to the neighbor's yard. I recommend never raising a
pole higher than the distance from the pole to your property line. It's one
thing to put a hole in your roof if you misjudged the guy requirements; it's
a whole different issue if the hole is in your neighbor's roof, or your
neighbor... 

Ron AC7AC



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