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 _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
