The center of a 'temporary' dipole here is supported on 35' of Radio
Shack steel mast. The antenna elements support it in one plane and two
guys support it in a plane perpendicular to that. The guys are
attached at about 20', to minimize the downward force and the length of
mast subject to serious 'slender column' loading. It has been up over
15 years, now. It won't hit anything fragile if it falls, and the
damage to the antenna wouldn't be expensive to repair, so I didn't take
time to analyze the loading.. Otherwise, I would have spent the time to
assure that mast is loaded within reasonable limits.
Conductive masts at the ends of the antenna will interact with it
somewhat. The farther they are from the ends, the less the
interaction. That can be modeled, but be aware of limitations of NEC-2
when modeling elements that touch the ground. There are various
approaches to dealing with them.
73 de WOØW
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|