In a message dated 6/8/01 7:58:27 AM Pacific Daylight Time,
SPELUNK.SUENO@prodigy.net writes:
<< Ken:
Thanks for your note. I agree that a BIG rotator can withstand and
survive many of the overloads that torque imbalances can place on it. I'm
not familiar with PP rotators, but I'll take your word on their robustness.
BUT, if the rotator survives, that means that the torque has to go
somewhere else. That's the tower itself. NOW I have the problem of
ensuring that my guys are strong enough, the tower material is beefy enough,
etc., etc., ad nauseum. All this co$t$. I'd rather not have those
headaches.
As I've been saying (writing), do your math, move things around on the
proper size mast, and sleep soundly each night.
73 de
Gene Smar AD3F
-----Original Message-----
From: K7GCO@aol.com <K7GCO@aol.com>
To: towertalk@contesting.com <towertalk@contesting.com>;
SPELUNK.SUENO@prodigy.net <SPELUNK.SUENO@prodigy.net>
To: <towertalk@contesting.com>
Date: Friday, June 08, 2001 6:52 AM
Subject: Re: [TowerTalk] Wind Loading redux, PP Motors
>>
Gene: You are right about the wind unbalanced stresses being transferred to
the tower and guys with any rotator--until it breaks. It's cheaper in the
long run to "over design" the tower and guys also. You make only one
purchase. I haven't done one single calculation of wind loads, concrete
stresses and all that dominates TT although I could have. I have done this
from day one way back and have had NO FAILURES of rotators, guys, beams,
tower, used no TT Band Aids and have spent the least $$$ and maintenance time
probably of any ham on all this over the years. I had up a LB quad using the
.06" aluminum welding wire supplied. 3 years ago we had some ice loading and
wind here and the wire did stretch some. Antenna Mart Quads use wire that
will take ice loads and wind.
K7GCO Rule Of Thumb:
"Use 1 to 2 sizes larger rotator, tower and guys etc than what the
Mfgs
tell you to use, install it properly and your worries are
over".
I also properly beef up the booms and elements in the middle. I don't use
boom support cables from the top either as my booms don't need them. Those
who follow these practices don't need a Reflector to find solutions to their
problems--they don't have any. Constant repairs after every wind storm get
very costly and sometimes long delays due to winter and even lack of money.
Those of us on retirement in comes can't afford all this. Actually no one
can. I'd like to start a "Retiree Metamuscil Web Site" stressing the best
and cheapest way to do our thing in ham radio. Wealthy spies can look in.
K7GCO
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