Hi Kurt,
I just wanted to say thanks for emphasizing the need for standardizing antenna
windload specifications. This is a poorly understood but extremely important
part
of the picture, as you well know. I have tried on more than one occasion to
explain the nature of the misunderstanding which revolves around the "derating
factor" which one can apply because an antenna is typically made of round
members. The problem stems from the fact that it is easy to apply the same
factor
TWICE to the same installation (once for increasing the tower windload capacity
and a second time for decreasing the antenna windload) which can result in
dangerously overloading a tower. I have seen this done MANY times and the tower
owner insists he has done everything correctly and "according to the
manufacturer's specs". What the tower owner often fails to understand is that
there are TWO manufacturers (antenna manufacturer and tower manufactuer)
involved
and they do not use the same spec standard . . . Both manufacturers tend to use
the spec to their own advantage to make their towers look stronger and their
antennas look smaller, when in reality, the derating should be applied only ONCE
to any given antenna/tower system and NOT once to EACH PART of the system . . .
So maybe if we keep talking about this where others can "overhear" the
conversation, a standard spec will finally emerge and we can actually get
agreement between tower and antenna makers.
Stan w7ni@teleport.com
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