On 11/1/17 11:37 AM, Jim Thomson wrote:
Date: Wed, 1 Nov 2017 06:06:10 -0700
From: jimlux <jimlux@earthlink.net>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] FW: Wind survival + load ratings... vs,
reality.
<Overall, hams are probably more comfortable running and believing an
<electrical model than a mechanical one (more time to become familiar,
<etc.? or just because the ham tests ask you about electrical stuff, but
<don't ask you about mechanical stuff)
## Both YS and YM have been around for a loooong time, esp YS.
They are both within 1% of a megabuck finite analysis eng program.
Dont kid yourself. Both M2 + optibeam have not incorporated any
safety factor into their designs. They are both selling smoke. If they were
to actually incorporate a safety factor, M2 would be rating it at 50 mph.
yeah, but unlike NEC, neither is free, nor are there countless articles
in QST and books on how to run them, so I think it's more about
"familiarity with the tools"..
I think a lot of hams (at least the ones designing and caring about
antennas) are a LOT more knowledgable about the electrical
characteristics than the mechanical ones.
And, of course, EM systems are *linear*, which deforming mechanical
systems in wind are not. As someone (you?) pointed out, the elements
deform - it's probably going well beyond the "linear infinitesimal"
assumption of a simple mechanical model of a bending beam, and that's
before you get into the complexities of the aerodynamics.
(and of course, there's plenty of misunderstandings about the electrical
behavior of antennas too...)
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