This from K4OJ was a good testimony!
".........so far so good for K4XS who has three 200 foot towers in the same
area you are moving to - all using Philly..."
> What tower flex? You mean torsionally? That'll happen no matter what
guy
> material you use.
But is not Phillystran more flexible at the same tension than EHS? Thus
would
it not allow a little more sway under high wind gust conditions?
> Vibration? Haven't run across that one before.
Are not the strands of EHS more stiff (and-to-end) than Phillystran, thus
vibrations
initiated at any point would be transmitted to anything connected? Or do
the insulators
effectively deaden that?
> Joint stress? Leg compression is the biggest factor in tower forces.
> The leg joints are stronger than the rest of the leg.
I was imaging the tower swaying a bit in 125-150mph gusts and rocking around
the connecting bolts. (Sounds like something from a song, "rocking around
the
tower bolts, have a happy hurricane ..." :-) )
> While I don't have the technical data in front of me, if you're
asking
> about possible elongation of EHS and Phillystran - for our ham purposes
they
> are both small enough that you don't have to worry about it.
Not permanent elongation but momentary under high stress moments?
> Here's a suggestion - use the EHS-with-insulators on the bottom set
and
> 50% Phillystran/EHS on the top set. I think this'll reduce your risk
exposure
> while giving you some Phillystran benefits.
> Cheers, Steve K7LXC
50%? I would use a 4 guy top rather than three? Will have to explore that.
Thanks! & 73, DavidC K1YP
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