[TowerTalk] Horizontal tower movement at the top

[W7CE]

Gerald,
Thanks for the pointers to the engineering data.  That gives me exactly what 
I need.  It also reminded me of an analysis that K7NV has on his website at:

http://k7nv.com/notebook/towerstudy/towerstudy1.html

I need to read it again in detail, but the baseline model in the study is 
very close to my situation.  A quick glance indicats that movement of 6" or 
so in a 90MPH wind might not be all that unusual.  It also reminded me that 
putting the tower on a pier pin will reduce the stress on the base.  I'll 
read the study more carefully and also do the calculations based on EHS 
stretch.

I originally planned to use the 25G only as a ladder, but if I can also 
mount the antenna to it, it will simplify the antenna installation.  I don't 
think it should make much difference structurally since the tree and the 
tower will move together.

Thanks again.

73,
Clay  W7CE

> If you stick a 25G on a pier pin, you can pretty much ignore what typical
> tower movement might be. The tree is going to be holding up the tower.
>
> I sort of liked the suggestion to put up a ladder instead. So, what would 
> be
> a good ladder? How about 100 feet of 25G?
>
> If you still want an answer to your initial question, it is relatively 
> easy
> to approximate when you know how much guy wire stretches and use the data
> from the Rohn catalog and the law of cosines equation.
>
> Law of Cosines Equation
> (http://www.ajdesigner.com/phptriangle/law_of_cosines_equation_angle_a.php)
>
> Guy Wire Stretch
> 6.77 inches of stretch per 100 feet of 3/16" EHS when under a 3000 pound
> load
> http://k7nv.com/notebook/topics/guycable.html)
>
> --
> Gerald Boutin, VE1DT