YagiStress Web Site was Re: [TowerTalk] Rohn Torque Bar confusion

[Pete Smith]

At 03:15 AM 8/4/2004, Michael Tope wrote:
>Offhand I don't know the value of the modulus for a typical
>EHS guy wire, but just imagine for a minute how hard you
>would have to pull on a guy wire that is already tensioned to
>600 lbs in order to get it to yield an additional 0.13 inches.
>Also consider that the difference between .008% and .006%
>is 33%, or in other words  adding the 12" torque arms to the
>Rohn 55 increased the resistance to torsional rotation by a
>factor of 1/3. That's nothing to sneeze at.

I believe the answer is "not much" -- it's not a question of modulus, but 
of sag in a catenary.

I'm working from memory here, but K7NV, the author of YagiStress, used to 
have an article on his web site comparing the characteristics of various 
guying materials, and another dealing with finite element analysis of a 
guyed tower model.  Both would be good reading in the context of this 
discussion, but neither the old freeyellow site nor the new URL Kurt 
announced in January (www.k7nv.com) seem to be working.  Does anyone have a 
more current URL???


73, Pete N4ZR
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