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

To: "Michael Tope" <>, <>,"Tom Rauch" <>,"TowerTalk" <>
Subject: YagiStress Web Site was Re: [TowerTalk] Rohn Torque Bar confusion
From: Pete Smith <>
Date: Wed, 04 Aug 2004 07:49:46 -0400
List-post: <>
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 ( seem to be working. Does anyone have a more current URL???

73, Pete N4ZR
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