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## [TowerTalk] Guys & Towers CORRECTION

 To: [TowerTalk] Guys & Towers CORRECTION aa0cy@robertwanderer.gardnerville.nv.us (ROBERT WANDERER) Wed, 4 Jun 1997 20:39:27 -0700
 ```Oops, that should be about 1/2, not 1/3rd. For those who are concerned about the turnbuckles, you need to run wire or strap from a feet feet above the turnbuckles to the guy ground system. Think INDUCTANCE, not resistance. The Vd due to inductance is far higher and of greater concern than the Vd due to resistance. A 150' tower with 35" sides has a total resistance of about 0.001 Ohm but 40 microHenries of inductance. Emblaze this formula Vd=L (di/dt) on your foreheads! 73, Bob AA0CY ---------- From: ROBERT A. WANDERER[SMTP:bobwanderer@polyphaser.com] Sent: Wednesday, June 04, 1997 6:48 AM To: no9z@prairienet.org; towertalk@contesting.com Subject: [TowerTalk] Guys & Towers Lynn All things being equal, a truly guyed tower (i.e. conductive and uninsulated) will have a voltage gradient between top and bottom of approximately 1/3rd that of a tower which is either freestanding or the guys are nonconductive or have insulators in them. Note that the TOTAL current will be the same in both cases as lightning is a constant current generator. But what you are achieving with the guys is current sharing (parallel paths). Since Vd=L (di/dt), the Vd associated with the tower will be less because the di is less down the tower. BTW, 2 or 3 ground rods at the base of the tower is insufficient as a good lightning ground. The scenario in the first paragraph also assumes a proper lightning ground is employed where the guys are anchored. We are, nevertheless, comparing apples to apples based upon the scenario you presented. Several years ago, the myth that uninsulated conductive guys would affect the beam pattern was dispelled in a QST article. Hope this helps! Sincerely & 73, Bob Wanderer (AA0CY) Senior Applications Engineer PolyPhaser Corp. -- FAQ on WWW: http://www.contesting.com/towertalkfaq.html Submissions: towertalk@contesting.com Administrative requests: towertalk-REQUEST@contesting.com Problems: owner-towertalk@contesting.com Search: http://www.contesting.com/km9p/search.htm -- FAQ on WWW: http://www.contesting.com/towertalkfaq.html Submissions: towertalk@contesting.com Administrative requests: towertalk-REQUEST@contesting.com Problems: owner-towertalk@contesting.com Search: http://www.contesting.com/km9p/search.htm ```
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