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[TowerTalk] Re: rope in elements

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Subject: [TowerTalk] Re: rope in elements
From: (
Date: Thu, 29 Mar 2001 08:13:31 +0200
      Well, it´s a matter how to express things I guess, if you
      want to call it poor or not.
      I know from personal experiense that it´s possible to
      construct Yagi elements that doesn´t vibrate and fall
      off due to mechanical resonance.
      I have right now on the HF bands 57 elements in the air,
      none vibrates and pieces doesn´t come down all of a
      In the past I have constructed elements that vibrates and
      cracks, I would call that a poor design, however that poor
      design could be fixed by adding ropes inside elements.
      In the case of Force12, good or bad I honestly can´t say
      since I have no personal experiense. If a lot of Force12
      antennas do fail it´s poor, however failures could also be
      due to other reasons. 
      Talking about Force12, there are one fellow in town that has
      some Force12 stuff. A 40 mtr thing and a 3 bander I think 
      it is. As far as I know he hasn´t had any failures, guess it´s 
      good then.
      Or it could be put this way, if ropes do fix the element problem
      you could say that with the aid of ropes the design becomes
      good, but ofcourse without since there is a problem one really
      cant call it good.

      73, Jim SM2EKM

-----Ursprungligt meddelande-----
Från: []
Skickat:         den 28 mars 2001 16:27
Ämne:   Re: [TowerTalk] rope in elements

Hi Jim,

>  An antenna that needs ropes in elements are poorly
>  constructed.

I disagree with that. My Rohn 25G with open ends at the top (I use 
it as a vertical antenna and for supporting ropes, no yagi's) vibrates.

I'm not worried about the vibration because it is steel. I did know of 
a fellow with an aluminum tower who lost the whole top 30 feet or 
so of the tower in a mild breeze, because it vibrated and cracked.

As I look back, most of my tubing antennas vibrated. Some of 
them had end caps and vibrated, but rope always fixed it. I had that 
problem with Wilson yagis, and everything else.

I don't think that means the antenna is a poor design...not when it 
is a problem so easily cured.

73, Tom W8JI 
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