I had assumed that rope was a passive component to prevent harmonic
oscillations that might be caused with varying winds.
I just found this fine article by PA9X about this exact subject.
Is your antenna making noise? Use a rope! - PA9X
<https://www.pa9x.com/is-your-antenna-making-noise-use-a-rope/>
Mickey Baker, N4MB
Palm Beach Gardens, FL
*“The servant-leader is servant first… It begins with the natural feeling
that one wants to serve, to serve first. Then conscious choice brings one
to aspire to lead." Robert K. Greenleaf*
On Mon, Aug 29, 2022 at 7:25 AM Paul N1BUG <paul@n1bug.com> wrote:
> I'm trying to get a better sense of how the rope in elements to stop
> vibration thing works. I've read that it works because as the element
> swings in one direction, the rope slams against the opposite side,
> providing a counter-force. What confuses me is that I don't understand
> how the rope is free to move around. Nylon or polypropylene seem to be
> recommended but those ropes come coiled or folded and they have a memory
> effect, so they don't lay flat. When put inside an element, they are
> going to be pressing against it in multiple places and directions. It
> seems like that would limit the rope's ability to move to do its job.
> What am I missing? I have seen braided rope with extremely fine strands
> that is soft and doesn't have the memory effect. Is that what I should
> be using?
>
> My 6 meter yagi was having a problem. The element tips were oscillating
> at about a ~200 Hz rate, and the tips were moving at least two inches!
> It took four trips up the tower to rig and get it down. It will take
> another four climbs to put it back up, and more if it still has a
> problem and needs to come down again. I'd like to try to get this right
> on the first try to avoid all that extra climbing. The four foot center
> section of each element is .750" OD, with .625" tips. Any practical tips
> or experiences with similar elements would be appreciated.
>
> Paul N1BUG
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