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[Towertalk] Guy wire resonance. Break it up or use stubs?

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Subject: [Towertalk] Guy wire resonance. Break it up or use stubs?
From: (Tom Rauch)
Date: Tue, 25 Jun 2002 06:51:01 -0400
> Not that my not hearing about it means it's wrong.  No, I'm not saying
> that. What I am saying is that, since this is the first time I've
> heard anyone say what you've said, and I've been a ham for over 40
> years and plugged into publications, listserves and clubs where these
> types of things might be brought up, I'm wondering if it's a
> wide-spread problem or not.  I suspect not, since I've not heard of
> it.  And if it's not widespread, what then?

I just modelled a two element phased array, and adding a "non-
resonant" wire right in the middle of a recommended "safe length" 1/8 
wl below the phased array center decreased the null from almost 
infinite to less than 20dB. It made a very profound pattern change in 
null directions.

Obviously it is also important guy wires be short compared to 1/2 wl 
at the operating frequency, at least near a directional antenna.

I agree with the insulator capacitance problem. The grips and 
insulators can also change things, I'd bet in some cases a large 
amount.73, Tom W8JI 

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