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Re: [TowerTalk] Elevated vertical

Subject: Re: [TowerTalk] Elevated vertical
From: Ken <>
Date: Fri, 23 Dec 2011 21:38:47 -0500
List-post: <">>
Okay, Gerald, I will agree that you and I are talking about different things.   
But most people talk about adjusting their antenna and saying it is resonant 
(or not) when they get a 1:1 SWR.

As you have clarified, you are thinking of  "system resonance".  I'm talking 
"antenna resonance".   

Would you consider my 130' center fed dipole "resonant" on 60 or 30 m because 
the antenna tuner inside the rig can tune the antenna/twin-lead/balun/coax to a 
1:1 SWR inside the rig?  Sorry to say but that one hurts my head to think of as 
"resonant".   Tuned? yes. Matched?  Yes. Resonant?  No.

In the chapter on Antenna Fundamentals, my 10th edition Antenna Book describes 
"resonance in linear circuits" in regard to a wave traveling along the antenna 
to the end, bouncing back, and being reinforced by the next wave coming from 
the feedline.  It needs a specific length for that to happen:  the standard  
length=492/frequency (or a multiple.)

73, Ken WA8JXM 

On Dec 23, 2011, at 8:18 PM, wrote:

> Hi Ken, we have a differing definition of what constitutes resonance: You are 
> talking about the radiating element only and I am talking about the radiating 
> element plus everything else that constitutes an antenna system; matching 
> devices, coax etc.
> Your example of .28 wavelengths does indeed move the R component to 50 ohms 
> but the +X that happens makes the vswr about 4 to 1 until the series 
> capacitor is added. The series capacitor cancels the +x leaving only 50R. In 
> my view and definition, that is a resonant system.
> I "think" we may be saying the same thing but from differing perspectives.
> 73,
> Gerald K5GW


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