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TopBand: Resonance

To: <topband@contesting.com>
Subject: TopBand: Resonance
From: km1h@juno.com (km1h @ juno.com)
Date: Fri, 15 Aug 1997 14:08:06 EDT
On Fri, 15 Aug 1997 13:23:26 -0400 (EDT) CQK8DO@aol.com writes:
>In discussing the fundamental  resonant frequency of an antenna 
>element,
>resonance is the frequency at which there is no reactive component, 
>i.e.
>J=0... It is also the frequency at which the antenna element is at the 
>lowest
>impedence within that octave.... 
>You can verify this with any of the RF analyzers.... When i am 
>installing or
>revising an antenna I simply tune my RF-1 Analyst to a frequency near 
>the
>expected resonant frequency, then switch to the Z mode and rock the 
>dial...
>As soon as I see which direction causes Z to decrease, I tune smoothly 
>in
>that direction until Z bottoms out and begins to increase... Then I 
>rock the
>dial until I have determined the minimum Z point, and that is the 
>resonant
>frequency...
>
>Now, whether or not that impedence is even close to 50 ohms is another 
>story
>entirely...


Only in the textbooks Denny. In the real world j0 can be, to paraphrase
Yogi Berra,
"whatever it thinks it is it is" . 
Unfortunately way too many hams and others are locked into a 50 or 75 Ohm
mindset and go downhill from there. 

Interested in your Autek comments, I have heard pros and cons, tell us
more please. I literally gave my MFJ  "analyzer" away a few years ago;
almost unusable IMO.

73....Carl  KM1H 

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