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...
Denny
--
FAQ on WWW: http://www.contesting.com/topband.html
Submissions: topband@contesting.com
Administrative requests: topband-REQUEST@contesting.com
Problems: owner-topband@contesting.com
|