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Old July 1st 10, 07:31 PM posted to rec.radio.amateur.antenna
Roy Lewallen Roy Lewallen is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 1,374
Default language and antenna gain

-.-. --.- wrote:
"Richard Fry" ha scritto nel messaggio
...

But that does not mean that it has all of the electrical
characteristics of a linear conductor that is inherently resonant,
without the need for inductive loading.


Yes, replying to Richard but also to Roy and Dave.. maybe i can't explain
very well, but the sense of my latest question is this:

if a half wave end-fed *monopole* antenna have the following primary
characteristics (if IIRC):

- High Z at the feedpoint (voltage maximum and current node);
- very small counterpoise lenght compared to the resonant wavelenght of the
antenna (typical 0.1-0.2 lambda)

can i mantain the same characteristics shortening the antenna in any way ??

Thanks for read and explain to those who want clarify my doubts.

-.-. --.-


You can add a top hat to a vertical that's shorter than a half
wavelength, and bring it to anti-resonance (high input resistance with
no reactance). The impedance won't be as high as if the antenna were a
half wavelength high, and it will have narrower bandwidth, so it won't
be a perfect imitation. Or you can use a combination of loading
inductance and top hat to get a somewhat poorer imitation.

Roy Lewallen, W7EL