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Old March 19th 08, 04:58 PM posted to rec.radio.amateur.antenna
Art Unwin Art Unwin is offline
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First recorded activity by RadioBanter: Mar 2008
Posts: 1,339
Default Antenna physical size

On Mar 19, 7:27 am, Michael Coslo wrote:
Art Unwin wrote:
On Mar 18, 12:26 pm, Michael Coslo wrote:
Roy Lewallen wrote:
Mike Coslo wrote:
On Fri, 14 Mar 2008 11:57:41 -0700, Roy Lewallen wrote:
Richard Harrison wrote:
Build a small scale model that can be tested indoors and report its
characteristics. Antennas are scaleable.
That's more easily said than done. One of the critical characteristics
of a small antenna is loss. And to correctly replicate loss in a scaled
antenna requires scaling the conductivity of the conductors as the
square root of the frequency. To scale to a higher frequency requires
that the conductivity be better than the original. Unless the original
is made from lead and the scale factor moderate, this wouldn't be
possible.
If what I suspect is true, would not the coax also need to be scaled?
Dunno. What do you suspect?
I suspect that the antenna is a tuned circuit on top of coax, and it
needs that coax to radiate effectively. So just scaling the antenna
wouldn't translate to the same results?


- 73 de Mike N3LI -


If you are familiar with computor programming then why not model it
instead of repeating over and over again this transmission line
radiation theory.?


It comes up in the conversation Art, I only rinse and repeat as necessary.

I'm still trying to wrap my mind around the antenna, I'm nowhere near
ready to model it. So as to not make any ignorant mistakes, the antenna
is counter-wound inductors, correct? and they are concurrently wound, as
in they sort of weave against each other? And this is a full wave
antenna? Do you use enameled wire, or what is the insulation? I'm
assuming that this might be important in regards to VF.

- 73 de Mike N3LI -


I think you should forget the whole idea. We have another expert
on line that can voutch for the fact that it is just a dummy load.
He joins the majority and I am only one,.....who actually has one no
less.!
Art