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Old October 21st 08, 07:33 PM posted to rec.radio.amateur.antenna
Jim Lux Jim Lux is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 801
Default Antenna design question

Dave Platt wrote:

I think that what you're looking for is in Kraus "Antennas for All
Applications", page 446 - "Self-impedance of a thin linear antenna".
The formula given is based on the induced-EMF method... it's an
approximation which apparently works well for cylindrical antennas
whose length is at least 100x the diameter.


And, interestingly, a LOT of amateur antennas don't meet this
slenderness constraint. Wire dipoles hanging in the air do. Fans,
cages, etc., often don't.

No problem with the model, just awareness of the footnotes and
limitations (which often get omitted in the less rigorously reviewed
internet literature..)