On Aug 30, 7:21*pm, Jeff Liebermann wrote:
On Sun, 30 Aug 2009 14:54:05 -0700 (PDT), Art Unwin
wrote:
Tom, W8ji *apparently is an expert with antennas *having lectured
at Dayton and has authored many technical articles around antennas,
states that radiators must be straight for maximum efficiency,
He might have been talking about small antennas:
That may have been at the back of his mind but he did not stipulate
that
http://www.w8ji.com/radiation_resistance.htm
"Small antennas require extraordinary care to obtain high efficiency."
Very true for electrically small antennas with emphasis on
electrically.
The 2004 Dayton PowerPoint presentation is at:
http://www.w8ji.com/Dayton/Limited%20Space%20Antennas.ppt
Using Google, I couldn't find any statement resembling the "straight
radiators" claim.
I never said this is a quote from the Dayton lecture. Tom has numorous
dissertations with regard to antennas
Ummm... fractal antennas are anything but straight and have the best
gain for their size of any antenna.
http://www.fractenna.com
That is what Chip states for his company but I have no idea how a
fractal would work on top band. Most on this group deride the claims
of Chip with more than a handful of insults
Also, efficiency isn't everything. *For example, the efficiency of the
typical mobile HF antenna is fairly lousy because the antenna is a
small fraction of a wavelength long.
Exactly because it takes a WL or multiple there of to attain
equilibrium
*
Still, it's the best that can be
done on HF without trailing a long wire to a balloon, and dragging a
grounding plate. *
No. You are incorrect in my eyes! A multiple of a wavelength does
not require a ground plain and can be condensed into any shape or form
whilst retaining the required equilibrium. This is per the laws of
Maxwell when considering all forces involved in radiation for maximum
efficiency.
Regards
Art
http://www.k0bg.com/eff.html
--
Jeff Liebermann * *
150 Felker St #D * *http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann * * AE6KS * *831-336-2558