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Old September 13th 09, 02:08 AM posted to rec.radio.amateur.antenna
christofire christofire is offline
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First recorded activity by RadioBanter: Oct 2008
Posts: 173
Default Spherical radiation pattern


"Richard Clark" wrote in message
...
On Sat, 12 Sep 2009 19:25:16 +0100, "christofire"
wrote:

I had seen papers about inverted F antennas before (at an IEE or IET
symposium some ten years ago), and I vaguely recall hearing that some
manufacturers use them in mobile phones, but I'd never seen a pattern as
uniform as the result of your simulation.


Hi Chris,

For a more academic treatment, the antenna is also known as the
"U-Shaped Antenna of Shtrikman." His has three wires, my fourth wire
is much like the J-Pole feed point attachment.

Now, one proviso: this is not an isotropic in the sense of providing
equal polarization at any angle. Nothing can accomplish that due to
that requirement being impossible to meet (the so-called "hairy ball"
problem).


I had understood it to be impossible on the basis of normal physics but Art
Unwin's claim wasn't clear in respect of polarisation.


So, I simply resolved that with my carbon golf ball with
its thermistor for detecting the Inverted F's total field to within
the degree of less than 2dB variation over the shell surrounding the
antenna.


Now I understand what you meant by 'total field' - sum of powers of
components in all polarisations.


Good. Maybe this will encourage Art to have a go at my challenge by
applying his own theories then.


As I've shown, they are not his theories. Art doesn't have theories,
they are illusions. Shtrikman's antenna has a model and a practical,
real example that agree with one another in performance. The design
is revealed and can be reproduced by anyone. No advanced math is
demanded to perfect the results. No allusion to nuclear forces is
required to explain any principle. Anyone can, and HAS built an
antenna that Art can only mumble about. Perhaps I am mislead about
this mumble, having kill-filed him, as I see his contribution (sic)
only through other's quotes; few of which are full quotes (I can
understand why).


Shtrikman's antenna sounds interesting. I will look up references.


This last week in my driving through rain city, I've seen a street
corner beggar who has worked one particular intersection for a couple
of years now. He has a weather protected laminated board describing
his plea, and he wears goretex weather gear that I couldn't afford. He
does have this hang-dog appearance and shambling shuffle tho'. What is
one to believe when it comes to claims? Clearly money talks. Who
knows? He may have a patented system and sells franchises.

73's
Richard Clark, KB7QHC


Over here we've recently been subjected to the phenomenon of 'Seasick
Steve' - who 'started out with nothing and still has most of it left' but
also has a substantial recording contract. What is one to believe, as you
so rightly say?

Chris