Several of us on the Ultralight Radio (ULR) yahoo group have been
experimenting with FSLs for a couple of months now, after reading Graham
Maynard's article. Most of the info we've learned has been discussed on that
group.
I think it's safe to say that none of us buy the (hogwash) theories espoused
by Graham Maynard, but the practical implementation does work for making an
antenna out of a ferrite sleeve, though some of his claimed performance
details have yet to be duplicated by anyone else. And he is far from the
first to try such an idea; others from years ago have already written about
it, though his own ideas about how it works are strictly unique to him.
For a practical example, using a Tecsun PL-380 ULR and a FSL with LF coil,
I've heard over 270 NDBs, listening indoors the past couple of months.
73,
Steve AA7U
NE Oregon
----- Original Message -----
From: "Tim Hills" <thi...@sio.midco.net>
To: "Mailing list for the International Radio Club of America"
<irca@hard-core-dx.com>
Sent: Sunday, April 10, 2011 7:57 PM
Subject: Re: [IRCA] (no subject)
Hi Terry,
I've seen designs using bundled rods before and his may very well perform
as described.
But his "Theory" of how and why ferrite based antennas work?
Before I was halfway through reading the link I had to get out my tinfoil
hat. I have to admit that citing Tesla, Moray and "free energy" sets off a
Kook alert for me so bear that in mind. He should read more of Tesla's
early writings when he was still honest enough to admit that he could
design, build and use his devices he had no clue why they worked.
What strikes me most is the misunderstanding of Field Theory. As pointed
out in another thread a tuned loop, air or ferrite, does effect the local
field for some distance greater than it's diameter and can be partially
absorbed in the windings. Any EM field has electrical and magnetic
components, if they didn't generators wouldn't work nor would the lowly
transformer which takes electrical energy, converts it to magnetic and
back again. A loop antenna with a pickup winding can be treated as an
unshielded transformer with it's primary excited by the EM that it's
resonant with instead of an applied current. In a ferrite rod antenna
neither the coil or the rod alone are the antenna, they interact with each
other to make the functioning whole in a predictable manner using standard
Field Theory .
Doesn't matter if the duck is black or white, you can't tell just from
it's quack and both taste the same rubbed with sage and stuffed with rice
dressing after being baked at 350 ;)
The idea that a ferrite rod 8" long is going to capture "photons" in the
MW band provoked an expletive that my Lady heard. She wondered if I was
shopping for fertilizer online...
True, one of the fundamental ides of Quantum Mechanics is that
Electromagnetic energy, radio frequencies or Gamma rays, behave like waves
sometimes and particles at other times. Design an experiment to detect
light as a particle and you'll find particles, an experiment to find light
waves will detect waves. In reality light is neither until it's detected
and it's probably something else entirely anyway. Light going through a
diffraction grating or properly sized dual slit behaves as if it were
waves, in a photomultiplier tube or a larger dual slit it acts like
particles.
The problem with looking for particles (photons) at say 1000KHz is that to
detect a photon the detector has to be bigger than the photon. With light
that's easy, you can read this because the rods and cones in your eyes
undergo chemical reactions because they are much bigger than a photon of
light, unless your blind and using a reader but I think my point is clear.
If Mr. Grahm were using a ferrite rod 300 meters or longer I might give
some credibility to his "Photon interaction" ideas. Even at microwave
frequencies where it would be practical I don't know of any practical uses
offhand.
The Electron spin stuff? The magnetic fields within a ferrite rod even in
the strongest EM fields is nowhere near enough to flip an Electron. Why do
you think they need such gawdawful powerful magnets to do an MRI?
I'd think spending more time looking into the properties of the ferrite
rods themselves would be more enlightening. The composition of the mix,
grain size, binding agent, how much pressure and what temperature was used
during forming all contribute to the rod's properties as much as it's
physical dimensions. A 1/2" diameter rod 8" long may work best at ELF or
HF depending on the above factors. Using them outside their designed
parameters in resonant circuits can cause unexpected results as I have
learned the hard way.
One reason I prefer air core loops for DXing, air is the same at ELF or
SHF.
Tim
On 4/10/2011 9:20, tbaugh wrote:
Hello All
Have been MW DXing& SWL for 50+ years, so fit the profile it would seem.
However I am late-to-the-table as far as this group is concerned, having
just joined this year. This is my first post.
Just recently, I have come across an explanation& description of the
Ferrite Sleeve Loop Antenna. Always a sucker for a new antenna, this
concept
seems quite interesting although I don't have the background to evaluate
this gentleman's claims. Nor just now, do I have enough cores to
duplicate
his work. However, I believe that he is based on the Emerald Isle, so
that
should count for something, tic.
Looking forward to comments on:
http://www.gmweb2.net/The%20FS%20Loop.htm
Regards Terry
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