Energy-sucking radio antennas!

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William Beaty

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Aug 14, 1999, 3:00:00 AM8/14/99
to

I finally at long last connected up two separate ideas in my mind, and
figured out something about antennas which I've never encountered before.

I've written it up here:

ENERGY-SUCKING ANTENNAS
http://www.amasci.com/tesla/tesceive.html


Atoms are far smaller than the wavelength of light waves, so how come they
can absorb light so well? No, it's not a quantum-mechanical effect
involving tiny photons hitting tiny atoms. Instead it involves classical
EM. Most amazing is the idea that the same physics can probably be used
to make very small Tx/Rx antennas.


Awhile back there was a furor about "Crossed-Field Antennas" (CFAs) which
supposedly allowed us to transmit efficiently on 80m with a tiny desktop
antenna. Well, that might not have been genuine, but I believe that the
above "energy sucking" process can do the same thing. The key is to build
a high-Q resonant system. It stores energy in the form of an immense EM
field, and the field itself acts as the antenna. In other words, if an
antenna is far, far smaller than one wavelength, we can still get the
signal out by superimposing a huge e-field (or b-field) on the antenna in
phase with the transmitter. The large field lets the transmitter couple
itself to empty space. To do this, either use a loop antenna with a
relatively huge current, or use a dipole with a relatively huge voltage.
The antenna itself is far too small to be resonant, and so we add a
corresponding coil or capacitor to create a resonator which allows
efficient transmission. And for a receiver, if the antenna is actively
resonating because of energy it had previously received, then that antenna
receives MORE energy than a non-resonating antenna would.

Maybe all the hams here will say "NO DUH!" If so, then why would anyone
care about those CFAs and their claimed ability to act as large antennas,
while remaining very small? Also, why didn't anyone ever tell me that
atoms act like electrically-small resonant loop antennas, and not like
electrically large quarter-wave dipoles? I never encountered this idea in
any physics class. Maybe only the amateurs know about it, while
physicists do not.


Super-regen receivers as well as AM portables have apparantly been using
this "energy sucking" effect all along. A resonant loop-antenna is NOT
just an inductive pickup coil with a narrow-band filter. It actually
behaves electrically far larger than its physical dimensions. And if two
resonant coils are near each other, they can behave like a well-coupled
transformer even though their mutual inductance is very small and the
distance between the coils is large. Weird! I bet this is no big news to
radio designers, but physicists never have encountered such a thing.


Another similar topic:

TESLA'S GREAT MISTAKE
http://www.amasci.com/tesla/tmistk.html

(Nicola Tesla was using 'G-line' microwave waveguides... at 10KHZ!???)

Lots more crack-brained detrius can be found at:

NEW WEBSITE ADDITIONS
http://www.amasci.com/news.html

ELECTRONICS HOBBYIST
http://www.amasci.com/amateur/elehob.html

AMATEUR SCIENCE EMAIL FORUM
http://www.amasci.com/sci-list/sci-list.html

--
((((((((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))))))))
William J. Beaty SCIENCE HOBBYIST website
bi...@eskimo.com http://www.amasci.com
EE/programmer/sci-exhibits science projects, tesla, weird science

James Meyer

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Aug 14, 1999, 3:00:00 AM8/14/99
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On 14 Aug 1999 04:40:03 GMT, bi...@eskimo.com (William Beaty) wrote:

>Atoms are far smaller than the wavelength of light waves, so how come they
>can absorb light so well?

Atoms, acting alone, do *not* absorb light well at all unless the
light's wavelength matches one of the resonances in the electron "shell" of that
atom.

A low pressure gas (or plasma) consisting of individual atoms all of the
same element will be almost completely transparent, absorbing no light, at most
wavelengths. At some resonant wavelengths, the gas will be almost opaque,
absorbing those wavelengths very well.

Your revolutionary breakthru is just a lot of wishful thinking. You
should stick to those things that you can demonstrate rather than things you
*think* you know that ain't so.

Your excellent writeup on holograms produced with a compass on a sheet
of plastic was a classic example of good science. This cross-fielded Tesla
stuff is a good example of very bad psuedo-science.

Jim


Helmut Wabnig

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Aug 14, 1999, 3:00:00 AM8/14/99
to
On 14 Aug 1999 04:40:03 GMT, bi...@eskimo.com (William Beaty) wrote:

>
>I finally at long last connected up two separate ideas in my mind, and
>figured out something about antennas which I've never encountered before.
>
>I've written it up here:
>
> ENERGY-SUCKING ANTENNAS
> http://www.amasci.com/tesla/tesceive.html
>
>

>Atoms are far smaller than the wavelength of light waves, so how come they

>can absorb light so well? No, it's not a quantum-mechanical effect
>involving tiny photons hitting tiny atoms. Instead it involves classical
>EM. Most amazing is the idea that the same physics can probably be used
>to make very small Tx/Rx antennas.
>
>

snip


>
>Maybe all the hams here will say "NO DUH!" If so, then why would anyone
>care about those CFAs and their claimed ability to act as large antennas,
>while remaining very small? Also, why didn't anyone ever tell me that
>atoms act like electrically-small resonant loop antennas, and not like
>electrically large quarter-wave dipoles? I never encountered this idea in
>any physics class. Maybe only the amateurs know about it, while
>physicists do not.
>

>........
You never attended a physics class.
No, you didn't.
Don't lie.

W.

Gary Coffman

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Aug 15, 1999, 3:00:00 AM8/15/99
to
On 14 Aug 1999 04:40:03 GMT, bi...@eskimo.com (William Beaty) wrote:
>I finally at long last connected up two separate ideas in my mind, and
>figured out something about antennas which I've never encountered before.
>
>I've written it up here:
>
> ENERGY-SUCKING ANTENNAS
> http://www.amasci.com/tesla/tesceive.html

HA HA HA HA!

Best laugh I've had today.

Gary
Gary Coffman KE4ZV | You make it |mail to ke...@bellsouth.net
534 Shannon Way | We break it |
Lawrenceville, GA | Guaranteed |

Al, N2NKB

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Aug 15, 1999, 3:00:00 AM8/15/99
to
You have discovered one of my life-long fantasies. You can
set up an array of antennas, rectify the energy, and power all of your
house-hold appliances.
Al

William Beaty wrote in message <7p2rv3$acn$1...@eskinews.eskimo.com>...


>
>I finally at long last connected up two separate ideas in my mind, and
>figured out something about antennas which I've never encountered before.
>
>I've written it up here:
>
> ENERGY-SUCKING ANTENNAS
> http://www.amasci.com/tesla/tesceive.html
>
>

>Atoms are far smaller than the wavelength of light waves, so how come they
>can absorb light so well? No, it's not a quantum-mechanical effect
>involving tiny photons hitting tiny atoms. Instead it involves classical
>EM. Most amazing is the idea that the same physics can probably be used
>to make very small Tx/Rx antennas.
>
>

>Awhile back there was a furor about "Crossed-Field Antennas" (CFAs) which
>supposedly allowed us to transmit efficiently on 80m with a tiny desktop
>antenna. Well, that might not have been genuine, but I believe that the
>above "energy sucking" process can do the same thing. The key is to build
>a high-Q resonant system. It stores energy in the form of an immense EM
>field, and the field itself acts as the antenna. In other words, if an
>antenna is far, far smaller than one wavelength, we can still get the
>signal out by superimposing a huge e-field (or b-field) on the antenna in
>phase with the transmitter. The large field lets the transmitter couple
>itself to empty space. To do this, either use a loop antenna with a
>relatively huge current, or use a dipole with a relatively huge voltage.
>The antenna itself is far too small to be resonant, and so we add a
>corresponding coil or capacitor to create a resonator which allows
>efficient transmission. And for a receiver, if the antenna is actively
>resonating because of energy it had previously received, then that antenna
>receives MORE energy than a non-resonating antenna would.
>

>Maybe all the hams here will say "NO DUH!" If so, then why would anyone
>care about those CFAs and their claimed ability to act as large antennas,
>while remaining very small? Also, why didn't anyone ever tell me that
>atoms act like electrically-small resonant loop antennas, and not like
>electrically large quarter-wave dipoles? I never encountered this idea in
>any physics class. Maybe only the amateurs know about it, while
>physicists do not.
>
>

Al, N2NKB

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Aug 15, 1999, 3:00:00 AM8/15/99
to
Thanks for your interesting story, Franz.
Many amateur radio operators like myself have lit up fluorescent
bulbs at close range to our transmitters. But I never heard of
someone living to a commercial station that had all of that energy
near by. I hope we hear more interesting stories about this on
this newsgroup; I think that the thread will be long.
Al

Ing. Franz Glaser wrote in message <37B73AE1...@eunet.at>...


>"Al, N2NKB" wrote:
>>
>> You have discovered one of my life-long fantasies. You can
>> set up an array of antennas, rectify the energy, and power all of your
>> house-hold appliances.
>>

>> William Beaty wrote in message <7p2rv3$acn$1...@eskinews.eskimo.com>...
>> >
>> >I finally at long last connected up two separate ideas in my mind, and
>> >figured out something about antennas which I've never encountered
before.
>> >I've written it up here:
>> > ENERGY-SUCKING ANTENNAS
>> > http://www.amasci.com/tesla/tesceive.html
>

>This is robbery, of course. When I was in school, very close to
>a transmitting station, we could have flourescent lamps light
>brightly without a wall connection. It was necessary to short
>circuit the lamps at night.
>It was possible to drive our pocket radio with the energy from
>the transmitter - but of course we did listen Radio Luxembourg,
>they had much better music :-)
>--
>Franz Glaser, Glasau 3, A-4191 Vorderweissenbach Austria +43-7219-7035-0
>Muehlviertler Elektronik Glaser. Industrial control and instrumentation
>http://members.eunet.at/meg-glaser/ http://members.xoom.com/f_glaser/
>http://www.geocities.com/~franzglaser/ http://start.at/bedarf

John Woodgate

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Aug 15, 1999, 3:00:00 AM8/15/99
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<7p7crl$856$1...@bgtnsc03.worldnet.att.net>, Al, N2NKB <n2nkb@n2nkb.?.world

net.att.net> inimitably wrote:
>You have discovered one of my life-long fantasies. You can
>set up an array of antennas, rectify the energy, and power all of your
>house-hold appliances.
>Al
Yes, you can. You need a lot of antennas, and the regulatory authorities
would take a very dim view of your activity, but it is possible. There
were cases in the 1920s in Britain, when the Daventry transmitter 5XX
(200 kHz) first went on-air. Using neon lamps, no rectification was
necessary.
--
Regards, John Woodgate, OOO - Own Opinions Only.
Phone +44 (0)1268 747839 Fax +44 (0)1268 777124.
Did you hear about the hungry genetic engineer who made a pig of himself?
PLEASE DO ****NOT**** MAIL COPIES OF NEWSGROUP POSTS TO ME!!!!

Ing. Franz Glaser

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Aug 16, 1999, 3:00:00 AM8/16/99
to
"Al, N2NKB" wrote:
>
> You have discovered one of my life-long fantasies. You can
> set up an array of antennas, rectify the energy, and power all of your
> house-hold appliances.
>

Mark Fergerson

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Aug 16, 1999, 3:00:00 AM8/16/99
to

William Beaty wrote:
>
> I finally at long last connected up two separate ideas in my mind, and
> figured out something about antennas which I've never encountered before.

I do that all the time, only to discover I'm not the first. <sigh>

> I've written it up here:
>
> ENERGY-SUCKING ANTENNAS
> http://www.amasci.com/tesla/tesceive.html
>

> Atoms are far smaller than the wavelength of light waves, so how come they
> can absorb light so well? No, it's not a quantum-mechanical effect
> involving tiny photons hitting tiny atoms. Instead it involves classical
> EM. Most amazing is the idea that the same physics can probably be used
> to make very small Tx/Rx antennas.

Making connections to (not to mention impedance matching to)
individual electron shells is a tad tricky...

> Awhile back there was a furor about "Crossed-Field Antennas" (CFAs) which
> supposedly allowed us to transmit efficiently on 80m with a tiny desktop
> antenna. Well, that might not have been genuine, but I believe that the
> above "energy sucking" process can do the same thing. The key is to build
> a high-Q resonant system. It stores energy in the form of an immense EM
> field, and the field itself acts as the antenna. In other words, if an

Congratulations! You have discovered the mysterious Near Field... that
gray area where inverse-square no longer applies. the "Bermuda Triangle"
of Maxwell's equations.

<snip>

> Maybe all the hams here will say "NO DUH!" If so, then why would anyone
> care about those CFAs and their claimed ability to act as large antennas,
> while remaining very small? Also, why didn't anyone ever tell me that
> atoms act like electrically-small resonant loop antennas, and not like
> electrically large quarter-wave dipoles? I never encountered this idea in
> any physics class. Maybe only the amateurs know about it, while
> physicists do not.

Depends where you went to school. Lots of "Physics Professors" never
get past inclined planes and carbon paper. You obviously read a lot, so
read more.

> Super-regen receivers as well as AM portables have apparantly been using
> this "energy sucking" effect all along. A resonant loop-antenna is NOT
> just an inductive pickup coil with a narrow-band filter. It actually
> behaves electrically far larger than its physical dimensions. And if two
> resonant coils are near each other, they can behave like a well-coupled
> transformer even though their mutual inductance is very small and the
> distance between the coils is large. Weird! I bet this is no big news to
> radio designers, but physicists never have encountered such a thing.

A looptenna generally has a core with mu much greater than unity. Are
you trying to make a case for atoms as transformers, with electron
orbits a single turns? Think of a nucleus as a coil core. What's its mu?
What's the mutual coupling between two orbits in different atoms? Small
quantities, small (not very useful) effects.

> Another similar topic:
>
> TESLA'S GREAT MISTAKE
> http://www.amasci.com/tesla/tmistk.html
>
> (Nicola Tesla was using 'G-line' microwave waveguides... at 10KHZ!???)

You know, that sounds loopy as all hell, but the diagrams are pretty
convincing. Might influence us "lightning antenna" addicts.

> Lots more crack-brained detrius can be found at:

<snip>

Bill, your "reality filter" may be a bit more broadband than most, but
you gather interesting reading.

Mark L. Fergerson

Mark Fergerson

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Aug 16, 1999, 3:00:00 AM8/16/99
to

John Woodgate wrote:
>
> <7p7crl$856$1...@bgtnsc03.worldnet.att.net>, Al, N2NKB <n2nkb@n2nkb.?.world

> net.att.net> inimitably wrote:
> >You have discovered one of my life-long fantasies. You can
> >set up an array of antennas, rectify the energy, and power all of your
> >house-hold appliances.

> >Al
> Yes, you can. You need a lot of antennas, and the regulatory authorities
> would take a very dim view of your activity, but it is possible. There
> were cases in the 1920s in Britain, when the Daventry transmitter 5XX
> (200 kHz) first went on-air. Using neon lamps, no rectification was
> necessary.

Why would they care? Don't commercial transmitter operators take a tax
loss for "unavoidable signal absorption"? They certainly ought to. No
real antenna can be sited for perfect radiation. Any signal lost heating
a mountainside (or my home) doesn't help get the ads out, which pay the
rent (and taxes). Don't electric utility companies do it? That 60 Hz
heats a lot of ground... If a power company has to pay "cancer taxes" in
California, could they sue for unpaid-for absorbed power from the
"victims"?

Mark L. Fergerson

Gerry Quinn

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Aug 16, 1999, 3:00:00 AM8/16/99
to
In article <37B73AE1...@eunet.at>, "Ing. Franz Glaser" <meg-g...@eunet.at> wrote:

>"Al, N2NKB" wrote:
>>
>> You have discovered one of my life-long fantasies. You can
>> set up an array of antennas, rectify the energy, and power all of your
>> house-hold appliances.
>>
>> William Beaty wrote in message <7p2rv3$acn$1...@eskinews.eskimo.com>...
>> >
>> >I finally at long last connected up two separate ideas in my mind, and
>> >figured out something about antennas which I've never encountered before.
>> >I've written it up here:
>> > ENERGY-SUCKING ANTENNAS
>> > http://www.amasci.com/tesla/tesceive.html
>
>This is robbery, of course. When I was in school, very close to
>a transmitting station, we could have flourescent lamps light
>brightly without a wall connection. It was necessary to short
>circuit the lamps at night.
>It was possible to drive our pocket radio with the energy from
>the transmitter - but of course we did listen Radio Luxembourg,
>they had much better music :-)

I remember reading about a guy (may have been German) who was prosecuted
for powering his apartment from a coil hung out the window near a
transmitter. Apparently his efficiency was such that he cast a 'shadow'
- although maybe that's something that was claimed in court so as to
'simplify' matters for the jurors!

The crystal radio, with no power supply, is another example of this
phenomenon.

- Gerry Quinn


Roy McCammon

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Aug 16, 1999, 3:00:00 AM8/16/99
to
William Beaty wrote:

> Super-regen receivers as well as AM portables have apparantly been using
> this "energy sucking" effect all along. A resonant loop-antenna is NOT

> just an inductive pickup coil with a narrow-band filter. \

Super regen is just positive feedback.

AM receivers don't require highly efficient antenna's.
Their performance is more governed by signal to noise
ratio and in most populated environments, the dominant noise
is not in the receiver or antenna. Its external. The signal
to noise ratio is fixed before the antenna has any effect.

> It actually
> behaves electrically far larger than its physical dimensions. And if two
> resonant coils are near each other, they can behave like a well-coupled
> transformer even though their mutual inductance is very small and the
> distance between the coils is large.

Well coupled means that M is not much smaller than sqrt (L1*L2)
where M is the mutual inductance and L1 and L2 are the individual
self inductances of the two coils.

> I bet this is no big news to radio designers, but
> physicists never have encountered such a thing.

The original radio designers were physicists.

Roy McCammon

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Aug 16, 1999, 3:00:00 AM8/16/99
to
William Beaty wrote:

> Maybe all the hams here will say "NO DUH!" If so, then why would anyone
> care about those CFAs and their claimed ability to act as large antennas,
> while remaining very small? Also, why didn't anyone ever tell me that
> atoms act like electrically-small resonant loop antennas, and not like
> electrically large quarter-wave dipoles? I never encountered this idea in
> any physics class. Maybe only the amateurs know about it, while
> physicists do not.

I think a physicist might say that an antenna acts like
a big atom, rather than the other way around.

John Miles

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Aug 16, 1999, 3:00:00 AM8/16/99
to
Mark Fergerson wrote:
>
>If a power company has to pay "cancer taxes" in
> California...

Whoa. This, I haven't heard of. Could you elaborate on that?

-- jm KE5FX

------------------------------------------------------
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

Walter Gray

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Aug 16, 1999, 3:00:00 AM8/16/99
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In article <STRXJ6Bjwzt3Ew$D...@jmwa.demon.co.uk>, John Woodgate <j...@jmwa.demon.co.uk> writes:
:<7p7crl$856$1...@bgtnsc03.worldnet.att.net>, Al, N2NKB <n2nkb@n2nkb.?.world

:net.att.net> inimitably wrote:
:>You have discovered one of my life-long fantasies. You can
:>set up an array of antennas, rectify the energy, and power all of your
:>house-hold appliances.
:>Al

:Yes, you can. You need a lot of antennas, and the regulatory authorities
:would take a very dim view of your activity, but it is possible. There
:were cases in the 1920s in Britain, when the Daventry transmitter 5XX
:(200 kHz) first went on-air. Using neon lamps, no rectification was
:necessary.


Last time I drove up the M1 I noticed that there were several
old farmhouses actually inside the antenna array. At that
distance I would have thought that drawing any useful amount
of power would be seen immediately as an antenna mismatch.


Walter

Disclaimer: My employer is not responsible for the above.
If you want to email me, please use a valid From: address.

James Meyer

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Aug 16, 1999, 3:00:00 AM8/16/99
to
On Mon, 16 Aug 1999 10:08:00 -0500, Roy McCammon <rbmcc...@mmm.com> wrote:

>William Beaty wrote:
>
>> Super-regen receivers as well as AM portables have apparantly been using
>> this "energy sucking" effect all along.
>

>Super regen is just positive feedback.

Super regeneration isn't "just" positive feedback. Ordinary
regeneration is just positive feedback. Super-regen involves positive feedback
with the feedback level set to cause the detector stage to oscillate *and* a
method to apply supersonic "quenching" to periodically stop the oscillation and
then allow it to begin again.

The quenching is usually done by biasing the oscillating detector stage
to cutoff which reduces its gain to zero and then allowing the bias to slowly
bleed off. The bias can be externally supplied or it can be "self-quenching" by
virtue of the oscillation its self. Such self quenching is also known as
"squegging". As the bias drops, the gain of the stage increases until it breaks
into oscillation. Any external RF signal present at the detector reduces the
time it takes to begin oscillating.

The external RF signal is converted to a sort of PWM signal. The
oscillations start and stop with the duty cycle dependant on the strength of the
received RF signal. Since the oscillations have a much larger amplitude than
the original RF signal, they are very easy to convert back to a DC level that is
a copy of the amplitude variations of the original low level signal. The
quenching is done at a supersonic frequency so that it can be filtered out later
or simply be ignored if we're just listening to the detector as a radio.

The end result is very high gain for the detector since it is always
operating with a high level of carefully controlled positive feedback.

I'm convinced that something very similar is going on in our ears. Our
ears are very sensitive to sound levels in the nano watt range. Recent reports
have indicated that some of the "sounds" like ringing and whistling associated
with a condition known as "tinnitus" can actually be measured with sensitive
microphones as sound generated *in* the ear. I think our ears are super
regenerative systems and that the annoying ringing in the ear that plagues some
of us is simply the supersonic bias dropping down into the audible range of
frequencies.

Jim


Rick Haub

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Aug 16, 1999, 3:00:00 AM8/16/99
to
Being a physisist and amatuer radio operator I'd just like to say to the
original poster, WTF? Have you ever observed, let alone taken a physics course?
Nuff said.

Anyway I was brought up on a farm and in the '60's before all the hubbub about
possible EMI biological hazards from hi tension wires a lot of farmers in our
area were paid a lot of money to let power companies run huge power lines
through there properties. In many cases the wires went close to homes and
outbuildings. Every now and again you'd hear a story of how some farmer out
twards this town or that little burg had been caught by the power company with
"coils in the ground" what happens is a farmer will get huge coils of copper and
bury them into the ground under the power lines, these lines generaly carried in
excess of 50kv. They could then apparantly send it into a portable generator
power converter (portable generaters were and still are very popular with dairy
famers) and use the resulting 120AC to power there homes and farms. The power
companies had to develop new means to dedect these "dips" in power as the lines
went over the country side.

I don't know how much of this happened or exactly how it was done since I never
met a farmer who did it but one of my Physics proffesors when I was in collage
swore up and down that it happened in the rural area that he grew up in all the
time. He even had plans and schematics on how to do it.

I'd be interested if anyone who worked or did work for any power company can
comfirm if this ever happened where they were employed.


Ing. Franz Glaser wrote:

> "Al, N2NKB" wrote:
> >
> > You have discovered one of my life-long fantasies. You can
> > set up an array of antennas, rectify the energy, and power all of your
> > house-hold appliances.
> >

> > William Beaty wrote in message <7p2rv3$acn$1...@eskinews.eskimo.com>...
> > >
> > >I finally at long last connected up two separate ideas in my mind, and
> > >figured out something about antennas which I've never encountered before.
> > >I've written it up here:
> > > ENERGY-SUCKING ANTENNAS
> > > http://www.amasci.com/tesla/tesceive.html
>
> This is robbery, of course. When I was in school, very close to
> a transmitting station, we could have flourescent lamps light
> brightly without a wall connection. It was necessary to short
> circuit the lamps at night.
> It was possible to drive our pocket radio with the energy from
> the transmitter - but of course we did listen Radio Luxembourg,
> they had much better music :-)

Roy McCammon

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Aug 16, 1999, 3:00:00 AM8/16/99
to
Interesting and informative.
Mark Kinsler may want it for his collection.

James Meyer

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Aug 16, 1999, 3:00:00 AM8/16/99
to
On Mon, 16 Aug 1999 12:22:26 -0500, Rick Haub <rh...@midwestmicro-tek.com>
wrote:

>I don't know how much of this happened or exactly how it was done since I never
>met a farmer who did it but one of my Physics proffesors when I was in collage
>swore up and down that it happened in the rural area that he grew up in all the
>time. He even had plans and schematics on how to do it.

This sort of story is known not as an "urban myth", but a "rural myth".
Everybody knows the story, but nobody actually did it or could tell you who they
knew that had done it.

It's like the little old lady that dried her wet pet dog in the
microwave.

Jim


Dirk Bruere

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Aug 16, 1999, 3:00:00 AM8/16/99
to

I see nobody has mentioned fractal antennas yet.

Dirk

Jan Panteltje

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Aug 16, 1999, 3:00:00 AM8/16/99
to
>. I think our ears are super
>regenerative systems and that the annoying ringing in the ear that plagues
>some
>of us is simply the supersonic bias dropping down into the audible range of
>frequencies.
>
> Jim
>
>
It is also possible it is a compensation system, where a waveform is generated
that compensates (nulls) the movement of the ear drum.
The wave form could be generated by combining all those separate frequencies,
each generated by a nerve moving a tuned 'hair' in the inner ear.
I thought about this some years agao, if would explain some things.
No proof, no experiments, no litterature, only theory of 'thougt experiment'.
?

John Woodgate

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
<37B8816F...@kbnet.co.uk>, Dirk Bruere <art...@kbnet.co.uk>

inimitably wrote:
>I see nobody has mentioned fractal antennas yet.

You just did. There is a short article on them in 'Scientific American',
July 1999, page 23, with a reference to a much longer one in the March
issue of 'Fractals'.

John Woodgate

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
<37be419a...@netnews.worldnet.att.net>, James Meyer

<notj...@worldnet.att.net> inimitably wrote:
>I'm convinced that something very similar is going on in our ears. Our
>ears are very sensitive to sound levels in the nano watt range. Recent reports
>have indicated that some of the "sounds" like ringing and whistling associated
>with a condition known as "tinnitus" can actually be measured with sensitive
>microphones as sound generated *in* the ear. I think our ears are super

>regenerative systems and that the annoying ringing in the ear that plagues some
>of us is simply the supersonic bias dropping down into the audible range of
>frequencies.

That would involve a lot of nerve activity in the inner ear in the
absence of sound, which AIUI, is not observed. The ear/brain system
seems to work like this (highly simplified):

The basilar membrane in the cochlea, in the inner ear, is a form of
band-pass filter array, like a graphic equalizer. Each filter has an
'inner hair cell' at its output, which sends nerve impulses to the brain
when the filter is activated by an incoming sound. The 'gain' of the
inner hair cell is controlled by a mechanical adjustment (!) via an
'outer hair cell', which in turn is controlled by nerve impulses coming
back from the brain. This is effectively an automatic gain control loop,
with a non-linear control law, giving the normal ear its logarithmic
response.

In a damaged ear with 'sensorineural deafness', the 'gain' of the inner
hair cell and the action of the feedback loop are compromised, usually
(AIUI) due to the loss of, or damage to, hair cells. This can have three
effects:

- loss of sensitivity at some (normally the higher) frequencies, if the
inner hair cells are lost or damaged.

- loss of the logarithmic a.g.c., leading to 'recruitment' - a linear
response to sounds above a certain level, which makes apparent loudness
increase very rapidly as sound pressure increases. This may be due to
loss of the feedback signal or loss of forward gain in the loop due to
damage to the inner hair cell.

- instability of, and/or noise generation in, the feedback loop, if
something a bit more subtle happens (I don't think this is well
understood at present), leading to tinnitus and actual low-level sound
emission from the ear canal.

At least, that explanation is consistent with observations, AFAIK, but
it is certainly a simplification.

James Meyer

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
On Mon, 16 Aug 99 22:39:03 GMT, j...@panteltje.demon.nl (Jan Panteltje) wrote:

>>. I think our ears are super
>>regenerative systems and that the annoying ringing in the ear that plagues
>>some
>>of us is simply the supersonic bias dropping down into the audible range of
>>frequencies.
>>

>> Jim
>>
>It is also possible it is a compensation system, where a waveform is generated
>that compensates (nulls) the movement of the ear drum.
>The wave form could be generated by combining all those separate frequencies,
>each generated by a nerve moving a tuned 'hair' in the inner ear.
>I thought about this some years agao, if would explain some things.
>No proof, no experiments, no litterature, only theory of 'thougt experiment'.
>?

It's time to do some web surfing for background information. I'll post
anything "interesting" that I run across. You could do the same.

Jim


James Meyer

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
On Mon, 16 Aug 1999 22:23:59 +0100, Dirk Bruere <art...@kbnet.co.uk> wrote:

>
>I see nobody has mentioned fractal antennas yet.
>

>Dirk

I had just finished installing a huge shortwave log periodic beam on a
50' tower for the maritime radio shore station, WJS, at Duke University's
Oceanographic facility when a nor' easter blew through. The temporary guy ropes
stretched too far and the whole thing came down with a crash.

It might have been a fractal antenna after it hit the ground. I know
for certain it was a *fractured* antenna.

Jim


Tom MacIntyre

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
John Woodgate <j...@jmwa.demon.co.uk> wrote:

><37be419a...@netnews.worldnet.att.net>, James Meyer
><notj...@worldnet.att.net> inimitably wrote:
>>I'm convinced that something very similar is going on in our ears. Our
>>ears are very sensitive to sound levels in the nano watt range. Recent reports
>>have indicated that some of the "sounds" like ringing and whistling associated
>>with a condition known as "tinnitus" can actually be measured with sensitive

>>microphones as sound generated *in* the ear. I think our ears are super


>>regenerative systems and that the annoying ringing in the ear that plagues some
>>of us is simply the supersonic bias dropping down into the audible range of
>>frequencies.
>

I lost ALL hearing in my left ear due to a skull fracture in
1983...there hasn't been any invasive examination, but I've been told
that the nerve was damaged, and irreversibly so. There's been no sign
of substantial facial nerve damage despite the close proximity of same
to the auditory nerve. I suffer from LOUD tinnitus 24/7. The loudness
and frequencies vary...loudness can increase due to physical exertion
and/or being in a high-dB SPL environment, and at random, which seems
to be the way frequencies vary. My equilibrium was severely affected
by this injury as well, and I think that, in the long term, such
things as concentration, memory, and mood control have suffered as
well...I look upon the ringing as a sign that my auditory center is
still alive, hopefully awaiting that magical surgical technique which
will restore my hearing. That's all now, because thinking about it and
talking about it make me more aware of it...Murphy's law, I suppose.

Tom

Science Hobbyist

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
In article <37b68075...@netnews.worldnet.att.net>,

notj...@worldnet.att.net (James Meyer) wrote:
> On 14 Aug 1999 04:40:03 GMT, bi...@eskimo.com (William Beaty) wrote:
>
> >Atoms are far smaller than the wavelength of light waves, so how come they
> >can absorb light so well?
>
> Atoms, acting alone, do *not* absorb light well at all unless the
> light's wavelength matches one of the resonances in the electron "shell" of that
> atom.

Exactly. Because of resonance, an atom can present a relatively
enormous cross-section to incoming photons. As you say,
resonance is the key. That was a big thing with Tesla too, no?
What was missing is the fact that classical concepts have bearing
on atomic resonance. At resonance, photons can't pass by an
atom, even though the atom is hundreds of times smaller than the
wavelength of the light.

> Your revolutionary breakthru is just a lot of wishful thinking. You
> should stick to those things that you can demonstrate rather than things you
> *think* you know that ain't so.

Did you read Dr. Bohren's excellent little paper in AJP? Or
the one in the Russian physics journal? To me your response
seems rife with prejudice. You hear the word "Tesla" and you leap
to a stance of hostile disbelief? You don't need to examine any
evidence before rendering judgement? A dangerous
practice for people in science. But perhaps warranted in my case,
since I do have that enormous "weird science" section on my
website, and the pseudoscience is bound to leak out and infect
any nearby "proto-science" material! :)

All I'm saying is that resonant electromagnetic systems behave
electrically larger than non-resonant EM systems. It works for
atoms, and it works in LC circuits. It is supported in the physics
literature and I certainly wasn't the first one to wonder about such
things. It definitely is not my discovery.

"Good Science" involves verifying the references before leaping
to a stance based on beliefs and emotions. "Believers" have
trouble with gullibility, while "skeptics" have trouble with
closemindedness. A good scientist should be careful to avoid
prejudice against certain topics, *AND* to avoid believing certain
topics without evidence.

> Your excellent writeup on holograms produced with a compass on a sheet
> of plastic was a classic example of good science. This cross-fielded Tesla
> stuff is a good example of very bad psuedo-science.

I agree that the "crossed-field" stuff doesn't work. Read my
article again, and pay attention to my circuit analysis. That is
my "evidence." If you want to rebut my claims, then poke
holes in my reasoning, don't just apply disrespectful lables.

I'm not discussing crossed-field antennas. I'm saying that tiny
antennas can behave electrically "large" in the
same way that resonant atoms can behave optically opaque.
A high-Q resonant circuit is not just a bandpass filter, instead it
processes incoming energy differently than an untuned circuit.
Once the energy has built up in the circuit, we can draw off a
higher level of power than we could in an untuned circuit. This
seems highly counterintuitive to me, that's why I'm making such
a big deal about it. It makes me think "damn, Tesla was right about
this crazy stuff after all."

Hams have used tuned loop receiving antennas for decades. I
always thought that the tuning capacitor was just there to filter out
unwanted stations. On the contrary, it appears that a resonating
antenna can become "opaque" to incoming frequencies and absorb
far more energy than a simple untuned inductive pickup loop. With
a good low-noise front end this might be irrelevant. If you need
greater sensitivity, just crank up the gain. (Or replace your tiny loop
with a 1/4-wave dipole.)

But if we want to light a light bulb via an alternating electrostatic field,
then a tuned circuit can make your antenna reach out and "grab
power" from the nearby transmitter. This stuff is all entirely
conventional, and from my viewpoint as an electonics experimenter I
already knew about it. My "physicist" side just discovered what my
"electronics" side knew all along.

((((((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))))))

William Beaty bbe...@microscan.com
Software Engineer http://www.microscan.com
Microscan Inc., Renton, WA 425-226-5700 x1135


Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.

Science Hobbyist

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
In article <37cc091b....@news.atl.bellsouth.net>,

>
> HA HA HA HA!
>
> Best laugh I've had today.

Watch out, I may have the last laugh!

What will happen is that everyone will realize that
this "energy sucking" stuff is entirely conventional.
It's just like sticking a resistor in a constant-current
conductor path and having the resistor get hot.
The high-ohms resistor "sucked energy" from the system,
whereas the lo-ohms wire did not. A tuned circuit
acts like a resistor, whereas an untuned circuit has
inductive or capacitive reactance only, and cannot
absorb much energy even if a resistve load is
attached to it. Simple stuff. Don't know why it
took me this long to notice it. But then, nobody else
noticed it either.

Science Hobbyist

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
In article <37B7A345...@home.com>,
Mark Fergerson <mferg...@home.com> wrote:


> Congratulations! You have discovered the mysterious Near Field... that
> gray area where inverse-square no longer applies. the "Bermuda Triangle"
> of Maxwell's equations.


Exactly. It is very weird in there. The impedance of free space isn't
an impedance anymore, and voltage and current can be manipulated
separatly. I never would have believed it if I didn't think it through
on my own (and if I didn't find some articles in a physics journal which
support the concept.) By adding an in-phase current to a loop
antenna, we can crank up the received power. It's very silly.
If it's real, why doesn't everyone know about it? For one thing, it only
works with short antennas. If you have a 1/4-wave dipole, you
already are presenting an enormous collection "cross section" to the
incoming waves. Whoda thunk that a little bitty antenna could do
a similar thing (if its Q-factor could be cranked up to immense values.)

> Depends where you went to school. Lots of "Physics Professors" never
> get past inclined planes and carbon paper. You obviously read a lot, so
> read more.

I've never stumbled across these ideas in any physics textbook
in my collection, but then physics textbooks don't tend to have much
EM except the very fundamental topics. This "energy sucking" thing
is much more like engineering than like physics. I don't recall
ever hearing it mentioned in my fields/waves engineering courses.
I would have remembered something this odd.

What's amazing to me is that the Bohren paper in AJP doesn't
reference an enormous number of similar papers, and also it was
published in the 1980s. Instead there is only one other paper that
discusses this topic (at least on the micro-scale version of the
phenomena.) That paper is also from the 1980s. Maybe there are
many papers in old engineering journals about this stuff.


> A looptenna generally has a core with mu much greater than unity. Are
> you trying to make a case for atoms as transformers, with electron
> orbits a single turns? Think of a nucleus as a coil core. What's its mu?
> What's the mutual coupling between two orbits in different atoms? Small
> quantities, small (not very useful) effects.

Nope, I'm seeing that a single atom is similar to a coil/capacitor
resonator. Hit it with an alternating e-field, and if you match its
resonant freq., you will pump the electrons to higher states. Or,
do the same thing with an alternating magnetic field. Or just
shine EM waves of the appropriate wavelength at it. In any case,
the atom will NOT behave as an antenna which is << the wavelength
of the radiation. Instead it will absorb far more energy than such a
tiny object has any right to do. In particle-accelerator jargon, the
photon collision cross-section of the atom is larger at resonance. The
weird part is that a macroscopic coil and capacitor ALSO has an
enlarged collision-cross-section at resonance, even if it's the photons
from the 550KHz AM band that are doing the colliding.


> You know, that sounds loopy as all hell, but the diagrams are pretty
> convincing. Might influence us "lightning antenna" addicts.

Here's something that's far loopier. WHAT IF there are some relatively
coherent vertical AC e-field modes in the earth's Shumann cavity?
Driven by thunderstorms all over the planet? As I mentioned in the
article, radios might not detect these signals if they were using loop
antennas. Perhaps these signals do not exist (meaning, the signal
strength is low compared to the broadband hash.) But if they do
exist, then a long-wire antenna connected to some sort of high-
voltage resonant circuit might be able to build up a fairly large
resonance. If this occurred, the resonator would essentially be
"storing" a high-voltage AC signal, and building it up with time.
The same thing can be done with a "Franklin Antenna" connected
to a capacitor: if you wait long enough the, tiny DC atmospheric
leakage will charge your capacitor to lethal levels. But if it's done at
AC, then something weird happens: if we draw off some of the energy
from the resonator, we can obtain an unexpectedly large power.
The amount of power received by the antenna is larger if we allow
a big AC signal to build up in the LC circuit attached to the antenna.
Maybe hang a little pickup-coil around the coil of the resonator, and
light an LED from the Earth's net AC output from lightning strikes
everywhere.

All speculation. One would need to build a tuned circuit of VERY
high Q and capable of standing off a very high voltage, and then tune
it to various frequencies down below the commercial AM band.

Science Hobbyist

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
In article <37be419a...@netnews.worldnet.att.net>,

notj...@worldnet.att.net (James Meyer) wrote:
> I'm convinced that something very similar is going on in our ears. Our
> ears are very sensitive to sound levels in the nano watt range. Recent reports
> have indicated that some of the "sounds" like ringing and whistling associated
> with a condition known as "tinnitus" can actually be measured with sensitive
> microphones as sound generated *in* the ear. I think our ears are super
> regenerative systems and that the annoying ringing in the ear that plagues some
> of us is simply the supersonic bias dropping down into the audible range of
> frequencies.

Dr. Thomas Gold (lately of Cornell Astrophysics) came up with the same
theory. When he presented it to hearing specialists, they refused to take it
seriously. The event is described in Gold's paper "New Ideas in Science",
http://www.amasci.com/freenrg/newidea1.html where he outlines some of the
damage that peer-review and "concensus-think" can have on science.

--

Daniel Haude

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
On Tue, 17 Aug 1999 06:11:21 GMT,
Science Hobbyist <bbe...@microscan.com> wrote
in Msg. <7paue6$crc$1...@nnrp1.deja.com>

> I've never stumbled across these ideas in any physics textbook
> in my collection, but then physics textbooks don't tend to have much
> EM except the very fundamental topics.

Well, it is sort of in any comprehensive book about electrodynamics. The
problem is that these books (like "the Jackson") are written by
theoretical physicists who don't give a damn about applications.

> This "energy sucking" thing
> is much more like engineering than like physics. I don't recall
> ever hearing it mentioned in my fields/waves engineering courses.
> I would have remembered something this odd.

And the engineers just say: "Of course, a resonant circuit will draw lots
more energy from the field than an untuned one", take that as granted
(because it sounds so reasonable) and don't worry about the physics behind
it.

> What's amazing to me is that the Bohren paper in AJP doesn't
> reference an enormous number of similar papers, and also it was
> published in the 1980s.

The effect, as you say, is entirely classic and well-known. It's therefore
not subject of extensive study. The peculiar thing is that neither
physicists nor engineers draw the interesting conclusion of "tuned
circuits sucking energy from the field", although the effect certainly
exists. People know about and exploit this phenomenon, it's just that
nobody has *phrased* the consequences this way.

On the other hand the need for a very high Q precludes drawing a lot of
power from the circuit, no?

Just a few thoughts. I'm neither into RF electronics nor electrodynamics,
let alone near-field optics.

--Daniel

--
"The obvious mathematical breakthrough would be development of an easy
way to factor large prime numbers." -- Bill Gates, "The Road Ahead"


Jan Panteltje

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
>>
>- instability of, and/or noise generation in, the feedback loop, if
>something a bit more subtle happens (I don't think this is well
>understood at present), leading to tinnitus and actual low-level sound
>emission from the ear canal.
>
>At least, that explanation is consistent with observations, AFAIK, but
>it is certainly a simplification.
Interesting, would the (outer?) hair be generating the sound? or the inner
perhaps, so the hairs ARE (or at least can be) moving the fluid in the inner ear?
Jan.


Roy McCammon

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
Science Hobbyist wrote:

> What will happen is that everyone will realize that
> this "energy sucking" stuff is entirely conventional.
> It's just like sticking a resistor in a constant-current
> conductor path and having the resistor get hot.
> The high-ohms resistor "sucked energy" from the system,
> whereas the lo-ohms wire did not. A tuned circuit
> acts like a resistor, whereas an untuned circuit has
> inductive or capacitive reactance only, and cannot
> absorb much energy even if a resistve load is
> attached to it.

Take a series R, L, C circuit. Drive it with a constant
current sinusoidally alternating source.

It will absorb the same amount of energy whether
the L and C resonate with the source or not.

Roy McCammon

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
Science Hobbyist wrote:

> Exactly. Because of resonance, an atom can present a relatively
> enormous cross-section to incoming photons. As you say,
> resonance is the key. That was a big thing with Tesla too, no?
> What was missing is the fact that classical concepts have bearing
> on atomic resonance. At resonance, photons can't pass by an
> atom, even though the atom is hundreds of times smaller than the
> wavelength of the light.

Not sure what you are saying here, some numbers
may be useful.

Whenever you have a bunch of atoms in proximity,
they can "share" electrons so that the relevant
"size" is the atom to atom spacing rather than
the size of a single atom.

So are you speaking of isolated atoms, such as
in a low pressure gas or clumps of atoms such
as in a chunk of glass or copper wire?

Roy McCammon

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
Science Hobbyist wrote:

> All I'm saying is that resonant electromagnetic systems behave
> electrically larger than non-resonant EM systems.

I guess I'll just have to ask; what is the electrical
size of a non-resonent EM system?

Lyle Koehler

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
Science Hobbyist wrote:
>

>
> All speculation. One would need to build a tuned circuit of VERY
> high Q and capable of standing off a very high voltage, and then tune
> it to various frequencies down below the commercial AM band.
>

It's easy to fall into the trap of confusing voltage with power. A
high-Q tuned circuit in the presence of an RF field can deliver a high
voltage to an open circuit, but since power is E^2/R and since R is
infinite, the "captured" power is zero. As soon as you load the circuit
with a finite resistance, the Q starts to degrade. Q of a small antenna
is important because it is related to the losses in the circuit, and
therefore to the efficiency of the antenna for either transmitting or
receiving. But there is nothing magic about high Q antennas that will
allow them to suck huge amounts of energy from an RF field.

It isn't difficult to estimate how much energy can be captured with a
small, tuned loop antenna. The amount of *power* available to the
receiver is equal to the incident power density times the effective area
of the antenna. Power density in watts per square meter is given by
E^2/377 or H^2*377, where E or H represents the field intensity. To
estimate the effective area of the antenna, use the formula A(eff) =
G*(wavelength)^2/(4*PI). G is the "real" gain of the antenna, which
includes the directive gain and the efficiency. The program RJELOOP3.EXE
by Reg Edwards can be downloaded from Reg's web site at
http://www.btinternet.com/~g4fgq.regp/. RJELOOP3 includes a calculation
of the Q and the gain (in dB) relative to a full-size quarter wave
antenna. The gain in dB must of course be converted to power gain for
use in the effective area equation.

For example, a 1 meter square loop wound with 20 turns of #18 (1 mm dia)
wire has a gain of -64 dB (about 4e-7) at 200 kHz. The wavelength is
1500 meters, and the effective area is about 0.07 square meters. It's
not going to "suck" much energy from a transmitter unless the field
strength is really huge. Note that the Q didn't show up explicitly in my
calculations; losses were already taken into account in Reg's
computation of the antenna gain.

Ferrite loading of a small loop antenna can provide a very large
improvement in gain. But a ferrite loopstick of practical size will
still have very low gain. Radiation resistance of a small loop is
proportional to area squared times the square of the effective
permeability, which is typically on the order of 100 to 1000. (Ferrite
materials with bulk permeabilities above 1000 are available, but the
effective permeability is much smaller than the bulk permeability except
for very large length-to-diameter ratios). So a ferrite loaded loop can
be a million times better than an air-core loop of the same dimensions.
However, the area squared term kills you. An LF loopstick antenna wound
on a 1/2 inch diameter rod is *much* less efficient than the 1-meter
square air loop in the example above.

Yes, it's possible to capture energy from RF fields. A friend of mine
has run a little electric motor with energy captured from 50-kW AM
station WCCO, several miles away. But he uses a fairly long wire
antenna, something like 200 feet if I remember correctly.

--
Lyle, K0LR

http://www.computerpro.com/~lyle


Jim Carr

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
Rick Haub <rh...@midwestmicro-tek.com> wrote:
}
} I don't know how much of this happened or exactly how it was done since I never
} met a farmer who did it but one of my Physics proffesors when I was in collage
} swore up and down that it happened in the rural area that he grew up in all the
} time. He even had plans and schematics on how to do it.

In article <37b958dc...@netnews.worldnet.att.net>

notj...@worldnet.att.net (James Meyer) writes:
>
>This sort of story is known not as an "urban myth", but a "rural myth".
>Everybody knows the story, but nobody actually did it or could tell you
>who they knew that had done it.

Well, I know someone who claims an EE friend of his did it, and
only got away with it after agreeing to cease and desist and show
the power company how he had done it in exchange for no prosecution.
Seems he had rigged a relay so that the theft (and it is theft) would
be disconnected if the meter was pulled (which is the first check the
power company did when tracking the loss). He had hidden that part
of his system really well.

>It's like the little old lady that dried her wet pet dog in the
>microwave.

More like the guy who killed a roommate's pet bird by doing so, since
we are talking about a crime rather than an accident.

--
James A. Carr <j...@scri.fsu.edu> | Commercial e-mail is _NOT_
http://www.scri.fsu.edu/~jac/ | desired to this or any address
Supercomputer Computations Res. Inst. | that resolves to my account
Florida State, Tallahassee FL 32306 | for any reason at any time.

John Woodgate

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
<934890929.3146....@news.demon.nl>, Jan Panteltje
No, AIUI it's the basilar membrane that vibrates, and the sound travels
'backwards' through the middle ear to the tympanum.

Science Hobbyist

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
In article <37B97D0...@mmm.com>,

Good question. Let's see. If the EM system is being
"illuminated" with propagating EM waves, and the
waves have a certain power density P/(meter^2), then
an ideal quarter-wave dipole antenna with an impedance-
matched resistive load would intercept X watts, and we could
calculate the "absorbtion cross-sectional area" of that antenna
from X/P, and if we assume that this area is circular, then the
"electrical size" of that antenna is SQRT(X/P/pi)

If we do the same for ANY antenna, we can figure out
how "large" it is electrically, and compare it to the "size"
of an ideal quarter-wavelength dipole.

Science Hobbyist

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
In article <37B97B22...@mmm.com>,

rbmcc...@mmm.com wrote:
> Science Hobbyist wrote:
>
> > Exactly. Because of resonance, an atom can present a relatively
> > enormous cross-section to incoming photons. As you say,
> > resonance is the key. That was a big thing with Tesla too, no?
> > What was missing is the fact that classical concepts have bearing
> > on atomic resonance. At resonance, photons can't pass by an
> > atom, even though the atom is hundreds of times smaller than the
> > wavelength of the light.
>
> Not sure what you are saying here, some numbers
> may be useful.
>
> Whenever you have a bunch of atoms in proximity,
> they can "share" electrons so that the relevant
> "size" is the atom to atom spacing rather than
> the size of a single atom.


Yes, I was imagining individual, widely-separated Sodium
atoms in a vacuum, or the individual Chromium atoms in a
doped aluminum oxide (ruby) laser resonator.

Me too, I would like to find some numbers to apply
to this. Right now all I have is thought-experiments,
and the analyses in those two research papers.
(Isn't SCI.PHYSICS a great place? People start spitting
on an idea even before reading the references. In my
opinion, anyone who wants to "spit" on colleagues had better
check and see if their victim is 'beneath' them. If they have to
spit 'upwards', chances are that they will embarass only
themselves.)


Rather than looking at atoms, those authors looked at
IR absorbtion by particles with diameter << than the IR
wavelength. One of their examples involved surface
plasmons in metal particles, the other involved phonons
in dielectric particles. I recall that, for IR light in the
absorbtion band of the particles (i.e. at resonance,)
they calculated that the "electrical size" of the particles
was about 15 times larger than the physical size, as if
the particles were reaching out and "sucking" EM
energy from a large area around themselves. Very
weird. The authors then pointed out that this is a well-
known phenomenon in particle physics: at resonance,
the collision cross-section of a particle can be far larger
than its physical size. Another way to say it: at resonance,
the particle grows to fill the electromagnetic "near field"
volume. Obviously this only becomes significant for
particles which are << than the wavelengths being
absorbed. And when applied to circuitry, it only becomes
significant for small dipoles and loop antennas, where the
physical size of the antenna is << than the wavelength
being received.

Science Hobbyist

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
In article <37B957A5...@mmm.com>,

rbmcc...@mmm.com wrote:
> Science Hobbyist wrote:
>
> > What will happen is that everyone will realize that
> > this "energy sucking" stuff is entirely conventional.
> > It's just like sticking a resistor in a constant-current
> > conductor path and having the resistor get hot.

> Take a series R, L, C circuit. Drive it with a constant
> current sinusoidally alternating source.
>
> It will absorb the same amount of energy whether
> the L and C resonate with the source or not.

Do the same for a parallel RLC circuit as shown in the
ASCII art in my "energy sucking" article. See what
happens? (Or perhaps I'm wrong about *ALL* of this
stuff, and I simply have not found my glaring error.)

--

Science Hobbyist

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Aug 17, 1999, 3:00:00 AM8/17/99
to
In article <slrn7ri87m...@insitu.physnet.uni-hamburg.de>,

ha...@physnet.uni-hamburg.de wrote:
> On Tue, 17 Aug 1999 06:11:21 GMT,
> Science Hobbyist <bbe...@microscan.com> wrote
> in Msg. <7paue6$crc$1...@nnrp1.deja.com>
>

> > What's amazing to me is that the Bohren paper in AJP doesn't


> > reference an enormous number of similar papers, and also it was
> > published in the 1980s.
>

> The effect, as you say, is entirely classic and well-known. It's therefore
> not subject of extensive study. The peculiar thing is that neither
> physicists nor engineers draw the interesting conclusion of "tuned
> circuits sucking energy from the field", although the effect certainly
> exists. People know about and exploit this phenomenon, it's just that
> nobody has *phrased* the consequences this way.

Right. The only reason I stumbled upon it is from reading a paper
on Tesla's Wireless Energy scheme. Skeptics state that it
cannot have worked, since you'd need an immensely long
dipole antenna hanging off your electric car or airplane. The
authors in the Tesla Symposium Proceedings paper mentioned
that resonant circuits intercept an anomalously large amount of
energy. I thought, "that's impossible!" Then I started remembering
my old niggling questions about the diameter of atoms and the
tuning capacitor on VLF loop antennas. Fortunately those authors
referenced the two physics papers, and suddenly the light bulb went
on for me.

What is REALLY UNSETTLING is the fact that Tesla's system
might have actually worked.


>
> On the other hand the need for a very high Q precludes drawing a lot of
> power from the circuit, no?

Definitely. We'd have to do the LC tuning by using a low-value
coil (less windings) and a very large capacitance. Either that
or make the coil physically large, so the inductance would go
up faster than the wire resistance. It certainly would help things
if the antenna was as large as possible (either a loop antenna
in series with the inductor, or a dipole antenna across the
capacitor.)

In the past I've heard claims from some college students that they
managed to light a small bulb by picking up energy from the 60Hz
lines in the walls of their dorm room. With an inductive pickup coil,
this is flat out impossible (unless they have kiloamperes in their
building wiring!) But now that I'm thinking in terms of resonant
systems, maybe such a thing is feasible. Use a physically large
inductor with very low series resistance, and pair it with a high
value capacitor for 60Hz resonance. I'd be suprised if this could
light up even an LED, but maybe there's something to their
claim.


--

Science Hobbyist

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
In article <37b7acc1...@news.netway.at>,
hwa...@netway.at (Helmut Wabnig) wrote:

> You never attended a physics class.
> No, you didn't.
> Don't lie.

Ah, a flamer. OK, flamer here's my specs:

BSEE U. of Rochester 1980
Resume at http://www.amasci.com/me.html
Science hobbyist all my life, almost exclusively
in physics.

And you, are you a bully who cruises newsgroups looking
for weak minds to attack? Watch out, some weak minds
will bite back. Are you unable to understand and refute an idea,
and so you can only attack on a personal level? Not the
characteristics of a thinking person, if you ask me. But I forgot,
this is Newsgroups, and I should expect this forum to be full of this
kind of thing. There's no way to elevate these discussions to
a civilized level, and so they decend into the depths. Very
sad.

If there is something wrong with the concepts I present,
pleas show the audience the glaring flaw you've uncovered,
then we will all benefit.

Roy McCammon

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
Jim Carr wrote:

> Well, I know someone who claims an EE friend of his did it, and
> only got away with it after agreeing to cease and desist and show
> the power company how he had done it in exchange for no prosecution.
> Seems he had rigged a relay so that the theft (and it is theft) would
> be disconnected if the meter was pulled (which is the first check the
> power company did when tracking the loss). He had hidden that part
> of his system really well.

I don't know, but I suspect, that if such a device existed,
it would function mainly as a current (in the transmission
line) to voltage mutual inductance. That would mean
that the available "voltage" would be proportional to
the load that the transmission line was carrying. I'd
expect 3:1 daily variations and maybe 10:1 (or even 10:0)
annual variations. Its not impossible to deal with, but
its not as simple as just stringing some wires.

Don Kelly, are you out there?

Science Hobbyist

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
In article <37B98A96...@mlecmn.net>,
Lyle Koehler <ly...@mlecmn.net> wrote:

> It's easy to fall into the trap of confusing voltage with power. A
> high-Q tuned circuit in the presence of an RF field can deliver a high
> voltage to an open circuit, but since power is E^2/R and since R is
> infinite, the "captured" power is zero.

That's what I thought initially. But look at my two examples.
When I load the untuned system down to V= .707x,
I get microwatts, but when I do the same with the tuned system,
I get watts. This is extremely counterintuitive. Just by allowing
a big voltage to build up, I should *NOT* be able to draw any
more power from the antenna, right? That's an understandable
conclusion. But unless there is a big error in my reasoning, that
conclusion is wrong, and it is possible to draw far more power from a
resonant receiver than can be drawn from an inductive or a capacitve
pickup alone.


> As soon as you load the circuit
> with a finite resistance, the Q starts to degrade. Q of a small antenna
> is important because it is related to the losses in the circuit, and
> therefore to the efficiency of the antenna for either transmitting or
> receiving. But there is nothing magic about high Q antennas that will
> allow them to suck huge amounts of energy from an RF field.

That's the central point. I think that there *IS* something magic
about small, high-Q antennas. (Remain aware that this only
applies to small antennas. Connectiing a resonator to a
half-wave dipole should not increase the received power.)


>
> It isn't difficult to estimate how much energy can be captured with a
> small, tuned loop antenna. The amount of *power* available to the
> receiver is equal to the incident power density times the effective area
> of the antenna.


Exactly. Exactly. Check out those two physics papers. At resonance, the
effective area of an electrically-small antenna increases. At resonance, the
antenna no longer behaves as we might expect. The authors demonstrate this as
applied to particles being illuminated by IR light, but this is a Classical
Physics (non-QM) effect, and so it applies to EM devices in general. A tiny
antenna can "expand" its effective area into the nearfield region if that
antenna is a resonator. This does not apply to 1/4-wave dipoles and larger,
since those antennas are already dominating the area of the nearfield region.

> Power density in watts per square meter is given by
> E^2/377 or H^2*377, where E or H represents the field intensity. To
> estimate the effective area of the antenna, use the formula A(eff) =
> G*(wavelength)^2/(4*PI). G is the "real" gain of the antenna, which
> includes the directive gain and the efficiency. The program RJELOOP3.EXE
> by Reg Edwards can be downloaded from Reg's web site at
> http://www.btinternet.com/~g4fgq.regp/. RJELOOP3 includes a calculation
> of the Q and the gain (in dB) relative to a full-size quarter wave
> antenna. The gain in dB must of course be converted to power gain for
> use in the effective area equation.

If that program does not include the effects of applying
a synchronised b-field to the nearfield region of the antenna loop,
then it does not include this bizarre "energy sucking" effect.

As I understand it, small resonant antennas rely on the
ability to apply EITHER an e-field OR a b-field to the
nearfield region, and therefor to affect the power seen
by the antenna. It's a nearfield-only effect. If we artificially
increase the current only, then the received power increases.
Impossible? Not if there's empirical evidence that this occurs.
"If it happens, it must be possible."

Please note: this is NOT my field of expertise, and there is still
a chance that this phenomenon is not real. If it wasn't supported
in the physics literature, I would insist performing my own
experiments before accepting that any of this is possible.

> Yes, it's possible to capture energy from RF fields. A friend of mine
> has run a little electric motor with energy captured from 50-kW AM
> station WCCO, several miles away. But he uses a fairly long wire
> antenna, something like 200 feet if I remember correctly.

As a kid we lived next to WENY in Elmira, NY. Crystal radios
worked very well, even without a tuned circuit or a longwire
antenna (although our selection of programming was somewhat
limited!) I can easily accept that a big loop or a longwire antenna
can intercept significant power. A small, high-Q tuned circuit might
build up a very large signal, and we'd expect that its impedance would
be so high that little energy could be withdrawn, but energy goes as
the square of voltage, and that is the key. Get your resonator going,
so the voltage goes way up, and you can withdraw a proportionally
larger amount of energy. Very weird. The phase-locked oscillating
fields around a high-Q resonator can distort the patterns of a nearby
transmitter's antenna: the "energy sucker" casts a shadow as
it absorbs energy from the transmitter.

Roy McCammon

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to
Science Hobbyist wrote:
>
> In article <37B957A5...@mmm.com>,
> rbmcc...@mmm.com wrote:
> > Science Hobbyist wrote:
> >
> > > What will happen is that everyone will realize that
> > > this "energy sucking" stuff is entirely conventional.
> > > It's just like sticking a resistor in a constant-current
> > > conductor path and having the resistor get hot.
>
> > Take a series R, L, C circuit. Drive it with a constant
> > current sinusoidally alternating source.
> >
> > It will absorb the same amount of energy whether
> > the L and C resonate with the source or not.
>
> Do the same for a parallel RLC circuit as shown in the
> ASCII art in my "energy sucking" article.

Oh that one we drive with a constant voltage.

At this point I'm not challenging your conclusions,
but I think the analogies may not be stiff.

John Woodgate

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Aug 17, 1999, 3:00:00 AM8/17/99
to
<7pcddb$fpa$1...@nnrp1.deja.com>, Science Hobbyist <bbe...@microscan.com>

inimitably wrote:
> Skeptics state that it
>cannot have worked, since you'd need an immensely long
>dipole antenna hanging off your electric car or airplane.

Yagi invented his type of antenna in the course of 'power by wireless'
experiments.

John Woodgate

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Aug 17, 1999, 3:00:00 AM8/17/99
to
<7pccld$f1u$1...@nnrp1.deja.com>, Science Hobbyist <bbe...@microscan.com>

inimitably wrote:
>(Or perhaps I'm wrong about *ALL* of this
>stuff, and I simply have not found my glaring error.)

You may not be wrong, but what you have found may not be novel, just
that your way of describing it is not the usual one. I wonder if you are
thinking along these lines:

To take a practical example of a tuned circuit interacting with an
external field, consider the 'passive amplifier' or whatever name you
like to call it, which is a large coil tuned by a variable capacitor to
the AM broadcasting band. You stand an AM portable radio, with a ferrite
antenna, beside it and tune the radio to a weak station. When you tune
the large coil to the same frequency, the radio gets louder, maybe much
louder. (If the coupling is too close, the radio can be pulled off-
tune.)

What is happening? Well, the current in the large coil sets up a local
field which interacts with the transmitted field. Off-tune, the coil
current is weak and has little effect. But at resonance, it is much
larger, maybe 100 times larger, and it distorts the field pattern so
that the field is stronger in the neighbourhood of the coil than it
would be in the absence of the coil, but it's correspondingly weaker in
other places. The tuned circuit acts as a *field concentrator*, which is
a reasonably correct name for the device. There are no strange,
unexplained effects, but a demonstration of the device leads people to
look for concealed batteries etc., because on the face of it, a tuned
circuit cannot do what it clearly does do.

Roy McCammon

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Aug 17, 1999, 3:00:00 AM8/17/99
to
Science Hobbyist wrote:

> Good question. Let's see. If the EM system is being
> "illuminated" with propagating EM waves, and the
> waves have a certain power density P/(meter^2), then
> an ideal quarter-wave dipole antenna with an impedance-
> matched resistive load would intercept X watts, and we could
> calculate the "absorbtion cross-sectional area" of that antenna
> from X/P, and if we assume that this area is circular, then the
> "electrical size" of that antenna is SQRT(X/P/pi)

That sounds like a definition that could be
made to work, maybe. I guess you wouild specify
plane waves from a source very far away? It would
seam that highly directional antennas for have an
advantage over less directional. Also, I'm
having trouble visualizing a non resonant antenna.
A log periodic comes to mind, but it is really
a collection of stagger tuned resonant elements.

I guess you come have a whip that was very much
smaller than a wavelenght, but to match it to a
load you would wind up resonating it. Maybe that's
the question; how do you have a non resonent antenna
that is matched to its load?

> If we do the same for ANY antenna, we can figure out
> how "large" it is electrically, and compare it to the "size"
> of an ideal quarter-wavelength dipole.

So now what does the "actual" or "physical" size mean?

Greatest dimension. Diameter of a bounding sphere?

And then we would get data showing ratioes of electrical
size to physical size for various antennas.

Roy McCammon

unread,
Aug 17, 1999, 3:00:00 AM8/17/99
to

and of course, the large coil is physically large.

Lyle Koehler

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Aug 17, 1999, 3:00:00 AM8/17/99
to
Science Hobbyist wrote:
>
> In article <37B98A96...@mlecmn.net>,
> Lyle Koehler <ly...@mlecmn.net> wrote:
>
> > It's easy to fall into the trap of confusing voltage with power. A
> > high-Q tuned circuit in the presence of an RF field can deliver a high
> > voltage to an open circuit, but since power is E^2/R and since R is
> > infinite, the "captured" power is zero.
>
> That's what I thought initially. But look at my two examples.
> When I load the untuned system down to V= .707x,
> I get microwatts, but when I do the same with the tuned system,
> I get watts. This is extremely counterintuitive. Just by allowing
> a big voltage to build up, I should *NOT* be able to draw any
> more power from the antenna, right? That's an understandable
> conclusion. But unless there is a big error in my reasoning, that
> conclusion is wrong, and it is possible to draw far more power from a
> resonant receiver than can be drawn from an inductive or a capacitve
> pickup alone.
>

Maybe we're just disagreeing on semantics. I think of the antenna as a
source with a certain internal impedance (mostly reactance in the case
of electrically small antennas). In order to extract maximum power from
that source, it's necessary to provide a conjugate match between the
source and load impedance. If we can arbitrarily choose the load
resistance to match the "R" part of the antenna's impedance, all that is
needed is a series tuning element (inductor for a short whip; capacitor
for a small loop), and we're simply "resonating" the antenna. To match a
fixed load resistance like 50 ohms usually requires a somewhat more
complex circuit, but the net effect is the same. The circuit has to be
tuned for optimum power transfer, and a small antenna (if it's at all
efficient) will exhibit narrow bandwidth, meaning that it has a high Q.

You lose me with the synchronized b-field stuff. Sounds akin to the
"theory" of the crossed-field antenna, and I don't want to get into that
discussion. Catch a Poynting vector, put it in your pocket, etc.

Again, maybe we just disagree on what is "bizarre" Yes, it's hard to
visualize a small antenna with an effective area that is much greater
than its physical dimensions, but it's easy to build one. Going back to
RJELOOP3, let's increase the size of the loop to 3.16 meters square, and
make it from a single turn of 25 millimeter copper tubing. (The number
of turns in the loop has little effect on efficiency -- what counts is
the amount of copper.) Now the gain at 200 kHz is -36 dB, or
approximately 2.5e-4, and the effective area is about 45 square meters.
That's pretty good for a loop that has an enclosed physical area of only
10 square meters. And if we increase the size of the loop to 15 meters
(still only 1/100th of a wavelength) square, the calculated effective
area is about 4500 square meters -- almost 20 times the physical area.
That sounds pretty bizarre all right, but it's what one would expect
from some pretty standard antenna calculations.

There is an ongoing related thread on "capture area" in the
rec.radio.antenna newsgroup, and it's obvious from the postings that the
idea of a large effective area from a small antenna bothers people with
a lot more antenna experience than I have. And the confusion doesn't
apply just to electrically small antennas. I used to believe that my
homebrew 2-meter "collinear" antenna (actually a combination of
collinear and broadside elements backed by reflectors) was a better
"receiving" antenna than a Yagi with the same gain. Intuitively this had
to be correct. How could a skinny little Yagi capture as much signal as
that big bedspring-looking affair? Observations also seemed to confirm
this. The collinear picked up signals off the back and sides that a Yagi
couldn't hear. But in my age and wisdom(?) I now concede that the
homebrew collinear simply had a lousy front-to-back ratio and lots of
sidelobes.

Lyle, K0LR

http://www.computerpro.com/~lyle

James Meyer

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Aug 18, 1999, 3:00:00 AM8/18/99
to
On Tue, 17 Aug 1999 19:16:57 GMT, Science Hobbyist <bbe...@microscan.com> wrote:


>than its physical size. Another way to say it: at resonance,
>the particle grows to fill the electromagnetic "near field"
>volume. Obviously this only becomes significant for
>particles which are << than the wavelengths being
>absorbed.

A small particle or a photon cannot be used realistically in a thought
experiment as though they were just smaller versions of golf balls. Photons,
electrons, and atoms at temperatures other than absolute zero cannot be
described as having a fixed position. The "uncertainty principle" must be
considered. Those small particles have only a probability for being in a
particular place, and they also have a probability for being anywhere in a
volume much larger than their size would imply.

It's the interaction of the atom's "volume of probability" (tm) with the
photon's volume of probability that makes them appear to have a larger area of
interaction than their size could justify.

> And when applied to circuitry, it only becomes
>significant for small dipoles and loop antennas, where the
>physical size of the antenna is << than the wavelength
>being received.

No. You cannot apply the same theories that work for submicroscopic
particles to macroscopic things like antennas. The larger an object is, the
more likely it is to not occupy a volume of probability larger than its self.

I'm surprised I have to explain these simple things to a science guy.

Jim


Science Hobbyist

unread,
Aug 18, 1999, 3:00:00 AM8/18/99
to
Lyle Koehler <ly...@mlecmn.net> 08/17 4:46 PM wrote

> Maybe we're just disagreeing on semantics. I think of the antenna as a
> source with a certain internal impedance (mostly reactance in the case
> of electrically small antennas). In order to extract maximum power from
> that source, it's necessary to provide a conjugate match between the
> source and load impedance.

Right. With perfect impedance matching, the antenna should absorb
all of the energy that hits it. But if this is *just* impedance
matching, then we wouldn't expect to change the effective area of the
antenna by very much. A high-Q antenna can intercept far more than
just the EM energy that hits it. THAT'S the "magical" part.

It might not seem like magic if we only raise the Q a little bit; only
making our loop antenna behave a few times larger than normal. But
in theory we could be using superconductors and high-value capacitors with
vacuum dielectrics, and making the Q absolutely humongous, and increasing
the effective size of the antenna by an impressive extent. Imagine a
little bitty device that sits on your desktop and totally wipes out
longwave radio reception for thousands of feet all around (on one narrow
frequency, of course) because its effective area has grown to, say, 1/10
of a wavelength? The coil inside that device might have mega-ampere-turns
of flux spewing out of it (remember, this is theory only, and maybe
difficult to do in practice, even if we use superconductors.) Because
it is phase-locked with the incoming waves, any field it generates
is going to seriously distort the pattern of the incoming waves.

A high-Q antenna is an oscillator. It's driven by the incoming waves,
and then stores their energy. As far as our instruments are concerned,
a high-Q antenna is surrounded by a powerful AC EM field. Yes, the
energy for that field was gathered from a distant transmitter
rather than from a local power supply. And it seems like coincidence
that the field is phased just right to "cancel out" some the incoming
EM waves for many meters around. This is the "energy sucking"
phenomenon in action. I still say it's counterintuitive: build a
powerful oscillator and adjust its phase and frequency so that it
cancels out the energy of EM waves which happen to pass by... and
the missing energy ends up inside the little oscillator?!!! It's the
reverse of radio transmission. With proper phasing, one transmitter
can steal energy from another (if they are in each other's near-field
region). Or, one transmitter can create a big shadow in the pattern
of waves coming from another transmitter, and the missing energy is
absorbed.

(Nasty cackle) if a number of high-Q resonant antennas were set up
around any transmitter, in theory they could swallow the transmitter's
entire output, even though the oscillators might be physically so
tiny that they might be hard to find. To be oqaque to sodium-light,
the cloud of sodium gas really doesn't need that many atoms!


> > If that program does not include the effects of applying
> > a synchronised b-field to the nearfield region of the antenna loop,
> > then it does not include this bizarre "energy sucking" effect.
>
> You lose me with the synchronized b-field stuff.

If we imagine a hi-Q resonant loop-antenna to be an oscillator
which produces its own surrounding field, we will see that its
b-field is in the proper phase to cancel a portion of the incoming
waves (which really means "absorb them"). When the effective area
of the loop antenna is made larger, it's because of this "oscillator"
effect, not because we've matched the antenna to the load resistor.
Although in a certain sense we HAVE matched the antenna to the
load. We've matched it so well that the resistor is receiving
far more than just the EM waves that physically touch the antenna.

> Sounds akin to the
> "theory" of the crossed-field antenna, and I don't want to get
> into that discussion. Catch a Poynting vector, put it in your
> pocket, etc.

Now I'm wondering if the "CFA" people were actually just
building high-Q resonant loop antennas without realizing it?
Maybe the CFAs do work, but not for the reasons that their
supporters claim.

Here's one very interesting aspect of those two physics papers
mentioned in my article. They give diagrams of the Poynting
vector field surrounding the resonant particle. When an
EM plane wave illuminates a resonant particle, the fields of
the resonator superpose on the plane wave. The resulting
Poynting-flow is bent inwards so it flows directly into the
tiny resonator. If the fields created by the resonator are
fairly intense (meaning that Q is very high) and as a result
they fill a significant volume of space around the resonator
with fields which rival that of the plane wave, then that
volume becomes a sort of "lens" for the Poynting vector field.
The plane wave becomes focussed onto the resonant particle.

I bet the same thing happens with Yagi director-elements. They
set up their own fields which then divert the Poynting energy-
flow and focus it on the active element. This stuff about the
"energy sucking resonator" is simply a more powerful version of
the "director" element of a Yagi. (But when the resonator is far
smaller than the length of the received waves, and there is no
large metal element, there's just a tiny "dot" that is generating a
powerful field, and the energy flow is forced to focus upon that
little "dot.")


> There is an ongoing related thread on "capture area" in the
> rec.radio.antenna newsgroup, and it's obvious from the postings
> that the idea of a large effective area from a small antenna bothers
> people with a lot more antenna experience than I have.

I have very little antenna experience, so this "capture area
enhancement" only bothers my physics intuition. But bother it
does! Doesn't it mean that, if we are within maybe 0.1 wavelength
of an AM tower, and if we are allowed to used superconductors in
our antenna loop, that we can expand the "capture area" of our
little antenna-coil to such an extent that it absorbs almost the
entire output of that AM transmitter?!!! I can't help but think
that it's weird. It's only NOT weird if we use low-Q circuits.

In your example with the 25cm copper pipe, what if we wound a
100-turn square coil with that pipe, so it weighed hundreds of
pounds. At 200KHZ, couldn't we make a loop antenna that punches
an enormous hole in the pattern of any plane waves which happen
to be passing by?

> And the
> confusion doesn't apply just to electrically small antennas. I used
> to believe that my homebrew 2-meter "collinear" antenna (actually a
> combination of collinear and broadside elements backed by reflectors)
> was a better "receiving" antenna than a Yagi with the same gain.
> Intuitively this had to be correct. How could a skinny little Yagi
> capture as much signal as that big bedspring-looking affair?

Heh heh. We can use a large-area "solar cell", or we can use a little
bitty solar cell with a great big lens in front of it.


============================================================
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It only has about 50 people as subscribers so far. For info
on subscribing, see http://www.amasci.com/sci-list/sci-list.html
=============================================================


((((((((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))))))))
William J. Beaty SCIENCE HOBBYIST website
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EE/programmer/sci-exhibits science projects, tesla, weird science
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Science Hobbyist

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Aug 18, 1999, 3:00:00 AM8/18/99
to
In article <37ba0abb...@netnews.worldnet.att.net>,
notj...@worldnet.att.net (James Meyer) wrote: > On Tue, 17 Aug 1999
19:16:57 GMT, Science Hobbyist <bbe...@microscan.com> wrote: > > > And when

applied to circuitry, it only becomes > >significant for small dipoles and
loop antennas, where the > >physical size of the antenna is << than the
wavelength > >being received. > > No. You cannot apply the same
theories that work for submicroscopic > particles to macroscopic things like
antennas. The larger an object is, the > more likely it is to not occupy a
volume of probability larger than its self. > > I'm surprised I have
to explain these simple things to a science guy. My advantage is that I've
been reading those physics papers. Sometimes the wave physics works at the
atomic level and also at the macro-level. It's clear that this is a matter
of wave-models versus particle-models, and when the wavelength is long
compared to our instruments (or to our thought experiments' size), then the
wave-models dominate. I'm not saying that QM doesn't raise its head when
antenna theory is applied to atoms or to IR absorbtion by atomic clusters.
But it mostly applies to the quantization of the energy being stored, and
not to the shape of the EM fields surrounding the atoms. Although the atoms
emit and absorb distinct quanta, when those photons are flying between atoms,
they behave very much like radio waves. If I build an "energy sucking"
resonator, it acts like a single atom, but it's an atom which can store a
large number of quanta in a single narrow energy band. C. F. Bohren, "How
can a particle absorb more than the light incident on it?", Am J Phys, 51
#4, pp323 Apr 1983 H. Paul and R. Fischer "Light Absorbtion by a
dipole", SOV. PHYS. USP., 26(10) Oct. 1983 pp 923-926 ENERGY-SUCKING
ANTENNAS? http://www.amasci.com/tesla/tesceive.html ((((((((((((((((((((( (

Science Hobbyist

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Aug 18, 1999, 3:00:00 AM8/18/99
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In article <O1yMaoB7...@jmwa.demon.co.uk>, John Woodgate
<j...@jmwa.demon.co.uk> wrote: > <7pccld$f1u$1...@nnrp1.deja.com>, Science
Hobbyist <bbe...@microscan.com> > inimitably wrote: > What is happening?

Well, the current in the large coil sets up a local > field which interacts
with the transmitted field. Off-tune, the coil > current is weak and has
little effect. But at resonance, it is much > larger, maybe 100 times larger,
and it distorts the field pattern so > that the field is stronger in the
neighbourhood of the coil than it > would be in the absence of the coil, but
it's correspondingly weaker in > other places. The tuned circuit acts as a
*field concentrator*, which is > a reasonably correct name for the device.
There are no strange, > unexplained effects, but a demonstration of the
device leads people to > look for concealed batteries etc., because on the
face of it, a tuned > circuit cannot do what it clearly does do. Yes,
that's it exactly. One way to use a resonant antenna is to wind a small
coupling coil around the inductor in the resonator, so that
high-current/low-voltage energy can be tapped off. By putting the AM
receiver's loop antenna near the larger resonator, it acts as coupling. The
resonator works its magic by supplying an enlarged "collection area" for
incoming waves. Then the AM radio connects to it inductively. The device
can only divert energy, not create it. However, I'm amazed by the *size* of
the region of diverted energy. If the Q is very high, the device can divert
the RF from hundreds of feet around itself, limited only by the 1/4
wavelength radius of the nearfield region. In the AM band, the nearfield
region is around 300 feet in diameter. If I wasn't being an idiot, I might
have called it a "field concentrator" or an "RF lens" rather than an "energy
sucker." Got people's attention, though! :) In theory, if the "amplifier"
device had a high enough Q, the fields around it might become so intense that
it would kill the front end of the AM radio. In practice, I wouldn't be
suprised if this actually happened to people who live a few blocks from a big
AM tower. (Or maybe the coil within the "amplifier" would smoke!)
((((((((((((((((((( ( ( ( ( (O) ) ) ) ) ))))))))))))))))))) William
Beaty bbe...@microscan.com Software Engineer http://www.microscan.com
Microscan Inc., Renton, WA 425-226-5700 x1135

John Woodgate

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Aug 18, 1999, 3:00:00 AM8/18/99
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<37B9D991...@mmm.com>, Roy McCammon <rbmcc...@mmm.com>

inimitably wrote:
>and of course, the large coil is physically large.

Well, one uses a convenient cardboard box for the demo, maybe a cereal
box (still occupied!). So it's very small compared with a wavelength,
even at 1.6 MHz.

John Woodgate

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Aug 18, 1999, 3:00:00 AM8/18/99
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<7pdjer$b2f$1...@nnrp1.deja.com>, Science Hobbyist <bbe...@microscan.com>

inimitably wrote:
>(Or maybe the coil within the "amplifier" would smoke!)

It is interesting to look at the value of current in the final IF
transformer in a portable radio. The collector signal current may be 2
mA p-p and the loaded Q may be 100 (it ought to be less but selectivity
is more important that audio bandwidth!). So the current in the tuned
circuit is 200 mA p-p! In valve/tube receivers of yesteryear, currents
of greater than 2 A could occur, but the IF transformers were much
larger, of course.

NEW SUBJECT: Could you please check your newsreader settings, because
your posts are being received with the '>' quote marks scattered
throughout the lines, and that makes them very difficult to read.

Lyle Koehler

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Aug 18, 1999, 3:00:00 AM8/18/99
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Science Hobbyist wrote:

> It might not seem like magic if we only raise the Q a little bit; only
> making our loop antenna behave a few times larger than normal. But
> in theory we could be using superconductors and high-value capacitors with
> vacuum dielectrics, and making the Q absolutely humongous, and increasing
> the effective size of the antenna by an impressive extent. Imagine a
> little bitty device that sits on your desktop and totally wipes out
> longwave radio reception for thousands of feet all around (on one narrow
> frequency, of course) because its effective area has grown to, say, 1/10
> of a wavelength? The coil inside that device might have mega-ampere-turns
> of flux spewing out of it (remember, this is theory only, and maybe
> difficult to do in practice, even if we use superconductors.) Because
> it is phase-locked with the incoming waves, any field it generates
> is going to seriously distort the pattern of the incoming waves.
>

> (Nasty cackle) if a number of high-Q resonant antennas were set up


> around any transmitter, in theory they could swallow the transmitter's
> entire output, even though the oscillators might be physically so
> tiny that they might be hard to find. To be oqaque to sodium-light,
> the cloud of sodium gas really doesn't need that many atoms!
>

The popular NEC or MININEC-based antenna modeling programs will probably
let you simulate this. Download the demo for EZNEC, NEC4WIN or NF (NF is
a stripped-down version of AO 6.5, used for near-field RF safety
evaluation). I know that in AO (or NF), you can specify any of several
common wire materials or ideal, zero-loss wires. Set up one antenna in
NF as a source with one or more "sucker" antennas near it, and do a
near-field analysis. You can get a tabulation of the field strengths in
the vicinity of the antennas, as well as the details on the current
distributions in every "pulse" in each antenna.

> Now I'm wondering if the "CFA" people were actually just
> building high-Q resonant loop antennas without realizing it?
> Maybe the CFAs do work, but not for the reasons that their
> supporters claim.
>

My own belief is that they simply built a small, high Q, end loaded
dipole with a lot of feedline radiation. It's possible to get better
efficiency (hence higher gain and greater capture area) with a short
top-loaded vertical than with a loop of the same volume, and certainly
with less mass of copper. I used to have a copy of a paper, probably in
the IEEE Transactions on Antennas and Propagation from 30 or 40 years
ago, and probably by R. C. Hansen, that went through the math.
Unfortunately I can't find the paper and am too lazy to search for the
reference. It's just as easy nowdays to run a couple of models for the
particular antenna geometries of interest.

>
> > There is an ongoing related thread on "capture area" in the
> > rec.radio.antenna newsgroup, and it's obvious from the postings
> > that the idea of a large effective area from a small antenna bothers
> > people with a lot more antenna experience than I have.
>
> I have very little antenna experience, so this "capture area
> enhancement" only bothers my physics intuition. But bother it
> does! Doesn't it mean that, if we are within maybe 0.1 wavelength
> of an AM tower, and if we are allowed to used superconductors in
> our antenna loop, that we can expand the "capture area" of our
> little antenna-coil to such an extent that it absorbs almost the
> entire output of that AM transmitter?!!! I can't help but think
> that it's weird. It's only NOT weird if we use low-Q circuits.
>

Yep, you could absorb much of the power if you have a reasonably
efficient antenna (fairly large or very high Q) close enough to the
transmitter. But it would be easier to run a piece of coax:-) "Absorb"
may not be totally correct, either, because some (probably half) of the
power will be re-radiated. Again, this can be simulated with today's
modeling software if you really want to explore the effect.

> In your example with the 25cm copper pipe, what if we wound a
> 100-turn square coil with that pipe, so it weighed hundreds of
> pounds. At 200KHZ, couldn't we make a loop antenna that punches
> an enormous hole in the pattern of any plane waves which happen
> to be passing by?
>

It's easier to improve the efficiency of a small antenna by increasing
the size, which is admittedly cheating, than by trying to reduce the
losses to zero. That's because you have to contend not only with the
losses in the antenna itself, but in any object in the near field.
Ground losses are very significant in short verticals as well as in loop
antennas in close proximity to ground. That places a practical limit on
the efficiency attainable with very small antennas. No matter how high
you make the Q, the best gain you can achieve with a small antenna is
slightly less than that of a half-wave dipole. By the way, a 15 meter
square loop with 100 turns of 25 mm pipe has a self-resonance well below
200 kHz, so it would be a lousy antenna.

I have a LowFER beacon antenna that consists of a top-loaded vertical
less than 15 meters high, with a loading coil Q of around 600. The
actual Q of the antenna system is between 100 and 200, depending on time
of year and how long since the last rainfall. It's tuned to 186.75 kHz
and should have a reasonably large capture area, probably a few thousand
square meters. Does it create a "black hole" for LF? Nope. In fact,
because of re-radiation the signals on a nearby longwire receiving
antenna are enhanced at frequencies near 186.75, in the same way that
you can use a large passively-coupled loop to improve the sensitivity of
a transistor radio.

Rick Haub

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Aug 18, 1999, 3:00:00 AM8/18/99
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You know, this is all very interesting. Especialy since the power company in
my area just built a sub-station with lots of hi-tension wires running all
over the place about 200 yards from the building that my company currently
occupies. Perhaphs some experimentation is in order.

Rick

Gary Coffman

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Aug 18, 1999, 3:00:00 AM8/18/99