jimp@specsol.spam.sux.com> wrote in message news:pq43l4-7k8.ln1@mail.specsol.com...

In article <tKzfi.17049$RX.4099@newssvr11.news.prodigy.net> you wrote:

jimp@specsol.spam.sux.com> wrote in message news:kop2l4-lla.ln1@mail.specsol.com...
Bill Habr <billhabr@sbcglobal.net> wrote:

jimp@specsol.spam.sux.com> wrote in message
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Bill Habr <billhabr@sbcglobal.net> wrote:

"Benj" <bjacoby@iwaynet.net> wrote in message
news:1182661489.785821.81800@q69g2000hsb.googlegroups.com...

j...@specsol.spam.sux.com wrote:

What he's describing isn't a helical antenna, it's a helically wound,
continuously loaded, short antenna.

That is correct. If the antenna had no pitch it would be termed the
DDRR antenna.
With a pitch J.D. Kraus terms it the "normal mode helix" which is
quite different from the usual helix that radiates out the end.

Benj


With no pitch it is a loop antenna

Maybe.

A helix with no (0) pitch is a loop. The helix starts at the feed point abd
returns to
it.
There would be no other element.

What part of the word "if" are you having a problem understanding?
So you want to talk about something other than what we are talking about?

Re-read (or maybe read for the first time) the next to last sentence in
the post that you originally replied to.

I am talking about x and am right about x if you want to talk about y and then say I am
wrong about x you have your head up your butt.

Why, what do my eyes see at the end of that sentence!

The phrase "DDRR antenna".

If it has a short by comparison linear element tangent to the loop,
it is a DDRR.

In a DDRR, the radiation comes from the short linear element and the
loop is just loading.

jimp@specsol.spam.sux.com> wrote in message news:l653l4-7k8.ln1@mail.specsol.com...
Bill Habr <billhabr@sbcglobal.net> wrote:

jimp@specsol.spam.sux.com> wrote in message news:nbp2l4-0c8.ln1@mail.specsol.com...
Bill Habr <billhabr@sbcglobal.net> wrote:

jimp@specsol.spam.sux.com> wrote in message
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Bill Habr <billhabr@sbcglobal.net> wrote:

jimp@specsol.spam.sux.com> wrote in message
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Bill Habr <billhabr@sbcglobal.net> wrote:

"Benj" <bjacoby@iwaynet.net> wrote in message
news:1182563824.001900.260800@q75g2000hsh.googlegroups.com...

Mark wrote:
Polarization of low frequency radio waves, in spite of
everyone pretending it happens, has always seemed to me to be
experimentally suspect.

Huh?
Ask any ham radio operator.

Um. Ok. I'll ask myself (WD8ASL). Lessee. I've got this 7 mHz
relatively small antenna. It's a normal mode helix mounted on a nice
long PVC pole. And the question in my mind was how should I mount it?
Does polarization really occur and create THAT much of an effect at
these wavelengths? A normal mode helix has a kind of donut pattern so
if you mount it flat (helix axis vertical) it is more or less an omni
pattern with a null directly overhead. And it matches the presumed
polarization you expect to receive. Mounted vertically however, you
can now rotate the antenna to use the side null to reduce
interference, but according to polarization expected it shouldn't pick
up squat. The actual measured results are it makes virtually NO
difference (except for the noise-nulling thing) which way you mount
it.

Well, the helical antenna does have, under the right dimensions, true
circular
polarization and if not it does approximate circular polarization so what
the
HELL
do
you
expect?

What he's describing isn't a helical antenna, it's a helically wound,
continuously loaded, short antenna.


Then it is a helical antenna; 'normal mode' (helix diameter is small compared
to
wavelength) helical antenna acts like a monopole antenna with circular
polarization,
when
the circumference is close to 1 wavelength it radiates in the 'axial mode'
with
close
to
circular polarization near the axis.

Semantics.

Not everyone calls a linear loaded element a "normal mode helix".

To say "it's a helically wound, continuously loaded, short antenna" is to say that
it
is a
helical antenna which is operating as a monopole, depending on dimensions its
polarization
can be true circular, elliptical or linear from the context it is clear that it is
either
circular or very close to it.

Am I going to have to post the equations to show what I mean.

Did you miss the 7 MHz part?

It would have to be close to 100 feet in diameter to get non-linear
polarization and you aren't mounting that on a "nice long PVC pole"
as he stated.

Care to post your calculations?

Sure.

The diameter of an axial mode helical antenna is typically on the
order of around a wavelength in diameter.

One wavelength at 7 MHz is about 140 feet.

(300/7)*3.28 = 140 feet

Well, DUH, but we are not talking about an AXIAL MODE we are talking about NORMAL MODE
for 7 Mhz .

Perhaps not "direct" enough for you, but: NMR, 21 cm hydrogen line,
blackbody spectrum at low temperature (eg microwave background radiation),
sufficiently Doppler-shifted to the red visible light being identical to
radio waves.

What I mean is it is well known that light frequency waves are not
continuous waves in space. They are rather limited pulses of energy
both in time and space.

Why do you say this is well known, since it isn't true, at least in the
sense that you imply? OK, a physically realisable EM wave - optical or
radio frequencies - is spatially and temporally limited, but that has
essentially nothing to do with photons. Wavefunction of X != X.

Consider an atomic dipole transition. The classical wave associated with
the photon is basically the same as the EM wave emitted by a short dipole
antenna. The photon - including all of the radiated energy - is absorbed
by a receiving atom in one particular direction. The ultimate is a photon
in a (unphysical) plane wave mode. The classical EM fields (effectively
the wavefunction) extend everywhere and everywhen. Look for the photon,
and find it in one spot and time. Try the physically realisable
approximation, and get a similar result. A "point-like" photon doesn't
imply a localised wavefunction.

Recommended reading: Lamb's classic "Anti-photon", App Phys B 60, 1995
iirc, and the special section on photons in Optics and Photonics News a
few years ago.

And oh yeah. Just how would one build a radio transmitter that had an
output of just ONE photon per second? :-)

Antenna and absorber surrounding it.

Timo A. Nieminen wrote:

Perhaps not "direct" enough for you, but: NMR, 21 cm hydrogen line,
blackbody spectrum at low temperature (eg microwave background radiation),
sufficiently Doppler-shifted to the red visible light being identical to
radio waves.

Microwave radiation as we've discussed DOES show polarization effects
so really isn't low enough in frequency to be "direct".

Originally
physicists thought light was waves like radio. But the photoelectric
effect showed that something weird was going on. For one thing the
energy of the "wave" was being absorbed in an extremely short time.
The energy in a continuous wave simply won't act like this.

No need to
review the photo-electric data but the bottom line is that light (and
much of the microwave stuff people propose here) is generated by
energy level transitions. EM absorption also results in energy level
transitions.

The question that arises is what if I have a RADIO
transmitter that is not using energy level transitions to create EM
waves. Is that the SAME?

What I mean is it is well known that light frequency waves are not
continuous waves in space. They are rather limited pulses of energy
both in time and space.

Why do you say this is well known, since it isn't true, at least in the
sense that you imply? OK, a physically realisable EM wave - optical or
radio frequencies - is spatially and temporally limited, but that has
essentially nothing to do with photons. Wavefunction of X != X.

No , what you say isn't true.

Wavefunctions have nothing to do with
reality. They are PROBABLITY functions. Yes probability tells you
something!

But it doesn't represent something as hard and fast as an
electric or magnetic field.

Radio waves do NOT appear to have the
rapid energy transfer that optical transitions do. Radio waves appear
to operate in the classical sense. So my question is: is that just
apparent or are there actually differences in the two cases.

Consider an atomic dipole transition. The classical wave associated with
the photon is basically the same as the EM wave emitted by a short dipole
antenna. The photon - including all of the radiated energy - is absorbed
by a receiving atom in one particular direction. The ultimate is a photon
in a (unphysical) plane wave mode. The classical EM fields (effectively
the wavefunction) extend everywhere and everywhen. Look for the photon,
and find it in one spot and time. Try the physically realisable
approximation, and get a similar result. A "point-like" photon doesn't
imply a localised wavefunction.

No but does a non-localized radio wave imply the ability to create
nearly instantaneous "photon" energy transfers from the wave to the
receiver?

The quantum dot thing sort of implies it does if the
frequency is submillimeter. OK. But that's pretty close to light, no?

Recommended reading: Lamb's classic "Anti-photon", App Phys B 60, 1995
iirc, and the special section on photons in Optics and Photonics News a
few years ago.

And oh yeah. Just how would one build a radio transmitter that had an
output of just ONE photon per second? :-)

Antenna and absorber surrounding it.

Well, that is the classic theory for light and that certain works in
that case. But back to the original question. IF one did that, has
anyone observed "photon" interactions (example being the reception of
energy in short periods of time, (much shorter than required for the
absoprtion of energy from the radio wave) with low frequency waves. I
don't think so. But maybe I'm wrong. Which is why I asked. The
quantum dot thing was good, but still doesn't really go far enough
IMHO.

I mean let's lay it right out here. I can generate a low frequency
radio wave with a MECHANICAL device! Is that device making photons?
Inquiring minds want to know!

So what? RF is polarised. Or are you claiming that radio waves are scalar
waves? Polarisation has nothing to do with quantisation; polarisation is a
classical phenomenon.

Experimentally, it does. Quantisation doesn't mean that the _wave_ is
discontinuous.

Why do you think that a radio transmitter doesn't use energy level
transitions? From a quantum picture, the energy level transitions are
pretty much the same as free-free transitions giving rise to continuous
spectra in visible light.

For EM fields created by RF sources to be somehow fundamentally different
from the EM fields created by higher frequency sources would require
classical electrodynamics to be fundamentally wrong. Parsimony suggests
classical EM + quantisation as the simplest explanation.

Oh? Do you mean that a physically realisable EM wave can be infinite in
space or time? Do you mean that a wavefunction of X _is_ the same as X?

Or are you claiming that energy being exchanged between an EM field and an
atom, experimentally observed to occur in < 10^-10 seconds (iirc, and
that's a 20 year old number), means that low-photon-number radiation comes
in discrete pulses of temporal length of less than 10^-10 seconds? If so,
that's simply wrong. Get hold of a decent book on QED and read.

Nothing to do with reality, according to you, it seems.

But it doesn't represent something as hard and fast as an
electric or magnetic field.

Take a monochromatic EM field. What is the energy density? What is
the probability of detecting a photon at a particular location? What is
the definition of a wavefunction? OK, there's stuff in the literature
about why the EM field can't be the wavefunction of a photon, but it
clearly tells you what the wavefunction of a photon is. And conversely,
photon detection, eg by a CCD, tells you stuff about an EM field.

Given that we know that, if the RF wave is quantised, the quanta are too
low energy to be individually observed, then there is little reason to
doubt that it is just apparent. There is also the matter of more direct
evidence, mentioned previously, eg NMR, 21cm line.

We observe observable effects of radio waves in the high photon number
limit. They behave very much like light visible light waves in the high
photon number limit. Why suspect a fundamental difference?

Why not? A non-localised visible light wave manages this just fine.

The quantum dot thing sort of implies it does if the
frequency is submillimeter. OK. But that's pretty close to light, no?

No, it isn't close to visible light. Visible light spans a mere octave;
orders of magnitude different is not "pretty close".

Take some mechanism by which you can generate RF EM waves, or visible EM
waves, or whatever frequency you want. Eg, acceleration of electrons.
Consider synchrotron radiation. Perhaps there is joy to be had with
Cherenkov radiation, too. Brehmsstrahlung.

So, assuming RF is quantised:

(a) explains the observations

(b) gives a unified framework for EM fields of all frequencies that is
well-verified experimentally

Assuming that RF is not quantised, but visible light is:

(a) explains the observations, apart from things such as, again, NMR, 21cm
line, etc

(b) demands some kind of magic transition between the two regimes

(c) Doppler shift makes (b) even more problematic.

Perhaps your anti-RF-photon stance is in part due to a lack of
appreciation of how far a purely classical description of visible
light can go, and how classical EM theory is used in the quantum realm? To
repeat: quantised != discontinuous.

Bill Habr <billhabr@sbcglobal.net> wrote:

jimp@specsol.spam.sux.com> wrote in message news:l653l4-7k8.ln1@mail.specsol.com...
Bill Habr <billhabr@sbcglobal.net> wrote:

jimp@specsol.spam.sux.com> wrote in message
news:nbp2l4-0c8.ln1@mail.specsol.com...
Bill Habr <billhabr@sbcglobal.net> wrote:

jimp@specsol.spam.sux.com> wrote in message
news:d5j2l4-4vk.ln1@mail.specsol.com...
Bill Habr <billhabr@sbcglobal.net> wrote:

jimp@specsol.spam.sux.com> wrote in message
news:03u0l4-r5t.ln1@mail.specsol.com...
Bill Habr <billhabr@sbcglobal.net> wrote:

"Benj" <bjacoby@iwaynet.net> wrote in message
news:1182563824.001900.260800@q75g2000hsh.googlegroups.com...

Mark wrote:
Polarization of low frequency radio waves, in spite of
everyone pretending it happens, has always seemed to me to be
experimentally suspect.

Huh?
Ask any ham radio operator.

Um. Ok. I'll ask myself (WD8ASL). Lessee. I've got this 7 mHz
relatively small antenna. It's a normal mode helix mounted on a nice
long PVC pole. And the question in my mind was how should I mount
it?
Does polarization really occur and create THAT much of an effect at
these wavelengths? A normal mode helix has a kind of donut pattern
so
if you mount it flat (helix axis vertical) it is more or less an
omni
pattern with a null directly overhead. And it matches the presumed
polarization you expect to receive. Mounted vertically however, you
can now rotate the antenna to use the side null to reduce
interference, but according to polarization expected it shouldn't
pick
up squat. The actual measured results are it makes virtually NO
difference (except for the noise-nulling thing) which way you mount
it.

Well, the helical antenna does have, under the right dimensions, true
circular
polarization and if not it does approximate circular polarization so
what
the
HELL
do
you
expect?

What he's describing isn't a helical antenna, it's a helically wound,
continuously loaded, short antenna.


Then it is a helical antenna; 'normal mode' (helix diameter is small
compared
to
wavelength) helical antenna acts like a monopole antenna with circular
polarization,
when
the circumference is close to 1 wavelength it radiates in the 'axial mode'
with
close
to
circular polarization near the axis.

Semantics.

Not everyone calls a linear loaded element a "normal mode helix".

To say "it's a helically wound, continuously loaded, short antenna" is to say
that
it
is a
helical antenna which is operating as a monopole, depending on dimensions its
polarization
can be true circular, elliptical or linear from the context it is clear that
it is
either
circular or very close to it.

Am I going to have to post the equations to show what I mean.

Did you miss the 7 MHz part?

It would have to be close to 100 feet in diameter to get non-linear
polarization and you aren't mounting that on a "nice long PVC pole"
as he stated.

Care to post your calculations?

Sure.

The diameter of an axial mode helical antenna is typically on the
order of around a wavelength in diameter.

One wavelength at 7 MHz is about 140 feet.

(300/7)*3.28 = 140 feet

Well, DUH, but we are not talking about an AXIAL MODE we are talking about NORMAL
MODE
for 7 Mhz .

Are you even reading any of these posts for context or just picking out
words at random to respond to?

--
Jim Pennino

Remove .spam.sux to reply.

Timo A. Nieminen wrote:

So what? RF is polarised. Or are you claiming that radio waves are scalar
waves? Polarisation has nothing to do with quantisation; polarisation is a
classical phenomenon.

I"m not "claiming" that, I'm only questioning it. The assertion has
been made that em waves consist of a scalar portion. The lower the
frequency the the great the scalar portion. I'm asking what is the
experimental evidence of this either way.

The standard answer (which
you provide in abundance here) is that "everybody knows" that light
behaves a certain way, therefore it's only "reasonable" that ALL EM
regardless of frequency behave the same way in spite of a total lack
of actual data. But is that so?

Experimentally, it does. Quantisation doesn't mean that the _wave_ is
discontinuous.

Nobody said that.

Why do you think that a radio transmitter doesn't use energy level
transitions? From a quantum picture, the energy level transitions are
pretty much the same as free-free transitions giving rise to continuous
spectra in visible light.

Well, this is what I'm having trouble getting my mind around. Atomic
energy levels are firmly established. Bandgap energy levels in certain
materials are also established. But if I generate EM with a mechanical
process, I guess you are saying that the energy levels are there, they
are just a continuum and hard to see. They are hard to see alright if
they don't exist! Is a continuum just "closely packed" energy levels
or it is another animal?

For EM fields created by RF sources to be somehow fundamentally different
from the EM fields created by higher frequency sources would require
classical electrodynamics to be fundamentally wrong. Parsimony suggests
classical EM + quantisation as the simplest explanation.

See, now here is where you get on the pulpit and start preaching!
Look at what you just said! First you are implying that if a new
theory somehow makes an older more "accepted" theory "fundamentally
wrong" then the new theory must be rejected for that reason.

This is
science? I don't think so. Excuse me I have to leave now to have some
blood drained out to remove the "bad humors" from my body. And then
you drag out Occam's Razor (suitably disguised with words, of
course). Hey, by Occam's razor all electric power distribution should
be using the Edison DC method because it's simpler.

Oh? Do you mean that a physically realisable EM wave can be infinite in
space or time? Do you mean that a wavefunction of X _is_ the same as X?

No.

Or are you claiming that energy being exchanged between an EM field and an
atom, experimentally observed to occur in < 10^-10 seconds (iirc, and
that's a 20 year old number), means that low-photon-number radiation comes
in discrete pulses of temporal length of less than 10^-10 seconds? If so,
that's simply wrong. Get hold of a decent book on QED and read.

I'm sorry I'm not as smart as you! [Oh man! I REALLY don't want to be
forced to go back and open up all those old books on quantum theory! I
was hoping this discussion would be fun!]

But yeah, If radio waves
are photons I'd expect some quantum effects. There is no reason to
assume the numbers are identical to light (the suggestion was
properties vary with frequency) but I'd expect something!

Nothing to do with reality, according to you, it seems.

If you wish to believe that God plays dice with the universe and all
fundamental things are "unknowable", that's fine. Everyone is entitled
to believe in their own religion.

But it doesn't represent something as hard and fast as an
electric or magnetic field.

Take a monochromatic EM field. What is the energy density? What is
the probability of detecting a photon at a particular location? What is
the definition of a wavefunction? OK, there's stuff in the literature
about why the EM field can't be the wavefunction of a photon, but it
clearly tells you what the wavefunction of a photon is. And conversely,
photon detection, eg by a CCD, tells you stuff about an EM field.

I take it that you do NOT believe the "stuff" in the literature that
suggests that the world is not at a fundamental level a probability
wave (whatever that is!)

Given that we know that, if the RF wave is quantised, the quanta are too
low energy to be individually observed, then there is little reason to
doubt that it is just apparent. There is also the matter of more direct
evidence, mentioned previously, eg NMR, 21cm line.

The MNR thing is an interesting suggestion I hadn't thought of, which
is indeed a step down in frequency from say the quantum dots. However,
I have to point out the connection in that case to internal atomic
energy levels. Quantum effects at the molecular level aren't the
question though. The question has to be what exactly would a DC photon
look like?

We observe observable effects of radio waves in the high photon number
limit. They behave very much like light visible light waves in the high
photon number limit. Why suspect a fundamental difference?

Standard argument. I lost a quarter over here, but I'll look for it
over there where the light is better! Why suspect a fundamental
difference? Why not?

Ever see those hippie bumper stickers that say
"Question Authority"?

Why not? A non-localised visible light wave manages this just fine.

Yes it does. And quite frankly in my mind the model of why it does
isn't clear at all. But why a non-localized radio wave should do so is
even LESS clear.

The quantum dot thing sort of implies it does if the
frequency is submillimeter. OK. But that's pretty close to light, no?

No, it isn't close to visible light. Visible light spans a mere octave;
orders of magnitude different is not "pretty close".

Puhlease! Let's not argue semantics! How many octaves from
submillimeter to VLF? Huh?
Now you are grasping at straws. If it walks like a duck etc.
Submillimeter walks like a duck!

Take some mechanism by which you can generate RF EM waves, or visible EM
waves, or whatever frequency you want. Eg, acceleration of electrons.
Consider synchrotron radiation. Perhaps there is joy to be had with
Cherenkov radiation, too. Brehmsstrahlung.

Sure, pick things up in the high frequency range. I thought you said
ANY frequency I want.

How about a multi-pole rotating machine?

Next
you'll be telling me a bowling ball has a finite probability of being
reflected from the edge of a table or all the air might end up in the
corner of the room. That is crap science and you know it.

So, assuming RF is quantised:

(a) explains the observations

SOME observations.

(b) gives a unified framework for EM fields of all frequencies that is
well-verified experimentally

In the "light" frequency range. The theory "only" requires an
assumption that it also holds for any other condition we choose to
specify (without any definitive experimental proof).

Assuming that RF is not quantised, but visible light is:

(a) explains the observations, apart from things such as, again, NMR, 21cm
line, etc

No, the theory doesn't necessarily prevent molecular interactions.

(b) demands some kind of magic transition between the two regimes

Ahem. "magic" is YOUR choice of demeaning words. I don't know about
where you are, but around here a frequency-dependent (which would also
mean energy-dependent) variation in properties usually isn't called
"magic".

(c) Doppler shift makes (b) even more problematic.

Yes. I think I agree with that.

Perhaps your anti-RF-photon stance is in part due to a lack of
appreciation of how far a purely classical description of visible
light can go, and how classical EM theory is used in the quantum realm? To
repeat: quantised != discontinuous.

If quantized != discontinuous then explain "particle" properties. What
you are saying is that probability waves are not discontinuous. And
I'm saying, what in the world does THAT say?
So do probability waves go to infinity? OR is that just what the
mathematics say? Is math more real than reality? Does God play dice?
Are frequency dependent effects "magic"?

Are there any reliable claims of scalar EM waves? There's no experimental
evidence for them. Stop and think: what are the definitions of E and B?
Think Lorentz force law. E is defined by F=Eq; F is a vector - how can E
be anything other than a vector?

"Total lack of actual data"? Bullshit. It's also more the other way
around, that "everybody knows" how RF radiation works, and assumes that
visible light behaves the same way. Specifically, note that you can
measure the phase of RF waves much more easily than visible light.

You implied it, with your talk of "photons -> classical wave comes in
short pulses".

Think of all the energy levels in an atom with energy higher than the
ionisation energy. They form a continuum. Theoretically,

For EM fields created by RF sources to be somehow fundamentally different
from the EM fields created by higher frequency sources would require
classical electrodynamics to be fundamentally wrong. Parsimony suggests
classical EM + quantisation as the simplest explanation.

See, now here is where you get on the pulpit and start preaching!
Look at what you just said! First you are implying that if a new
theory somehow makes an older more "accepted" theory "fundamentally
wrong" then the new theory must be rejected for that reason.

No. Go back and actually read what I wrote. I didn't write that any
theory must be rejected, just that one theory is simpler than another.

Bullshit. That's about the stupidest strawman I've seen erected in an EM
thread.

Well, you're the one who claimed what I typed was untrue. Was that just a
cheap debating tactic you're not willing to back up?

Btw, your old books on quantum theory might not cover it very well. As I
wrote: QED. Cohen-Tannoudji covers it well. Consider quantisation of plane
wave modes (monochromatic infinite plane waves, where the photon has
energy and (vector) momentum with zero uncertainty), where there is
absolutely _no_ localisation of the EM field (or the wavefunction of the
photon) in either space or time.

Assuming E=hf holds for RF, what is the energy involved? How do you
observe energy in those increments?

You're the one who claimed that wavefunctions have nothing to do with
reality.

Standard argument. I lost a quarter over here, but I'll look for it
over there where the light is better! Why suspect a fundamental
difference? Why not?

Why not? Because there is no experimental or observational evidence?
Because there is no adequate replacement theory for classical
electrodynamics?

Your standard argument is misleading. My argument as presented is more
along the lines of "I lost a quarter here, I'll look for it here." If your
contribution to the discussion will consist of crap like that, then fuck
off. If you want to engage in a serious discussion, then do so.