Light,Lazers and HF
 

On Thu, 11 Sep 2008 13:21:15 -0700 (PDT), Art Unwin
wrote:

Read your own question. *There is no such thing as a "straight
radiator" of light. *There is everything to do with wavelength or you
could never see light.

If you say so and are comfortable with that then stick with it !
My thoughts are with the reflector and it's design

Let's just confine this to light, wavelength, and reflection. Try
looking at yourself in a full wavelength mirror. It would be
somewhere between 450 and 650 nanometers wide or roughly the size of a
virus or bacteria.

Practicality demands a reflector vastly larger than that for simple
and ordinary usage. I seriously doubt you have seen a mirror smaller
than 20,000 times that size. Even so you wouldn't be able to see
anything more than your eye in it - or with advanced optics, your
face.

Would that larger mirror have any more gain that one that was one
thousandth its size? No, not to speak of in any practical sense.
Texas Instruments invented the DMD for today's projection TV systems
that use mirrors that small.... for one pixel of light. Their DMD
chip has a vast array of at least 1000000 of these mirrors. Most of
the light in the system is lost. Efficiency is thus very poor, but
that is not an economic issue.

In a way, it most conforms to the same issues of poor efficiency in a
small radiator: most of the RF power is wasted before it gets into the
sky. Unfortunately, for most practicing Hams, this is a very serious
economic issue.

Here's a practical challenge for the reader: Take a Christmas tree
bulb of 7.5W. Employing every trick of the trade of optics, how much
of that available power can you get into a 100 micron fiber optic?

73's
Richard Clark, KB7QHC

Light,Lazers and HF
 

Art Unwin wrote:
On Sep 11, 2:05?pm, wrote:
Art Unwin wrote:
On Sep 10, 10:05?pm, wrote:
Art Unwin wrote:
On Sep 10, 8:45?pm, wrote:
Art Unwin wrote:
What is the main factor that prevents HF radiation from focussing
for extra gain?

Money.

If you can afford to build a 20m parabola about 2,000 feet in diameter
and the place to mount it, you'll get lots of gain.

--
Jim Pennino

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Then are you saying it is the antenna size that is the main factor?.

Of course.

Everyone knows the gain of a parabola is directly proportional to
the size in wavelengths, or:

Not so!,

Well, yes, I guess that's true as only those with an education in
electromagnetics would know that.

So I doubt many participants in rec.folk-dancing would know that, but
this isn't rec.folk-dancing, though some posters here do seem to dance
around a lot.

--
Jim Pennino

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Yes Jim. Unless one accepts the weak force for what it is, what
creaates it

You mean the weak interaction which is often called the weak force or
sometimes the weak nuclear force which is due to the exchange of
W and Z bosons and which affects all left-handed leptons and quarks
and whose typical field strength is 10^11 times less than that of
the electromagnetic force?

What about it?


--
Jim Pennino

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Light,Lazers and HF
 

On Sep 11, 4:05*pm, wrote:
Art Unwin wrote:
On Sep 11, 2:05?pm, wrote:
Art Unwin wrote:
On Sep 10, 10:05?pm, wrote:
Art Unwin wrote:
On Sep 10, 8:45?pm, wrote:
Art Unwin wrote:
What is the main factor that prevents HF radiation from focussing
for extra gain?

Money.

If you can afford to build a 20m parabola about 2,000 feet in diameter
and the place to mount it, you'll get lots of gain.

--
Jim Pennino

Remove .spam.sux to reply.

Then are you saying it is the antenna size that is the main factor?.

Of course.

Everyone knows the gain of a parabola is directly proportional to
the size in wavelengths, or:

Not so!,

Well, yes, I guess that's true as only those with an education in
electromagnetics would know that.

So I doubt many participants in rec.folk-dancing would know that, but
this isn't rec.folk-dancing, though some posters here do seem to dance
around a lot.

--
Jim Pennino

Remove .spam.sux to reply.

Yes Jim. Unless one accepts the weak force for what it is, what
creaates it

You mean the weak interaction which is often called the weak force or
sometimes the weak nuclear force which is due to the exchange of
W and Z bosons and which affects all left-handed leptons and quarks
and whose typical field strength is 10^11 times less than that of
the electromagnetic force?

What about it?

--
Jim Pennino

Remove .spam.sux to reply.

No. You are referring to what Feynman brought about with his vector
scheme which analyses the progression of partical format.
The standard model of our Universe has four forces.
Gravity which is the weakest
The weak force a misnomer is the second weakest
The electromagnetic force and the strong force.
For a state of equilibrium all of these vectors must sum to zero.
The weak force can be ascertained from the sum of the other vectors
From Newtons law on action and reaction both the weak force and that
which produces it
is a combination of two forces that evolves from a single force.
Thus when you apply a time varying current to a non magnetic radiator
you also produce the weak force which is the Newton reaction force
which
is a rotating surface current which amateurs refer to as "skin depth"
which is not a homogenous
resistive skin but the Newton opposing current which is a requirment
for equilibrium.
When Yagi used a planar arrangement of parallel conductors parallel to
the ground surface he does
not include this weak force and just assumes that the arrangement is
one opposing the gravitational pull.
This is a good approximation but not totaly accurrate since the
arrangement is not in equilibrium which
is a requirement with respect to all the laws of the Masters including
Maxwell.
The inclusion of the weak force is the rotating force at right angles
ie the Foucault current ala skin depth
which is what a helicopter has at the rear to provide stabalization.
Thus when this force vector is added
to the gravitational force it tips the radiator as opposed to being
equal and opposite to the gravitational force
as is often surmised by physiscists. I t is this weak force that is
directed away from a radiator which also produces a magnet field
when in contact with a resting particle which has its own magnetic
field which was imposed on entry to Earth
and thus in conflict with the initial time varying field results in
the parting of the ways in the form of levitation.
When levitation is shown in experiments in high school you may
remember the difficulty of achieving stabalization
since the article levitated always want;'s to turn ala the circulating
field.
The above is How I see as the weak force in action with radiation tho
you will not see it in books as the weak
force has not been presented as I have above. Important note the two
vectors of the magnetic fields imp[osed upon the partical
creates a spinning motion as well as a elevating motion and it is this
combination applied to a static particle that profides a straight
line
ejection to the particle which is straight like the bullet of a rifle
and where the spin makes it impervious to gravity which is why some
tem it as a anti gravity force All the above is a result of my work
over the last few years and has not as yet been acknowledged as b eing
correct in the scientific world
unless an academic comes along with the same thinking for examination
an impossibility based on the not invented here syndrome.
A long answer to your question but a simple yes or no would not
involve sharing which is what I alway strive for despite the loose
mouths of naysayers

Because of my above findings I am comfortable calling the particles
neutrinos as nearly spent nuclear particals ejected from the suns
border
without spin which do arrive to alight on a diamagnetic material in
the Universe with varying intensity according to the suns 11 year
cycle
Best regards
Art Unwin KB9MZ.......XG

Light,Lazers and HF
 

On Thu, 11 Sep 2008 15:07:37 -0700 (PDT), Art Unwin
wrote:

...the weak nuclear force which is due to the exchange of
W and Z bosons and which affects all left-handed leptons and quarks
and whose typical field strength is 10^11 times less than that of
the electromagnetic force?

The standard model of our Universe has four forces.
Gravity which is the weakest
The weak force a misnomer is the second weakest
The electromagnetic force and the strong force.

Try reading the two again. They are identical. The only difference
is you don't know the magnitudes of those forces (the length of their
vectors) like Jim obviously does.

Gravity is abysmally pathetic where it needs several trillion tons of
earth's mass to keep us glued to the surface. If you were an electron
and earth was a proton, you couldn't survive being on the surface
without being crushed by the staggering electromagnetic force.

The Weak force, as Jim carefully explained, is only slightly more
powerful than gravity - which is to say feeble to 11 decimal places.

73's
Richard Clark, KB7QHC

Light,Lazers and HF
 

On Sep 11, 5:33*pm, Richard Clark wrote:
On Thu, 11 Sep 2008 15:07:37 -0700 (PDT), Art Unwin

wrote:
...the weak nuclear force which is due to the exchange of
W and Z bosons and which affects all left-handed leptons and quarks
and whose typical field strength is 10^11 times less than that of
the electromagnetic force?
The standard model of our Universe has four forces.
Gravity which is the weakest
The weak force a misnomer is the second weakest
The electromagnetic force and the strong force.

Try reading the two again. *They are identical. *The only difference
is you don't know the magnitudes of those forces (the length of their
vectors) like Jim obviously does.

Gravity is abysmally pathetic where it needs several trillion tons of
earth's mass to keep us glued to the surface. *If you were an electron
and earth was a proton, you couldn't survive being on the surface
without being crushed by the staggering electromagnetic force.

The Weak force, as Jim carefully explained, is only slightly more
powerful than gravity - which is to say feeble to 11 decimal places.

73's
Richard Clark, KB7QHC

I don't know what you are talking about
At the top I stated Gravity was the weakest force .At the bottom of
your post
you state gravity was the weakest force and the weak force was a bit
stronger,
again what I said.
So what are you talking about, a bunch of IFs. What exactly do you
want me to confirm or deny?

Light,Lazers and HF
 

There is obviously a lot of confusion between some of the posters that
need to be corrected
Mention has been made of a bosun' and higgs field as something as
being factual.
In fact it is very contraversal an d is only a theory that has not
been confirmed™
CERN experiments are trying to put something substantial behind this
theory but
nobody really knows the extent of a Higg field and nobody has caught a
bosun'
Feynman with his vectors took the notion that a additional particle
combination
provided mass, this at a time that neutrons were considered without
mass.
Feymans assumption lingers on inspite of the fact that it is now
proven that
neutrinos really do have mass. All of this talk is based around
something
that is not present on this earth, not seen thus not counted just
names
searching for a subject to be tagged upon.
Now we come to the subject of "wave length" as in radiation , the
subject of this post.
Wavelength only has meaning if a radiator only has two degrees of
freedom which means "straight".
But a wavelength can move in many directions and elevations such that
it has a shape of a sphere or worse.
To talk of something of" such and such" a wavelength does not pertain
to a straight line or a three
dimensional shape such as a cube or sphere so the idea of refering to
a wavelength as a linear length
is absolutely meaningles because one is using a three dimensional
object to describe a two dimensional linear dimention.
And for the last one I refer to Newtons law of action and reaction. On
this earth of ours there is no such thing as a single force
which is why Newton refers to "action": If one tries to pull a piece
of caramel apart there is not just one force at play but four fources
since one must include the right angle forces that is "necking" the
caramel at the center. Thus a force cannot exist in a straight line
but must include a rotational force for equilibrium. It is that action
which Newton is referring to and not a single straight vector
The confusion comes about when Newtons laws are paraphrased as a
"force" when it must state an "action"
My posting is clearly placed within the Earth's boundary so talk of
Quarks ,Bosun" Higgs field etc is clearly irrevalent to the subject
of radiation
unless it is a attempt to bait me or to create confusion about the
subject of radiation when its aim should be education and debate.
Art Unwin KB9MZ....xg

Light,Lazers and HF
 

Art Unwin wrote:
There is obviously a lot of confusion between some of the posters that
need to be corrected

Only one that I've seen.

Mention has been made of a bosun' and higgs field as something as

Bosun?

Are we in the Navy now?


--
Jim Pennino

Remove .spam.sux to reply.

Light,Lazers and HF
 

On Sep 11, 4:02*am, Jon Kåre Hellan wrote:
writes:
On Sep 10, 10:29*pm, Art Unwin wrote:
No. The shoebox size antenna would approximate an isotropic if it did
radiate. It would still have to be placed at the focal point of a very
large parabola due to the size of the wave length. Such an antenna, I
believe, on the island of Puerto Rico (the SETI antenna) although it
is currently used primarily as a receiving antenna. That parabola is
positioned to have a very high radiation angle and might not be be
that good for terrestrial DX.

I believe that hams once were allowed to use Arecibo for EME on 80m.

I wonder what the used at the focal point. Assuming a yago directed to
the center was impractical, next best choice would be a full wave loop
(in my opinion).

Light,Lazers and HF
 

On Sep 11, 9:18*am, Art Unwin wrote:
On Sep 11, 2:53*am, Jon Kåre Hellan wrote:





writes:
Roy Lewallen wrote:
wrote:

Of course.

Everyone knows the gain of a parabola is directly proportional to
the size in wavelengths, or:

G=10*log k(pi*D/L)^2

Where G= gain in DB over an isotropic, k ~ .55 for most real parabolas,
D is the diameter, and L is the wavelength (wavelength and diameter
in the same units.

So a 2,000 foot parabola on 20m would have just about 58db gain.

Hm. I get 47.

Roy Lewallen, W7EL

Hmm, when I use 14 Mhz and 6 decimal places I get 37; must have fat
fingered it the first time.

Going a different way, I also get about 37.

Aperture of a dish is the area, pi*r^2. r is about 14.2 wl, so area
is about 635 sq. wl.

Aperture of a dipole is 1/4 * 1/2 wl = 1/8 sq. wl.

That makes gain 635/(1/8) = 635*8, i.e about 5100 or just over 37
dBd. This assumes 100 % illumination of the dish, which we won't
achieve. So make it 35 dBd or so, i.e. 37 dBi. Using the o.p.'s
formula, I get 36.5 dBi. *

It's odd that pi is squared in the formula. The squared part must be
to account for the area of the dish, which is pi*r^2. Obviously, this
can has been compensated for by the choice of 'k'.

Whoaaa guys............!

*Let us think a bit more regarding the basics presented instead of
parrotting
dish's as used in the present state of the art.
Isn't a dish built around phase change of a half wave dipole in inter
magnetic coupling?
If I have a flash light that is focussed does this wavelength aproach
still apply?
*I thought it would be a question of action and reaction. Trow a ball
against the wall and it bounces back
in a reflective manner to the angle of velocity.
A dish as presently used changes the phase of a given signal to
reverse it's direction.
In physics we can also talk about mechanical force that rebound and
rebound has nothing to do
with wavelength! * * *If we consider radiation as being the projection
of particles instead of wavelike oscillation
then surely the size of the reflector is solely based on what can be
collected from the
*emmitter such that it rebounds to a point or a focussed form ?
*I ask the question as I know nothing about the reflective phenomina
of dish's tho I have visited
*the one in P.R. where the dish is formed with the knoweledge that the
radiation spreads out
according to the emmiter used and thus when it reaches the reflector
the unit strength is weaker which the
dish attempts to reverse by refocussing. But then I could be totally
in error thus the question to the experts
Best regards
Art Unwin KB9MZ
.- Hide quoted text -

- Show quoted text -

I think you cannot use the particle analogy with HF when dish size is
not greater than wavelength. For a small dish at HF, the waves will
simply bend around the dish and act as if it wasn't there. At much
higher frequencies, particle concepts become more accurate.

Light,Lazers and HF
 

On Sep 11, 12:28*pm, "Tom Donaly" wrote:
Roy Lewallen wrote:
[Slaps self upside the head] 47 dB for a 2000 meter dish, 37 dB for a
2000 foot dish. And that's why I didn't choose bridge design for a
career. . .

Roy Lewallen, W7EL

wrote:
Roy Lewallen wrote:
wrote:
Of course.

Everyone knows the gain of a parabola is directly proportional to
the size in wavelengths, or:

G=10*log k(pi*D/L)^2

Where G= gain in DB over an isotropic, k ~ .55 for most real parabolas,
D is the diameter, and L is the wavelength (wavelength and diameter
in the same units.

So a 2,000 foot parabola on 20m would have just about 58db gain.

Hm. I get 47.

Roy Lewallen, W7EL

Hmm, when I use 14 Mhz and 6 decimal places I get 37; must have fat
fingered it the first time.

Working backward from 47 I get a wavelength of 21 feet.

It's always dangerous to do math in public.
73,
* * *Tom Donaly, KA6RUH- Hide quoted text -

- Show quoted text -

Yes! I think it is best to just give the formula and tell the reader
to calculate!