On Sep 11, 2:04*pm, Art Unwin wrote:
On Sep 10, 10:56*pm, wrote:





On Sep 10, 10:29*pm, Art Unwin wrote:

On Sep 10, 9:23*pm, 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?..
So my antenna which is physically small
can be focussed on a dish which would provide straight line radiation
or a radiation beam?
Working on a single element on the ground with a optimizer instead of
a half sphere I got a
straight vertical line at the sides which suggested a gun barrel
radiation with a perfect earth as the reflector.
Gain was around 8db vertical which is why the question regarding
focussing! If it was properly focussed the gain should be more.
2000 foot dish seems somewhat odd, probably based on a "straight"
wavelength and not a small volume in equilibriumas the directer
right?
Art

Let me ask the question another way. Whether it is believed or not,
if a 80 Metre antenna was compressed to the size of a couple of shoe
boxes
would the dish be reduced in size accordingly?
Regagards
Art- Hide quoted text -

- Show quoted text -

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.

The antenna at PR has a stable reflector and a moveable receiver
thus the take off angle depends on the angular position of the
receiver
and the center of the reflector. The receiver is moved regularly so
the
sky can be traversed for listening. This was the idea when the antenna
*was set up initialy by Princeton University before they gave up
possesion of it.
With respect to WL no facts have been presented to support that fact.
If you go back to the arbitrary border analysis a force thru the paper
of the center
of the border will present resultant forces around the outside of the
border representing
ripples on water in wave like fashion, that does not correlate to the
ejection
*of a particle thru a fissure in the border. Mixing apples and oranges
no less
Nuf said- Hide quoted text -

- Show quoted text -

That is interesting. I thought the PR dish was parabolic. As a
parabola, the reflected waves (or particles if you will) of a
transmitter at focal point can only traverse in one direction, that
is, in a direction parallel to the tangent of a line drawn at the
lowest point of the parabola. If the parabolic reflector is
stationary, how can transmitted waves/particles go in any direction
but straight up in that perpendiculr direction? If you move the focal
point as you say they do, then the antenna does not finction as
parabola anymore and gain should drop drastically, agree? I am afraid
I must be missing something and request your technical advice. Thanks.

wrote:

That is interesting. I thought the PR dish was parabolic. As a
parabola, the reflected waves (or particles if you will) of a
transmitter at focal point can only traverse in one direction, that
is, in a direction parallel to the tangent of a line drawn at the
lowest point of the parabola. If the parabolic reflector is
stationary, how can transmitted waves/particles go in any direction
but straight up in that perpendiculr direction? If you move the focal
point as you say they do, then the antenna does not finction as
parabola anymore and gain should drop drastically, agree? I am afraid
I must be missing something and request your technical advice. Thanks.

The Arecibo radio telescope has a spherical reflector, not parabolic.
This is mentioned on the official web page:

http://www.naic.edu/public/the_telescope.htm

It also gives details on how the telescope operates.

--
Mark Cudworth

I am running the numbers on several 10 meter OWA 6 element antennas
with boom lengths of 24 to 26 ft. Tools on hand are "Yagi Analyzer",
"Yagi for Windows" by Dean Straw, and the spreadsheets by W6NL.
Several designs look promising, but I've gotten myself confused about
how to correctly model the clamps. The official Hygain YO files from
Roger Cox are not consistant as to equivalent diameter or length in
comparing the 203BA, 204BA, and the 205CA.
"What's the problem?" you say. Well, I'd like to use the inboard
sections of some 204BA elements for the driven element and the first,
close-spaced director.
An email to ARRL Technical Services was not enlightening, and
re-reading Jim Lawson's and Dave Leeson's works did not give me that
warm, confidant feeling that I'd like.
Anyone care to enlighten me with actual numbers, or websites??
Gud Lk in the contest!

Mike W5CHR
Memphis Tenn

On Thu, 11 Sep 2008 16:14:56 -0700 (PDT), Art Unwin
wrote:

Try reading the two again. =A0They are identical. =A0The only difference
is you don't know the magnitudes of those forces (the length of their
vectors) like Jim obviously does.

I don't know what you are talking about

Two identical statements, one is yours. How is it that you don't
understand?

The electromagnetic vector for a 1V field imparts 100 Billion times
more force than the "weak force." This is why they call it "Weak."

The Gravity vector is weaker than that by far.

All of this has been known for years. The experiments at CERN are
merely adding precision to that number of 100 Billion to say it may
actually be 100.015 Billion instead (or perhaps 99.8992 Billion times
more force). This goal too, has been reported for years. One day in
the future they will know it to that higher precision which will allow
them to discern the finer degree of weaker Gravity's disturbance,
which, after all, is the whole point of this.

No one gives a **** about the Weak force. It is merely the universe's
S9+50dB noise from a 5th dimensional neighbor's aquarium heater that
is blanking out the S1 DX signal from a graviton.

73's
Richard Clark, KB7QHC

"Art Unwin" wrote in message
...
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

well, art, how dare you think we could be trying to bait you or create more
confusion. i hardly think we could possibly create more confusion than you
have right now. try to explain these for instance... if it takes that
magical mystery particle settling on diamagnetics to create an
electromagnetic wave, how does the sun which is all plasma create
electromagnetic waves? and if the weak force is so much stronger than
gravity, and it interacts with the multitude of these magical mystery
particles that spew forth from the sun how come we haven't collapsed into a
weak force black hole? it takes lots of mass to create a black hole because
gravity is so weak, but if the weak force is stronger than it should
collapse us even easier. and if the neutrino's well measured interaction
with matter is so weak it must take a huge number of them to be your magical
mystery particle so we should really have collapsed under their weak force a
long time ago! oh wait, maybe their weak force is what does spin so we are
really talking about a spindizzy effect that if captured would allow remote
manipulation of matter, i always wondered where Blish came up with that
device, maybe you have hit on the secret! come on art, the wx is going to
be bad across much of the country here this weekend and we need some good
entertainment!

On Sep 12, 6:18*am, "Dave" wrote:
"Art Unwin" wrote in message

David, what I have stated is based on known laws and phenomina and
started with the recognision
that applying a time varying field and radiators to a Gaussian field
equates to Maxwell's laws.
Right from the start you could not concentrate on proving or
disproving that statement !
Until you can determine whether that is correct or not you cannot
move forward.
As yet, nobody has disproved that statement with counter facts. If you
cannot explain that simple fact
you surely cannot understand Newtons laws and how the use of such laws
provide the presence
of eddy current which provides a skin depth of mechanical resistance.
I use the term mechanic
because I recognise the importance of the four forces in the standard
model and the Grand Universal Theory.
So until you are able to concentrate and tackle the Gauss and Maxwell
connection that I started with
there is no hope for you to procede in a scientific matter, and that
goes for every body, not just you.
Best regards
Art

On Fri, 12 Sep 2008 01:12:13 -0500, "Mike Lucas"
wrote:

"What's the problem?" you say. Well, I'd like to use the inboard
sections of some 204BA elements for the driven element and the first,
close-spaced director.

Hi Mike,

I would say "have at it," but what has this got to do with clamps?

They cannot present any perturbation to the calculations that wouldn't
be lost in the fourth right most digit after the decimal point. Even
more un-compelling, modeling probably wouldn't get you any closer to
reality than the second right most digit after the decimal point.

There are too many confounding properties of earth, nearby objects,
and the usual variability in materials and construction to imagine you
are going to both model and build one right out of the box, so to
speak.

On the other hand, actually setting your mind to it and doing it is
merely a matter of planning and performance right down to the size of
the clamp nuts. This is nothing more than a geometrical description
using wire sections of various diameters. The clamp is a half turn of
a loop of a certain wire diameter, and the nut is merely a wider wire
short section along the straight part of that half loop. Getting it
to wrap around an even thicker wire (the boom), and pierce thick wires
(the elements) will be a trick, and you will soon discover that you
have violated at least one rule of the MANA engine (about proximity
of, or overlapping segments). Myself, I would simply make the boom of
a series of sections, where the clamp area has a slightly greater
diameter.

This exercise is useful to do once for the drill. You get to learn
what counts and what does not, and then keep only those lessons that
actually offer something that lifts above the background noise of
mathematical error.

73's
Richard Clark, KB7QHC

"Richard Clark" wrote:
Hi Mike,

I would say "have at it," but what has this got to do with clamps?

Richard: Tnx for the post- I enjoy slogging through the math to 4 places,
but then I usually round off to the nearest 1/16th when building something.
My brain had become numb from particals (sic) with spin, dripping from
tilted elements. I decided to restart a construction project, just on the
odd chance that I'll get it finished and on the tower before (if) the next
Solar Cycle happens. So why not some poetry or at least free verse
next time???

Mike W5CHR
Memphis Tenn

"Art Unwin" wrote in message
...
On Sep 12, 6:18 am, "Dave" wrote:
"Art Unwin" wrote in message

David, what I have stated is based on known laws and phenomina and
started with the recognision
that applying a time varying field and radiators to a Gaussian field
equates to Maxwell's laws.
Right from the start you could not concentrate on proving or
disproving that statement !

around and around we go... i quoted the required passages from jackson and
ramo/whinnery/vanduzer to show that adding time to gauss'es law was
incorrect. the law is time independent, meaning it does not require a time
term, it applies for all time instantaneously and it is properly included in
maxwell's equations as is. your addition of 't' is not necessary. proof
is not necessary, it is by definition and intuitively obvious to anyone with
the proper background.

I have never built a yagi using Hygain elements, but I have built
some 6 element OWA's like you want to build. The effect of
the clamps will be larger than "4th digit", probably a couple of
inches at 28 MHz. But you can ssume to a very good approximation the clamp
will just shift the resonant freq of those elements by a certain amount.

When I built my OWA's I used DX engineering insulated element mounts. With
these, the SWR curve of the real antenna matched the tapered NEC2 model
perfectly. I didn't even need to adjust the length of the driven element.

If you were using a Hygain element for only the driven element, I would
just allow for a few inches of adjustment + or - (hose clamp on last segment),
and just adjust the tip length of the final antenna to get the correct
SWR curve. If you want to use Hygain elements for Dr and 1st Dir, just do
the same, but adjust the lengths of both Dr and 1stDir by the same amount.
In the OWA design changing the length of the Dr and 1st Dir is mostly
going to affect the matching of the antenna.

Tor
N4OGW