I did rotate it and placed it on the ground, the gain dropped
by 4db and the circular lobe
pointed straight up. Some time I will look at same at 1 WL
Art
"Cecil Moore" wrote in message
...
wrote:
If the phases and and magnitudes of the paired elements
are exactly the same, then radiation to the rear is zero.

If you rotate the elements by 90 degrees, can you make the
radiation toward the ground zero?
--
73, Cecil http://www.qsl.net/w5dxp


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O.K..O..K Seems like everybody has forgotton the basics of the polygon of
forces
and other uses of vector so I will go over the basics.
At the age of 14 yearsI entered the School of Engineering and Navigation
where they hashed things from first principles, Since I had little schooling
during those war years it gave me an accelerated course on what I had missed
during those schoolless years which meant a lot of homework and I had to
work like hell.
From the name of the school it was evident that I would get a quick
introduction
on vectors for forces and navigation
.. This went as follows:
When you swim across a swimming pool then you can swim point to point.
If you swim across a river and tried to swim point to point you finish up on
the
other side but down, stream thus to get to the original point of the
endeavor you
must swim upstream. If you are a ship or a plane it is obvious that you
must have enought fuel
to get from point to point so this becomes very important.
Thus going back to the river swim you can draw a vector or line
that follows the path you took first to cross the river. Since you have
units such as time and distance
you can draw that line in scalar form. Then you add on to the tail end of
the line the journey upstream
again in scalar form which will be something less than a 90 degree angle.
If you then look back at the point that you started from it becomes obvious
that when you swim across stream
the angle you must follow is the angle which is shown from the beginning of
the triangle to
the point that you finished up. Next time you are on a plane look downwards
and pick up the flight pattern
of small private planes and you will see that their flight path is different
from the angle projected by the fuselage
All this is in accordance with Newton's law that 'every action has an equal
and opposite reaction.'
Now look below at my original post to what I said and you will see that I
applied a scalar drawing that consisted
of many scalae directions in the same way a sailing ship would do if it had
to keep changing
direction to get to shore. The first vector drawn for an element with known
phase and current was drawn
which happened to be a vertical line of known length. The next line was then
added at the end
to reflect the current and phase of the next element chosen and then onto
the next element chosen.
But this element presented a phase and current that was equal and opposite
to the one previously drawn
which meant that I was back to the tail end of my first vector chosen ! Thes
two elements are termed destructive
In fact this happened several times
where vectors cancelled each other so we are just left with a singe vector
in our scalar drawing .This
meant to get back to the point of origin and remembering Newton's law
previously alluded to the scalar
drawing it represents a vector that is equal to the starting vector drawn,
THE SAME PHASE and same
CURRENT. Thus the polygon reflects an array where the phase is constant but
the currents are ADDITIVE
This represents the radiation pattern of a figure eight EXCEPT all the
radiation is now to one
side of the feed point and comprising of a single and larger circle.
All of this reflects exactly what I stated below except I assumed that the
pologon phase drawing was
already known to all, for which I apologise.
With NEC I constructed a model that closely followed this format though
the real world did not
make elements exactly equal but when I rehashed in my mind the basic
priciples the polygon aproach verified
that this aproach does give extraordinary front to back/rear figures that
gave rise to mistrust of the
softwear being used where you may remember that I commented on a model that
I made and where
the response was that the f/b was to high a point that had troubled me for
many a month.
Sorry for the long winded response which reflects what I have gone thru with
my postings which
apparently projected me as a total fool that gave rise to dirisive
comments.
Now I ask again, is there any written work that pertains to max gain and f
to b/rear being on the same frequency?
Best regards to all, no hard feelings
Art KB9MZ................XG




" wrote in message
news:dySVd.30807$r55.174@attbi_s52...
I have just come to realise that if one drew a polygon of element phases in
a array
and all elements were 180 degrees to its companion element and excluding
the
driven element, the max gain and max front to back will occur at the SAME
frequency!
Until now I was of the understanding that these two max figures could not
occur at
the same frequency. Is there anything written about this possibility?
Regards
Art

Art

If your question is "is there any written work that pertains to how gain
and sidelobes are related", the answer is Yes. I dont know where back
issues of the IRE Proceedings can be found. But, the Proceedings of the
Professional Group on Antennas will have so much information on current
distribution on a planer array that you may not have enough time left to
read it all.
The current distribution across an antenna aperature has been studdied
very seriously.

I am not qualified to discuss phased arrays. I am convinced that max gain
will not be acheived with the same current distribution as for minimum side
lobes. I realize that you write only "back lobes". But, thats a side lobe
at that special angle
I am rather simple minded when it comes to phased arrays. I use Referance
Data For Radio Engineers as a referance book. It has alot of information on
phased arrays. I suspect all the information I have has already been
concidered by you.

Jerry


" wrote in message
news:2w_Xd.52445$Ze3.8223@attbi_s51...
O.K..O..K Seems like everybody has forgotton the basics of the polygon of
forces
and other uses of vector so I will go over the basics.
At the age of 14 yearsI entered the School of Engineering and Navigation
where they hashed things from first principles, Since I had little
schooling
during those war years it gave me an accelerated course on what I had
missed
during those schoolless years which meant a lot of homework and I had to
work like hell.
From the name of the school it was evident that I would get a quick
introduction
on vectors for forces and navigation
. This went as follows:
When you swim across a swimming pool then you can swim point to point.
If you swim across a river and tried to swim point to point you finish up
on the
other side but down, stream thus to get to the original point of the
endeavor you
must swim upstream. If you are a ship or a plane it is obvious that you
must have enought fuel
to get from point to point so this becomes very important.
Thus going back to the river swim you can draw a vector or line
that follows the path you took first to cross the river. Since you have
units such as time and distance
you can draw that line in scalar form. Then you add on to the tail end of
the line the journey upstream
again in scalar form which will be something less than a 90 degree angle.
If you then look back at the point that you started from it becomes
obvious that when you swim across stream
the angle you must follow is the angle which is shown from the beginning
of the triangle to
the point that you finished up. Next time you are on a plane look
downwards and pick up the flight pattern
of small private planes and you will see that their flight path is
different from the angle projected by the fuselage
All this is in accordance with Newton's law that 'every action has an
equal and opposite reaction.'
Now look below at my original post to what I said and you will see that I
applied a scalar drawing that consisted
of many scalae directions in the same way a sailing ship would do if it
had to keep changing
direction to get to shore. The first vector drawn for an element with
known phase and current was drawn
which happened to be a vertical line of known length. The next line was
then added at the end
to reflect the current and phase of the next element chosen and then onto
the next element chosen.
But this element presented a phase and current that was equal and opposite
to the one previously drawn
which meant that I was back to the tail end of my first vector chosen !
Thes two elements are termed destructive
In fact this happened several times
where vectors cancelled each other so we are just left with a singe vector
in our scalar drawing .This
meant to get back to the point of origin and remembering Newton's law
previously alluded to the scalar
drawing it represents a vector that is equal to the starting vector drawn,
THE SAME PHASE and same
CURRENT. Thus the polygon reflects an array where the phase is constant
but the currents are ADDITIVE
This represents the radiation pattern of a figure eight EXCEPT all the
radiation is now to one
side of the feed point and comprising of a single and larger circle.
All of this reflects exactly what I stated below except I assumed that the
pologon phase drawing was
already known to all, for which I apologise.
With NEC I constructed a model that closely followed this format though
the real world did not
make elements exactly equal but when I rehashed in my mind the basic
priciples the polygon aproach verified
that this aproach does give extraordinary front to back/rear figures that
gave rise to mistrust of the
softwear being used where you may remember that I commented on a model
that I made and where
the response was that the f/b was to high a point that had troubled me for
many a month.
Sorry for the long winded response which reflects what I have gone thru
with my postings which
apparently projected me as a total fool that gave rise to dirisive
comments.
Now I ask again, is there any written work that pertains to max gain and f
to b/rear being on the same frequency?
Best regards to all, no hard feelings
Art KB9MZ................XG




" wrote in
message news:dySVd.30807$r55.174@attbi_s52...
I have just come to realise that if one drew a polygon of element phases
in a array
and all elements were 180 degrees to its companion element and excluding
the
driven element, the max gain and max front to back will occur at the SAME
frequency!
Until now I was of the understanding that these two max figures could not
occur at
the same frequency. Is there anything written about this possibility?
Regards
Art

Yes I have those reference books but I do not have access to IRE procedings.
My quest was not an easy one and I reflected long as to why the NEC model
did not reflect an absolute zero Front to back. On reflection I realised
that a straight
element in an array is not necessarily the most efficient radiator. Then you
have the position
that a deformed radiator must have a definite coupling on other elements as
shown by Moxon
to have a resistive impedance, he used the bending of elements to pursue
this.
And there are other things to be concerned about such as element diameter
change as we move
away from the center as well as the element structure that is tubular and
not solid which would portray
a different aproach with respect to skin resistance. One thing I did look at
was the difference in F/B
when I went for maximum gain and the change that occured when I went for
maximum F/B and I was
surprised to see the F/R increase at a large rate and reach its maximum of
more than
50 percent improvement ( actually 100 % improvement for the low TOA )at the
loss of less than
one half db loss in gain because the range of maximum gain was reduced. In
retrospect this is not
surprising as the frontal lobe became larger in diameter at a lesser
percentage rate of what was
taken from the rear

Hopefully the weather will change soon so I can see exactly what is
happening with a full scale
array
Regards
Art

"Jerry Martes" wrote in message
news:Mf0Yd.43497$uc.34067@trnddc01...

Art

If your question is "is there any written work that pertains to how gain
and sidelobes are related", the answer is Yes. I dont know where back
issues of the IRE Proceedings can be found. But, the Proceedings of the
Professional Group on Antennas will have so much information on current
distribution on a planer array that you may not have enough time left to
read it all.
The current distribution across an antenna aperature has been studdied
very seriously.

I am not qualified to discuss phased arrays. I am convinced that max
gain will not be acheived with the same current distribution as for
minimum side lobes. I realize that you write only "back lobes". But,
thats a side lobe at that special angle
I am rather simple minded when it comes to phased arrays. I use
Referance Data For Radio Engineers as a referance book. It has alot of
information on phased arrays. I suspect all the information I have has
already been concidered by you.

Jerry


" wrote in
message news:2w_Xd.52445$Ze3.8223@attbi_s51...
O.K..O..K Seems like everybody has forgotton the basics of the polygon of
forces
and other uses of vector so I will go over the basics.
At the age of 14 yearsI entered the School of Engineering and Navigation
where they hashed things from first principles, Since I had little
schooling
during those war years it gave me an accelerated course on what I had
missed
during those schoolless years which meant a lot of homework and I had to
work like hell.
From the name of the school it was evident that I would get a quick
introduction
on vectors for forces and navigation
. This went as follows:
When you swim across a swimming pool then you can swim point to point.
If you swim across a river and tried to swim point to point you finish up
on the
other side but down, stream thus to get to the original point of the
endeavor you
must swim upstream. If you are a ship or a plane it is obvious that you
must have enought fuel
to get from point to point so this becomes very important.
Thus going back to the river swim you can draw a vector or line
that follows the path you took first to cross the river. Since you have
units such as time and distance
you can draw that line in scalar form. Then you add on to the tail end of
the line the journey upstream
again in scalar form which will be something less than a 90 degree angle.
If you then look back at the point that you started from it becomes
obvious that when you swim across stream
the angle you must follow is the angle which is shown from the beginning
of the triangle to
the point that you finished up. Next time you are on a plane look
downwards and pick up the flight pattern
of small private planes and you will see that their flight path is
different from the angle projected by the fuselage
All this is in accordance with Newton's law that 'every action has an
equal and opposite reaction.'
Now look below at my original post to what I said and you will see that I
applied a scalar drawing that consisted
of many scalae directions in the same way a sailing ship would do if it
had to keep changing
direction to get to shore. The first vector drawn for an element with
known phase and current was drawn
which happened to be a vertical line of known length. The next line was
then added at the end
to reflect the current and phase of the next element chosen and then onto
the next element chosen.
But this element presented a phase and current that was equal and
opposite to the one previously drawn
which meant that I was back to the tail end of my first vector chosen !
Thes two elements are termed destructive
In fact this happened several times
where vectors cancelled each other so we are just left with a singe
vector in our scalar drawing .This
meant to get back to the point of origin and remembering Newton's law
previously alluded to the scalar
drawing it represents a vector that is equal to the starting vector
drawn, THE SAME PHASE and same
CURRENT. Thus the polygon reflects an array where the phase is constant
but the currents are ADDITIVE
This represents the radiation pattern of a figure eight EXCEPT all the
radiation is now to one
side of the feed point and comprising of a single and larger circle.
All of this reflects exactly what I stated below except I assumed that
the pologon phase drawing was
already known to all, for which I apologise.
With NEC I constructed a model that closely followed this format though
the real world did not
make elements exactly equal but when I rehashed in my mind the basic
priciples the polygon aproach verified
that this aproach does give extraordinary front to back/rear figures that
gave rise to mistrust of the
softwear being used where you may remember that I commented on a model
that I made and where
the response was that the f/b was to high a point that had troubled me
for many a month.
Sorry for the long winded response which reflects what I have gone thru
with my postings which
apparently projected me as a total fool that gave rise to dirisive
comments.
Now I ask again, is there any written work that pertains to max gain and
f to b/rear being on the same frequency?
Best regards to all, no hard feelings
Art KB9MZ................XG




" wrote in
message news:dySVd.30807$r55.174@attbi_s52...
I have just come to realise that if one drew a polygon of element phases
in a array
and all elements were 180 degrees to its companion element and excluding
the
driven element, the max gain and max front to back will occur at the
SAME frequency!
Until now I was of the understanding that these two max figures could
not occur at
the same frequency. Is there anything written about this possibility?
Regards
Art

Sorry, Art, but the reason I don't appreciate your ideas isn't because I
don't understand vectors or analysis from first principles or because I
have some sort of prejudice against something in your background. It's
simply that you're unable to communicate your ideas in a way I can
understand them and, for all your many postings, I've yet to see any
data that show you've done something extraordinary. I can only speak for
myself, but suspect that some others might be in the same boat.

Roy Lewallen, W7EL

wrote:
O.K..O..K Seems like everybody has forgotton the basics of the polygon of
forces
and other uses of vector so I will go over the basics.
At the age of 14 yearsI entered the School of Engineering and Navigation
where they hashed things from first principles, Since I had little schooling . . .

Well we shall see Roy, but I find it hard to believe that you
with your antenna knoweledge plus being an engineer do
not understand vectors. I can only believe that American
education skirts this issue but then all of my engineering books
including those by known antenna engineering gurus dwell
upon it as well as authors in subjects such as classical
electromechanical fields.
Frankly, I see you as an expert in the field with long experience
and as such feel that all is known about antennas and you
cannot contemplate the idea that this is not so and you of all
people missed the importance of what I stated. This is very much
like the editing of a movie when it is found that the most interesting parts
finished up on the cutting room floor as it was deemed insignificant.
If what I state is confirmed then I will present it to the Radcom people
since QST is now firmly in the hands of experts that believe all is known
and has lost touch with the experimentor to which many of the ham
fraternity still belong.
I am aware that to some I am a poor communicator, but I went out of
my way to clearly inform people on the subject of vectors and
carefully tied the subject back to my original post such that those
with a non science background can follow step by step the trend of
thought of my original posting.
Regards
Art

"Roy Lewallen" wrote in message
...
Sorry, Art, but the reason I don't appreciate your ideas isn't because I
don't understand vectors or analysis from first principles or because I
have some sort of prejudice against something in your background. It's
simply that you're unable to communicate your ideas in a way I can
understand them and, for all your many postings, I've yet to see any data
that show you've done something extraordinary. I can only speak for
myself, but suspect that some others might be in the same boat.

Roy Lewallen, W7EL

wrote:
O.K..O..K Seems like everybody has forgotton the basics of the polygon of
forces
and other uses of vector so I will go over the basics.
At the age of 14 yearsI entered the School of Engineering and Navigation
where they hashed things from first principles, Since I had little
schooling . . .

On Thu, 10 Mar 2005 20:30:15 GMT, "
wrote:

Well we shall see Roy, but I find it hard to believe that you
with your antenna knoweledge plus being an engineer do
not understand vectors.

This in response to Roy's post that states in part:

"...but the reason I don't appreciate your ideas isn't because I don't
understand vectors."

[snip]


I am aware that to some I am a poor communicator,

Here is the problem, simply stated.


but I went out of
my way to clearly inform people on the subject of vectors and
carefully tied the subject back to my original post such that those
with a non science background can follow step by step the trend of
thought of my original posting.

We don't need a long convoluted pseudo treatise on vectors, give us
some raw meat that simply states what it is that you're trying to/are
doing.

And, I have to ask since it is the subject, why is necessary or
important to have max gain and F/B at the same frequency?

Oh come on Wes look at your last posting where you poked fun at the idea of
a polygon phasor array. And look at the other postings where it was obvious
that many were not familiar with the same and needed more direction. Look at
Roy,
he admitted he knows nothing about the subject
which when he next argues with the like of Cecil and others I will now have
to think twice instead of accepting his typical
riposte that he supplies. But I give Roy credit for being honest in the face
of personal embarassment regarding his lack of knoweledge
You say it was not necesary to provide a long convoluted pseudo treatise on
vectors but many asked for it and you made a joke of the idea,
Regarding front to rear occuring at the same frequency. An operator wants as
much gain as possible when communicating
so he does not need to resort to more power than needed. For best
communication it is nice to block of interference to the rear and thus he
needs best front to rear at the frequency of communication even tho it is of
interest that he had better rejection at a lower frequency. The fact of the
matter is that it is not the frequency being used, he has to live with a
lesser value of rejection, your opinion may well be different.

Now you also remarked that you do not want explanations, just the meat. I
gave what you call a "treatise" that explained the theoretical
underpinnings of what I have stated. It would be unwise at this point to
declare success without not only having a NEC model to confirm it but also a
20 meter antenna and not say a 144 meg equivalent. Today we had snow, wind
and rain so I could not complete the job.If by chance the antenna gives a
third aproval i.e.Nec model then polygon discussion plus the antenna then I
will forward it to RADCOM for peer review. It is at that time you can vent
your displeasure that you rejected my offer to share the actual mathematical
and physical findings. If you were looking for a way to undermine what I had
stated then my " treatise" now arms you with the knoweledge to disprove what
I have stated as it is one factor that convinces me of my origonal findings.
If you need more information regarding vectors I will be happy to aid you in
your quest
Regards
Art...KB9MZ....XG

"Wes Stewart" wrote in message
...
On Thu, 10 Mar 2005 20:30:15 GMT, "
wrote:

Well we shall see Roy, but I find it hard to believe that you
with your antenna knoweledge plus being an engineer do
not understand vectors.

This in response to Roy's post that states in part:

"...but the reason I don't appreciate your ideas isn't because I don't
understand vectors."

[snip]


I am aware that to some I am a poor communicator,

Here is the problem, simply stated.


but I went out of
my way to clearly inform people on the subject of vectors and
carefully tied the subject back to my original post such that those
with a non science background can follow step by step the trend of
thought of my original posting.

We don't need a long convoluted pseudo treatise on vectors, give us
some raw meat that simply states what it is that you're trying to/are
doing.

And, I have to ask since it is the subject, why is necessary or
important to have max gain and F/B at the same frequency?

Thank you for your polite response. Hopefully the written description of my
thought processes will satisfy a few tho not probably all
Regards
Art
" wrote in message
news:dySVd.30807$r55.174@attbi_s52...
I have just come to realise that if one drew a polygon of element phases in
a array
and all elements were 180 degrees to its companion element and excluding
the
driven element, the max gain and max front to back will occur at the SAME
frequency!
Until now I was of the understanding that these two max figures could not
occur at
the same frequency. Is there anything written about this possibility?
Regards
Art

Art Unwin wrote:
"I have just come to realise that if one drew a polygon of element
phases in an array and all elements were 180 degrees to its companion
element and excluding the driven elemment, the max gain and max front to
back will occur at the same frequency!"

Would an antenna made entirely of pairs of identical out of phase
elements be a good antenna?

A "polygon of element phases" must refer to the resultant current in
each element and their combined effect at a point (P) for example in
the far field. Art must have resolved and composed vectors or phasors at
some time. The resultant of any number of vectors can all add to zero or
to some other number and direction. A zero sum often happens in physics
when systems are in equiblirium. Newton said that any action results in
an equal and opposite reaction. Application of a new force often causes
no loss in equilibrium, just a corresponding added reaction.

The reflected wave from an antenna may change in magnitude in proportion
to an incidebt wave yet be nearly exactly equal in magnitude and
180-degrees out of phase with the incident wave, if the reflection is
perfect.

A polygon is a closed plane bounded by straight sides. It can represenht
forces.

Art asked if there were anything written about complete front to back
cancellation in two radiators carrying oppositely directed signals if I
understood the question. Indeed Kraus of W8JK fame has a lot to say
about the possibility.

Kraus writes about an "Array of Two Driven 1/2-wavelength El;ements.
General Case with Equal Currents of Any Phase Relation." in his 1950
edition of "Antennas".

It includes on page 294, field patterns for physical spacings and feed
phasings. For example, at a spacing of 1/8-wavelength and a phasing of
135-degrees, there is complete cancellation in one direction while there
is maximum radiation in the opposite direction.
That`s the good news. Now the bad.

On page 297 Kraus says:
"However, in the flat-top (an advantage placing all elements at maximum
height) antenna such losses may have considerable effect on the gain (as
the feedpoint resistance is very low). Therefore, the question of losses
and of radiating efficiency will be treated in this section in
connection with a discussion of arrays of two closely spaced,
out-of-phase elements. The term "closely-spaced" will be taken to mean
that the elements are spaced 1/4 wavelength or less."

Then, Kraus shows another fly in the ointment on page 300:

"Hence the Q for 1/8 wavelength spacing is about four times the Q for
1/4 wavelength spacing. Very large Q indicates a large amount of stored
energy near the antenna in proportion to the energy radiated per cycle.
This also means that the antenna acts like a sharply tuned circuit."

So much for bandwidth!



Best regards, Richard Harrison, KB5WZI