"Roy Lewallen" wrote in message
...
wrote:
. . .
Now Roy I have a problem with what you are saying here
I spend hours modelling an array to lower the TOA or angle of max
radiation
which directly controls the main lobe dimension both in width and height.

And, as I've said quite a few times in one way or another, it's largely a
waste of time.

Why? A single word question
On what authority do you base that statement on?



I model an antenna array such that it emulates in a way a "stacked"
array where as low as a 9/10 degree TOA. The 3 db gain window is broader
in width and narrower
in height than say the normal array. It is this "TOA" that determines
what window we have and
where it hits the ionesphere which thus determines its point of arrival
on the earths surface

That's absolutely incorrect. All antennas radiate at all angles. The
ionosphere doesn't know or care at what angle your antenna is radiating
the most -- propagation will occur at the angle favored by the ionosphere
at the time. Your antenna's pattern doesn't dictate the geometry of the
path.

Not propagation which is the "environment" of all antenners in the
vicinity and the same
for all antennas at a particular time.
The ARRL clearly shows that it is the TOA that determines the range as it
were of one antenna
comparered to the others with different TOA.. For the life of me I cannot
concurr with the statement
as stated.

By speaking of "environment" I was not including propagation, and in
conforming to traditional usage, I also don't include propagation when
speaking of antenna patterns. An antenna pattern is a polar plot of the
field intensity of the antenna at a distant point, but with the assumption
that the propagation to all points is lossless. The actual signal received
at a distant point requires the inclusion of propagation effects. The
pattern is one element in the equation, but only one.

. . .


Is this the error of my ways where any change I make to an antennas
pattern
is rendered of no use because I must first find a way to manipulate
propagation
where all the action is really at?
. . .

Close. Sometimes two or more propagation modes are possible, such as
single and double hop. From here to say, New York, I might have single hop
at 3 degrees and double hop at 12. (Please forgive me if those particular
propagation angles can't really occur at the same time, but they're in the
ballpark.) It doesn't matter one iota what the angle of maximum radiation
from my antenna is. All that matters is the gain or field strength at
elevation angles of 3 and 12 degrees. All the rest of the radiation will
go some place besides New York. As a general rule, I can get a stronger
signal to New York with X dBi at 3 degrees than the same gain at 12,
because the single hop path loss is usually less. So it might pay me to
maximize my gain at that angle at the expense of 12 degrees. On the other
hand, the other station's antenna pattern is just as important -- if it
has a lot more gain at 12 degrees than 3, he might not hear me if I put
out most of my energy at 3 rather than 12. But in any case, it doesn't
matter how much I'm radiating at 1, 5, 7, or 15 degrees, or what my
antenna's maximum angle is. All that counts is how much I'm radiating at 3
or 12 degrees. Other than manipulating your antenna to radiate more or
less at those two angles, you don't get to "manipulate propagation" to
support other angles at a given time, frequency, and path. You're stuck
with those until the ionosphere changes. Knowledgeable DXers (which I'm
not) spend a lot of time working out what the angles will be for
propagation to various target locations, and how to design, build, and
switch antennas to maximize the amount of radiation at those angles.


I also want to make it clear that I appreciate your post which I see as
an attempt to clarify matters
that are presently being discussed ie.It is propagation and not the
antenna that determines the
TOA. Or "antenna pattern is determined by propagation" so that we
don't get hung up
on the term TOA

No, antenna pattern isn't determined by propagation.

Whoopee

The signal strength
at the other end of the path is determined by the gains of both the
transmit and receive antennas at the elevation angle of propagation, and
the loss along the path. Period. Notice that "takeoff angle" and "pattern"
didn't appear in that sentence. And you don't get to choose the angle of
propagation (unless more than one are supported at a given time, which is
only sometimes true, and then you can only choose between the supported
angles).

It is up to the user to design the antenna with the pattern of choice
and that is what I did. And you can do it to since you are familiar
with antenna programs. You just have to point the initial program so it
is able to spot what dimensions are required to produce the required
pattern.
Roy please go back to the top and answer that simple one word question
and let it all hang out
Best regards
Art


I suggest downloading the excellent, free, and easy to use propagation
software by Shel Shallon, W6EL, http://www.qsl.net/w6elprop/. In a few
minutes, you'll be able to see what angles are supported at a given time
and frequency for a given path.

Roy Lewallen, W7EL

wrote:
"Roy Lewallen" wrote in message
...

wrote:

. . .
Now Roy I have a problem with what you are saying here
I spend hours modelling an array to lower the TOA or angle of max
radiation
which directly controls the main lobe dimension both in width and height.

And, as I've said quite a few times in one way or another, it's largely a
waste of time.


Why? A single word question
On what authority do you base that statement on?

Because "takeoff angle" as you use the term does not bear a direct
relationship to the ability to communicate.

Roy Lewallen, W7EL

On Tue, 26 Apr 2005 19:15:44 -0700, Roy Lewallen
wrote:

wrote:
"Roy Lewallen" wrote in message
...

wrote:

. . .
Now Roy I have a problem with what you are saying here
I spend hours modelling an array to lower the TOA or angle of max
radiation
which directly controls the main lobe dimension both in width and height.

And, as I've said quite a few times in one way or another, it's largely a
waste of time.


Why? A single word question
On what authority do you base that statement on?

Because "takeoff angle" as you use the term does not bear a direct
relationship to the ability to communicate.

Right on.

Let's look at it this way. If I have an antenna with a "pencil beam"
and it's pointing at 90 degree azimuth and the station I want to
communicate with is at 0 degrees, I don't know of anyone who would say
that this is an optimum situation.

Yet, many (okay, one) would say that an antenna with (pardon me) a
"take off angle" of 3 degrees is *always* superior to one with a TOA
of 20 degrees, notwithstanding the fact that the desired station's
signal is maximum at 20 degrees.

This is like saying that I have room for a rhombic pointed at Asia so
I'm going to work my ass off optimizing it when all of the stations I
want to work are in Europe.

Why is this so? I'm completely baffled.

"Roy Lewallen" wrote in message
...
wrote:
"Roy Lewallen" wrote in message
...

wrote:

. . .
Now Roy I have a problem with what you are saying here
I spend hours modelling an array to lower the TOA or angle of max
radiation
which directly controls the main lobe dimension both in width and
height.

And, as I've said quite a few times in one way or another, it's largely a
waste of time.


Why? A single word question
On what authority do you base that statement on?

Because "takeoff angle" as you use the term does not bear a direct
relationship to the ability to communicate.

O.K. Roy if you are going to let this discussion revolve solely around the
term
of TOA which is a datum line around which the main lobe evolves,, A term you
have voiced
opposition to over the years and which you personally use in your own
antenna program design
then you will be succesfull in any debate regarding antennas. I have stated
many times that the
elevation angle denotes the line of maximum gain and the lobe that surrounds
this angle denotes
the area of communication ability represented by the oft used term of the 3
dB window.
You are refusing to accept the use of this term because of personal
emotional reasons,
that you only use the term under protest because of commercial reasons and
now as a basis for rejecting.
new knoweledge supplied by computor programs.,. presumably by clinging to
"all is known" mantra
I will never persuade you to view this thread with an open mind.
You have stated that TOA as I describe the term does not bear a direct
"relationship "
to the ability to communicate which obviously must relate to a part of a
post where you
envision that you have accomplished a "gottcha".
One person stated that everybody knows that I am right which I question,
especially
since you have now come forward with contrary thoughts.
Roy, there can be no debate if one must always accept
all your statements in Pope like fashion that excludes discussion.
Best regards
Art
Roy Lewallen, W7EL

wrote:
. . .
You are refusing to accept the use of this term because of personal
emotional reasons,
that you only use the term under protest because of commercial reasons and
now as a basis for rejecting.
new knoweledge supplied by computor programs.,. presumably by clinging to
"all is known" mantra
I will never persuade you to view this thread with an open mind.

. . .

Roy, there can be no debate if one must always accept
all your statements in Pope like fashion that excludes discussion.
Best regards

This sort of response doesn't constitute a debate, and it's nothing I
see any need or desire to respond to.

Roy Lewallen, W7EL

On Wed, 27 Apr 2005 03:11:34 GMT, "
wrote:

a basis for rejecting.
new knoweledge supplied by computor programs

Hi Art,

More baloney cut thick. You have NOWHERE offered any discussion of
ANY new knoweledge (sic); but you hug such manufactured sentiments
like an emotional life preserver.

You rctleeny challngeed Roy for his athortuy. You wloud do well to
leran spllenig bfoere ripeteang that aigan.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Wed, 27 Apr 2005 03:11:34 GMT, "
wrote:


a basis for rejecting.
new knoweledge supplied by computor programs


Hi Art,

More baloney cut thick. You have NOWHERE offered any discussion of
ANY new knoweledge (sic); but you hug such manufactured sentiments
like an emotional life preserver.

You rctleeny challngeed Roy for his athortuy. You wloud do well to
leran spllenig bfoere ripeteang that aigan.

What I want to know is how we are going to alter reality when the
computer program shows it is wrong!




- Mike KB3EIA -