On Wed, 16 Mar 2005 05:21:29 GMT, "
wrote:

He infers that he has improved the design,
specifically with respect to F/B
What was it before and to what amount was it improved ?

Hi Art,

What are the answers to these same questions applied to your design?

73's
Richard Clark, KB7QHC

On Tue, 15 Mar 2005 22:35:18 -0800, Richard Clark
wrote:
On Wed, 16 Mar 2005 05:21:29 GMT, "
wrote:
specifically with respect to F/B
What was it before and to what amount was it improved ?
Hi Art,

What are the answers to these same questions applied to your design?

Tuff question. No doubt, not all is known about antennas....

If I remember correctly the worst point to the rear 180 degrees
was more than 40 db down. But I must point out that nobody
accepted my theoretical analysis regarding the phase/ current magnitude
theory and even tho my models show an INCREASE in lobe width because
it reflected a circle on the gain side one should certainly question what I
say.
There are many better educated people than I on this group and if not one
came forward and blest the theory then it would appear that my theory is
flawed,
my vector diagram is flawed and also my modelling is flawed. My only
disapointment was that none came forward to point out the flaw or just
assumed without mathematical reason that it must be flawed.
Yet at the same time many are anxious to find out how I managed
to lower the TOA. even in the face of presumed flawed analysis.
Weird. very weird yet again none declared it impossible
Regards
Art



"Richard Clark" wrote in message
...
On Tue, 15 Mar 2005 22:35:18 -0800, Richard Clark
wrote:
On Wed, 16 Mar 2005 05:21:29 GMT, "
wrote:
specifically with respect to F/B
What was it before and to what amount was it improved ?
Hi Art,

What are the answers to these same questions applied to your design?

Tuff question. No doubt, not all is known about antennas....

On Thu, 17 Mar 2005 04:13:02 GMT, "
wrote:
If I remember correctly

Hi Art,

No notes? No model? No data?

But I must point out that nobody
accepted my theoretical analysis regarding the phase/ current magnitude

What theory? You simply described a trivial draughting exercise.

My only
disapointment was that none came forward to point out the flaw or just
assumed without mathematical reason that it must be flawed.

Let's see, I gave you the rationale that supported your results, I
named the mathematical curve, and then pointed out the necessary
premise to arrive at the results.

Yet at the same time many are anxious to find out how I managed
to lower the TOA. even in the face of presumed flawed analysis.
Weird. very weird yet again none declared it impossible

This is more flawed remembrance.

73's
Richard Clark, KB7QHC

All understood so now we can put the thread aside
Art
"Richard Clark" wrote in message
...
On Thu, 17 Mar 2005 04:13:02 GMT, "
wrote:
If I remember correctly

Hi Art,

No notes? No model? No data?

But I must point out that nobody
accepted my theoretical analysis regarding the phase/ current magnitude

What theory? You simply described a trivial draughting exercise.

My only
disapointment was that none came forward to point out the flaw or just
assumed without mathematical reason that it must be flawed.

Let's see, I gave you the rationale that supported your results, I
named the mathematical curve, and then pointed out the necessary
premise to arrive at the results.

Yet at the same time many are anxious to find out how I managed
to lower the TOA. even in the face of presumed flawed analysis.
Weird. very weird yet again none declared it impossible

This is more flawed remembrance.

73's
Richard Clark, KB7QHC

On Thu, 17 Mar 2005 04:13:02 GMT, "
wrote:



Yet at the same time many are anxious to find out how I managed
to lower the TOA. even in the face of presumed flawed analysis.
Weird. very weird yet again none declared it impossible


Perhaps my pestering you for the "secret" to lower "TOA" without
changing the antenna height was too oblique to qualify as "declaring
it impossible."

Therefore, let me as my congressman would say (actually not *my*
congressman, he's not that bright), "I would like to revise and expand
my remarks: It's impossible."

Actually, it is possible to lower the takeoff angle (the elevation angle
at which the pattern is maximum) without changing the antenna height.
The method is to narrow the free-space elevation radiation pattern. For
example, modify the EZNEC example file W8JK.ez by changing the height (Z
coordinates) to 0.5 wavelength. The takeoff angle is 25 degrees. Delete
one of the elements to make a dipole and note that the dipole's takeoff
angle is 28 degrees. The lowering is due to the substantially greater
elevation directivity of the W8JK. There aren't too many modestly sized
horizontal arrays that have enough elevation directivity to make much of
a difference in takeoff angle, however, so the difference is generally
small at best. It's also interesting to note that the takeoff angle of
this dipole over real ground is 2 degrees lower than the takeoff angle
of the dipole over perfect ground.

But as we and others have pointed out before, lowering the "takeoff
angle" (as the term is used by modeling programs) doesn't guarantee
better DX performance, and really doesn't mean much at all. For example,
the modified W8JK has a gain of 5.66 dBi at an elevation angle of 10
degrees and 0.31 dBi at 5 degrees. If we change source 2 phasing to -144
degrees for a nominally unidirectional pattern (see the recent
discussion about the impact of current distribution on front/back
ratio), the takeoff angle rises slightly to 26 degrees. But the gain at
10 degrees elevation is now 6.55 dBi and at 5 degrees 1.15 dBi, both
greater than the W8JK with its lower takeoff angle. And at very low
elevation angles, the gain of the dipole over real ground is very nearly
the same as the gain of the dipole over perfect ground, despite the
difference in takeoff angles. At higher angles, the dipole over perfect
ground is better, despite its higher takeoff angle.

Actual gain at elevation angles of around 2 to 10 or 12 degrees is a
valid and useful measure of DX performance; "takeoff angle" isn't. But
based on past performance, I'm not holding my breath that we'll be
seeing any actual numbers from Art about his innovations.

Roy Lewallen, W7EL

Wes Stewart wrote:
On Thu, 17 Mar 2005 04:13:02 GMT, "
wrote:




Yet at the same time many are anxious to find out how I managed
to lower the TOA. even in the face of presumed flawed analysis.
Weird. very weird yet again none declared it impossible



Perhaps my pestering you for the "secret" to lower "TOA" without
changing the antenna height was too oblique to qualify as "declaring
it impossible."

Therefore, let me as my congressman would say (actually not *my*
congressman, he's not that bright), "I would like to revise and expand
my remarks: It's impossible."

"Roy Lewallen" wrote in message
...
Actually, it is possible to lower the takeoff angle (the elevation angle
at which the pattern is maximum) without changing the antenna height. The
method is to narrow the free-space elevation radiation pattern. For
example, modify the EZNEC example file W8JK.ez by changing the height (Z
coordinates) to 0.5 wavelength. The takeoff angle is 25 degrees. Delete
one of the elements to make a dipole and note that the dipole's takeoff
angle is 28 degrees. The lowering is due to the substantially greater
elevation directivity of the W8JK. There aren't too many modestly sized
horizontal arrays that have enough elevation directivity to make much of a
difference in takeoff angle, however, so the difference is generally small
at best. It's also interesting to note that the takeoff angle of this
dipole over real ground is 2 degrees lower than the takeoff angle of the
dipole over perfect ground.

But as we and others have pointed out before, lowering the "takeoff angle"
(as the term is used by modeling programs) doesn't guarantee better DX
performance, and really doesn't mean much at all. For example, the
modified W8JK has a gain of 5.66 dBi at an elevation angle of 10 degrees
and 0.31 dBi at 5 degrees. If we change source 2 phasing to -144 degrees
for a nominally unidirectional pattern (see the recent discussion about
the impact of current distribution on front/back ratio), the takeoff angle
rises slightly to 26 degrees. But the gain at 10 degrees elevation is now
6.55 dBi and at 5 degrees 1.15 dBi, both greater than the W8JK with its
lower takeoff angle. And at very low elevation angles, the gain of the
dipole over real ground is very nearly the same as the gain of the dipole
over perfect ground, despite the difference in takeoff angles. At higher
angles, the dipole over perfect ground is better, despite its higher
takeoff angle.




Actual gain at elevation angles of around 2 to 10 or 12 degrees is a valid
and useful measure of DX performance; "takeoff angle" isn't.

That is exactly what I pointed to in the discussion. The top half of the
forward
lobe of a directive array is of no use say for opening a band. The important
point
is the underside contour of the main lobe where there is useful gain at the
angles
that Roy stated. For instance; a 60 foot + boom yagi with a gain of around
16 dbi
will have a TOA at say 13 degrees but it is also possible to construct a
directive array
of 10 degrees TOA that has the same underside contour as the yagi design and
thus equal
in performance. The difference is that a yagi design has a fat lobe with
narrow beam width,
where asyou can construct a radiator or an array that has a larger beam
width,
but with a thinner lobe that covers the aforementioned degrees of coverage
required.
Another point of mention is that many associate low TOA with antenna height
but
without specificity with respect to feed point height or as in other cases
such as a top hat or "unused" array as with stacked antennas
For me it is a question of phase angle provided by a transmitting point
where its optimum angle is directly opposite the earths surface and
supplimented
by a secondary radiation of a similar phase, but to explain why
would be impossible with respect to this group so don't ask

One particular poster hit things right on the head when he referred to
resistive impedance
THRU OUT the length of any radiator./s, he obviously knows his stuff tho I
question
the thin wire aproach to accomplish this i.e. negate reactance



But
based on past performance, I'm not holding my breath that we'll be seeing
any actual numbers from Art about his innovations.



Just for me, try to hold your breath for ten minuits.
You well know that no figures are accepted by the know
alls on this group. Even observed tests undertaken are not accepted unless
the so called guru is actually present which would be impossible , since the
gurus
wish is to preserve their perceived stations and not subject to ridicule
On this actual thread I have given explanations and figures and only
ommited how I achieve it ,which I will save until I have completed pertinent
studies.
As a former engineer which apparently you say that you are one also, it is
important
to review and check your work several times to ensure that it is in
presentable state
to fellow engineers for review. One says that it is impossible, another
somehow
turns his responses to unfounded gibberish and another declares the whole
thing as hillarious and so on, such that any comment made, even when made
in approval,
is meaningless as comments made are emotional and without any technical
depth.
Art Unwin KB9MZ..............XG



Roy Lewallen, W7EL

Wes Stewart wrote:
On Thu, 17 Mar 2005 04:13:02 GMT, "
wrote:




Yet at the same time many are anxious to find out how I managed
to lower the TOA. even in the face of presumed flawed analysis.
Weird. very weird yet again none declared it impossible



Perhaps my pestering you for the "secret" to lower "TOA" without
changing the antenna height was too oblique to qualify as "declaring
it impossible."

Therefore, let me as my congressman would say (actually not *my*
congressman, he's not that bright), "I would like to revise and expand
my remarks: It's impossible."

On Thu, 17 Mar 2005 20:44:34 GMT, "
wrote:

For me it is a question of phase angle provided by a transmitting point
where its optimum angle is directly opposite the earths surface and
supplimented
by a secondary radiation of a similar phase,

My design is simpler and does it better.

but to explain why
would be impossible with respect to this group so don't ask

Hi Art,

Time has proven when we do ask, you can't answer - so your advice is
commendable on two counts.

You well know that no figures are accepted by the know
alls on this group.

You haven't offered any
1. Data;
2. Notes;
3. Models
and certainly no
4. Figures.

Even observed tests undertaken are not accepted unless
the so called guru is actually present which would be impossible

Then they are not "observed tests."

73's
Richard Clark, KB7QHC

On Thu, 17 Mar 2005 10:54:50 -0800, Roy Lewallen
wrote:

Actually, it is possible to lower the takeoff angle (the elevation angle
at which the pattern is maximum) without changing the antenna height.
The method is to narrow the free-space elevation radiation pattern. For
example, modify the EZNEC example file W8JK.ez by changing the height (Z
coordinates) to 0.5 wavelength. The takeoff angle is 25 degrees. Delete
one of the elements to make a dipole and note that the dipole's takeoff
angle is 28 degrees. The lowering is due to the substantially greater
elevation directivity of the W8JK. There aren't too many modestly sized
horizontal arrays that have enough elevation directivity to make much of
a difference in takeoff angle, however, so the difference is generally
small at best. It's also interesting to note that the takeoff angle of
this dipole over real ground is 2 degrees lower than the takeoff angle
of the dipole over perfect ground.

All true. I see my response was too encompassing. What I was trying
to refer to was Art's "magic" design.

To wit: "Would hams have an interest in a two element 20 M antenna
that have (sic) lower TOA than the norm, say 9 degrees instead of the
normal 14 degrees?"

I can't imagine anything that will make a 2 (or any other number)
element horizontal antenna of any configuration have a TOA of 9
degrees other than placing the array center at a height of ~105' above
real ground at 14 MHz.