Vertical Antenna Performance Question
 

OK, I apparently drifted off the beaten path plus I seem to be
experiencing some serious brain fade.

What I was doing was preparing a short presentation for new hams on
the subject of vertical antennas. I was using EZNEC to produce some
antenna pattern graphics. It was then that I noticed that when I
overlayed the pattern from a vertical half wavelength dipole with that
of a horizontal half wave dipole at the same center height over real
ground that the pattern from the vertical was completely enclosed by
the horizontal dipole pattern, at least broadside to the horizontal
dipole that is. The vertical dipole pattern definitely showed a lower
angle of peak radiation but no greater gain a low angles than the
horizontal dipole.

At first, seeing the vertical dipole gain the same as the horizontal
dipole, even at low elevation angles, was a little confusing but I had
just scanned a bit of text on vertical antenna operation including
calculation for reflected waves and stuff like the pseudo Brewster
angle.

But then... I remembered talking to a couple guys in Germany on 75
meters the previous evening. From my location here in Missouri, I was
hearing their signals on my 75 meter inverted L much stronger at 10 to
20 over S9 than on my dipole at S4 to S5. They noted the same
difference in performance between the two antennas. As both the
Dipole height and the top of the inverted L were at 50 feet, I thought
this was a reasonable comparison. Also, the dipole is in the clear,
resonant, and has been performing as well or better than other
horizontal dipoles used by other hams in this area.

Furthermore, my experience switching between horizontal and vertical
antennas on 75 meters matched that of other guys with both. I was
starting to wonder why the mismatch between the theory I was familiar
with and my experiences.

Jumping back in to the text books and spending some time 'googling'
for more info I found nothing to conflict with the material I had
previously covered. That was disconcerting. About the only glimmer
of a solution to the question popped up when I looked at papers on
ground or surface wave propagation. There were some vague comments
about diffraction that seemed to indicate one of the loss factors
involved with ground wave propagation is that some of the signal does
not get diffracted low enough to keep in from being 'lost' to sky wave
radiation.

As I continued chasing that thought, I found that discussions of sky
wave propagation ignored ground wave and discussions of ground wave
propagation considered sky wave as lost RF.

Now, after all that windup, what am I missing? I acknowledge ahead of
time that I may be a dummy so don't bother explaining that to me. Why
do reasonable size vertical antennas with proper radial systems under
them outperform horizontal dipoles for DX operation for typical ham
antenna support structure heights of 50 feet or so?

The interesting question then: Is the improved performance of
vertical antennas over horizontal dipoles on 75 meters at DX distances
due to a combination of direct radiation plus radiation from the
ground in the area of strong ground wave strength out hundreds of
meters? Is the ground wave leakage providing additional low signal
strength in both transmit and receive?

Gary - N0GW

Vertical Antenna Performance Question
 

On Wed, 13 Feb 2008 20:58:31 -0800 (PST), N0GW
wrote:

It was then that I noticed that when I
overlayed the pattern from a vertical half wavelength dipole with that
of a horizontal half wave dipole at the same center height over real
ground that the pattern from the vertical was completely enclosed by
the horizontal dipole pattern, at least broadside to the horizontal
dipole that is. The vertical dipole pattern definitely showed a lower
angle of peak radiation but no greater gain a low angles than the
horizontal dipole.

Hi Gary,

You have so much left unsaid, that it is shooting in the dark.
However, proceeding with that risk in mind....

A vertical dipole described above is not the vertical antenna that you
describe following:
The interesting question then: Is the improved performance of
vertical antennas over horizontal dipoles on 75 meters at DX distances
due to a combination of direct radiation plus radiation from the
ground in the area of strong ground wave strength out hundreds of
meters? Is the ground wave leakage providing additional low signal
strength in both transmit and receive?

Better? You are relying too heavily on anecdotal reports.

For one, I seriously doubt you compared a 75M vertical dipole to a 75M
horizontal dipole in your lecture - no one in your audience would have
the financial clout to go there I suspect. That vertical dipole tip
would have to be hoisted quite a distance to see that the bottom tip
wasn't buried in the earth.

The next problem is height (again) and how it contributes to (or
subtracts from) gain as that varies. There is no "similar" comparison
between the two. You could model and present variations on horizontal
dipole elevation alone for two hours, much less both of them.

Rule 1 of presentations: Don't give them off the cuff unless you are
prepared to follow the surprises.

Rule 2: If you are willing to follow the surprises; then you aren't
really giving a presentation.

73's
Richard Clark, KB7QHC

Vertical Antenna Performance Question
 

N0GW wrote:
OK, I apparently drifted off the beaten path plus I seem to be
experiencing some serious brain fade.

What I was doing was preparing a short presentation for new hams on
the subject of vertical antennas. I was using EZNEC to produce some
antenna pattern graphics. It was then that I noticed that when I
overlayed the pattern from a vertical half wavelength dipole with that
of a horizontal half wave dipole at the same center height over real
ground that the pattern from the vertical was completely enclosed by
the horizontal dipole pattern, at least broadside to the horizontal
dipole that is. The vertical dipole pattern definitely showed a lower
angle of peak radiation but no greater gain a low angles than the
horizontal dipole.

That's because the energy radiated at lower angles with vertical
polarization is actually absorbed and dissipated in the ground, while
very little of the horizontally polarized antenna energy is.

At first, seeing the vertical dipole gain the same as the horizontal
dipole, even at low elevation angles, was a little confusing but I had
just scanned a bit of text on vertical antenna operation including
calculation for reflected waves and stuff like the pseudo Brewster
angle.

But then... I remembered talking to a couple guys in Germany on 75
meters the previous evening. From my location here in Missouri, I was
hearing their signals on my 75 meter inverted L much stronger at 10 to
20 over S9 than on my dipole at S4 to S5. They noted the same
difference in performance between the two antennas. As both the
Dipole height and the top of the inverted L were at 50 feet, I thought
this was a reasonable comparison. Also, the dipole is in the clear,
resonant, and has been performing as well or better than other
horizontal dipoles used by other hams in this area.

Furthermore, my experience switching between horizontal and vertical
antennas on 75 meters matched that of other guys with both. I was
starting to wonder why the mismatch between the theory I was familiar
with and my experiences.

Tom Rauch, W8JI, has the capability to run some pretty good comparisons
under near-textbook conditions, and he's consistently observed the same
thing on 160 and 80.

Jumping back in to the text books and spending some time 'googling'
for more info I found nothing to conflict with the material I had
previously covered. That was disconcerting. About the only glimmer
of a solution to the question popped up when I looked at papers on
ground or surface wave propagation. There were some vague comments
about diffraction that seemed to indicate one of the loss factors
involved with ground wave propagation is that some of the signal does
not get diffracted low enough to keep in from being 'lost' to sky wave
radiation.

As I continued chasing that thought, I found that discussions of sky
wave propagation ignored ground wave and discussions of ground wave
propagation considered sky wave as lost RF.

Now, after all that windup, what am I missing? I acknowledge ahead of
time that I may be a dummy so don't bother explaining that to me. Why
do reasonable size vertical antennas with proper radial systems under
them outperform horizontal dipoles for DX operation for typical ham
antenna support structure heights of 50 feet or so?

The interesting question then: Is the improved performance of
vertical antennas over horizontal dipoles on 75 meters at DX distances
due to a combination of direct radiation plus radiation from the
ground in the area of strong ground wave strength out hundreds of
meters? Is the ground wave leakage providing additional low signal
strength in both transmit and receive?

The short answer is that I don't think anyone really knows. I'm
convinced that the program accurately calculates the field from the
antenna and environment specified by the model. But there are some
pretty significant ways in which the model doesn't represent reality.
EZNEC uses the NEC ground model which is highly simplified - its ground
is perfectly flat, homogeneous to an infinite depth, and infinite in
extent. Real ground is curved and stratified with many layers of
sometimes highly differing conductivity and permittivity. Besides the
deficiency of the ground models, there might be some interesting
phenomena like ground wave energy following the ground for a while, then
launching some distance from the antenna. This wouldn't be modeled
properly by EZNEC or NEC. And although polarization is rotated during
ionospheric propagation, maybe there's some inherent advantage to
launching a vertically polarized signal. EZNEC and NEC make no attempt
at modeling propagation. Anecdotal evidence seems to find more of a
disparity between model results and observations at low frequencies (80
meters and below) than higher frequencies. Whether this is due to the
greater ground skin depth at lower frequencies, different propagation
effects, or maybe just the vagaries of anecdotal reporting, is something
I don't think anyone knows.

Roy Lewallen, W7EL

Vertical Antenna Performance Question
 

Roy Lewallen wrote:
... there might be some interesting
phenomena like ground wave energy following the ground for a while, then
launching some distance from the antenna. This wouldn't be modeled
properly by EZNEC or NEC.

Could that possibly be the result of the curvature
of the earth?
--
73, Cecil http://www.w5dxp.com

Vertical Antenna Performance Question
 

On Feb 14, 12:03 am, Richard Clark wrote:

You have so much left unsaid, that it is shooting in the dark.
However, proceeding with that risk in mind....

A vertical dipole described above is not the vertical antenna that you
describe following:

Better? You are relying too heavily on anecdotal reports.

The next problem is height (again) and how it contributes to (or
subtracts from) gain as that varies. There is no "similar" comparison
between the two. You could model and present variations on horizontal
dipole elevation alone for two hours, much less both of them.

Rule 1 of presentations: Don't give them off the cuff unless you are
prepared to follow the surprises.

Rule 2: If you are willing to follow the surprises; then you aren't
really giving a presentation.

73's
Richard Clark, KB7QHC

Richard, thanks for the comments. Yep, I thought of the thing about
the model versus the inverted L mentioned after I had already sent the
message. What I should have mentioned is that the EZNEC pattern for
the inverted L showed lower gain than the vertical dipole.

As for the anecdotal evidence thing: It's my observation. My
756ProIII S meter may not be a calibrated piece of test equipment but
the deflection of the needle was much higher while listening with the
inverted L. While I can't give an quantitative number to the
difference in strength, I can say qualitatively that the Inverted L
provided a much stronger and clearer signal.

As for the presentation, that is why I'm here asking the question. No
point in putting out info if it is going to be bogus. I saw a
discrepancy between my experience and the text books. I'm just trying
to resolve that.

Thanks again.

Gary - N0GW

Vertical Antenna Performance Question
 

On Thu, 14 Feb 2008 06:10:23 -0800 (PST), N0GW
wrote:

As for the presentation, that is why I'm here asking the question. No
point in putting out info if it is going to be bogus. I saw a
discrepancy between my experience and the text books. I'm just trying
to resolve that.

Hi Gary,

Experience is often the most confounding experience you will ever
experience.

After all, does experience explain the angle at which you
receive/transmit that portion of signal in a circuit (the jargon for
connection between you and that distant operator)? NVIS can hammer a
vertical, if that is what you want; even if you forget to lift the
horizontal into the air. So a horizontal dipole on the ground is the
best antenna compared to the best vertical? Not when you shift bands
and target a DX station.

Does experience explain the difference in (at what would be a strain
to justify) "a vertical at the same height as a horizontal dipole?" To
fill in that last parenthetical: What makes a vertical dipole at an
EQUAL height to a horizontal dipole? The equal high feed points? The
equal highest point of metal? The equal average height of both?
Choose any one of three and the other two could have better
performance over the other - and still someone in the audience could
cry nothing can be said to be EQUAL.

Does the experience at 160M with a ground mounted vertical translate
into the same experience at 10M? Experience in the 'burbs with trees,
homes, sheds, cars, playsets in the vicinity would suggest no. An
antenna 16 times taller can see over those same things which are
barely dimples to the field.

A head-to-head comparison will quickly resolve; but as this is an
amateur society with limited antenna options and a multitude of band
choices, experience will often roller-coaster between disappointment
and elation - and as so often proven in threads of amazing inventions
here, those inventors demand classical text books should be discarded
as being obviously counter to "experience."

The emerging new invention of an 160M band antenna the size of two
shoe-boxes should show how plastic and flexible experience is such
that it can stretch to fit into a suit 300 times it size.

73's
Richard Clark, KB7QHC

Vertical Antenna Performance Question
 

On Feb 14, 12:13 am, Roy Lewallen wrote:
snip

The short answer is that I don't think anyone really knows. I'm
convinced that the program accurately calculates the field from the
antenna and environment specified by the model. But there are some
pretty significant ways in which the model doesn't represent reality.
EZNEC uses the NEC ground model which is highly simplified - its ground
is perfectly flat, homogeneous to an infinite depth, and infinite in
extent. Real ground is curved and stratified with many layers of
sometimes highly differing conductivity and permittivity. Besides the
deficiency of the ground models, there might be some interesting
phenomena like ground wave energy following the ground for a while, then
launching some distance from the antenna. This wouldn't be modeled
properly by EZNEC or NEC. And although polarization is rotated during
ionospheric propagation, maybe there's some inherent advantage to
launching a vertically polarized signal. EZNEC and NEC make no attempt
at modeling propagation. Anecdotal evidence seems to find more of a
disparity between model results and observations at low frequencies (80
meters and below) than higher frequencies. Whether this is due to the
greater ground skin depth at lower frequencies, different propagation
effects, or maybe just the vagaries of anecdotal reporting, is something
I don't think anyone knows.

Roy Lewallen, W7EL

Thanks Roy, but darn, I was hoping that was not the answer. I was
hoping this was a subject someone had worked through definitively. Oh
well. What counts is how well an antenna works, not what calculations
show.

At no point did I think that EZNEC and NEC2 were busted. The output I
saw matched expectations arrived at from digging through text books
and scientific papers. I was eventually looking for a clue as to what
the NEC2 algorithms might be missing. I found the "leaky ground wave"
thing for lower frequencies an intriguing idea. I expect that above
about 10 MHz, where ground wave propagation becomes a fairly minor
consideration, NEC2 should provide a fairly accurate prediction of
vertical antenna performance.

Gary - N0GW

Vertical Antenna Performance Question
 

AI4QJ wrote:

I suspect that the EZNEC program is not designed for taking into account
such "rare" phenomena as "ground wave propagation". So much for EZNEC
analysis at 75m.


My own experiments with vertical vs dipole led me to the conclusion
that they both work better than the other, and they both work worse than
each other.

I based my analysis on signal strength using a db pad to match for the
weakest signal vs the strongest one. You can't do this one with just the
S-Meter, they aren't very accurate.

Sometimes the vertical "worked" better, and sometimes the horizontal
did. And while a generalization could be made for distance, therefore
"take off angle" between the two antennas, the reception could change
in the middle of a QSO, favoring one other the other.


Comparing one antenna against another is quite difficult - at least to
say which one "works" better.

And I'm curious - where is the propagation function in EZNEC?


- 73 de Mike N3LI -

Vertical Antenna Performance Question
 

On Feb 15, 12:52*pm, Michael Coslo wrote:
AI4QJwrote:
I suspect that the EZNEC program is not designed for taking into account
such "rare" phenomena as "ground wave propagation". So much for EZNEC
analysis at 75m.

* * * * My own experiments with vertical vs dipole led me to the conclusion
that they both work better than the other, and they both work worse than
each other.

I based my analysis on signal strength using a db pad to match for the
weakest signal vs the strongest one. You can't do this one with just the
S-Meter, they aren't very accurate.

* * * * Sometimes the vertical "worked" better, and sometimes the horizontal
did. And while a generalization could be made for distance, therefore
"take off angle" *between the two antennas, the reception could change
in the middle of a QSO, favoring one other the other.

Comparing one antenna against another is quite difficult - at least to
say which one "works" better.

* * * * And I'm curious - where is the propagation function in EZNEC?

* * * * *- 73 de Mike N3LI -

There is none, of course. You would have to construct the lobes on an
asimuth chart but this is only useful for take-off angle and skywave
propagation. EZNEC information tells you nothing about ground wave
propagation.

Vertical Antenna Performance Question
 

On Fri, 15 Feb 2008 12:37:55 -0800 (PST), wrote:

AI4QJwrote:
I suspect that the EZNEC program is not designed for taking into account
such "rare" phenomena as "ground wave propagation". So much for EZNEC
analysis at 75m.
....
EZNEC information tells you nothing about ground wave
propagation.

Two things wrong with this:
1. EZNEC does provide information about the radiation characteristics
along ground at any distance on an infinite, flat plane and at any
elevation above it;
2. EZNEC is not a propagation modeler as its users are well aware;
3. EZNEC models the 100M work of Brown, Lewis, & Epstein quite
closely. There is nothing in the body of RF literature to suggest
that the nature of radiation shifts suddenly in 7/8ths of a megahertz.

73's
Richard Clark, KB7QHC

Vertical Antenna Performance Question
 

The interesting question then: Is the improved performance of
vertical antennas over horizontal dipoles on 75 meters at DX distances
due to a combination of direct radiation plus radiation from the
ground in the area of strong ground wave strength out hundreds of
meters? Is the ground wave leakage providing additional low signal
strength in both transmit and receive?

Gary - N0GW

That's always interesting - and usually without a good explanation.
I don't know how many times I've switched from one anntenna to another just
to have the quote"inferior in theory" antenna get better results than the
"better" antenna.
Antennas are magic. There may be a metal building or some
near-but-out-of-sight tv antenna mast or tin roof or aluminum-foil-lined
insulation giving some directivity.

Vertical Antenna Performance Question
 

On Fri, 15 Feb 2008 20:33:04 -0500, "AI4QJ" wrote:

But I am a heretic for not having mindlessly bowed in adoration at the altar
of the EZNEC god in blind faith as you and others have done.

Hi Dan,

Heretic? More Arthur's heathen love-child. Heretics, afterall,
reject the scripture they've studied to present alternatives.
Heathens' marginal knowledge is a limited skill for making soup from
missionaries. Run out of missionaries and heathens starve; at least a
heretic can scrounge up a meal by holding out a hat on a street
corner.

Do you claim to have a hat?

73's
Richard Clark, KB7QHC

Vertical Antenna Performance Question
 

On Feb 15, 7:33 pm, "AI4QJ" wrote:


But I am a heretic for not having mindlessly bowed in adoration at the altar
of the EZNEC god in blind faith as you and others have done. However, those
fanatic evangelists who live by blind faith alone have wisely plonked me so
as not to let their blood pressures rise at the spectre of the EZNEC god
being angered.

73

I'm confused... Art, is that you?
MK

Vertical Antenna Performance Question
 

"AI4QJ" wrote in
:


2. EZNEC is not a propagation modeler as its users are well aware;

If it cannot predict take-off angle then what good is it? It doesn't
matter if we warm the clouds directly above?

You may have issues with Roy, but it is pretty unprofessional to deride his
program on that account.

It does predict the angle of maximum radiated power. "Take off
angle" is a great term for those who believe that the energy exits the
antenna as a blob, all in one place, and no energy elsewhere.

It isn't a propagation tool, it's a design tool, and as such
propagation is not at issue. Apples/Oranges.

But you're a smart fellow, so I guess you are pulling our collective legs
here.. 8^)

- 73 de Mike N3LI -

Vertical Antenna Performance Question
 

Vertical Antenna Performance Question
 

Richard Clark wrote in
:

Heretic? More Arthur's heathen love-child. Heretics, afterall,
reject the scripture they've studied to present alternatives.
Heathens' marginal knowledge is a limited skill for making soup from
missionaries. Run out of missionaries and heathens starve; at least a
heretic can scrounge up a meal by holding out a hat on a street
corner.

Do you claim to have a hat?

Not even a banjo, I'll bet.

- 73 de Mike N3LI -

Vertical Antenna Performance Question
 

Vertical Antenna Performance Question
 

Mike Coslo wrote:
"AI4QJ" wrote in
:

2. EZNEC is not a propagation modeler as its users are well aware;
If it cannot predict take-off angle then what good is it? It doesn't
matter if we warm the clouds directly above?

You may have issues with Roy, but it is pretty unprofessional to deride his
program on that account.

It does predict the angle of maximum radiated power. "Take off
angle" is a great term for those who believe that the energy exits the
antenna as a blob, all in one place, and no energy elsewhere.

It isn't a propagation tool, it's a design tool, and as such
propagation is not at issue. Apples/Oranges.

But you're a smart fellow, so I guess you are pulling our collective legs
here.. 8^)

- 73 de Mike N3LI -

Watch it, Mike, he may plonk you, a fate worse than running out of
beer.
73,
Tom Donaly, KA6RUH

Vertical Antenna Performance Question
 

AI4QJ wrote:

"Richard Clark" wrote in message
...
On Fri, 15 Feb 2008 12:37:55 -0800 (PST), wrote:

AI4QJwrote:
I suspect that the EZNEC program is not designed for taking into
account
such "rare" phenomena as "ground wave propagation". So much for EZNEC
analysis at 75m.
...
EZNEC information tells you nothing about ground wave
propagation.

Two things wrong with this:
1. EZNEC does provide information about the radiation characteristics
along ground at any distance on an infinite, flat plane and at any
elevation above it;

Really? Can it follow the curvature of the earth from say, Illinois to
Germany?

Is there some part of "infinite, flat plane" that you fail to understand?

2. EZNEC is not a propagation modeler as its users are well aware;

If it cannot predict take-off angle then what good is it? It doesn't matter
if we warm the clouds directly above?

EZNEC provides horizontal, vertical and 3D radiation patterns. Is there
some other dimension you are interested in?

3. EZNEC models the 100M work of Brown, Lewis, & Epstein quite
closely. There is nothing in the body of RF literature to suggest
that the nature of radiation shifts suddenly in 7/8ths of a megahertz.

Yes, there is no abrupt shift at 75m (most obviously). Quite simply, as you
approach larger wavelengths, skywave characterstics lessen and groundwave
characteristics increase.

Which are functions of propagation, not antenna modeling.

But I am a heretic for not having mindlessly bowed in adoration at the altar
of the EZNEC god in blind faith as you and others have done. However, those
fanatic evangelists who live by blind faith alone have wisely plonked me so
as not to let their blood pressures rise at the spectre of the EZNEC god
being angered.

No, you sound more like someone with a grudge mixing apples and oranges.


--
Jim Pennino

Remove .spam.sux to reply.

Vertical Antenna Performance Question
 

On Sat, 16 Feb 2008 13:04:45 -0500, "AI4QJ" wrote:

defend yourself when I begin highlighting the
things that EZNEC CAN'T do

Hi Dan,

"EZNEC can't whiten my teeth" sounds like so much of your naive
whining; why would ANYONE put any effort to "defending" against that
kind of boorish trolling?

Well, obviously I do. When technical content is so lacking in your
complaint, all that is left are the humorous gaffs like:
EZNEC does provide information about the radiation characteristics
along ground at any distance on an infinite, flat plane
and at any elevation above it;

Really? Can it follow the curvature of the earth
where the distance between "flat plane" and "curvature" are separated
by only eleven words - a netzheimer's record for cognitive fading.

After all, as you are one of my groupies, you were trolling for this
response weren't you? ;-)

73's
Richard Clark, KB7QHC

Vertical Antenna Performance Question
 

On Sat, 16 Feb 2008 14:53:09 -0500, "AI4QJ" wrote:

Get my gist?

Yes, unimaginative trolling.

73's
Richard Clark, KB7QHC

Vertical Antenna Performance Question
 

On Sat, 16 Feb 2008 17:18:09 -0500, "AI4QJ" wrote:

I am going to seriously reconsider my participation
in this newsgroup.

Dan, you've taken a long time to get serious - but this sentimentality
you offer is still unimaginative trolling. This group has seen it
done far better. Far, far better. At least Punchinello had
intelligence, experience, and gave Hams tools they still use.

73's
Richard Clark, KB7QHC

Vertical Antenna Performance Question
 

AI4QJ wrote:
I am at all loss to how real scientists like Cecil Moore and Gene
Fuller can continue to participate here.

Although I try to use the scientific method, I am
but a lowly EE who tends to think outside the box.
--
73, Cecil http://www.w5dxp.com

Vertical Antenna Performance Question
 

On Sat, 16 Feb 2008 17:18:09 -0500, AI4QJ wrote:

"Richard Clark" wrote in message
...
On Sat, 16 Feb 2008 14:53:09 -0500, "AI4QJ" wrote:

Get my gist?

Yes, unimaginative trolling.

Technical content noted. I am going to seriously reconsider my
participation in this newsgroup. Too many people here do not wish to
discuss real science, they just want to argue and flame.

And yet you criticize Roy for plonking *you*?


I have seen
many times here where a person makes an assertion that I know is true,
even by use of such elementary tools as a smith chart, yet yahoos who
know nothing about engineering try to shoot the assertion down in flames
based on personality differences or whatever.

Yup, and there is a fringe element of folks with apparent sexual
hangups. That's why God made killfiles! ;^)

Defending such assertions
that are based on first principles violates the politics of the alleged
gurus. It all reduces to a non-technical word game (semantics becomes
the norm) where the search for scientific truth and understanding is
suborned by personality cults and word games.

Art says pretty much the same thing.

And oh, by no means must
anyone *ever* question the EZNEC software tool! My god, software is
scientific perfection itself.

Odd, people question it all the time, and get reasonable and polite
answers. Perhaps a difference in question style?

However, when the Apollo made the landing
on the moon I wonder what would have really happened hadn't Niel
Armstrong assumed manual control of the craft at the last moments? So we
have the software addiction of antenna modeling and we find the author
of this thread puzzled as to why he cannot explain to his class the
problems associated with software modeling in conducting real world
QSO's.

Roy has made several mentions of what his software will and won't do. I
don't recall anyone saying it is infallible.

Try to explain and wham! You get hit. You are a heretic. On the
other hand, you have some crackpot trying to explain antenna theory as
quasi cosmic particles spewing out of the ends of a shoebox sized
antenna and you have a private pilot offering to fly over to his QTH and
test the new concept.

You must not understand the offer, Dave. It was a "put your money where
your mouth is" offer. And Art reacted just as expected.

I am at all loss to how real scientists like Cecil
Moore and Gene Fuller can continue to participate here.

They enjoy a good row. They like it here, arguing with each other.
Everyone here is getting something out of the group. You may not.

I think I will
just stand by and lurk for a while and if I see no changes, I will
simply write this off as a flame group and go someplace else like eham.

I think that you cannot control the group. I think that you may have an
issue with that.


"73" de AI4QJ (my real call sign and I have no qualms at all in
writing under my true identity)



--
-73 de Mike N3LI -

Vertical Antenna Performance Question
 

"Mike Coslo" wrote in message
. ..
On Sat, 16 Feb 2008 17:18:09 -0500, AI4QJ wrote:

"Richard Clark" wrote in message
...
On Sat, 16 Feb 2008 14:53:09 -0500, "AI4QJ" wrote:

Get my gist?

Yes, unimaginative trolling.

Technical content noted. I am going to seriously reconsider my
participation in this newsgroup. Too many people here do not wish to
discuss real science, they just want to argue and flame.

And yet you criticize Roy for plonking *you*?


I have seen
many times here where a person makes an assertion that I know is true,
even by use of such elementary tools as a smith chart, yet yahoos who
know nothing about engineering try to shoot the assertion down in flames
based on personality differences or whatever.

Yup, and there is a fringe element of folks with apparent sexual
hangups. That's why God made killfiles! ;^)

Defending such assertions
that are based on first principles violates the politics of the alleged
gurus. It all reduces to a non-technical word game (semantics becomes
the norm) where the search for scientific truth and understanding is
suborned by personality cults and word games.

Art says pretty much the same thing.

And oh, by no means must
anyone *ever* question the EZNEC software tool! My god, software is
scientific perfection itself.

Odd, people question it all the time, and get reasonable and polite
answers. Perhaps a difference in question style?

However, when the Apollo made the landing
on the moon I wonder what would have really happened hadn't Niel
Armstrong assumed manual control of the craft at the last moments? So we
have the software addiction of antenna modeling and we find the author
of this thread puzzled as to why he cannot explain to his class the
problems associated with software modeling in conducting real world
QSO's.

Roy has made several mentions of what his software will and won't do. I
don't recall anyone saying it is infallible.

Try to explain and wham! You get hit. You are a heretic. On the
other hand, you have some crackpot trying to explain antenna theory as
quasi cosmic particles spewing out of the ends of a shoebox sized
antenna and you have a private pilot offering to fly over to his QTH and
test the new concept.

You must not understand the offer, Dave. It was a "put your money where
your mouth is" offer. And Art reacted just as expected.

I am at all loss to how real scientists like Cecil
Moore and Gene Fuller can continue to participate here.

They enjoy a good row. They like it here, arguing with each other.
Everyone here is getting something out of the group. You may not.

I think I will
just stand by and lurk for a while and if I see no changes, I will
simply write this off as a flame group and go someplace else like eham.

I think that you cannot control the group. I think that you may have an
issue with that.


"73" de AI4QJ (my real call sign and I have no qualms at all in
writing under my true identity)



--
-73 de Mike N3LI -

Hi Mike

I have some limited accuracy test equipment for evaluating antennas.
Recently Richard Clark prodded me till I couldnt take it any more so I got
some of Roy's software. Richard even told me how to use it. It has become
clear that *my* test equipment is is very good agreement with Roy's EZNEC.
.. EZNEC works so well for my situation that I thought it was woring well for
everyone. I can make real radiation patterns of my prototype antennas
(using POES signals for the illuminator) that are in agreement with EZNEC
prediction. Even the inpedance of the eklements are well predicted by
EZNEC. Do you know where any real data is in disagreement with EZNEC
predictions? I'd like to know more about any data anyone has that shows
where EZNEC gives wrong data.

Jerry KD6JDJ (who is extreemely happy with his EZNEC
"tool")

Vertical Antenna Performance Question
 

Cecil Moore wrote in news:r7Ltj.12156$R84.3863
@newssvr25.news.prodigy.net:

AI4QJ wrote:
I am at all loss to how real scientists like Cecil Moore and Gene
Fuller can continue to participate here.

Although I try to use the scientific method, I am
but a lowly EE who tends to think outside the box.

In this case, you would have to think outside the sphere... ;^)

- 73 de Mike N3LI -

Vertical Antenna Performance Question
 

"Jerry" wrote in news:MJMtj.457$kD3.85@trnddc08:


"Mike Coslo" wrote in message
. ..
On Sat, 16 Feb 2008 17:18:09 -0500, AI4QJ wrote:

redundant stuff snipped

Roy has made several mentions of what his software will and won't do.
I don't recall anyone saying it is infallible.

Try to explain and wham! You get hit. You are a heretic. On the
other hand, you have some crackpot trying to explain antenna theory
as quasi cosmic particles spewing out of the ends of a shoebox sized
antenna and you have a private pilot offering to fly over to his QTH
and test the new concept.

You must not understand the offer, Dave. It was a "put your money
where your mouth is" offer. And Art reacted just as expected.

I am at all loss to how real scientists like Cecil
Moore and Gene Fuller can continue to participate here.

They enjoy a good row. They like it here, arguing with each other.
Everyone here is getting something out of the group. You may not.

I think I will
just stand by and lurk for a while and if I see no changes, I will
simply write this off as a flame group and go someplace else like
eham.

I think that you cannot control the group. I think that you may have
an issue with that.

more redundant stuff snipped

Hi Mike

I have some limited accuracy test equipment for evaluating antennas.
Recently Richard Clark prodded me till I couldnt take it any more so I
got some of Roy's software. Richard even told me how to use it. It
has become clear that *my* test equipment is is very good agreement
with Roy's EZNEC. . EZNEC works so well for my situation that I
thought it was woring well for everyone. I can make real radiation
patterns of my prototype antennas (using POES signals for the
illuminator) that are in agreement with EZNEC prediction. Even the
inpedance of the eklements are well predicted by EZNEC. Do you
know where any real data is in disagreement with EZNEC predictions?
I'd like to know more about any data anyone has that shows where EZNEC
gives wrong data.

Jerry KD6JDJ (who is extreemely happy with his EZNEC "tool")

I can't recall offhand, but I think there are a few instances in which
the engine has difficulty. But any softare using the engine would, and
for almost any application, it wouldn't matter.

Otherwise, it is one nice piece of software, and functions well and as
advertized.

Possibly embarrassing accolade follows.......

We are lucky to have someone like Roy posting here. So many truly
competent folks have been run off from the newgroups by the crazies over
the years that people like him are becoming more and more rare.

- 73 de Mike N3LI -

Vertical Antenna Performance Question
 

AI4QJ wrote:
"Richard Clark" wrote in message
...
On Sat, 16 Feb 2008 14:53:09 -0500, "AI4QJ" wrote:

Get my gist?
Yes, unimaginative trolling.

Technical content noted. I am going to seriously reconsider my participation
in this newsgroup. Too many people here do not wish to discuss real science,


Great! Don't go away mad. just go away.

tom
K0TAR

Vertical Antenna Performance Question
 

Jerry wrote:

Hi Mike

I have some limited accuracy test equipment for evaluating antennas.
Recently Richard Clark prodded me till I couldnt take it any more so I got
some of Roy's software. Richard even told me how to use it. It has become
clear that *my* test equipment is is very good agreement with Roy's EZNEC.
. EZNEC works so well for my situation that I thought it was woring well for
everyone. I can make real radiation patterns of my prototype antennas
(using POES signals for the illuminator) that are in agreement with EZNEC
prediction. Even the inpedance of the eklements are well predicted by
EZNEC. Do you know where any real data is in disagreement with EZNEC
predictions? I'd like to know more about any data anyone has that shows
where EZNEC gives wrong data.

Jerry KD6JDJ (who is extreemely happy with his EZNEC
"tool")

There are many very serious commercial users of EZNEC who have the
capability to compare its results with professionally made measurements.
They regularly report very good agreement -- if the agreement wasn't
good, in fact, they'd certainly quit using it. You'll find antennas
designed with the help of EZNEC on military and civilian vehicles,
aircraft, and satellites, in use by domestic and international broadcast
stations, and countless other places as well as in many, many amateurs'
back yards.

I can't take credit for its accuracy, however. The basic calculations
are done by NEC-2, which has been even more extensively tested and
shaken down for several decades now. As a result, its limitations are
quite well known and documented, and I've tried to pass these along in
the EZNEC manual, correspondence with users, and in postings here.
NEC-2's ability to accurately predict antenna performance is also very
well known. NEC-2 uses some very fundamental equations which have been
well established by over a century of theory as being those which all
real antennas abide by.

But when using *any* model, including the models we all use in circuit
analysis -- resistance, inductance, capacitance, transmission lines, and
many more -- you always have to keep in mind that the analysis applies
to the *model*, not to any real object. So the results are only as good
as the match between the model and the physical circuit, antenna, or
object the model represents. Anyone not able to recognize when and where
a model differs in any significant way from the modeled object shouldn't
be using modeling for analysis, because his results are bound to be
wrong and he won't know it. On the other hand, one who recognizes the
differences can still often get useful information from the model even
though it might not fully represent the actual antenna. As just one
example, I've recently been designing a number of antennas which are
fabricated as traces on a circuit board. They have requirements for
pattern and SWR bandwidth, and have to share a fairly small board with
one or more other antennas and a substantial number of other conducting
objects which aren't electrically small at the operating frequency.
Although EZNEC has no way to accommodate the effect of the dielectric
(which is quite significant), it has nevertheless given critical
information about interaction among the antennas and other conductors
and its effect on pattern and bandwidth, allowing me to optimize my
designs for adequate performance in the difficult environment. I've
produced designs which have worked as intended with only a minimal
amount of modification. Several are now in use in the client's products,
and they keep asking for more.

Models can be made for many antennas and systems which represent the
real antennas or systems to a very good approximation, and those will
agree very well. The ground model is a weakness of NEC-2 and therefore
EZNEC. Fortunately, it's still good enough for all but a relatively
small number of applications. Making the ground model curved according
to the Earth wouldn't make any real difference in results except for
extremely high antennas or for ground wave communication at distances
greater than about 100 km. Perhaps the greatest shortcoming is the
homogeneous ground assumption, which can be very different from real
ground. I'm not convinced that a single "equivalent" homogeneous ground
can be found which behaves like real stratified ground(*). But the skin
depth in average soil at 1.8 MHz is about 20 feet. So to properly model
it would require the ability to include strata extending perhaps to 60
feet or so. And even if you added this capability to the program, how
would you measure the ground conductivity and permittivity at all the
necessary levels, to that depth, over the area necessary for
calculation? And how about hills, houses, buried water and power lines,
and roadway rebar?

So, like any other tool, today's modeling programs don't do everything.
But in the hands of someone with a basic understanding of their
applications and limitations, they can be a tremendous tool, solving in
seconds problems which were beyond the capabilities of the very best
engineers and scientists just a short while ago.

(*)AM broadcasters determine an equivalent ground conductivity by
measuring the ground wave attenuation of an AM signal. However, this is
equivalent only in that it results in the same attenuation. The effect
of the ground on a radial ground system or far field pattern might be
affected differently, and require different "equivalent" values. But
it's possible that no "equivalent" would correctly predict, say, an
elevation pattern from a vertical radiator over stratified ground.

Roy Lewallen, W7EL

Vertical Antenna Performance Question
 

"AI4QJ" wrote in
:


"Mike Coslo" wrote in message
. ..

-73 de Mike N3LI -

No, it's 73 de LAWRENCE COUNTY AMATEUR RADIO ASSOCIATION, right
"Mike"? Check N3LI on QRZ.COM ) http://www.qrz.com/detail/N3RI. And
then tell me that their direct reference to the FCC database got it
wrong. Does the trustee "Cliff" know you are using the "club"
callsign?

Ahem.....

I'm N3LI. Its true, I swear! I looked it up in the database, and was
pleased to see mine very own name.

You wrote:

http://www.qrz.com/detail/N3RI

Ayup, * that * will give you the group in Lawrence County.

Feel free to tell "CLiff" about my malfeasance! Might as well tell Riley
that someone is masquerading as someone else by using a callsign that is
only 6 letters away from his actual one too! What a trickster I is....


Note: Better tell your "club" that it's call sign expired in June
2007.

I'll pass, though you might if you care. I suspect that they might
have let it expire, as the FCC is trying to cut down on the groups who
hoard callsigns. Lawrence county is probably just doing the right thing
here. Its also possible that that group doesn't exist any more. I can't
find a reference online.

And you tell *me* about fringe groups?

Ayup.

Just what do all the guys
in your "club" do to pass the time since you can't get on the radio
anymore?

My guess is that the Hams in Greencastle use NC3LC as a club call

Shall I inform "Cliff", as trustee, how badly you are
abusing his call sign, or are you really "Cliff".

Oh would you please? I might be a little suspicious of that other group
in Lawrence County also with their club call of NC3LC. After all, if you
drop the first C from their callsign, and add 9 letters to the last C,
you'll come up with that N3LI callsign again.

The mystery
deepens....(hi hi)

Oy. Is there an emoticon for shaking one's head?

- 73 de Mike N3LI -

Vertical Antenna Performance Question
 

Jerry wrote:
I'd like to know more about any data anyone has that shows
where EZNEC gives wrong data.

Here's one where all the geometry and segmentation checks
are OK but the conductors are too close together. It results
in an omnidirectional antenna with a 24 dBi gain.

http://www.w5dxp.com/SUPRGAIN.EZ
--
73, Cecil http://www.w5dxp.com

Vertical Antenna Performance Question
 

Mike Coslo wrote:
"AI4QJ" wrote in
:

"Mike Coslo" wrote in message
. ..

Shall I inform "Cliff", as trustee, how badly you are
abusing his call sign, or are you really "Cliff".

Oh would you please? I might be a little suspicious of that other group
in Lawrence County also with their club call of NC3LC. After all, if you
drop the first C from their callsign, and add 9 letters to the last C,
you'll come up with that N3LI callsign again.

The mystery
deepens....(hi hi)

Oy. Is there an emoticon for shaking one's head?

Take it easy on him, Mike. He has to be feeling like a fool right about
now.

Dave K8MN

Vertical Antenna Performance Question
 

Mike Coslo wrote:
I'm N3LI. Its true, I swear!

The Japanese hold the prize for confusing R's and L's.
When General MacArthur was running for the Republican
presidential nomination in 1952, the Japanese put up a
large banner in the Ginza district of Toyko that said:

Congratulations
General MacArthur
On Your Coming Erection
--
73, Cecil http://www.w5dxp.com

Vertical Antenna Performance Question
 

On Sun, 17 Feb 2008 14:29:36 +0000, Cecil Moore wrote:

Mike Coslo wrote:
I'm N3LI. Its true, I swear!

The Japanese hold the prize for confusing R's and L's. When General
MacArthur was running for the Republican presidential nomination in
1952, the Japanese put up a large banner in the Ginza district of Toyko
that said:

Congratulations
General MacArthur
On Your Coming Erection

HAR! yeah, I thought about the R an L connection, but didn't pursue it.

Great quip tough!!

--
-73 de Mike N3LI -

Vertical Antenna Performance Question
 

On Sun, 17 Feb 2008 21:56:07 -0500, "common sense"
wrote:

Hey Tom, good one. You're the guy who said you can sign a check with your
call sign and improper use is identity theft. Are you an attorney? Is this
you? http://www.maplewoodvoterscoalition....ringfinal2.pdf

"In search of...common sense"

Hi Dan,

Gone back to the shadows of anonymity? ;-)

73's
Richard Clark, KB7QHC

Vertical Antenna Performance Question
 

AI4QJ wrote:
I am at all loss to how real scientists like Cecil Moore and Gene
Fuller can continue to participate here.

Dan,

I am a real scientist, but I would never dream of attempting "real
science" on RRAA. I try to say only things I believe to be correct, as
do most people, but this is far more like a blog than a scientific
journal. The burden of proof is simply based on who runs out of gas first.

There is some very useful information here along with quite a bit of
more questionable lore. There is some trolling. But it is all basically
entertainment. Put on your waders and remain skeptical.

Even scientists need entertainment once in a while.

73,
Gene
W4SZ

Vertical Antenna Performance Question
 

Cecil Moore wrote:
Mike Coslo wrote:
I'm N3LI. Its true, I swear!

The Japanese hold the prize for confusing R's and L's.
When General MacArthur was running for the Republican
presidential nomination in 1952, the Japanese put up a
large banner in the Ginza district of Toyko that said:

Congratulations
General MacArthur
On Your Coming Erection

Easily explainable, they were ahead of the times. And, quite obviously,
were making reference to the development of viagra!

There crystal ball failed them though; they must have been counting on
life extending medicine which failed to be developed--however, they got
it half-right. grin

Regards,
JS

Vertical Antenna Performance Question
 

Mike Coslo wrote:
We are lucky to have someone like Roy posting here. So many truly
competent folks have been run off from the newgroups by the crazies over
the years that people like him are becoming more and more rare.

What may be the real objection is the arrogance demonstrated
by some of the contributors. Please see my new thread concerning
some of Roy's "Food for Thought" statements.
--
73, Cecil http://www.w5dxp.com

Vertical Antenna Performance Question
 

common sense wrote:

Hey Tom, good one. You're the guy who said you can sign a check with your
call sign and improper use is identity theft. Are you an attorney? Is this
you? http://www.maplewoodvoterscoalition....ringfinal2.pdf

"In search of...common sense"


Sorry, that's not me.

tom
K0TAR

Vertical Antenna Performance Question
 

On Sun, 17 Feb 2008 02:11:56 GMT, "Jerry"
wrote:


I have some limited accuracy test equipment for evaluating antennas.
Recently Richard Clark prodded me till I couldnt take it any more so I got
some of Roy's software. Richard even told me how to use it. It has become
clear that *my* test equipment is is very good agreement with Roy's EZNEC.
. EZNEC works so well for my situation that I thought it was woring well for
everyone. I can make real radiation patterns of my prototype antennas
(using POES signals for the illuminator) that are in agreement with EZNEC
prediction. Even the inpedance of the eklements are well predicted by
EZNEC. Do you know where any real data is in disagreement with EZNEC
predictions? I'd like to know more about any data anyone has that shows
where EZNEC gives wrong data.

Jerry KD6JDJ (who is extreemely happy with his EZNEC
"tool")



I believe there are still a lot of unknowns about antenna theory and
propagation and that something may someday come along that EZNEC
cannot properly calculate and model. There are several hams who may
or may not be lurking about this group that have invented 'new'
antenna designs that cannot be properly modeled by EZNEC.
Unfortunately, for the ones I know about, the information is held so
secretly close to the inventors that their designs cannot be properly
compared to other antennas of known design to validate the inventors'
claims.

I have been a ham for 29.5 years now and for HF base, I have almost
exclusively operated from my own home-brew antennas. I learned a few
things over the years, rules of thumb so to speak. For Yagi antennas,
the longer the boom, the greater the gain, the shorter the boom, the
wider the beam width. For wire antennas, (within certain constraints)
the more wire, the more gain, the longer the antenna, the better the
gain, the shorter the antenna (shortened antenna) the narrower the
bandwidth. It is very hard to get a 1/16th wave antenna to work as
well as a decent 1/2 wave antenna for the same frequency. Most
importantly, any antenna (that won't destroy the radio) will
communicate given adequate propagation between the two points.

I don't use EZNEC. I haven't had the time set aside for studying that
and antenna theory long enough to make good use of the program. I have
tried, but it isn't capable of modeling the antenna design that I want
to experiment with,

I don't say this to discredit Roy, as, in all honesty, from the bottom
of my heart, I acknowledge that by far he has greater intelligence in
the antenna field than I hope to have. But, his software has certain
limitations and he states at least some of the limitations in his user
manual.

There are a number of professional antenna specialists here, some
real, some wanna-be. Some of those professionals don't care for us
amateurs being here asking questions anyone with a Masters degree in
antenna science shouldn't have learned by their fifth or sixth year of
study. Others are glad to help as long as we have shown to have made
some effort to understand the basics of how an antenna works.

I have respect for both Roy and Cecil, even tho they are quite often
at odds with each other, and I have respect for others here as well.
In time you will know who you want to trust and who you don't want to
hear from.

Good luck,
Buck
N4PGW

--
73 for now
Buck, N4PGW

www.lumpuckeroo.com

"Small - broadband - efficient: pick any two."