Help with EZNEC
 

On Thu, 14 Jun 2007 15:24:43 -0700, art wrote:

No, comparison would quickly reveal all this and thus I will leave you
with the last gasping denial. ;-)

Do you think I didn't realise what direction you was heading?
Look at mine not at his!

Hi Arthur,

Now, if you want us to look at yours, let's compare with something
real and not just your stale boasting that is short on technology:

First point - non planar (you can't beat this)
design fits within a box with a volume of 0.122 by 0.196 by 0.210
wavelength.

Second point - greatest length efficiency (you can't beat this either)

Third point - best TOA in comparison at 10 degrees (you certainly
can't beat that) and at less than 1/8th wave of the highest tip off
the ground!

Fourth point - more than 10dB F/B (you don't even come close)

Fifth point - a fractal! You don't know how to do it, do you?

Home Run!

And now for the full details:
http://www.qsl.net/kb7qhc/antenna/fr...r/k2/index.htm
(hint, this stuff is so old, it is going on 10 years). Even the EZNEC
file is found here.

Now, you are up to bat. Going to bunt for a sacrifice at first base?

Gasp out another denial and save us a comparison with your pale
designs retread from what Gauss forgot to do. Modern analysis wins
over your grave robbing through books every time. ;-)

73's
Richard Clark, KB7QHC

Help with EZNEC
 

On Thu, 14 Jun 2007 18:02:58 -0500, "amdx" wrote:

Hey you two, stop it,

Hi Mike,

Aw c'mon now. It's Arthur's favorite game of spitting on everything
to get me wet by chance. I cheat and wear a Nor'Wester. ;-)

this is my thread about EZNEC modeling and Flag antennas.

Well, you got an EZNEC model from me (if you follow the link); and it
is for a small low antenna which has more gain, less loss than the
flag (woops, Art will be entertaining us with classical phlegm casting
about being un-amurricun now).

73's
Richard Clark, KB7QHC

Help with EZNEC
 

On 14 Jun, 16:49, Richard Clark wrote:
On Thu, 14 Jun 2007 15:24:43 -0700, art wrote:
snip his!

Hi Arthur,

snip

SHHHHHus

It is not yours or my thread
I agree with you, that antenna is dead
Now go away.

Help with EZNEC
 

On Thu, 14 Jun 2007 17:18:19 -0700, art wrote:

I agree with you, that antenna is dead

Hi Arthur,

As I said, you don't understand what you are criticizing, or why. That
antenna is not DEAD, but we can both agree you can't find anything
better - I can however, and it was published on the same page. You
looked, didn't you? This IS a technical forum afterall, not a fashion
runway.

73's
Richard Clark, KB7QHC

Help with EZNEC
 

On 13 Jun, 23:01, Richard Clark wrote:
On Wed, 13 Jun 2007 19:45:35 -0500, Tom Ring
wrote:


snip

... tsk, tsk, tsk. Such a fall from grace for the fractal antenna.
Gone, and long forgotten.

Make up your mind. I'll now change it back to
"It is NOT gone and NOT forgotten"

It will be exhibited at the antenna exposition in Denver this year.
Maybe your name will be mentioned as the one that knew about it
all the time.And you tell me that you are heavily sought after
by entropreneurs to oversee technical propositions before
a committment is made? Brevity is not your strong point, 400
pages of index is way to much, 300 pages on a fractal
is also way to much. Remember your attempt at a patent,
to large to fit into a "shoe", to large to fit in any cabinet
thus placed on the floor never to be found or read and where
pages were sucked in by passing vacuum cleaners.
Hark the phone is ringing again, maybe it is IBM begging you again.



73's
Richard Clark, KB7QHC

Help with EZNEC
 

On Thu, 14 Jun 2007 18:56:29 -0700, art wrote:
"It is NOT gone and NOT forgotten"
this is simply passing gauss.

Hi Arthur,

When was the last time you SAW one in front of you, and not simply in
a book or on the screen? When was the last time you USED one? Have
you ever BUILT one? Do you REMEMBER how one works? :-0

Offer us something that could beat my page's 10 year old example that
fits within the defined bounds, at a nearly zero height, and
demonstrate yours has a better efficiency, smaller turn radius, is
non-planar, and the rest....

73's
Richard Clark, KB7QHC

Help with EZNEC
 

With respect to EZNEC. MANA is much more ambedextrous than
Eznec. It does provide all the old stuff that eznec does
but it also supplies what is new from the last decade.
[...]
Ofcourse even optimisation is not new to antennas
which is why the program is offered for free to
amateurs.

Unfortionally however, it uses the old MiniNec 3.13 engine. Those
interested in antenna modelling should know the drawbacks and pitfalls
as compared to then Nec2 or Nec4 engine used by EZnec and others...

Help with EZNEC
 

On Fri, 15 Jun 2007 01:18:12 -0700, 4nec2 wrote:


Unfortionally however, it uses the old MiniNec 3.13 engine. Those
interested in antenna modelling should know the drawbacks and pitfalls
as compared to then Nec2 or Nec4 engine used by EZnec and others...

The exception to that is Antenna Model

http://www.antennamodel.com/


Danny, K6MHE

Help with EZNEC
 

On Fri, 15 Jun 2007 05:54:12 -0700, Danny Richardson wrote:
On Fri, 15 Jun 2007 01:18:12 -0700, 4nec2 wrote:


Unfortionally however, it uses the old MiniNec 3.13 engine. Those
interested in antenna modelling should know the drawbacks and pitfalls
as compared to then Nec2 or Nec4 engine used by EZnec and others...

The exception to that is Antenna Model

http://www.antennamodel.com/

"Best viewed at 6400x4800" :-/

Help with EZNEC
 

On 15 Jun, 01:18, 4nec2 wrote:
With respect to EZNEC. MANA is much more ambedextrous than
Eznec. It does provide all the old stuff that eznec does
but it also supplies what is new from the last decade.
[...]
Ofcourse even optimisation is not new to antennas
which is why the program is offered for free to
amateurs.

Unfortionally however, it uses the old MiniNec 3.13 engine. Those
interested in antenna modelling should know the drawbacks and pitfalls
as compared to then Nec2 or Nec4 engine used by EZnec and others...

There are many view as what is advantageous and what is not.
In the early days I compared mininec and NEC programs both of
which had pitfalls that you had to be aware of and that really
was the key in achieving most for what you bought. To me EZNEC
is for people who like crossword puzzles in that the progam
tells you that what you have is no good. Where as the other
program puts out a helping hand to show the direction changes
that are needed for success and frankly the majority of program
users need more than the realisation that what they have
designed is no good. It is like the carrot and the stick aproach,
if a bite of the carrot seems implausable you stop trying to
bite and put the program away Now we have NEC programs that
posses optimizers that older programs such as eznec e.t.c.
cannot supply but with the increase of availability of newer
programs such as yours the cost becomes a powerful motivator
such that the modern programs which are more than suitable for
a amateurs needs are now available, for free no less.
To have a program that meets all my needs for the cost of nothing
carries much more weight than owning just a calculator or a
slide rule of yesteryear. True there are many users of the eznec
computor programs by those who purchased many years ago many
of which have tired of it but for a person at the entry level
to fork out hundred of dollars for an antique when he can get
more for free and keep his money to me there is no argument
At the same time should we not inform newcomers to the hobby
of the pitfalls that could delusion those who we need so badly?

Help with EZNEC
 

On 15 Jun 2007 14:11:02 GMT, Allodoxaphobia
wrote:

On Fri, 15 Jun 2007 05:54:12 -0700, Danny Richardson wrote:
On Fri, 15 Jun 2007 01:18:12 -0700, 4nec2 wrote:


Unfortionally however, it uses the old MiniNec 3.13 engine. Those
interested in antenna modelling should know the drawbacks and pitfalls
as compared to then Nec2 or Nec4 engine used by EZnec and others...

The exception to that is Antenna Model

http://www.antennamodel.com/

"Best viewed at 6400x4800" :-/

Well, I don't know what you are using for a browser, but it works fine
for me using Firefox and my screen resolution is 1280 X 1024

Help with EZNEC- Hey Roy!
 

Ian White GM3SEK wrote:

FYI, Roy will be at the Friedrichshafen hamfest in Germany next week, so
he may already be traveling.

Like most travelers, he may have access to e-mail, but is unlikely to
have a newsgroup feed.



Google groups can be used to send/receive newsgroup messages

Help with EZNEC
 

On 15 jun, 14:54, Danny Richardson wrote:

The exception to that is Antenna Model

http://www.antennamodel.com/

Yes, you are correct. I did not mention 'old mininec 3.13 engine' by
accident. :-)

Arie.

Help with EZNEC
 

On 15 Jun, 01:18, 4nec2 wrote:
With respect to EZNEC. MANA is much more ambedextrous than
Eznec. It does provide all the old stuff that eznec does
but it also supplies what is new from the last decade.
[...]
Ofcourse even optimisation is not new to antennas
which is why the program is offered for free to
amateurs.

Unfortionally however, it uses the old MiniNec 3.13 engine. Those
interested in antenna modelling should know the drawbacks and pitfalls
as compared to then Nec2 or Nec4 engine used by EZnec and others...

Do you know of a program that for optimisation can work with all
dimensions being variable
AT THE SAME TIME?
At the moment I am confined to using a number of variables in a
antenna array
until the objective is achieved and then by moving these variables to
the bottom of the list
it allows me to work on the next series of variables and so on until
acceptability
is obtained for the whole antenna array. Doing this takes a very long
time when each line
or wire comprises of seven (7) variables even with a high speed
computor.

Help with EZNEC
 

On 16 jun, 21:45, art wrote:

Do you know of a program that for optimisation can work with all
dimensions being variable AT THE SAME TIME?

Yes, maybe. If I am correct you do have some AO experience. 4nec2 does
contain an optimiser based on the same principles, however it's not
Mininec based as OA was, but Nec2 based (or Nec4 based if you own a
Nec4 license).
You can directly read-in your *.ao files into 4nec2, they will be
automatically converted. Complicated ao files may need some minor
manual changes afterwards.

You can include as much variables as you like in your antenna model
and for each run, you can select the variables to optimise from the
list. When the run has completed and the selected quality of your
model has been optimized as good as possible, you can (partly)
deselect previous variables and select another set of variabels and
continue optimization based on the outcome of previous run.

Furthermore it also contains a GA (genetic algorithms) based optimizer
similar to the one included in the commercial SuperNec package.

When optimizing multiple variables at the same time, this type of
optimizer is prefered. It also avoids the model of being trapped in
local maxima. The drawback of this is the increase of optimization
time needed.

However be aware, it needs some 'learning curve'.
There seem to be two distinct groups of people, those who adore it and
those who think it's much to complicated. It seems not possible to
'sit' anywhere between those both extremes.

Help with EZNEC
 

4nec2 wrote:
On 16 jun, 21:45, art wrote:


Do you know of a program that for optimisation can work with all
dimensions being variable AT THE SAME TIME?


Yes, maybe. If I am correct you do have some AO experience. 4nec2 does
contain an optimiser based on the same principles, however it's not
Mininec based as OA was, but Nec2 based (or Nec4 based if you own a
Nec4 license).
You can directly read-in your *.ao files into 4nec2, they will be
automatically converted. Complicated ao files may need some minor
manual changes afterwards.

You can include as much variables as you like in your antenna model
and for each run, you can select the variables to optimise from the
list. When the run has completed and the selected quality of your
model has been optimized as good as possible, you can (partly)
deselect previous variables and select another set of variabels and
continue optimization based on the outcome of previous run.

Furthermore it also contains a GA (genetic algorithms) based optimizer
similar to the one included in the commercial SuperNec package.

When optimizing multiple variables at the same time, this type of
optimizer is prefered. It also avoids the model of being trapped in
local maxima. The drawback of this is the increase of optimization
time needed.

However be aware, it needs some 'learning curve'.
There seem to be two distinct groups of people, those who adore it and
those who think it's much to complicated. It seems not possible to
'sit' anywhere between those both extremes.


I think this is true of all optimizers..
The more complex the thing being optimized, the more difficult it is to
have a generic interface that provides a way for the user to tell the
optimizer what the constraints and desires are. In the limit, you wind
up writing a program to implement the constraints, and another program
to implement the evaluation function, and yet another program to take
the optimized variables and turn it into a model which the modeling
engine can run.

Help with EZNEC
 

On 18 Jun, 12:08, Jim Lux wrote:
4nec2 wrote:
On 16 jun, 21:45, art wrote:

Do you know of a program that for optimisation can work with all
dimensions being variable AT THE SAME TIME?

Yes, maybe. If I am correct you do have some AO experience. 4nec2 does
contain an optimiser based on the same principles, however it's not
Mininec based as OA was, but Nec2 based (or Nec4 based if you own a
Nec4 license).
You can directly read-in your *.ao files into 4nec2, they will be
automatically converted. Complicated ao files may need some minor
manual changes afterwards.

You can include as much variables as you like in your antenna model
and for each run, you can select the variables to optimise from the
list. When the run has completed and the selected quality of your
model has been optimized as good as possible, you can (partly)
deselect previous variables and select another set of variabels and
continue optimization based on the outcome of previous run.

Furthermore it also contains a GA (genetic algorithms) based optimizer
similar to the one included in the commercial SuperNec package.

When optimizing multiple variables at the same time, this type of
optimizer is prefered. It also avoids the model of being trapped in
local maxima. The drawback of this is the increase of optimization
time needed.

However be aware, it needs some 'learning curve'.
There seem to be two distinct groups of people, those who adore it and
those who think it's much to complicated. It seems not possible to
'sit' anywhere between those both extremes.

I think this is true of all optimizers..
The more complex the thing being optimized, the more difficult it is to
have a generic interface that provides a way for the user to tell the
optimizer what the constraints and desires are. In the limit, you wind
up writing a program to implement the constraints, and another program
to implement the evaluation function, and yet another program to take
the optimized variables and turn it into a model which the modeling
engine can run.- Hide quoted text -

- Show quoted text -

Yes I would agree thus the use of MINNINEC that is used within
the confines of its known limitations is just as good as any program
that use know applicable laws. If a program what you wan't to use
has a optimiser then the results should be similar tho one may have
an accurracy that is outside the field of amateur radio but not
so correct as to prove the MINNINEC inaccurate.
For myself I would like to model a dish antenna with multi elements
in Gaussian form but the movement of variables would be horrible
in terms of time consumed assuming some 60 odd elements each
consisting
of some 10 lines with all units variable.
Regards
Art

Help with EZNEC
 

On Mon, 18 Jun 2007 12:08:09 -0700, Jim Lux
wrote:

I think this is true of all optimizers..
The more complex the thing being optimized, the more difficult it is to
have a generic interface that provides a way for the user to tell the
optimizer what the constraints and desires are. In the limit, you wind
up writing a program to implement the constraints, and another program
to implement the evaluation function, and yet another program to take
the optimized variables and turn it into a model which the modeling
engine can run.

Hi Jim, Arie,

It goes WAY beyond that (as if there weren't enough problems). In the
GA community, the introduction of unlimited variables leads to (very
quickly with even a few of them) what is called "combinatorial
explosion."

A second issue (and it seems that Arie probably has at least one
algorithm to tackle this) is with an engine becoming stuck at a local
minima or maxima. This false solution ignores a better one nearby (or
further down the road) simply because it satisfied the criteria within
a restricted region of a curve.

Arthur's models quite obviously exhibit this last problem when his
designs can be bested with mediocre examples that have been drawn from
the dusty bookshelves. The science of GA has moved well beyond the
Paleolithic era of AO.

73's
Richard Clark, KB7QHC

Help with EZNEC
 

Richard Clark wrote:
On Mon, 18 Jun 2007 12:08:09 -0700, Jim Lux
wrote:


I think this is true of all optimizers..
The more complex the thing being optimized, the more difficult it is to
have a generic interface that provides a way for the user to tell the
optimizer what the constraints and desires are. In the limit, you wind
up writing a program to implement the constraints, and another program
to implement the evaluation function, and yet another program to take
the optimized variables and turn it into a model which the modeling
engine can run.


Hi Jim, Arie,

It goes WAY beyond that (as if there weren't enough problems). In the
GA community, the introduction of unlimited variables leads to (very
quickly with even a few of them) what is called "combinatorial
explosion."

A second issue (and it seems that Arie probably has at least one
algorithm to tackle this) is with an engine becoming stuck at a local
minima or maxima. This false solution ignores a better one nearby (or
further down the road) simply because it satisfied the criteria within
a restricted region of a curve.

Arthur's models quite obviously exhibit this last problem when his
designs can be bested with mediocre examples that have been drawn from
the dusty bookshelves. The science of GA has moved well beyond the
Paleolithic era of AO.

73's
Richard Clark, KB7QHC
My comment was not so much about the details of the optimizers (for
which you've given some typical problems) but with the difficulty of
coming up with a generic optimizer that can manage generalized models,
generalized constraints, etc. Since the underlying optimizer algorithms
are available as canned packages/library routines in most cases, the
hard work is in formulating the stuff that goes to the optimizer.

Help with EZNEC
 

On 18 Jun, 14:22, Jim Lux wrote:
Richard Clark wrote:
On Mon, 18 Jun 2007 12:08:09 -0700, Jim Lux
wrote:

I think this is true of all optimizers..
The more complex the thing being optimized, the more difficult it is to
have a generic interface that provides a way for the user to tell the
optimizer what the constraints and desires are. In the limit, you wind
up writing a program to implement the constraints, and another program
to implement the evaluation function, and yet another program to take
the optimized variables and turn it into a model which the modeling
engine can run.

Hi Jim, Arie,

It goes WAY beyond that (as if there weren't enough problems). In the
GA community, the introduction of unlimited variables leads to (very
quickly with even a few of them) what is called "combinatorial
explosion."

A second issue (and it seems that Arie probably has at least one
algorithm to tackle this) is with an engine becoming stuck at a local
minima or maxima. This false solution ignores a better one nearby (or
further down the road) simply because it satisfied the criteria within
a restricted region of a curve.

Arthur's models quite obviously exhibit this last problem when his
designs can be bested with mediocre examples that have been drawn from
the dusty bookshelves. The science of GA has moved well beyond the
Paleolithic era of AO.

73's
Richard Clark, KB7QHC

My comment was not so much about the details of the optimizers (for
which you've given some typical problems) but with the difficulty of
coming up with a generic optimizer that can manage generalized models,
generalized constraints, etc. Since the underlying optimizer algorithms
are available as canned packages/library routines in most cases, the
hard work is in formulating the stuff that goes to the optimizer.- Hide quoted text -

- Show quoted text -

The bottom line is that if they are both based around the same
theme then they should be similar. Buying a new shiny radio
does not change the news supplied by the old radio.
Ofcourse there are different types of optimisers, for instance
the latest antenna program using NEC has an optimiser that can only
be
used for Yagi's where other optimisers are not so limited.
Yes it may have the latest bells and whistles but if it is
designed only for yagis then it wouldn't meet my needs.
Regards
Art

Help with EZNEC
 

I've been out of the country for three weeks during which Internet
access was unexpectedly spotty. I did put a priority on answering email,
however. Emailing me is a better way to get support for EZNEC than
posting on a newsgroup -- assuming you purchased EZNEC rather than
obtaining it by some other means. I apologize if I did fail to answer an
email message. The volume has been too high to quite keep up with.

To answer the question: There's no way to add gain to an antenna pattern
unless you want to save it in a trace (plot) file and modify the file.
The binary file format is described in detail in the EZNEC manual.

It's easy, however, to reduce the gain of the other antenna -- just add
a resistive load in the same segment as the source. You can reduce the
gain by any amount you'd like by using this method.

Roy Lewallen, W7EL

amdx wrote:
I'm comparing elevation plots of an antenna. They have different
forward gains, this makes it difficult to compare the lobe shape.

Is there a way to equalize the gains to do a comparison?


Example: I have an antenna that is -19dbi and one that is -23dbi.
Can I add 4db of gain to one to make the comparison easier?
Mike

Help with EZNEC- Hey Roy!
 

By the way, with EZNEC v. 4.0 or higher, you can also get a direct
readout of the difference in gains between the reference trace (the
current model when in regular operation, or the primary trace in
TraceView mode) and any added trace: After adding one or more traces,
just click on the name of the desired comparison trace in the upper left
corner of the 2D plot window. The gain difference is the last item in
the right column in the data window below the plot.

Roy Lewallen, W7EL

Jim - NN7K wrote:
Try this (with Eznec 5)

Step 1 Open (or write) your file. . .

Help with EZNEC- Hey Roy!
 

Ian White GM3SEK wrote:

FYI, Roy will be at the Friedrichshafen hamfest in Germany next week, so
he may already be traveling.

Like most travelers, he may have access to e-mail, but is unlikely to
have a newsgroup feed.

True.

But the very pleasant dinner with Ian and his lovely wife was a much
better way to spend an evening than sorting through the flotsam of a
newsgroup!

Roy Lewallen, W7EL

Help with EZNEC
 

On Jul 3, 1:15 am, Roy Lewallen wrote:
I've been out of the country for three weeks during which Internet
access was unexpectedly spotty. I did put a priority on answering email,
however. Emailing me is a better way to get support for EZNEC than
posting on a newsgroup -- assuming you purchased EZNEC rather than
obtaining it by some other means. I apologize if I did fail to answer an
email message. The volume has been too high to quite keep up with.

To answer the question: There's no way to add gain to an antenna pattern
unless you want to save it in a trace (plot) file and modify the file.
The binary file format is described in detail in the EZNEC manual.

It's easy, however, to reduce the gain of the other antenna -- just add
a resistive load in the same segment as the source. You can reduce the
gain by any amount you'd like by using this method.

Roy Lewallen, W7EL



amdx wrote:
I'm comparing elevation plots of an antenna. They have different
forward gains, this makes it difficult to compare the lobe shape.

Is there a way to equalize the gains to do a comparison?

Example: I have an antenna that is -19dbi and one that is -23dbi.
Can I add 4db of gain to one to make the comparison easier?
Mike- Hide quoted text -

- Show quoted text -

Roy, I have a serious complaint about Eznec+ 5.0... I can't believe
you could drop the ball this badly... Come on man, get a grip... I
expect better of you...

Every time I click on the far field plot it now comes up so fast I
don't have time to get a sip from my beer... Ya know, I'm not a
camel! A man could die of thirst using this program... sheeeesh...

denny / k8do

Help with EZNEC
 

Denny wrote:


Roy, I have a serious complaint about Eznec+ 5.0... I can't believe
you could drop the ball this badly... Come on man, get a grip... I
expect better of you...

Every time I click on the far field plot it now comes up so fast I
don't have time to get a sip from my beer... Ya know, I'm not a
camel! A man could die of thirst using this program... sheeeesh...



Just put it on a Vista machine. That'll slow anything down! ;^)


- 73 de Mike KB3EIA -