Am trying to run an optimization on my 3 element yagi which I finally
got into the editor, which was difficult enough.
The optimizer says: no variables selected
but there are none to select.
Empty list field.

Oh, how I hate this.
Praise Bill Gates for his user-friendly WINDOWS
and to hell with all amateur softwares.

Nowhere in the helps and getting started they explain that.
I do not want to learn from examples, I rather work from the
basics upwards. Would anyone learn math from a calculus
formula without knowing the arabic numbers first?

Am in a baad mood tooday.


w.

On Sat, 13 Aug 2011 21:07:17 +0200, Helmut Wabnig [email protected] ---
-.dotat wrote:

Am trying to run an optimization on my 3 element yagi which I finally
got into the editor, which was difficult enough.
The optimizer says: no variables selected
but there are none to select.
Empty list field.

I have no experience with 4nec2 to speak of, but what it sounds like
is for an optimizer to work, you must first describe (name as a
variable) what characteristic you would like to vary until the
optimizer achieved an optimal result.

One guess for a three element yagi, I would suspect you would name
three variables, the elements, changing each by by an incremental
length (another variable) at a fixed frequency (another variable) for
maximum gain (another variable) in a particular direction (another
variable). Having said that little at seven variables (some fixed in
value), it is quite a page full of algebra stated in a formulaic way
for the optimizer (However, I fully expect that would be in a table
description, not a literal formula).

Having said even that little, it lends a peek into the number of all
the combinations and permutations of design this leads to. Each
variable taken individually against all the possible others - and then
repeated for the others in turn - leads to what mathematicians call
Combinatorial Explosion (you don't have enough time to wait for the
best solution). This is where constraints are added to the algebra,
and you offer "close enough" as one of them to limit testing.

Nowhere in the helps and getting started they explain that.
I do not want to learn from examples, I rather work from the
basics upwards. Would anyone learn math from a calculus
formula without knowing the arabic numbers first?

Proving the validity of numbers consumed a volume of proofs back when
Whitehead and Russell wrote "Principia Mathematica." It was logically
dead on arrival BEFORE it was published - and yet it was the best
description of simple math known. Calculus was simpler as it is
principally symbol dominated.

73's
Richard Clark, KB7QHC

Would anyone learn math from a calculus
formula without knowing the arabic numbers first?

Proving the validity of numbers consumed a volume of proofs back when
Whitehead and Russell wrote "Principia Mathematica."

"From this proposition it will follow,
when arithmetical addition has been defined, that
1+1=2."

Volume I, 1st edition, page 379

73's
Richard Clark, KB7QHC

On Sat, 13 Aug 2011 21:07:17 +0200, Helmut Wabnig [email protected] ---
-.dotat wrote:

Am trying to run an optimization on my 3 element yagi which I finally
got into the editor, which was difficult enough.
The optimizer says: no variables selected
but there are none to select.
Empty list field.

Are you using symbols, or did you hard code all the dimentions in ft
or meters? The optimizer won't work without using symbols.

4NEC2 forums. Where to ask such questions:
http://fornectoo.freeforums.org

Oh, how I hate this.

If it were easy, it would not be fun.
One must suffer before enlightenment.

Praise Bill Gates for his user-friendly WINDOWS
and to hell with all amateur softwares.

If you were around in the bad old days of computing, you might be
praising Bill Gates for saving us from the evils of big computer
companies. There was a time when you had to buy pre-formatted
floppies to work in DEC PC's, and when every machine had a different
floppy disk format. Anyway, your frustration with not reading the
manual and learning to use 4NEC2 has nothing to do with Windoze or
Bill Gates.

Nowhere in the helps and getting started they explain that.

True. Found with Google in a few minutes:

4NEC2 tutorial including optimizer and evolver:
http://heplx3.phsx.ku.edu/~dzb/antcal/nec-files/_GetStarted.txt
See section 5.

Video of optimizer (25 min):
http://www.youtube.com/watch?v=kYy6Yur127A

I do not want to learn from examples,

Then you will fail or at least be more frustrated. Hacking your own
path throught the wilderness is far more work than following in
someone elses footsteps.

I rather work from the
basics upwards. Would anyone learn math from a calculus
formula without knowing the arabic numbers first?

Most certainly possible. There are numerous tools the devices that I
use with only a minimal understanding for how they work. For example,
there are many drivers on the road that could not even begin to
explain how a gasoline engine works. (Hint: Carnot heat engine). I
suspect that such basic knowledge would not improve their driving
ability.

Am in a baad mood tooday.

Have a better day.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sat, 13 Aug 2011 14:15:22 -0700, Jeff Liebermann
wrote:

..........

I am making progress, though.
Got the optimizer running and edited a few of the example files
to have the variables selection available.

Works.

Now I watch the optimizer quickly de-optimizing the antennas
until they radiate into the wrong direction or get stuck in a
circular radiation diagram. In one case the optimizer bent
and rotated the dipoles around, I bet no specialist can do what I can.

Real fun, that is :-)


Video of optimizer (25 min):
http://www.youtube.com/watch?v=kYy6Yur127A


Yeah, thats good. Sitting back and watch.
Thanks for the idea of watching the Youtube demos.
Better than endless trial-and-error.
My goal is to find out what makes a direction finding antenna
different from a gain optimized antenna.
F/B ratio is all that matters for ARDF, for example.
Gain is secondary and side-lobes should be absent.
I must get that NEC working by all means.

Regards,
w.

On Sun, 14 Aug 2011 00:59:40 +0200, Helmut Wabnig [email protected] ---
-.dotat wrote:

My goal is to find out what makes a direction finding antenna
different from a gain optimized antenna.

That's easy (having helped design 2 commercial direction finders). Low
side lobes and good front to back. Gain is well down the list of
requirements. Side lobes will drive any direction finding scheme
towards insane results by generating false peaks in the direction. The
ability to recognize these is a function of how much time you want to
put into the software. Reflections will also cause problems, but more
so with side lobes.

To prove a point, I once threw together a rotating antenna direction
finder using a low gain directional antenna (but with low side lobes,
and no rear lobe). Due to the low gain, the -3dB beam width was a
rather wide 60 degrees. I rotated the antenna slowly, and the
computah made lots of signal level measurements. The result was that
I could determine the direction within about +/-2degrees. Of course a
higher gain antenna would resolve the signal direction much better,
and could probably be rotated faster, but all would be much larger.
However, there's a problem. High gain antennas tend to have boresight
errors. Small asymmetries, such as mountings, gamma matches, and
baluns, will have an effect.

F/B ratio is all that matters for ARDF, for example.

F/B could be considered a side lobe at 180 degrees. Like other side
lobes, it needs to be minimized.

Gain is secondary and side-lobes should be absent.

Absent is difficult. Minimized might be a better goal. With a log
amp driving the signal level measuring device, three orders of
magnitude should be sufficient.

I must get that NEC working by all means.

Slow down. Such things take time.

What manner of direction finder are you building and what frequency?
Doppler? Rotating antenna? Phasing? Time difference of arrival?
Homer? Adcock? Ouija board?

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sat, 13 Aug 2011 14:15:22 -0700, Jeff Liebermann
wrote:



Am in a baad mood tooday.

Have a better day.

Sorry, bad mood again.
Watched the tutorials on Youtube.
Remarkably he starts loading an antenna and then deleting the elements
to get a blank builder screen.
The 4nec2 cannot start with a "new" file, it must load something from
before. Only then I may select NEW. This is a bug.

I copied the moves from the tutorial on my NEW antenna,
and I cannot place a source on the dipole. Does not work.
No error message, nothing.
So I will load some old antenna, delete everything and try again
as shown in the tutorial.

Within 5 minutes of work I have a list of 5 errors,
program errors, repectively bugs, mis-leading the user.
Can't type as fast as the bugs occur, I just described only one.
Of course I have no right to complain because it's free.
Yeah.

w.

On Sun, 14 Aug 2011 22:02:32 +0200, Helmut Wabnig [email protected] ---
-.dotat wrote:

On Sat, 13 Aug 2011 14:15:22 -0700, Jeff Liebermann
wrote:



Am in a baad mood tooday.

Have a better day.

Sorry, bad mood again.
Watched the tutorials on Youtube.
Remarkably he starts loading an antenna and then deleting the elements
to get a blank builder screen.
The 4nec2 cannot start with a "new" file, it must load something from
before. Only then I may select NEW. This is a bug.

I copied the moves from the tutorial on my NEW antenna,
and I cannot place a source on the dipole. Does not work.
No error message, nothing.
So I will load some old antenna, delete everything and try again
as shown in the tutorial.

Within 5 minutes of work I have a list of 5 errors,
program errors, repectively bugs, mis-leading the user.
Can't type as fast as the bugs occur, I just described only one.
Of course I have no right to complain because it's free.
Yeah.

w.
Now I watched the tutorial again and again
http://www.youtube.com/watch?v=3AqMq0J3WBc
and after 14:11 he adds a voltage source.
He does a horizontal movement with the cursor on the dipole wire
and only then the 4nec2 will place the voltage source on the dipole.
He does not mention that or explain that move.

This stupid bug -and a program bug that is, and a large one-
this stupid bug has cost me 2 hours of struggling.

Ready for the next bug.

w.

On Sun, 14 Aug 2011 22:24:29 +0200, Helmut Wabnig [email protected] ---
-.dotat wrote:
.........
This stupid bug -and a program bug that is, and a large one-
this stupid bug has cost me 2 hours of struggling.

Ready for the next bug.


Want one?
4nec2 from time to time destroys it's saved antenna files.
Just lost another 2 hours of work.


Now I understand why it's free.
Can't charge money for bugs.


w.

On Sun, 14 Aug 2011 22:02:32 +0200, Helmut Wabnig [email protected] ---
-.dotat wrote:

On Sat, 13 Aug 2011 14:15:22 -0700, Jeff Liebermann
wrote:
Sorry, bad mood again.

Like I said. One must suffer before enlightenment.

Watched the tutorials on Youtube.
Remarkably he starts loading an antenna and then deleting the elements
to get a blank builder screen.
The 4nec2 cannot start with a "new" file, it must load something from
before. Only then I may select NEW. This is a bug.

Well, there is no "new" button or choice under "File". Ask Arie Voors
for the feature. It seems easy enough to add to the program.

I copied the moves from the tutorial on my NEW antenna,
and I cannot place a source on the dipole. Does not work.
No error message, nothing.
So I will load some old antenna, delete everything and try again
as shown in the tutorial.

Well, I've never had that problem because I don't try to "paint" the
antenna using the isometric or 3D views. It's not accurate enough
unless you snap to a grid. I create the antenna either externally,
with a text editor, or using the spreadsheet style editor. I import
that into 4NEC2 and make any necessary changes (and fix any screwups).
For geometric shapes, I use the external shape generator, which will
do surfaces, parabolic dishes, etc. 4NEC2 is not a drawing program.

Within 5 minutes of work I have a list of 5 errors,
program errors, repectively bugs, mis-leading the user.

Impressive. You might want to search the 4NEC2 forums to see if any
of them have been previously reported.
http://fornectoo.freeforums.org
Note that there is a section specifically for requesting new features.

Can't type as fast as the bugs occur, I just described only one.
Of course I have no right to complain because it's free.

In my limited experience, people complain more about free software
than paid software. That's usually because the author(s) encourage
feedback in order to improve their product.

Yeah.

Thanks for ignoring my questions.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558