Modelling Program Help

[KB5HAB]

I've read till my eyes hurt and didn't see this answered so ...if y'all would be so kind as to post up the names of the top 2 or 3 free and or pay antenna modelling programs I sure would be grateful. I'm not sure of what to even search for and I think I saw a couple of reccomendations but I just can't seem to find them now. Thanks for your help.

[VK1OD]

I've read till my eyes hurt and didn't see this answered so ...if y'all would be so kind as to post up the names of the top 2 or 3 free and or pay antenna modelling programs I sure would be grateful. I'm not sure of what to even search for and I think I saw a couple of reccomendations but I just can't seem to find them now. Thanks for your help.

I cannot comment on two or three 'top' progs. I have run tens of thousands of models, possibly hundreds of thousands, so I have some extensive experience.

I use 4NEC2 with either the distributed NEC2 engine (free) or an NEC4 engine (which costs lots).

I run lots of models using the NEC engines without using a front end like 4NEC2.

I have a licenced copy of EZNEC which I basically never use.

Owen

[AD7N]

Another vote for 4nec2, and a link: http://home.ict.nl/~arivoors/

One distinct benefit (besides being free): full color 3D antenna pattern plots, which make comparing antennas visually "at a glance" much easier in both E & H planes.

For pay? Depends on cash reserves, but FEKO is by and far *the* most advanced antenna modeling software I've come across: http://www.feko.info/

It is definitely a professional electromagnetic radiation simulator, and has a host of things you could do with it. Just look at their commercial customer list: http://www.feko.info/references

They do have a limited free trial if you're wanting to play with it.

For most purposes, 4nec2 should do the trick. FEKO is the "Rolls Royce" as far as I can tell, if you're looking for that kind of thing

[KB5HAB]

Thanks a heap. I'm more of a plain jane pickup person than a rolls royce.
Now to learn how to use it. Thanks again.

[K9FV]

A very powerful modeling program with good support from yahoo group is MMANA-GL.

http://mmhamsoft.amateur-radio.ca/pages/mmana-gal.php

I find it one of the easier modeling programs to use, and it's seems to be good.

Have fun,
Ken H>

[KB5HAB]

OK I've downloaded the 4nec2 and the mmana-gal both and I need some "for dummies" type help. I can't get them to work and I'm positively almost nearly 100% sure it's me. Is there a cheat sheet somewhere that has an example and somewhat simplistic explanation of what to put where and a brief why? There are help files with the programs but they assume I know what it all means and what it does...I don't. I do have a kind of beginners guide for mininec in the vertical antenna classics book from arrl. Does all that carry over to other programs? Just point me in the right direction to learn and let's see what I can pick up. Thanks

[AC0FP]

OK I've downloaded the 4nec2 and the mmana-gal both and I need some "for dummies" type help. I can't get them to work and I'm positively almost nearly 100% sure it's me. Is there a cheat sheet somewhere that has an example and somewhat simplistic explanation of what to put where and a brief why? There are help files with the programs but they assume I know what it all means and what it does...I don't. I do have a kind of beginners guide for mininec in the vertical antenna classics book from arrl. Does all that carry over to other programs? Just point me in the right direction to learn and let's see what I can pick up. Thanks

I can use the "crippled" (free) EZNEC version but it isn't worth much, other than building dipoles etc... There are instructions but I really just had to "hack" my way through it. When I have a lot of time on my hands I'm going to try the non-crippled mmana-gal program. These programs assume some level of electronic RF expertise!

Good luck,

fp

[K9FV]

it took me a while to get started with any of the programs myself - I've used the NEC versions where you "create" an antenna in the txt file - and it does work, but it does seem to me that MMANA-GL is less hassle.

Download the MMANA-GL program, open one of the simple dipoles - one with only 1 wire, then 2 wires, then 3 wires - The trick is in the first page where you build the antenna using the coordinate system.

I make a X, Y, Z plane on paper, then sorta plot out the coordinates there - first by using feet, tenths of an inch. Then convert to meters - Once you get the antenna built, put the source at the feed point.

For instance, for a one wire dipole for 40 meters.

On the Geometry tab, enter the following:

X1 = 0
Y1= -10.161
Z1=0
X2=0
Y2=10.161
Z2=0

You have just created a wire that is 20.322 meters long for a 40 meter dipole.

Now, at the Sources down at bottom of same tab, under "Pulse" put w1c - that says put the feed point on wire #1, in the center.... or words to that effect anyway.

Now go to the View tab - there is your antenna. You can rotate, zoom, lots of neat stuff there.

Now to the Calculate tab; in the freq block use the drop down and select 7.050. In the Ground you can select "Free Space", Perfect, or "Real" - Since the "Z" is at zero, you must add some height if using "real" - maybe 10 meters? Low for a 40 meter dipole, but you can play with heights. Now click "Start".

Look at some of the other tabs - I think this will get you started with MMANA-GL.

Have fun, 73 de Ken H>

[AD7N]

OK I've downloaded the 4nec2 and the mmana-gal both and I need some "for dummies" type help. I can't get them to work and I'm positively almost nearly 100% sure it's me. Is there a cheat sheet somewhere that has an example and somewhat simplistic explanation of what to put where and a brief why? There are help files with the programs but they assume I know what it all means and what it does...I don't. I do have a kind of beginners guide for mininec in the vertical antenna classics book from arrl. Does all that carry over to other programs? Just point me in the right direction to learn and let's see what I can pick up. Thanks

I learned 4nec2 with working examples, figuring out what worked and what didn't. Some parts of it I have yet to explore, it's a pretty thorough program!

If this is any help, here's my two bits: learn by example

1) start with "example1.nec". Straight dipole - as simple as they get
2) Spend a lot of time looking in the "edit" section - really try to understand what these numbers mean. First, start off with going to the "settings" menu, select "Geometry Edit", and then in the "main" window click the 6th icon from the left that looks like a notebook. Play around with the "3d" "xz" "yz" "xy" etc icons. get a feel for the geometry edit.

Big hint: say you're modeling a dipole. The dipole isn't modeled as "two legs" but rather "one wire" with a single feed point. The "feed point" is also referenced as a "current source" or "voltage source", and is indicated in the diagrams as a small magenta circle. This is placed wherever the feed point is. Each wire is broken up into "segments" of a specific length, and the more segments you have the better the model. By looking at the examples you'll get a good idea of what a good # of segments per wire is. A feed point can only be placed at the intersection of two "segments"


Next go back to "settings" "nec editor (new)", and click that same notebook icon. Now you'll see a basic spreadsheet view, with wire tab, symbols, etc.

Default measuring units is meters - I'd leave this as a LOT of models come in this form. after a while, I really prefer meters - I don't have to worry about converting between feet/inches, just move the decimal point.

Also note: Don't start playing with the "Z axis" or adding grounds until you're comfortable with "free space". Once you've got a good grasp of the editing functionality, then open up the 3rd dimension and start modelling height! I just use "average" "real ground" for most models - works well enough.

HELP MENU: explore it!
From the main window, click "help" - "general help". Alternate between the help menu (which is broken down by each menu and icon) and the various parts of the program. Doing this a lot with different menus, windows etc. will get you familiar with each section's function.

Also, under the "help" menu which I'd recommend exploring too.

It also doesn't hurt to explore the 4nec2 forums: http://fornectoo.freeforums.org/

I hope that helped some. You may or may not find a super-duper tutorial that will teach you everything. But the built-in "general help" and "getting started" help sections are actually pretty useful, if you go menu by menu, window by window and explore the related help topics.

good luck and have fun! If you get over your head and feel like throwing the monitor out the window, stop immediately and come back later after a long walk, a cold one or a good sleep. Makes all the difference in the world.

Big carrot: when you're comfortable with the above, you'll be ready for the *Optimizer*. This is where you can use that secretive "symbol" tab and make your own x,y,etc. variables that are then placed in the main editing spreadsheet (make sure you read the help! don't worry so much about "cards" etc, just concentrate on the basic stuff first). Then you'll be ready to start using fancy stuff like genetic algorithms, sweeps, etc. to optimize antennas for your specific needs.

[VK2FXXX]

KB5HAB
Gday,try this.
This is a 4 part series by a guy named Cebik.
The following link is the first part.
I suggest you copy and print it,then in your address bar at the top of your screen ,change the number towards the end of the bar after the letters _part to a" 2" to get the second article,repeat until all 4 articles are copied and printed.

http://wireless.ictp.it/school_2005/.../nec_part1.pdf

Cebik also has a web site ,just google ,register and enjoy.
Be warned ,once you learn how to model ,you will spend hours playing,and getting not much else done.
Enjoy
Brendan