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There are many software packages on
the internet useful in designing various types of antennas. I've been
playing with a software package named "YagiCad 4.1" since about 1992. I first
installed a copy of it on our TEARA
webpage back in late 1994. Since then, I've received many emails from
users of this software who praised it's performance and simplicity. Here,
many years later, I find myself updating this website with 'work-arounds'
and tips, as the user base continues to grow. Seems the software's author has
developed quite a following!
Yagicad 4.1 was written by Paul McMahon VK3DIP. It's shareware, so you
can download it (and lots of antenna profiles) below. It's a DOS
program and can be run outside of windows if you like. It requires a
minimum of a 386 PC platform to run and a math co-processor really speeds
things up, but isn't required. The program runs best in DOS ('real DOS, not
the fake stuff rolled up inside of WIN95/WIN98/NT, hehehe) or when executed from
WIN3.x, but there are simple 'work-arounds' for 95/98/NT users. As computers
and operating system have become more complex, users have come up with
methods of keeping Yagicad4.1 running. Despite a little bug with newer operating
systems, I LOVE this program and have designed/built many antennas with
it. I've used a lot of other programs, but find myself back using
VK3DIP's YagiCad 4.1.
Hey, this is a great reason to drag out one of those
older PC's you've had packed away, trying to figure out a 'real use' for it!
I used to toss everything that wouldn't run on my newer computers, but have
since discovered there were MANY great programs that were somewhat simpler to use
and developed for the older PC platforms. Don't automatically discount software
just because it won't run well on your newest machines or operating systems.
Anyway, c'mon and lets get started with YagiCad 4.1!
Download YagiCad
4.1 here. This file will download as yagi.zip. Once the download is complete,
unzip the file into an empty directory. To start the program, type yagi41
from the dos prompt (first, switch to the yagicad's working directory) or
double click on yagi41.exe from your file manager in windows. First, before
trying to start and run this program, read the rest of the notes and tips below.
NOTES FOR
WIN95/98/NT USERS:
#1- Keep the .yag file names exactly 7 characters long (not counting
the extension). Example: 1234567.yag or WB4IUY1.yag , etc. Since I didn't
write the source code for this program, I can't explain why it grumbles over
files names of other lengths. When running on older systems with Win3.1 or just DOS6.22 (or lower),
you can name the files in any length you like, but WIN95/98/NT etc only
allows file names of 7 characters long to be opened. Windows NT is especially
finicky about this. Since you may wish to
send me your files to add to this page, share with others, or maybe run
Yagicad on a newer operating system in the future, I'd recommend always
naming them 7 characters long. Simple fix. Also, if you download a file
somewhere with a name of a different length, simply rename it to something
7 characters long, and you're set. Easy!
#2- When you design or modify antenna designs,
you'll want to give them a unique name (so you'll know what they are!).
Never use more than 60 characters (spaces included) in the NAME/TITLE
or COMMENTS sections. No problem, another easy work-around.
#3- NEVER us a COMMA (,) in the NAME/TITLE
or COMMENTS sections. It'll keep your work from opening later,
and sometimes crash the program. Yet another easy work-around.
#4- When used with
WIN95/WIN98, Yagicad will only display/open the first antenna
file (.yag files) it finds, when they reside in the same directory as the
program. It doesn't do this when running under DOS or 3.1
and earlier systems, and works OK on Windows NT...go figure, heheheheeh.
If that should ever happen to you, I recommend you make a directory
named 'yagicad', and a subdirectory called 'template'. Once you unzip
the file contents into the 'yagicad', move all of the .yag files into the
'template' subdirectory. Only move the file you're going to model from or
look at into the 'yagicad' directory. In nearly EVERY instance of a user
having problems with WinNT, Fix #1 above
solved it.
I've not found any other oddities when running
Yagicad on newer computers with WIN95/98/NT. Should any of you run across
other glitches, or come up with a better 'fixes', please drop me a note to
webmaster@teara.org.
USING THE
PROGRAM:
The program has all the help files
contained within, and can answer most questions. It will allow you to design
a basic antenna based on a NBS antenna standard, and then scale it to your
desired frequency. You can then modify element diamaters, boom length, match
type, element spacing and lengths, etc. You can also generate E and H plane
radiation plots. All data can be sent to a local printer. You can save your
designs once complete.
Yagicad 4.1 comes with a host of sample
antenna designs, thus allowing you to use a working design and simply
scale it to your operating frequency. You can add or subtract elements, compensate
for different element diameters, conductive or non-conductive booms, etc.
A word of warning, however... When you open a sample antenna, click on "create" and
name the antenna session to your own unique file name BEFORE you make
changes (scale it, etc). Otherwise, your sample antennas will be forever
modified. Remember, when you name a file, use 7 characters as outlined in
Note #1 of 'NOTES FOR WIN95/98/NT USERS' above.
Once you've designed/modified your
antenna, go to "calculate", select "auto", and then select "resonate".
Set a residual reactance of 0.0 ohms. This step of the program will alter
the driven element
to be resonant at your target frequency. If the Actual "Z" (impedance) is not
approximately 50 ohms, go to "edit" and move the location of the driven element
back and forth on the boom a little and then resonate the driven element again.
Continue this process until the actual Z is about 50 ohms.
You can add files that you and
others design to your library for future reference. You can also store the
designs of commercially manufactured antennas in your library and scale to
other bands later. Below is a list of the supplied antenna designs (to replace
yours when you forget tip #1 above, hehehe), and a few others I've added. If
you scale or design any antennas of your own, send me a copy of the .yag file
and I'll include them here for others to play with.
The following files are available from
this page in 2 formats. The first is the .yag file in text format. You can copy
the text from the page, paste it to a text reader like notepad, and save it
as whatever.yag. Then move that file into your yagicad 4.1 program directory.
You can also read the .yag file from here. The first info in the file is the
title and description. The first number is the forward gain in db. The second
number is the front-to-back ratio. The 3rd number is the actual impedance of
the antenna. The 4th number is the reactance. The 5th number is the # of elements.
The columns are: element length, distance from the end of the boom, and element
diameter. All measurements are in meters.
Following the .yag file is the same file
in a zip format that can be downloaded and unzipped directly into your .yag
storage directory (may be 'template' if you're running yagicad4.1 on WIN95/98/NT, or
the main Yagicad4.1 working directory if you're running it in DOS or Win3.x or
lower).
A 3 element 2 meter 'sniffer yagi design by WB2HOL for Fox hunting. Designed for easy
transport during foxhunting, and a great front-to-back raito. 7.3 dbd fwd with > 50 dbf/b !!
Visit WB2HOL's Website
for a full write up on this cool antenna!
This is a 8 element ATV yagi for 432 mhz scaled from a 144 mhz Rutland yagi
and optimized by KD2BD for ATV use. Constructed on a PVC
boom. Very wide banded and excellant for 70 cm ATV use.
![[bullet]](pinpurpl.gif)
There are many software packages on
the internet useful in designing various types of antennas. I've been
playing with a software package named "YagiCad 4.1" since about 1992. I first
installed a copy of it on our