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VE3SQB ANTENNA DESIGN
PROGRAMS BY AL
LEGARY Notice! Due to high demand for these programs,
long download times may be encountered on the links below. If you
experience delays..... just
click here to go direct to Al's new
website!
With surface mount technology and microcircuitry,
most hams no longer build their own equipment. One area that is still open
to amateurs is in antenna building! For a hundred years the amateurs have made more
breakthroughs in antenna design than the professionals. We do not know the
rules so we go ahead and build the antennas anyways, Some work, some
don't. We are still looking for that PERFECT antenna that is small, easy
to build and is super efficient. You may be that designer. If not, you
will still have the satisfaction of working that DX with a homebrew
antenna. I believe there is not a
commercial antenna that you can't make better and for a quarter of the
price!
To get you
started, I have made up programs that cover the most common types of
antennas and a few experimental designs. Click on
the icons to download. The programs do not
write to the Windows registry so just delete the files when you no longer
wish to keep them. They do require that the dll
files are up to date, so if you are unsure or the programs do not run,
download the full install version of HFQuad2002 first, then all will
run.. Most programs have inch and metric
calculations.
 Quads are my specialty. The Standard quad is designed from the textbook
equations and is compliments of Roger Clement KC5LCA. It is designed for 50 ohms and is the tried and
true method. The HF version is my program taken from research done by
W3GNR who must have spent many hours of field
research to develop his formulae. He discovered that odd number of
elements perform better than even and developed the wire size scaling. No
other quad program uses this information. I find this best for HF or VHF
with few elements. My version 3 was developed from the original HF
version but was optimized using two different computer modelling programs.
This allowed me to tweak the original formulae for maximum gain. I also
developed 50, 75 and 125 ohm feeding. If you want a multiband quad, drop
me an e-mail with the specs and I will tweak it with the modelling program
to cancel out interactions. See WHY QUADS (click here to link to the page on Al's
site)for
information on feeding and choice of a quad then come back
here. I just replaced my
original version quad with a new V3 version that is 30% smaller and almost
as much gain. Gain is roughly 9.4 db for a 3 element and .9 more for each
element. The gain per element reduces with large numbers. The gain is
always less than a yagi with equivalent numbers but other factors still
make it the better choice in my
opinion..
 The coaxial dipole or bazooka is the best keep
secret. Made
out of coax, it matches closely to 50 ohms and can be set up horizontally
or in an inverted V. It is very broadband for a dipole and makes a great
field day antenna. The loaded dipole is not as good as a full size antenna but it can
be used in limited spaces and even
indoors. The quagi-uda antenna is the most recognized
antenna. It produces maximum gain but requires tweaking for the
number of elements. This program uses different formulae for 2, 3 or
multi-element designs and includes element
tapering.
 Verticals covers all the common types with a coil
calculator built in for the antennas that require
them. The
quagi may be the best of two worlds.
It has the yagis gain and the quads direct feed and signal capture. I
could not find any published formula for them but only sample antennas.
From these samples, and computer modelling, I developed the program. I
have only built a 440mhz version which works very well but would like to
hear about your results. The discone
is most seen as a receive antenna but is under-rated. It can cover
multiple bands and has more gain than verticals. This also is true of
transmitting. It does have a variance across its range that can't be
easily predicted so if the match is not what you want, just increase or
decrease the starting range to shift the "nulls". HF versions have been
built that cover many bands.
 The Skyhopper
was named after the first one was compared to a grasshopper . The antenna
is basically a quad opened up on the bottom. This up and over, over and
down design had been used in HF wire antennas. The antenna acts like a
stacked pair on the vertical and a standard yagi on horizontal. The
prototype for 2 meters made its first contact of over 200 miles while
lying upside down on a picnic table. This lead to the discovery that it
can be used very low to the gound by inverting it. This method can also be
used when there is match problems due to nearby objects. A 440 version
with suction cups allowed an apartment dweller to have a beam antenna
stuck to his ceiling. The antenna is very forgiving of dimensions. The
prototype had screws in the end of the elements for adjusting but at 2
meters, 1/4 inch changes did not affect performance. I highly recommend this for
new builders. The only problem
is that it fires off to the corner opposite the feed. Over the years I
have seen the design renamed and modified by others, and posted on other
web sites. This
is the original.
Parabolic
antennas are the most directional of all antennas and
have the most
gain. Because
of their size, they are usually used for UHF and up. They are much easier
to built than you think. Any long bar will bend to a parabolic arc when
stressed on the end. If you mount 1 X 1 inch wood strips solidly to a
center hub, a wire can be strung through loops on the outer ends. When the
wire is drawn tight, the ends will curl up forming the
dish.
FOR THE
EXPERIMENTER
 Homebrew capacitors, gamma match and homebrew
feedline If you don't have the means for measuring
reactance, resistance and capactance on your antenna, the gamma program
will give you a starting point for for designing the gamma
match.
Single line next to the tower, twin ladder line, 4 wire line
and even HOMEBREW HARD LINE can be designed with the Feedline
program.
 Back in the days when CB was at its height, with
CBers in the millions, the antenna companies strived to build the best.
Two interesting designs emerged. Avanti Antennas produced a little quad
called the PDL-II. This quad , fed by 2 coax lines, was able to work both
vertical and horizontal. Its "co-inductive" secret was that it used a
folded dipole to feed the quad. This gave the antenna more gain than a
simple quad. I modelled the program to find out how it worked. The loops
of folded antenna have been replaced by V shaped elements without any
changes and easier matching. This antenna is worth experimenting with
especially with its reduced size. Co-inductive and PDL-II are trademarks
and this antenna is most certainly covered by patents. You are allowed to build a
not for
monetary gain, experimental version for
yourself.
 The other antenna was made by Antenna Specialist
who are still in business and may still produce the Super Scanner. This
antenna beams into three quadrants without the use of a rotator. By using
relays, a single feed line could be switched to 1 of 3 elements or to all
for an omni position.The coax jumpers made the other 2 unactive elements
appear to be longer and act as reflectors. Later versions grounded the
inactive elements through a tuned capacitance/inductance circuit. I found
that the jumpers work better at times when made of 75 ohm coax. This
antenna is recommended for advanced antenna builders only as it is VERY
sensitive to element length and spacing changes. Some adjusting will
probably be required. This antenna and the name SuperScanner
have patents and trademark restrictions. No patent, trademark or any
other type of infringement is intended against the Antenna Specialist
Company!
 NEW As soon as I saw QUAD in Quadrifilar Helicoildal Antenna, I had to
investigate it. Used for weather satellite reception, this omni
directional antenna has everything you want. It is small in size, has a
very low angle of radiation and up to twice the normal verticals gain.
The program has 6 variations of the design, with different
formulae for each. This is the most interesting design I have ever
researched. After 200 hours, the program is still in the research stages
but I have discovered many points about its operation and decided to post
what I have.
There is no construction or matching details in
the program yet, so check out qha sites on the net for this info. I built
a 2 meter desk top version out of foam disks and 20 awg wire. Wrapping the
coax around the 3/8 fiberglass pole about ten times was good enough to
reduce the match to 1.5 over a mhz. It measures at 5.1 db gain and I can
work all the local repeaters and about 15 miles simplex with the antenna
sitting on the BASEMENT floor. It also appears to work like a discone on
receive. Receive is good outside the band both above and below the 2
meters. It easily hears from 137 to 174 mhz. The use of small wire
instead of tubing did not affect the bandwidth but it did shift the
frequency down about 3/4 of a mhz. To correct this, I found that
shortening the large loop shifted the frequency much more than changing
the small loop. THIS IS VERSION 3 ...... All except the RCA version are
designed to be made out of 3/8 inch tubing which is easier to work with.
The dimensions are NOT designed for use with elbows or bent radius
corners. Cut the tubing 1 diameter longer than the required length ,
flatten the ends in a vise and drill bolt holes at the correct dimensions.
After assembly you may still solder the joints. All are designed to be
used 5 meters or more above ground. Patterns and phasing are lost if you
place them on the ground. Using an A/D converter hooked up between the
receiver and a computer plotted out the receive pattern of the 1/2 turn .3
ratio Wxsat Qha mounted 20 feet up on the rooftop. The pattern was almost
identical to the modelling results shown on the patterns page. The signal
is solid from horizon to horizon , being out only seconds from predicted
passes. NEW Matching calculator for low impedance QHA
...HERE
While researching the Qha,
I wanted something easier for checking out circular polarization. I
discovered that 70% of all commercial FM radio stations run circular
polarization. Home receivers are usually horizontal while mobiles are
vertical. After looking up the types of antennas they use, I came up with
two designs. The first has as much gain as a QHA but is much easier to
build. I recommend this to new builders as small errors will not greatly
affect performance. The QHA can be rendered useless by errors of only a
few millimeters. The FM station antennas use a round horizontal element
which is difficult to scale and build. By changing the elements to square,
the antenna scales from 500 to 1 mhz and is easy to
build.
The second antenna is
even simpler, consisting of only two bowed elements. While not as good as
the first , it still shows promise and anybody could build it. Although
originally designed for 137.5 wefax reception, circular polarized antennas
can make nice standby omni antennas to monitor band openings, both
horizontal base, vertical mobile communications or even for a beacon
xmitter.
The omniquad is a very simple but excellent standby
vertical antenna. I've built many over the years but just got around to
making up a program. The main advantage is the extreme bandwidth. Make all
the dimensional errors you want, and it will still work. You can use wire
or tubing. A broom handle ,some 1/4 dowels and under 10 feet of wire will
make a 2 meter antenna. There is very little gain or pattern difference
between the 3 and 4 sided versions but the 4 sided version does give a
better match. It can even be used as a desk top
antenna.
The log periodic antenna is the ultimate broadband
beam. It can provide high gain on a single band or moderate gain on
multiple bands. On vhf you can easily design a single feed 2 and 6 meter
antenna. On hf the size and element diameters are usually a drawback .Wire
versions are usually the answer. Although 4 bands is usually stretching
it, don't be afraid to try more. I had an inverted 'T' loaded 13 element
designed for 160 to 6 meters and it worked. It covered an acre ,was 120
feet wide ( 40 meters), 350 feet long (105 meters) and was suspended from
3 towers. The 1/2 mile of wire looked like a suspension bridge. The
neighbours are still cautious to talk to me and the XYL doesn't want to
discuss it.
FREE ICOM BAND SCOPE
SOFTWARE There are some good
programs on the net for controlling Icom radios but I just wanted
something to monitor a band for openings. My 746Pro does have a scope
function but you have to keep an eye on it. The solution was to make a
program that would reduce itself in size after setup to an "always on top"
program that would allow me to continue working on other things on the
computer. The picture below shows the "actual size" with the option of a
Scope or Bar graph display.
The Scope display only is
shown below.

The
program is designed for a homebrew interface requiring the RTS to be on to
supply power. Icom Civ owners can request a version with the RTS turned
off. The program may be obtained free from Degen Antenna
Designs HERE
in their download
section. This should work on most Icom radios but has only
been tested on a 746Pro. Please inform me of your
results and any bugs.....VE3SQB...AL
Antenna Design Programs and info on
this page courtesy of, and written by Al
Legary, VE3SQB Many Thanks Al! PLEASE DROP HIM A LINE OF THANKS
FOR THESE GREAT PROGRAMS VIA EMAIL Al responds to all antenna related
questions. Make certain you use the word ANTENNA in your subject line EMAIL Al HERE
GIVE AL, VE3SQB YOUR INPUT! WHAT ANTENNA DESIGN PROGRAMS WOULD
YOU LIKE TO SEE? Please be advised
that Al, is very busy designing these programs. All of your
suggestions for antenna design programs are considered and only the
best are
chosen.

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