OMNIQUAD Publisher's description
Antenna Design Programs--With surface mount technology and microcircuitry, most hams no longer build their own equipment.
Antenna Design Programs--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 all 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
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 DLLS ARE UP TO DATE, SO IF YOU GET AN ERROR OR THE PROGRAMS WILL NOT RUN, DOWNLOAD THE FULL VERSION OF HF QUAD 2002 AND IT WILL INSTALL THE PROPER DLLS SO ALL THE PROGRAMS WILL RUN. Also some European machines use a comma instead of the decimal point. The program will give an error 13 when you try to compute. They require numbers like 14. 255 (14dot255) to be put in as 14,255 (14comma255). Most programs have inch and metric calculations. MOST ARE AVAILABLE ON THE 2003 AMATEUR FUNK ( German Ham Radio magazine) CD. There are few construction details here. I am a builder not a writer. If you are new to building, check out other sites for construction details. There are lots of good websites out there. Originally I started writing the programs for my own use but I decided to make them available for the amateur community. They are continually evolving as I gather new information. If you discover anything that would make a program better or more accurate, please forward the info to me. THX ahead of time.
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 ( 50 ohm error corrected Dec16/03 ) 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. See WHY QUADS for information on feeding and choice of a quad. 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 yagi-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. Modelling has shown the formulae to be out a bit at the higher frequencies. For 900mhz or higher, the center frequency shifts up to 1% higher. I will upgrade the program to reflect this as soon as actual built versions verify it. Until then design the antenna for a 1% lower frequency and inform me of the results.(Updated to fix bug in metric conversion of element spacings after director number six)
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 J-POLE antenna is a quick and easy plumbers delight. Some swear by it but I am sorry , I have never heard one that worked that well. The correct method of attaching the coax is the live to the stub except for some super designs which are really dipoles next to the radiator. Here come the arguments as about half the designs attach to the radiator. This is correct for mobile j-poles. If you want to get technical, a real j-pole is feed with 200 to 600 ohms.You make the choice.The program is here if you want it. NEWS I have been informed by a local ham that the problem with bad j-poles is the fault of the builder. An old 1938 US army mil specs recommends choking the coax to prevent rf on the shield. Try coiling the coax into a 6 turn ,4 to 6 inch coil just below the attachment point. I have not tried this, but it makes sense as the coax is connected to the tuning stub and the main radiator is connected to the braid. The rf on the shield would also give builders wrong swr readings and improper tuning for the attachment points. I have heard back from enough builders that state that the choking does help whether you are attached to the radiator or the stub.
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 ground 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.
System Requirements:No special requirements.
Program Release Status: New Release
Program Install Support: Install and Uninstall