The following is an article which i wrote and was published in the february 20 edition of the central coast arc. About quad calculator the resource is currently listed in in 3 categories. Having had a gem quad hf 201510m for a few years, back in the early 80s, i can testify to the quad s slight advantages over a tribander yagi with the same number of elements. Quad antenna javascript calculator for cb and amateur radio. This link is listed in our web site directory since tuesday apr 18 2000, and till today quad calculator has been followed for a total of 61551 times. Now its time to step it up just a little bit and fabricate a bigger antenna.
Its coinductive secret was that it used a folded dipole to feed the quad. My experience has been that a well designed, 3element triband quad has. Who needed a linear when you had this much power without one. Heres what we did and how you can build a twoelement, lightweight 10 and 15meter quad using parts availa ble at local hardware and radioparts stores and a sportinggoods mailorder supplier. Arrl lab measurements confirmed the computerpredicted antenna pattern. The main category is antenna design calculators that is about antenna design calculators. A new trend in antenna modeling software is to build antennas that are resonant.
You may wish to read further about tuning adjustments in the arrl handbook. Added 3,60 dxbeam 1el yagi and the 5,40 5el wulf in eznec battle. All have delivered the goods with no adjustment of element size, giving good gain, fb, and bandwidth. The optimum gain of any antenna with parasitic elements varies with the spacing and tuning of the antenna s elements.
Its a comparative analysis of gain you can expect by these aerials, 11 meter up over average ground, for 10degree elevation angle. Dipole antenna length calculator dipoles antennas are easy to build and can be very effective when placed half a wavelenth or more above ground. The mfj1890 is a lightweight aluminum antenna designed to operate in the 10 meter band and we had hoped that with a little messing around we could get it to tune to the 11 meter cb band. The measurements below are for building a simple dipole antenna. A quarterwavelength antenna is easy and inexpensive to build and can be an effective antenna with a low angle of radiation that is, power is radiated out, not up. I emphasize once more, that if you use insulated wire, or bare copper, different to what i have used, the above measurements will not be correct. The formula for calculating the approximate length of a quarterwave vertical antenna is.
The most popular book on antennas ever written, widely known as the antenna builders bible, joseph j. Here is a simple antenna calculator for two popular forms of ham radio hf wire antennas. Building a 4 element cubical quad iw5edi simone hamradio. Wire antenna calculator amateur radio station ws6x.
Heres what we did and how you can build a twoelement, lightweight 10 and 15 meter quad using parts availa ble at local hardware and radioparts stores and a sportinggoods mailorder supplier. It describes how to check the antenna with a fieldstrength meter, or by using. Hence here is the double biquad antenna and biquad antenna calculators for handmade antenna based on average data. Antenna calculator for hf antennas ham radio secrets. Below you can find the dimensions for a 3el cubical quad. This calculator is designed to give the horizontal length of a particular dipole including tees antenna, or one side of it, for the frequency chosen. Remember please, this is not necessarily and always the max gain of each yagi. Would it be better to use the rg59rg58 and then use a tuner. This calculator will help you to calculate the different wavelength of antennas based on the frequency. The 40m loop antenna ed, vk2ji this antenna is also known under the names sky loop and dxbuster and is very similar to a horizontal delta loop. If you have no particular preference within a given ham radio band, then simply enter its center frequency i. I have a comercial build 2 element quad made by cubex,the antenna came with the 14 wave 75 ohms rg11 matching stub.
I missed a part and i will never know the answer it had aluminum spreaders. A 3element cubical quad has more gain than a 3element yagi. However i highly recommend to follow my instructions, which are based on computer antenna simulation software 4nec2, to maximize performance. Building and experimenting with antennas can be an interesting part of the radio hobby. The separation will remain the same for all the elements and the lengths of these extra directors will all be the same as the 1st director. The following program will calculate the lengths needed to construct several popular wire antennas.
Back in 75 i helped a friend build a quad beam using bamboo rods and copper wire. When all was said and done, my swr readings were 1. A number of these quads have been built, using these formulae, with slight variations in wire diameter, but always using bare hard drawn copper wire. Antenna, ve3sqb ham radio antenna design software programs. Horizontal or vertical polarization of an cubical quad antenna is determined by placement of the feed point feed gap on the driven element parasitic elements need to be mounted in the same orientation as the driven element.
The correct lengths for the various models will be displayed in the chart. However, adding quad elements produces diminishing returns. The dl6wu yagi is highly regarded as being easy to build with repeatable results, broad bandwidth and a useful pattern. Enter the desired operating frequency in megahertz to get a good starting length for a dipole in both feet and meters. William orrs book11 shows a 101520 meter, 2element cubical quad with boom length of 6. Here is the short version of his fantastic antenna software work, with some gain graphs. I have a comercial build 2 element quad made by cubex,the antenna came with the 14 wave 75 ohms rg 11 matching stub. Antenna per tv dvbtanalogico fai da te 2 mac blog giorno 477 costruire una quad loop antenna wifi duration. Save 11 meter quad antenna to get email alerts and updates on your ebay feed. Most parts are available on the world wide web or at some larger hardware stores. Here are a couple of pictures i took this morning showing my current home brew base antenna. The plans call for a piece of rg59 to match with the rg58, can i just skip that step and use rg58 and an antenna tuner. Spacing is the distance from the boom to the gammamatch. Quoting from william orr, whereas parasitic beams having twenty or thirty parasitic directors are efficient, high gain antennas, it would.
Ok well start with a specification of my present quad 2 element. I cut one down for the 11 meter band long before i became a ham. Enter the desired frequency and select the desired calculation from the drop box. This is where you input the center frequency in megahertz.
The pattern of left is for a twoelement 20 meter quad 35 feet high 12 wave high. The cubical quad antenna calculator for citizens band cb radio and amateur radio communications to calculate the spacing between the reflector and driven elements and directors. The distance between one point to another adjacent point in a wave is known as the wavelength. Long yagis are commonly used from the 144mhz amateur band to the 2. This tool will help you dynamically to calculate the spacing between the reflector, driven element and directors. We all laughed at him when he got on channel 11 asking for volunteers to help him build and assemble the antenna on his twostory roofed house.
The audible rejection of less than 1 db is gained but a loss of 3 db in punch is lost. This twoelement cubical quad antenna is designed for use on either the 10 meter ham band or the 11 meter citizens band. But also wire antennas, bobtail curtains, cpole and hentenna. Quad antenna javascript calculator for cb and amateur. Enter center frequency to be calculated for a quad. Jul 14, 2014 hence here is the double biquad antenna and biquad antenna calculators for handmade antenna based on average data. The calculators for other antenna types such as parabolic,horn,dipole and patch are also mentioned. First you can taylor it to the needs of your communication local or dx and optimize it for the frequency you talk on and to the needs of your environment make it strong if you live in a harsh one where ice and wind is a problem. Wc7i provides a calculator for a 3 element yagi design. If you wish to visite them, i believe they still are availible on.
Dxantenna project in the summer of 1987, we soon discovered the real challenge. Listed under the antennas antenna calculators category that is about antenna design calculators. The 2element quad has almost the same gain as a 3element yagi. It is inversely proportional to the frequency which means the wave with higher frequency will have shorter wavelength. The formula and basics of yagi antenna calculator are also explained with example. If you decide you really need a yagi with more elements, here are the lengths of them.
Due to material, i decided on a 5 element yagi built for vhf since all i would have to buy is more 38. Ive taken what i learned from the gmrs continue reading homebrew 5 element vhf yagi. The following is an article which i wrote and was published in the february 20 edition of the central coast arc smoke signals magazine. The loops came with some wire aparenttly precut,but in the manual said that any excces to be trim after all the loop wire is in position and tigh. Carrs practical antenna handbook, third edition is a work for anyone, ham radio operators, shortwave radio listeners anyone with an interest in antennas, from the newest of novices to the. This page covers 3 element yagi antenna calculator. Horizontal or vertical polarization of an cubical quadantenna is determined by placement of the feed point feed gap on the driven element parasitic elements need to be mounted in the same orientation as the driven element. Click on calculate to display the critical antenna measurements in both inches and centimeters. This gave the antenna more gain than a simple quad. Yagi calculator is a windows program that also runs well on linux, ubuntu 8.
The gain of an an antenna with parasitic elements varies with the spacing and tuning of the elements, and thus for any given spacing there is a tuning condition that will give maximum gain this spacing. All you need to do is enter the desired resonant center frequency in the form below, then click calculate. There are many reasons you should considering building your own antenna. I like to combine the vhf and field day events with camping so my antennas need to be portable. Btw the more graphics images are by yagi analizer by k6sti brian beezley. Feeding the antenna can be done at the director or at the reflector. The strongest signal produced from northern australia is from 43tr299 the 3 element above is the reason why. Design and adjustement is easy, as with the capacitor you can tune the resonance by some mhz with no effort. This calculator will help you to calculate the different wavelength of. The antenna is designed to be fed with 50 or 75 ohm coax cable of most any length with a balun. Summer contests are a great reason to get away from it all and enjoy the pleasures of amateur radio. The optimum gain of any antenna with parasitic elements varies with the spacing and tuning of the antennas elements.
A fiveelement quad antenna for 2 meters by jim reynante. It uses a single coax line to a homebrew antenna switch. Well in the early days of amateur radio nearly everything was matched by either, a gamma match, beta match, hairpin match, 75 ohm 14 wave coax match, or one of a few hundred other home made matching devices. Yagi calculator this is where you input the center frequency in megahertz. Here we have collected some links to building instructions for 11m antennas on the internet.
The pattern of left is for a twoelement 20meter quad 35 feet high 12 wave high. You can find information here from vertical antennas to loops and from moxonsyagis to quads. Small beam antenna maco yquad dual polarity quality that lasts. This quad,fed by 2 coax lines, was able to work both vertical and horizontal. Order practical antenna handbook with cd rom by joseph j. If you build the antenna as shown, the computer model predicts 11 dbi gain and a fronttoback ratio of 20 db. At one point during the tuning phase, i had a reading of 1. This calculator requires only the entry of the center of the frequency range your quad antenna will be used in. Dx antenna project in the summer of 1987, we soon discovered the real challenge.
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