Analysis of thinwire structures in the presence of finite ground. This calculator will help you to calculate the different wavelength of antennas based on the frequency. Cars magnet antenna above the roof of the car cabin on military vehicles an antenna ddrr usually places on one of edges as it is shown in figure 5. The biggest advantage of this ddrr antenna is the fact that it puts the whole cophased system at earth potential which kills the static that usually plagues verticle antennas. Wire antenna calculator amateur radio station ws6x. There are several online articles about the ddrr antenna. This does not take into consideration the type or size of horizontal reflectors, of even if there is a need for them. I believe comrad is out of business, but i may be wrong. Antenna design freeware 1d and 2d arrays from mei software. All you need to do is enter the desired resonant center frequency in the form below, then click calculate.
Design and adjustement is easy, as with the capacitor you can tune the resonance by some mhz with no effort. This formula to obtain the length of a halfwave dipole antenna will give a good ballpark value to start with. Spacing is the distance from the boom to the gammamatch. Antenna calculator calculate your dipole, 3 element yagi etc find the length of a dipole. The untenna, a direct driven ring radiator ddrr kirbys. With the proliferation of personal computers and affordable even free software, antenna modeling has become a popular amateur activity. This is not according to the directions in antenna books and articles but it works.
For 80 meters wed have an antenna 40 times taller and thicker, or a 10 inch diameter copper pipe element 10 feet above a metal plate a wavelength in radius as a groundplane, and only be about 3db down from. Dec 5, 2014 two diy dual band antennas i built for vhfuhf stay safe and healthy. The dl6wu yagi is highly regarded as being easy to build with repeatable results, broad bandwidth and a useful pattern. Antenna modeling software mininec, winnec, and eznec for windows. Calculate the frequency length of antennas please enter one value only and calculate the result.
Here is some information i found that i scanned from comrad. Formulas are taken from this excellent page by on7yd. Please practice handwashing and social distancing, and check out our resources for adapting to. This link is listed in our web site directory since thursday feb 22 2007, and till today hb9mtn ddrr antenna for 50. Here is some information i found that i scanned from comra. As such, you need a lot of current in this first few feet of conductor, which dictates a 14 wave antenna. Antenna calculator for hf antennas ham radio secrets. Online calculators for designers, engineers, scientists, and the scientifically curious. Hb9mtn ddrr antenna for 50 mhz resource detail the. I took my insipiration for the antenna from les moxons excellent hf antennas for all locations, which details italian experiments with the half lambda ddrr from several decades ago. This calculator can be used to design a quarter wave ground plane antenna, with radials.
If you have no particular preference within a given ham radio band, then simply enter its center frequency i. Boyer from northrop, for military applications in the 50s. Yagi calculator is a windows program that also runs well on linux, ubuntu 8. The ddrr antenna as presented in the arrl handbook is just an approximation of the real thing. Boyer titled surprising miniature low band antenna. The untenna, a direct driven ring radiator ddrr kirby. Doug vk3um was a friend from our days at unley high school during the mid 1950s, a common interest was that of radio and electronics leading to our introduction to ham radio through the 288mhz band now no longer part of australian allocations. Here is a useful cheat sheet converting vswr to the percentage of reflected power. The antenna is designed to be fed with 50 or 75 ohm coax cable of most any length with a balun.
This calculator is designed to give the vertical length height of a particular antenna, for the frequency and wavelength chosen. I found this image which shows, on the right hand side, the antenna i mention which, usefully, doesnt appear to require a high voltage capacitor. Antennas ddrr often serve as enclosure of the roof. The above image mentions all the steps needed to determine antenna coverage range based on following inputs. I received so many inquiries about a program to compute the dimensions that i decided to write a second section explaining the math behind the ddrr and wrote a program to do the calculations below. Ive built a few ddrr antennas down through the years including one for the 27 mhz cb band. An antenna s antenna factor af is a comparison between the field level presented to the antenna and the actual voltage produced by the antenna at its connector. The list will grow with your help so lets start and share the knowledge. There are usually four radials, three being a minimum, but you could use up to six. Here is a simple antenna calculator for two popular forms of ham radio hf wire antennas. An antenna loading coil is an inductor placed in series with an antenna element in order to lower the antenna s resonant frequency.
Enter the desired frequency and select the desired calculation from the drop box. Antenna, ve3sqb ham radio antenna design software programs. It is inversely proportional to the frequency which means the wave with higher frequency will have shorter wavelength. This calculator provides quick estimation of antenna size required for a given gain and frequency.
The following program will calculate the lengths needed to construct several popular wire antennas. Antenna efficiency calculator antenna efficiency calculator, parabola antenna antenna eirp calculator enter power, antenna type, frequency, coax type, coax lenght, press for eirp antenna gain vs height this calculator computes the gain and elevation angles for various antennas that are mounted over a perfect or lossy ground. June 1991 helped me understand what essential considerations i had to take into account. The distance between one point to another adjacent point in a wave is known as the wavelength. Dual antennas left the slot antenna, right the dipole antenna. Comments that it is based on idiotic theory are completely wrong. Long yagis are commonly used from the 144mhz amateur band to the 2. To calculate the length of a half wave dipole at a given frequency, use the following simple formula.
Gauding, nf0r ddrr for 40m directional discontinuity ring radiator antenna. An evaluation of a ddrr antenna december 1989 issue of sky. It allows to install other antennas on the roof of the communication car. It stayed classified until dr boyer published an article titled hula hoops antennas in electronics jan 11, 1963. When running frequency sweeps, linear or logarithmic style swr, gain, fbratio and impedance linecharts are produced. The formula for calculating the approximate length of a quarterwave vertical antenna is. The other antenna was made by antenna specialist who are still in business and may still produce the super scanner. About hb9mtn ddrr antenna for 50 mhz the resource is currently listed in in a single category. My homemade amateur radio antenna for the 160 meter band is the result of many considerations, inner debates and tests.
This link is listed in our web site directory since thursday feb 22 2007, and till today hb9mtn ddrr antenna for 50 mhz has been followed for a total. Nevertheless, the love of experimenting with antennas played a critical part in the successful. It consists of a 14wavelength element, grounded at one end and wound into a single coil, a short distance above ground. 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. The feedline of the ddrr antenna is coaxial cable connected such that the. A vertical antenna effectively half a dipole operating against a ground plane is resonant at onequarter wavelength. Wire antenna software free antenna modeling software. Antenna gain calculator software free download antenna.
The antenna calculator above uses this formula as a starting point to calculate wire lengths for the dipole. Antenna design calculators category is a curation of 83 web resources on, parallel square conductor transmission line calculator, analysis of antenna mast strength and bending stress, full wave loop antenna calculator. The correct lengths for the various models will be displayed in the chart. The ddrr was also used with an sdrplay 1 software defined radio to.
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. Works either in standard and metric units, and let you choose on material, and loop shape, as. The ddrr direct driven ring radiator was invented by dr. Antenna modeling used to be the domain of scientists and engineers with very expensive antenna ranges covering acres and acres of land strewn with expensive equipment. It allows to quickly calculate dimensions for quads antennas, yagi antenna, inverted vees antennas as well as jpoles and traps to extend dipoles band coverage. The biggest difference being the height of the antenna and the feed point. Because i found w5gves article before the w6wyqs 1971 qst a 40meter ddrr antenna article, i followed the w5gve instructions, which differ slightly. The measurements below are for building a simple dipole antenna.
The ddrrdirectional discontinuity ring radiator see other formats by kent britain, wa5vjf3 connecting the radio to the sky the ddrr directional discontinuity ring radiator es, it kind of looks like a halo, but the ddrr is a verti i cally polarized antenna photo a. In first part i talked about modeling the two ring ddrr and patterns. Boyer for northrop in the 60s and first described in electronics jan 11 1963 hulahoops antennas. The dual of a slot antenna would be if the conductive material and air were interchanged that is, the slot antenna became a metal slab in space. This calculator will calculate the radiation resistance of a marconi antenna which is short compared to the wavelength. Listed under the antennas6m category that is about homemade antennas for 6 meters. Note that a voltage source is applied across the short end of the slot. The ddrr directional discontinuity ring radiator is a vertically polarized antenna. Works either in standard and metric units, and let you choose on material, and loopread more. Feeding the antenna can be done at the director or at the reflector.
An antennas antenna factor af is a comparison between the field level presented to the antenna and the actual voltage produced by the antenna at its connector. A standard dipole antenna is resonant if constructed with a length of onehalf wavelength. Hf dipole antenna this antenna software will help you design a simple wire dipole. Antenna range calculator converters and calculators. A good engineering library should have the original article in electronics magazine. Antenna calculator and design software electroschematics. The ddrr is best considered a current mode antenna. Following equation or formula is used for antenna range calculator. Design of a dual patch triangular microstrip antenna.
The coax jumpers made the other 2 unactive elements. As such, you need a lot of current in this first few feet of conductor, which dictates a. You may need to refer to the arrl antenna handbook for some explanations about antennas as. The main category is homemade antennas for 6 meters band 50 mhz that is about 50mhz antennas plans, homemade antennas for the six meters. The antenna calculator is a very simple and easy piece of software. The untenna is a direct driven ring radiator ddrr which was manufactured in new york by comrad industries, inc. 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 results are conveniently displayed in inches, centimeters, feet and meters. Youll get links to diverse technical articles about this cool thing. The antenna was about 3 inches tall, and it fit on top of my van without hitting the garage on the way in. The effective isotropic radiated power eirp is the apparent power transmitted towards the receiver, if it is assumed that the signal is radiated equally in all directions, such as as a spherical wave emanating from a point source.
835 36 1321 654 704 602 973 1539 1224 555 1437 1039 443 1259 868 1604 635 575 819 899 1320 489 824 340 687 548 1165 224 1279 931 73 1505 1528 319 680 69 1144 1444 1400 776 752 1148 487 1228 1029 225 1248 1492