Due to the variety of methods of analysis and design, and the different antenna structures available, the applications covered in this book are made to some of the most basic and practical. Other names include the tuned doublet and dipole with tuned feeders. The dimensions include the width between the balun connections. Note 1pages 710 and 11 of the arrl antenna book, qst. Contents introduction to the fourth edition ix 1 introduction to radio broadcasting and communications 1 2 radiowave propagation 5 3 transmission lines 59 4 the smith chart 95 5 fundamentals of radio antennas 123 6 highfrequency dipole and other doublet antennas 141 7 vertically polarized hf antennas 173 8 multiband and tunablewire antennas 203 9 longwire directional antennas 2. The antenna top is not cut to resonate at any particular frequency unlike the halfwave dipole, and any length may be chosen to suit an individual location. This edition includes recent antenna innovations and applications. A doublet antenna dipole, cut for 80 meters, will not work on 40 meters because 7 mhz is an even harmonic multiple of 3. The allband doublet is actually an antenna system and not just an antenna alone. Matthew w0zzy had built one with homebrew ladder line and it seemed to work fine. Open wire or balanced feeders are able to operate as part of the actual antenna.
Describe your experience with the w7fg tuned doublet antenna and tell us why you give it the rating you did required. This is the antenna for you guys who want to get on hf effectively, and havent too much space or cash to throw around. In response, constantine balanis has updated his classic text, antenna theory, offering the most recent look at all the necessary topics. Introducing the allband doublet universitas padjadjaran. Im just a true amateur experimenter, antenna modeler and voracious reader of every book on antenna theory and design that i have been able to get my hands on, some 50 years old. These antennas are fed in the center, which point will be either a current node or voltage node depending on the design of the particular antenna. One end of it is opencircuited and the other end is fed with ac source. I had also heard reports that this antenna is just a hair better than a dummy load on 7580m. The dipole is any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole with a radiating structure supporting a line current so energized that the current has only one node at each end. Sure cebik advised the 88 doublet for 80m and up and the 44 variation for 40m and up and its. The horizontal centerfed wire forms the antenna proper, which accounts for the radiation of transmitted energy and the reception of incoming energy. Antenna theory fullwave dipole if the length of the dipole, i. The key to the doublet antenna is the form of feeder used.
Ictpituursi school on wireless networking for development the abdus salam international centre for theoretical physics ictp, trieste italy, 5 to 24 february 2007. This book covers various architectures from the simple dipole to the newer antennae that can be found in smart phones and gps systems. What these numbers have in common is the belief that the feedpoint is the 300ohm point along the antenna element. For a discussion of balance line tuners, check out owen, vk1ods webpages. Overall this 728 page book is good reference to ham antennas as well as antenna theory. New material includes smart antennas and fractal antennas, along with the latest applications in wireless communications. It was with surprise and delight that i noted that clerks in one radio. Like the previous editions, antenna theory, third edition meets the needs of electrical engineering and physics students at the senior undergraduate and beginning graduate levels, and those of practicing engineers as well. What the student and the instructor should keep in mind l. It is a benchmark text for mastering the latest theory in the subject, and for better understanding the technological applications. The doublet has a long history and its longevity is perhaps down to two factors. They confirmed that the types of people who buy the book meet the profile above. The g5rv or a doublet antenna of no particular significance. The discipline of antenna theory has experienced vast technological changes.
A further factor which influences antenna resonant length is the diameter of the wire used for that antenna. In the original planning of the book it was the intention of the editors to integrate all of. Iw5edi 160 meter linear loaded tee vertical doublet antenna. As an avid antenna experimenter, i have spent approximately 10 years in the field experimenting with this. In radio and telecommunications a dipole antenna or doublet is the simplest and most widely used class of antenna. In its broadranging, analytic treatment, replete with supporting experimental evidence, antenna theory and design conveys fundamental methods of analysis that can be used to predict the electromagnetic behavior of nearly everything that radiates. Its a classic doublet which is a half wavelength long on 80 meters fed in the center with ladder line. You may have a pair of 70foot trees perfectly positioned to sup port a wire beam aimed at your favorite dx area. I just didnt know if the ladder line to coax junction was going to land in the right place. The zs6bkw multiband hf antenna iw5edi simone hamradio. Perhaps too many new hams embarking on their first hf adventures think only of resonant dipoles fed with coaxial cable and plugged directly into the transceivers output connector.
In its broadranging, analytic treatment, replete with supporting experimental evidence, antenna theory and design conveys fundamental methods of analysis that can be used to predict the electromagnetic behavior of. The lengths given in the chart above are those of the full overall length total breadth of the bottom half of the linearloaded dipole. Nonresonant dipole balun for ladder line page 2 qrz. Louis doublet, that used small wire for the radiators and computer cable for the feedline. Analysis and design, 3ed by balanis and a great selection of related books, art and collectibles available now at. These are preliminary notes, intended only for distribution among the participants.
Seeing all the useful comments and some confusion, i hope what follows helps. Portable doublet the doublet has a long history and its longevity is perhaps down to two factors. All the information you need to design your own complete antenna system. The doublet can be remarkably efficient, despite the relatively high swr along its feed line.
With a 1064m2 14 acre town block with a depth of 60mtr 200 i intended to improve on my previous all band hf doublet with an antenna that would be suitable for all the hf amateur bands, including the so called warc bands and including the 160 metre band. Actually, its a design from zs6bkw aka g0gsf, similar to the g5rv, but it actually resonates on five bands, well 6, actually and doesnt rely on a tuner atu to make it work. The folded dipole antenna consists of a basic dipole, but with an added conductor connecting the two ends together. The impedance at the centre of a doublet will vary enormously, depending on the frequency. I think that if you can deal with the open wire line routing issues, and use an efficient matching network tuner it may well be. A halfwavelength dipole is the first antenna that a new ham operator or shortwave listener may put up.
The models were initially all referenced to 50 ohms, and later repeated with a 200 ohm reference. Other useful information would include your experience with similar products, infomation on a product that you would purchase instead of this one, and so on. As an avid antenna experimenter, i have spent approximately 10 years in the field experimenting with this antenna design and its variants 14, 38, 12 wave. The antenna length should be about a half wavelength at the lowest frequency of interest for best results. The arrl antenna book uses the formula carr gives the figure as 0. But if a power line runs between the trees, forget it. Contents introduction to the fourth edition ix 1 introduction to radio broadcasting and communications 1 2 radiowave propagation 5 3 transmission lines 59 4 the smith chart 95 5 fundamentals of radio antennas 123 6 highfrequency dipole and other doublet antennas 141 7 vertically polarized hf antennas 173 8 multiband and tunablewire antennas 203 9 longwire. Dave gauding, nf0r, is a close friend of mine, and he had told me about a st. There is an explosion of available books and articles on the subject of antennae and antenna systems. I think that if you can deal with the open wire line routing issues, and use an efficient matching network tuner it may well be the very best multiband antenna. Ladder line, and to a certain extent twinlead, are much less lossy transmission lines than coax. The norcal doublet antenna came about due to my desire for a simple antenna that could be erected very fast, only needed one center support, and did not take up much storage room. This is my experiment with the 80 meter doublet antenna, using tv twinlead wire, which is 300 ohms. Ive put up the same multiband doublet i had at mont vernon.
This website is intended to be a source of knowledge for learning about and understanding antennas. A more efficient version would be to feed a linearloaded dipole short ham antenna directly with 450 ohm ladder line or 300 ohm twinlead. It is also the first text to treat physical theory of diffraction ptd. I think i need to find a slot for my the optimised doublet antenna talk at the club which ive given 3 times in the last 20 or so years. Nothing at all wrong with a 12 wave transmission line, in fact, 12 wave is the only length of transmission line that will repeat the antenna impedance at the transmitter end of the transmission line. Perhaps too many new hams embarking on their first hf adventures think only of resonant dipoles fed with coaxial cable and plugged directly into. For years the handbook has shown the foot center fed doublet, using open wire line to be a recommended multiband antenna. Do not install a balun between the ladder line and antenna.
Dec 28, 20 another antenna that is designed for 20m but works on 7580m is the g5rv. This book has been designed for both the undergraduate and postgraduate in electronic engineering, electrical communication engineering and electrical. The doublet antenna is essentially a balanced system and each half of the top plus each wire in the feed line must be equal in length. My initial aim was actually for a 60 meter dipole antenna. Doublet multiband antenna that is not resonant on a particular band. Dipole antenna length calculator dipoles antennas are easy to build and can be very effective when placed half a wavelenth or more above ground. It provides a broadside pattern on every band it works. The doublet antenna is a form of dipole operated with balanced feeder, typically open wire feeder and used with a tuning unit to provide multiband operation. This is my 1 st contribution and i see the hot topic is the g5rv. This was a serious contender because i figured it would probably load up just fine on some of the other bands with a pattern. If you are wondering, the g5rv antenna is mentioned.
Since the first edition in september 1939, radio amateurs and professional engineers have turned to the arrl antenna book as the source of current antenna theory and a wealth of practical howto construction projects. This book introduces the fundamental principles of. Clerks in radio stores told me that this book was outselling other titles 2. No wonder then that lb cebik, w4rnl picked the doublet as one of his top five multiband backyard antennas cebik, 2009. Doublet antenna article about doublet antenna by the. The overall antenna is in the form of pcb, regarded to consist of a doublet antenna in the lower portion of figure 1a and an elliptic loaded monopole antenna with a skirted dipole in the upper half of figure 1a. The folded dipole antenna or folded dipole aerial is widely used, not only on its own, but also as the driven element in other antennas like the yagi antenna and various other types of antenna. Elliotts antenna theory and design is one of the most significant works in electromagnetic theory and applications. It features a succinct treatment of the finite difference, time domain fdtd computational technique. What is the best book regarding antenna systems excluding. Doublets, ladder line and automatic remote tuners the. Doublet antenna article about doublet antenna by the free. One of the most important considerations when operating a radio is the type of antenna to be used.
The doublet is a nonresonant antenna that is intended to be used over very wide range of frequencies. This book introduces the fundamental principles of antenna theory and explains how to apply them to the analysis, design, and measurements of antennas. To do this the g3rwf doublet antenna had to be modelled three times. If your doublet was around 2 ft long, then the impedance at. A doublet antenna is a form of a dipole that is balanced with respect to ground. This book covers various architectures from the simple dipole to the newer antennae. The 80 meter doublet antenna 88 ft25ft 300 ohm twinlead. Highly respected authors have reunited to update the well known 1981 edition which is still hailed as one of the best in its field. Grounded antenna theory 219 types of ground s 220 counterpoise 222 ground screen 223 section iii. In terms of magic lengths, ideally the antenna wires on a shack tuned doublet should be at least 38 wavelength on the lowest band of interest so that the antenna presents a reasonable matching impedance on that band and is reasonably efficient. The success of the three previous editions of practical antenna handbook has been most gratifying. Yes, i know its dipole length will give it 1 resonant frequency. In theory, we could fashion a fourwire antenna for the 80, 40, 30, 20, 15 and 10meter bands. Of course the first ham project here has been to get an hf antenna up.
However it is my hope that newer, subsequent editions corrected a few of these glaring omissions like the slingshot, doublet, st louis, gotham and hamstick. My shack is in the basement which presented a bit of a problem of how to get the ladder line in. The range of frequency in which short dipole operates is around 3khz to 30mhz. Enter the desired operating frequency in megahertz to get a good starting length for a dipole in both feet and meters. If you have plenty of room for a real antenna farm, then a separate antenna and feed line for each band is the. Improved all band hf doublet was constructed and refined from the experience from my previous all band hf doublet for use with a zmatch antenna matching unit. The third edition of antenna theory is designed to meet. I built this antenna and quickly tried it out in february of 20.