The jpole antenna, more properly known as the j antenna, was first invented by hans beggerow in 1909 for use in zeppelin. Remember the longer the antenna is the lower in the band it will operate, you can tune a long antenna with an antenna runer but you cannot tune a short antenna. It seems then that the impedance at the tuner would be closer to 50 ohms and easier to deal with. Rated at 100w they are great for backpacking or emergency deployment. In dealing with both antenna theory and radio wave propagation, a theoretical. This double extended version provides 3 db gain over a dipole on the band it is designed for and each side or leg is about 58 wavelength long.
When measuring the wire it is very important to get each of the two sides as close. In response, constantine balanis has updated his classic text, antenna theory, offering the most recent look at all the necessary topics. Mfj endfed zepp antennas mfj6120 free shipping on most. Zepp antenna theory heres an alternative explanation.
Btw counterpoise is also described in my ancient antenna book as a generic term for elevated radials. Developed specifically for engineers and designers who work with radio communications, radar and rf engineering, this book offers practical and handson treatment of antenna theory and techniques, and. One of the easiest, and cheapest is the extended doublezepp, or edz. To me, it seems like a full wavelength dipole a zepp might prefer a 14 wave matching section, just as an end fed zepp is recommended to have.
I have two standard textbooks on antennas, namely, antenna theory by balanis and antennas by kraus both third edition. Antenna theory analysis and design 2nd ed internet archive. Antenna tuner, matching network, matchbox, transmatch, antenna tuning unit atu, antenna coupler, and feedline coupler are all equivalent names for a device connected between a radio transmitter and its antenna, to improve power transfer between them by matching the specified load impedance of the radio to the combined input impedance of the feedline and the antenna. Understanding antennas for the nontechnical ham by n4ja. As i mentioned you could use ropes to support the extra feed length. Matching to the feedline is achieved by sliding the connection of the feedline back and forth along the stub until an impedance match is obtained.
This book is about common medium wave and high frequency short wave antennas, but the. If youve ever been intrigued by zeppelins, then these mfj endfed zepp antennas are for you. In a discipline that has experienced vast technological changes, this text offers the most recent look at all the necessary topics. Chapter 1 one of the bestknown cardinal doctrines of antenna theory is the concept of reciprocity. Ver2calwireantenna actuallyaver2callyorientated resonate12wavedipolewith theearthbeingthe return half duetopoorground conduc2vitya. In the centerfed zepp, concerns about antenna feedpoint. Many of the antenna books show this antenna fed via a 0. Double extended zepp antenna iw5edi simone hamradio. Heres an alternative explanation of how the popular zepp or zeppelin antenna works. West mountain radio extended double zepp antenna calculator. That is, it is a piece of wire onehalf wavelength long with the feedline connected at one end. New material includes smart antennas and fractal antennas, along with the latest applications in wireless communications. It features a succinct treatment of the finite difference, time domain fdtd computational technique. This book introduces the fundamental principles of antenna theory and explains how to apply them to the analysis, design, and measurements of antennas.
This website is intended to be a source of knowledge for learning about and understanding antennas. The extended double zepp or edz is one of the most successful wire antennas ever developed. Best suggestion is to make the antenna for the lowest operating frequency so that you can operate the entire band you desire. A simple and unique slide tuning system allows fine tuning once the antenna is trimmed to resonance. A zepp antenna for coverage of the amateur bands is a different proposition. The double extended zepp is a dipole type antenna consisting of two collinear 0. What is the best book regarding antenna systems excluding. The double extended zepp antenna can be fed directly with 450. The zepp name came from the use of the antenna on zeppelins in the 20s and 30s. The design was based on the endfed zep antenna as once trailed from zeppelin airships. An extended double zepp is a long dipole with 3dbd gain.
Double zepp the zepp is an endfed 12 wavelength antenna that once was trailed from a zeppelin airship. The antenna is constructed much like an ordinary dipole antenna but with 58 wavelength elements matched with an added impedance matching section of balanced feed line. The discipline of antenna theory has experienced vast technological changes. Chameleon antenna base hf endfed zepp antennas zepp.
The text explains both the basic theory of antennas and its application to practical designs. Practical, concise and complete reference for the basics of modern antenna design antennas. These are preliminary notes, intended only for distribution among the participants. Therefore, to achieve that goal, you should read this book from cover to cover. We are pleased to offer the 21st edition of the arrl antenna book. Building a double extended zepp antenna iw5edi simone. The latest resource for the study of antenna theory. It has a bit of gain and if high enough can be a great antenna on the hf bands. The extended double zepp revisited a vintage favorite still makes great single or multiband antenna. Highly respected authors have reunited to update the well known 1981 edition which is still hailed as one of the best in its field. Matching transformer the matching transformer provides impedance matching for the cha zepp antenna. It is also the first text to treat physical theory of diffraction ptd. This book is about common medium wave and high frequency short wave antennas, but the theory presented here relates to antennas of any frequency.
The main category is antennas for 40 meters band that is about 40 meter band antennas projects. The third reason is a desire to teach basic antenna theory to the average ham. The bands lie in quite good harmonic relation, and so one endfed zepp approximately 69 feet long flattop only will operate efficiently on the 40, 20 and 10 meter ham bands. Use of a dipole on several bands it is possible to use a center fed dipole over a wide range of frequencies by. The endfed zepp is a duplication of the endfed trailingwire antennas made famous by the giant airships. New material includes smart antennas and fractal antennas, along with the latest applications in wireless. The centerfed zepp can be remarkably efficient, despite the relatively high swr along its feed line. Analysis and design, 3ed by balanis and a great selection of related books, art and collectibles available now at. About 4080 halfextended double zepp antenna the resource is currently listed in in 2 categories. An antenna system is the antenna and everything else between the antenna and the radio. Use the 17 foot length and one 84 foot length to whip up a w3edpendfed zepp, or use the two 84 foot lengths for an ffd.
Balanis the discipline of antenna theory has experienced vast technological changes. Chameleon antenna endfed zepp antennas have been specially designed for apartment or attic antenna installation, and for operators who are trying to operate from condominiums under homeowners associations hoas, deed restrictions and covenants, conditions and restrictions ccrs. The extended double zepp edz a double extended zepp is a 3 db gain antenna. This link is listed in our web site directory since monday apr 2 2007, and till today 4080 halfextended double zepp antenna has been followed for a total of 11079 times. This is an antenna with a 84 foot wire on one side of the output port and a 17 foot wire on the other side. They are also very useful for ares, races, mars, emcomm, nvis, first responders and emergency preparedness. New coverage of microstrip antennas provides information essential to a wide variety of practical designs of rectangular and circular patches, including computer programs.
Horizontal antenna which is a multiple of a halfwavelength long and is fed at one end by one lead of a twowire transmission line that is some multiple of. Qikzepp antennas are light weight end fed monoband half wave wire antennas featuring portability and ease of deployment. This edition includes recent antenna innovations and applications. Arrl antenna book 24th edition is the leading resource in antenna theory. 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.
The lengths in the left column are the sum of the feedline. It was originally used on zeppelin airships in world war 1 as a trailing wire lowered from the airship while in flight. Zepp is short for zeppelinand that is where they were first used. It will also appeal to practicing engineers working on antenna development. Realizing many hams are mathematically challenged, only simple mathematics procedures are used. One of the earliest examples was the zepp antenna where the half wave antenna was end fed by an open transmission line. It is in a condensed form and the antenna theory is explained so most hams can understand it. The jpole antenna is an endfed omnidirectional halfwave antenna that is matched to the feedline by a quarter wave parallel transmission line stub of lecher system form. This length 7,050 and k or is also correct for f f 3440 and k 1. The edz is an excellent, easy to build, wire antenna that produces real usable gain with. But if i could keep only one book, i would definitely choose balanis because, in my nonexpert opinion, it is more coherent, more systematic, and has a stronger emphasis on principles. Theres been a lot of recent interest on qrpl in the w3edp antenna. The very common dipole antenna is a halfwave wire that is broken at the center for connection to the feedline.
But, i am not a theory book writer, only someone who likes to make sense of things as best i can. Think of the carolina windom antenna the modern version of the windom as an upside down vertical antenna, hanging down from its counterpoise strung more or less horizontally some 10 meters or more above ground in other words, the 22 feet vertical component of the carolina between the 4. Jerry haigwood, w5jh he extended double zepp edz antenna has been around for a lot of years. End fed antenna operating manual cross country wireless.
The frequency range of the amateur bands may be tolerated by this length even though the transmission line be terminated in an antenna impedance not a pure resistance. Yet, many amateurs still do not know much about it. Others have made up peg boards from wood with wooden dowelspeg to provde a lengthy s pattern in a short area to support extra feed lengths of owl. This antenna also requires the use of a matching network transmatch at the transmitter end of the feed line. Endfeeding a halfwavelength antenna has certain physical advantages over centerfeeding the same length of wire. Understanding antennas for the nontechnical ham by n4ja an. It can be erected in limitedspace situations where, for one reason or another, the length of feedline needed to reach a. The 58 wave vertical or the extended double zepp, at twice this length, generally represent the maximum gain scenario for singleelement antennas. A zepp is a tuned systemhalf wave antenna fed with a 14 wave feed. This antenna is often called a centerfed zepp, although any similarity to a true zepp antenna is purely visual. Parts of the antenna the cha zepp is comprised of the following components, see plate 1. Endfed zepp for receiving, november december 1941 radio. It was written primarily for the newcomer and the nontechnical oldtimer. Ictpituursi school on wireless networking for development the abdus salam international centre for theoretical physics.
The gain, directivity, radiation pattern, and electrical impedance of an antenna are the same, whether its used as a transmitting antenna or receiving antenna. The end fed half wave antenna is a classic hf antenna. End fed antenna counterpoise or matching transformer. Typically a dipole can be used down to 12 of its resonant frequency. Being a halfwave antenna, it provides a small gain over a. It theory 2016 arrl antenna book should be pretty much same when it comes to zepp description. The matter presented is essentially practical rather than theoretical. Antenna wire the antenna wire is black insulated wire and has a 25 foot matching section and 50 foot radiator section. The secret is the ladder lines low loss, but the antenna tuner is another story. There is an explosion of available books and articles on the subject of antennae and antenna systems. For a simple singlewire antenna, the gain advantage versus length reaches the point of diminishing returns on the order of a half wavelength or so. Kraus this text is for the course on antennas offered to the seniorgraduate level by most electrical engineering departments. The matching section is 450 ohm open wire feedline and is a compromise impedance between the 58 wave antenna elements and the feed point, a 4.
1356 1228 1456 1018 632 1513 138 255 986 317 923 1457 658 770 1032 170 776 204 1501 237 369 838 572 1015 321 1401 224 447 121