This article will introduce the halfextended double zepp hedz which has characteristics that a lot. It will not work well, if at all, on the 15meter band. Please read this operators manual so that you may maximize the utility you obtain from your cha zepp antenna. Base hf antenna cha zepp operators manual radiomanual. 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 load impedance of the radio to the combined input impedance of the feedline and the antenna. Measurements and simulation confirm the quarterwave stub modifies the circular hplane pattern shape increasing the gain slightly on the side of the j stub element and reducing the gain slightly on the side opposite the j stub element. Merely said, the antenna theory balanis solution manual 3rd edition pdf is universally compatible with any devices to read solutions manual to accompany antenna theory constantine a. Lets call it a efhw works on a similar principle to a zepp and jpole 0. The antenna went on to be known as a zepp antenna which was short for, you guessed it, zeppelin. Myantennas efhw80102k pass it around i want it back.
Best suggestion is to make the antenna for the lowest operating frequency so that you can operate the entire band you desire. When a straightwire antenna is fed at one end by a twowire line, the length of the antenna portion becomes critical if radiation from the line is to be held to a minimum. At hf, the dependence of q and bandwidth on antenna. It has no return conductor or shield, so the singlewire feeder.
Building a double extended zepp antenna iw5edi simone. Doublet multiband antenna that is not resonant on a particular band. The secret is the ladder lines low loss, but the antenna tuner is another story. Figure 8 moxons ideal end fed half wave length antenna with a bit added by aa5tb in the above diagram you can see that the half wave portion of the antenna presents very high impedance to the 0. History tells us this antenna originates from the days of the great air ships called zeppelins. This article will introduce the halfextended double zepp hedz which has characteristics that a lot of amateur radio operators should find quite interesting.
The performance characteristics are quite outstanding. On 20 meters the antenna is a double zepp wire or a 1 wave dipole. When tuning the length of an endfed zepp antenna, where do. Building a double extended zepp antenna iw5edi simone ham. March 1st, 2018 pdf the 40m extended double zepp nfarl pdf pdf n5. The student will construct an extended double zepp for 12meters. A very simple but very good omnidirectional vertical antenna for vhf fm simplex and repeaters. Zepp antenna theory windom antenna theory 4080 meter inverted v.
The end fed half wave antenna is a classic hf antenna. Usually, a good antenna tuner will easily adjust to these changes. The endfed zepp is a duplication of the endfed trailingwire antennas made famous by the giant airships. A marconi antenna always requires a counterpoise of some form. Unlike typical antennas, this is a nonresonant antenna. The anfig 2if the antenna length is 5 feet, a parallel. The double zepp doublet antenna is a classical antenna in our series of hs4 legendary multiband wire antennas. About 4080 halfextended double zepp antenna the resource is currently listed in in 2 categories. The third reason is a desire to teach basic antenna theory to the.
Zepp s actual feedpoint is not at the center of the dipole, but lies at the lower ends of the two vertical extensionsthat is, at the output of the antenna tuner. Windom off center fed antennas radios amplifiers baluns. Above is a diagram from the arrl antenna handbook silver 2011. This antenna will not work as an extended double zepp on 20 meters if it is. Jul 17, 2007 this book is about common medium wave and high frequency short wave antennas, but the theory presented here relates to antennas of any frequency. An improved double extended zepp by rudy severns, n6lf 32857 fox lane po box 589 cottage grove, or 97424 this article was orinally published in the arrl antenna compendium vol. Definition of the antenna and general wave motion 1 2. Because of its particular design the zepp antenna can be installed on the edge of a wooden fence, in a tree, on a house rooftop in a loop pattern, in an attic in a vertical loop pattern, twisted around a flagpole or even directly on the grass with limited communication range and performance.
The w3edp antenna is a development of the early zeppelin or zepp antennas that were used before the second world war. Theoretically, this type of antenna gives an approximate 3db gain over a conventional horizontal dipole designed for the same frequency. Extended double zepp broadside doublet lengths and amateur band coverage length feet bands covered 44 10, 12, 15, 17, 20, 30, 40 meters. In theory, with suitable selection of the feedpoint tap point and antenna length, a reasonable match should occur on multiple harmonically related bands. Endfeeding a halfwavelength antenna has certain physical advantages over centerfeeding the same length of wire. Submitted to the faculty of the worcester polytechnic institute in partial fulfillment of the requirements for the degree of bachelor of science by. Introduction an overview of common ham antennas for. The socalled end fed zepp efz is often cited as the basis for many more recent antenna designs, and is leveraged to provide and explanation though few hams understand how the efz actually works. Understanding antennas for the nontechnical ham ii preface one reason for writing this book is to educate you so you can make an informed choice concerning the best antenna for you. Occasionally, it may be necessary to add or remove a small amount of feedline, especially, in the case of this antenna, if it is desired to use it on bands other than 20 meters.
The edz is simply two 58wl monopoles configured as a dipole of about 1. Chameleon antenna base hf endfed zepp antennas zepp. Being a halfwave antenna, it provides a small gain over a. A detailed explanation of the theory of hf radio wave propagation is beyond the. Jerry haigwood, w5jh he extended double zepp edz antenna has been around for a lot of years. In theory, the 4wire antenna of fig 5 can be used with a coaxial feeder on five bands. This antenna is often called a centerfed zepp, although any similarity to a true zepp antenna is purely visual. It temporarily stores power and is related to the imaginary term of the input impedance. The design was based on the endfed zep antenna as once trailed from zeppelin airships. End fed antenna operating manual cross country wireless. Antennas built by chameleon antennatm are versatile, dependable, stealthy, and built to last.
Jun 06, 2015 a true zepp antenna works on the powers of 2 frequencies of the 12wave starting at the lowest frequency. On 15 meters and above, multiple lobes are produced as shown in the diagram below. End fed half wave antenna 285 techconnect radio club. By following fullers advice, you can build an antenna that will give you some gain and more dx in the process. Ver2calwire antenna actuallyaver2callyorientated resonate12wavedipolewith theearthbeingthe return half duetopoorground conduc2vitya. In the zepp or jpole antenna is actually 34 wave long, with the counterpoise folded back alongside the radiating element. End fed antenna choices recap end fed zepp uses ladder line for matching to coax end fed half wave even harmonics, requires special high impedance matching unit, high voltage at feed point nonresonant end fed is shorter, uses simple matching, low voltage feed. When the antenna was properly installed i adjusted its length along with a 1m long counterpoise to obtain. Balanis 1982 engineering electromagneticsbalanis 19891024 antenna theory constantine a. The september 2020 arrl vhf contest was coming and for this party i decided to make an antenna for the 6 meters band. 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.
Listed under the antennas 40m category that is about antennas for 40 meters band. Balanis 19960612 the latest resource for the study of antenna theory. The near field an electromagnetic field that exists within. The extended double zepp revisited a vintage favorite still makes great single or multiband antenna. Directional antennas yagiuda antennas feature a driven element with a passive reflector and directors monoband yagis have the best performance multiband yagis utilize traps and additional elements k4kay yagi antennas. The slot antenna can be considered as a loaded version of the inf antenna. It can be fed with ladder line from the center insulator to tuner or it can use an impedance. West mountain radio extended double zepp antenna calculator. An extended double zepp edz is a 54 wavelength centerfed dipole, i. In theory there is no difference between antennas at 10 mhz and up and those for lower frequencies. Such an antenna system for multiband operation is the endfed or zepp fed antenna shown in fig 3. When rolled in a bundle the antenna can easily fit.
They are also very useful for ares, races, mars, emcomm, nvis, first responders and emergency preparedness. They obtained their name from the fact that end fed wires were required for use on zeppelin airships. With our w3edpderived endfed zepp, the antenna will work satisfactorily on 40, 20, 15, and 10 meters. It is often measured in dbi, db above an isotropic nondirectional radiator. Zepp is short for zeppelinand that is where they were first used. 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. The achilles heel of the original single wire windom is the singlewire feeder. End fed 6 meter zepp antenna with resonance at 2 meter band. As with any homebrew antenna project, check the swr using low power and trim or add to each top half for lowest reading. This antenna is basically two 58 wave antennas end to end. Extended double zepp with formula and 8040 numbers extended double zepp e. Six meters is hot, and when six is open, all you need is a good horizontal antenna to work longdistant skip stations.
Eric webner k4fan dave tyndell kk4ly k4kl optibeam. If youve ever been intrigued by zeppelins, then these mfj endfed zepp antennas are for you. Zepp antenna a hawaii based amateur radio antenna blog focusing on the theory design and. If it is used on other bands, it is no longer an edz. Realizing many hams are mathematically challenged, only simple mathematics procedures are used. The september 2020 arrl vhf contest was coming and for this party i decided to make an antenna.
If you made the dipole antenna 530 feet long, you could use a 100 foot feeder and it would be good for the tuner on 160. The double extended zepp is a dipole type of antenna consisting of two collinear 0. 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. Below are some photos of an experimental setup for 20m that helped me understand what is going on with end fed half wavelength antennas. That would be maybe a 210 foot long antenna fed with 5060 feet of ladder line. By following fullers advice, you can build an antenna that will. Heres an alternative explanation of how the popular zepp or zeppelin antenna works.
The main category is antennas for 40 meters band that is about 40 meter band antennas projects. For example, a zepp that is 262feet long will work very well on 160meters, 80meters, 40meters, 20meters, and 10meters. The halfextended double zepp hedz antenna a dualbander. Ive had the pleasure of using chameleon antennas on several occasions and have had to fall back to the zepp on more than one occasion due to hoa rules and regulations, nosey neighbors and just ease of setup while i planned a more complete and permanent base station setup. Yet, many amateurs still do not know much about it. 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 11166 times. Jan 16, 2003 technically, an extended double zepp is a single band antenna. In the centerfed zepp, concerns about antenna feedpoint impedance matching. It is in a condensed form and the antenna theory is explained so most hams can understand it. May 29, 2014 basically, an extended double zepp is a centerfed dipole type antenna consisting of two collinear 0. The formula for figuring a 58 wave per leg is a 600 divided by the frequency in megahertz. When the feed point is moved to the shortcircuited. When the antenna and counterpoise wires are arranged in parallel, as in the zepp, it has a 67 ft long antenna wire 84 17 67 ft.
West mountain radio double extended zepp antenna calculator. A hertz antenna is selfresonant, operating independently of grounds or counterpoises. It can be fed at the low impedance point at the centre as a half wave dipole or fed at the high impedance point at either end. Today, the w3edp antenna is still widely used it is ideal where a straightforward end fed wire is needed for hf multiband. This book is about common medium wave and high frequency short wave antennas, but the theory presented here relates to antennas of any frequency. An endfed zepp will work on its fundamental frequency and on odd and even harmonic frequencies that is, where the flattop is an odd or even multiple of a half wave. Mar 15, 2011 basic antenna theory and application a major qualifying project report. The centerfed zepp can be remarkably efficient, despite the relatively high swr along its feed line. Read the article an extended double zepp antenna for 12 meters in chapter 10page.
The edz is an excellent, easy to build, wire antenna that produces real usable gain with. The 40m extended double zepp by jim streible, k4dli there were many new and somewhat unfamiliar antennas used at this years nfarl field day. The hertz antenna is an antenna with an electrical length of a half wavelength at its resonant frequency. With 85 of feeder the antenna would need to be shorter, or a whole lot longer, and then you get into other issues. 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 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. An extended zepp ez is an endfed 58 wavelength antenna. Vertical extended double zepp antenna for 2 metres fm and. Zepp antenna theory windom antenna theory 4080 meter inverted v dipole antenna antennas for difficult situations g7fek limited space antenna nested marconi antenna doublet aerial for hf amateur ham radio short wave bands some general talk about design and builds, worth watching, useful info.
An antenna s properties are the same, whether it is used for transmitting or receiving. Self impedance the impedance at the antenna s feed point not the feed point in the shack. The radio shack on board a zeppelin air ship would, at altitude, trail a half wave antenna with a quarter wave tuning stub behind the air ship. 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. End fed zepp antenna with qrp zmatch tuner, 30m80m. This antenna wire is fed via a section of parallelwire transmission line with 14 the length of the antenna wire i. He also offers some sage advice about computer modeling. Primarily a dipole, the jpole antenna exhibits a mostly circular pattern in the h plane with an average freespace gain near 2.
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