J pole antenna design calculator by k4abt ham universe. On this page you will find many illustrations ive drawn to help you understand the manner in which a j pole is built. I specialize in a certain type of antenna called a j pole. Kinsner, ve4wk jpole antenna for 2m 3 of 3 1 2 3 4 5 6 7 8 e d c b a e d c b a 1 2 3 4 5 6 7 8 5 june 1992 jpole parts list procedure p2 m1.
Unlike the popular ground plane antenna, it doesnt need ground the dbj2. Building jpole amateur radio antennas category is a curation of 86 web resources on, the jpole antenna revisited yet again, the copper cactus jpole, j pole antenna for 6 meters. A common feed line would also eliminate the need for a duplexer. Articles researching and discussing the famous jpole antenna. Aug 23, 20 i am going to build a dual band j pole antenna.
The great thing about jpole antennas is their simple design and excellent performance. In my spare time, i build uhfvhf antennas and design electronic circuits like the power pole distribution center for the advancement of ham radio. Kb9vbr jpole antennas amateur radio vhf and uhf antennas. Both plans call for 38 stainless threaded rod which i will be using. True plumbers delight for 2 meters an all copper j pole. Primarily a dipole, the j pole antenna exhibits a mostly circular pattern in the h plane with an average freespace gain near 2. Simply the best model osj 146440 open stub jpole we dont invent antennas. The j pole antenna is a popular antenna design among amateur radio operators because it is effective and easy to build. On most of the j pole designs out there, a choke should be used as close to the feed point of the antenna as possible to help prevent rf on the feedline and creating difficulty with swr readings. On most of the j pole designs out there, a choke should be used as close to the feedpoint of the antenna as possible to help prevent rf on the feedline and creating difficulty with swr readings. The picture to the right is of a 2m amateur radio band jpole i built from an eznec simulation. This calculator can be used to design a slim jim or a j pole antenna. J pole antenna design calculator by k4abt simple ham radio antennas a hawaiibased amateur radio antenna blog focusing on the theory, design, and use of homemade. The antenna is en closed in uvresistant pvc pipe and.
The j pole antenna is a 12 wave antenna with a 14 wave matching stub. Resources listed under j pole category belongs to antennas main collection, and. The construction plans presented in this newsletter are based on my new design, and describe such an optimal antenna. I am not sure if it will make any difference using 34 copper over the 12 conduit. Design of a dual patch triangular microstrip antenna. Building j pole amateur radio antennas category is a curation of 86 web resources on, the j pole antenna revisited yet again, the copper cactus j pole, j pole antenna for 6 meters. The basic j is reported to have 3db of gain over a. While there is no problem working the vari ous repeaters around town with my 14 wave antenna, simplex operation left a lot to be desired, so i felt something with a little more. It is an implementation of one of the oldest antenna designs. Ive had many requests for a readymade j pole design that will enable the amateur radio user to print the image from a web page and go directly to the construction table and build a j pole antenna for their ham radio station. A balun is necessary because a jpole antenna uses a balanced feed the. As many attest, there is an advantage when vertically combining 12 radiating sections to have a bit of separation between the halfwave end points. Aug 07, 2015 the j pole jpole antenna variations source.
Most of the big boys around my qth were regularly working a repeater which is located roughly 70 miles away. Used as a vertical vhfuhf antenna, the jpole has the advantage that it is omnidirectional, has a low angle of radiation, and does not require. I built the dualband jpole antenna from the article in the september. May 28, 2016 the collinear j pole, often known as the super j, does improve the behavior over a regular j pole. Copper dualband super jpole antenna by ka0nan, april 1993. The radiowavz portable j pole family of antennas comes with a carry pouch and 5ft of rg8x coax. Ive had many requests for a readymade jpole design that will enable the amateur radio user to print the image from a web page and go directly to the construction table and build a jpole antenna for their ham radio station. The simplest way to make a balun is to get a splitcore cylindrical ferrite such as an amidon 2x43251. This picture shows that the base of the antenna is mounted flush to the top of the mast. The feed point is usually placed at the centre of the dipole, for although this is not absolutely necessary, it can help prevent. The jpole antennas long and storied design history is due for one more chapter to mitigate the longstanding mast current and reliability issues. The super j has very little separation between the two halfwave radiators. J pole antenna design calculator by k4abt simple ham radio.
It is used to design jpole antennas for the desired frequency. The zepp antenna received a rebirth in the form of the j antenna or jpole. Copper dualband super j pole antenna by ka0nan, april 1993. The great thing about j pole antennas is their simple design and excellent performance. This is important because if the mast extends above the antenna ground plane.
Design your j pole for hf, 2 meters, 220, 440 and up. While still using copper pipe, you can build a less visible antenna with better performance than a jpole. The idea of a folding version of the copper antenna appealed to me. It has proven to be fairly insensitive to construction methods and materials. See more ideas about ham radio antenna and ham radio. J pole antenna dbj1 a vhfuhf dualband jpole antenna, pdf file. J pole antenna design calculator by k4abt simple ham radio antennas a hawaiibased amateur radio antenna blog focusing on the theory, design, and use of homemade antennas. Having recently expanded my amateur radio collection to include 6meters, i found myself needing something more than the wire dipole antenna i originally installed. The dualband openstub jpole antenna built out of heavy duty 316 angle aluminum, uhf so239 connector with 38 aluminum elements and all stainless steel hardware. The vhf dipole antenna at vhf and uhf, most antenna systems are derived from the dipole or its complement, the slot antenna.
This antenna was then tested on buchberg and i managed 4 contacts into north america on 15 metres with it using just 5 watts the amplifier had blown one of its transistors on weichberg without me realising until i saw it was not operating on buchberg. The super j pole antenna collinear design below is a javascript for calculating the lengths of tubing to be used for the construction of a super j pole. This is important because if the mast extends above the antenna ground plane it will affect the performance of the antenna. I specialize in a certain type of antenna called a jpole. This article describes how to convert the traditional single band ribbon j pole design to dualband operation.
Jul 22, 2015 the original ed fong dual band vhfuhf 70cm2m j pole pvc pipe antenna. Kb9vbr jpole antennas amateur radio, land mobile, scanner, low power fm, and airband antennas. Buck rogers sr 68 years as k4abt the jpole has been around since the early days of ham radio, and is a direct descendant of the windom like the windom or zepp, the jpole is a spinoff, or a modified windom for vhf and uhf. Jpole antenna is pretty easy to build and usually designed by amateur radio operators through this software, you can easily find out four important parameters to build this antenna namely, radiator length, driven stud length, gap space, and feedpoint. The radiating element of this antenna must be clear of nearby metal objects by at least inchey if side mounted on an use 6 foot side mount top of antenna may requne. Jpole antenna for this station, i used a stan dard 14wave ground plane vertical antenna. This made it all to easy for us to build the antennas. While there is no problem working the vari ous repeaters around town with my 14 wave antenna, simplex operation left a lot to be desired, so i felt something with a little more gain was necessary. Categories antennas tags inductance, jpole, simulation, stub, uhf, vhf. The jpole antenna is a common omni directional antenna used in amateur radio, particularly on the vhf and uhf bands. 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. For what its worth, the myths surrounding the j antenna have been sorted out resulting in an improved version. Its basically an endfed omnidirectional halfwave antenna, matched to.
Heavyduty super sturdy 58 coupling nut for added resilience. Building the antenna i like the copper jpole, so i started a design using that antenna as a model. The super j pole antenna for 430 450mhz was constructed and used for fm simplex and repeater operation at my previous residence in melbourne, victoria from 2002 2007 the super j pole antenna is a colinear vertical consisting of a number of half wave length vertical elements separated with halfwave length stubs tuning stub feed with a. Many antennas are based on halfwave dipoles fabricated from wire or tubing. The super jpole antenna for 430 450mhz was constructed and used for fm simplex and repeater operation at my previous residence in melbourne, victoria from 2002 2007 the super j pole antenna is a colinear vertical consisting of a number of half wave length vertical elements separated with halfwave length stubs tuning stub feed with a. The antenna is enclosed in uvresistant pvc pipe and can thus withstand the elements with only the antenna connector. This article describes how to convert the traditional single band ribbon jpole design to dualband operation. 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. Other very good j antenna designs published in 73 magazine have been.
Jpole is a free and portable antenna design software for windows. The superj has very little separation between the two halfwave radiators. Design a jpole antenna long radiating element, short stub element. I went to the local lumberyard and hardware store a home building supply will work, as well a backpackers delight the folding jpole a new twist on the old jpole. I am not sure if it will make any difference using 34. J pole antenna calculation calculate dimensions for. Dbjuhf was developed from a grant from ac daughty to develop a low cost medium gain mesh antenna for uhf. We will use this wavelength equation for all of our calculations. It is simply an airship zepp antenna standing upright. The j pole antenna is an adaptation of a 12 wavelength radiator end fed by a 14 wavelength transmission line that was developed as a trailing hf antenna for zeppelin airships in the 1930s. So a success with the coax fed half wave vertical antenna which was now being called a jpole. Measurements and analysis suggest why quarterwave stubs fail to completely. Copper pipe j pole antenna the j pole antenna form of the zepp antenna is one of the more popular homemade vhfuhf vertical antennas.
Unlike a vertical dipole, which because of its center feed is usually mounted alongside a tower or some kind of metal supporting structure, the radiation pattern of an endfed jpole mounted at. Online physics calculator that calculates the long, short section, feed point, spacing dimensions values for current frequency. J pole antenna for this station, i used a stan dard 14wave ground plane vertical antenna. However, the jpoles highly visible profile may be objectionable to some neighbors. The radiowavz portable jpole family of antennas comes with a carry pouch and 5ft of rg8x coax. Jpole and super jpole antenna the jpole antenna fig. Copper pipe jpole antenna the jpole antenna form of the zepp antenna is one of the more popular homemade vhfuhf vertical antennas. I built the dualband jpole antenna from the article in the september 1994 new ham companion an easy dualband vhfuhf antenna, page 61, but i just cant get it to work. The jpole antennas long and storied design history is due for one more chapter to mitigate. The jpole antenna is an adaptation of a 12 wavelength radiator end fed by a 14 wavelength transmission line that was developed as a trailing hf antenna for zeppelin airships in the 1930s. He decide to redraw the plans and he provided all of the needed dimensions. Used as a vertical vhfuhf antenna, the j pole has the advantage that it is omnidirectional, has a low angle of radiation, and does not require.
However, the j pole s highly visible profile may be objectionable to some neighbors. They look pretty weird, as can be seen in the following photo. Essentially, a jpole is a 12 wave resonant antenna connected to a quarter wave matching stub. For 2 meters, the coil is 4 turns of coax at 5 inches in diameter. Since the antenna needed to be vertically polarized, i hit upon the notion of a jpole.
While still using copper pipe, you can build a less visible antenna with better performance than a j pole. 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. My antennas have a low noise floor and a beautiful omnidirectional radiation pattern. Principles of the dbj1 the earlier dbj1 is based on the jpole,2 shown in figure 1. A portable vhfuhf rollup jpole antenna for public service edison fong, wb6iqn. For a 2 meter f 146 mhz jpole antenna, the 12 wavelength radiating section section a is equal to a 0. Some hams have even gone to the trouble of lining their computer cabinets with metal foil. Being a halfwave antenna, it provides a small gain over a. A touch of class, the windom and the jpole by glynn e. Its basically an endfed omnidirectional halfwave antenna, matched to the feedline by a quarter wave transmission line stub. The design and implementation of a 2m j pole antenna technical report, del921, november 1992, 40 pp.
The slim jim, designed by the late fred judd, g2bcx, can be a great portable roll up antenna, if made out of 300. Another great antenna for both home and portable operations is the classic delta loop, which you can use in. Vhfuhf antenna, page 61, but i just cant get it to work. Ive had many requests for a readymade jpole design that will enable the amateur radio user to print the image from a web page and go directly to the construction table. A tri band antenna for 2 meters, 220 mhz, and 70cm antenna. My name is michael, kb9vbr, and i carry a full line of vhf and uhf antennas for sale. The collinear jpole, often known as the superj, does improve the behavior over a regular jpole. The super jpole antennacollinear design below is a javascript for calculating the lengths of tubing to be used for the construction of a super jpole. This optimized portable jpole antenna can greatly increase the efficiency and coverage of your ht. The zepp antenna received a rebirth in the form of the j antenna or j pole.
The jpole antenna is a 12 wave antenna with a 14 wave matching stub. Pdf modified fractal super jpole antenna researchgate. Vhfuhf antenna, page 61, but i just cant get it to. The super jpole antennacollinear design mark twain. A balun is necessary because a jpole antenna uses a balanced feed the 14wavelength matching section connected to an unbalanced feed line the coax. If thats your situation, this may be the antenna for you. The original ed fong dual band vhfuhf 70cm2m jpole pvc pipe antenna. I have two different plans that i found on the internet. The basic jpole antenna is a halfwave vertical configuration. This optimized portable j pole antenna can greatly increase the efficiency and coverage of your ht. Please take a look at the products listed on the left, and see which fits your needs.
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