Dual band j pole pdf

Diy tv antenna ham radio antenna radios ham radio kits spy store spy tools qrp electronic engineering hams. Indeed, although many folks like to bandy the gain advantage of a collinear. Can the popular dbj1 dual band base antenna be adapted to also work. Some hams have even gone to the trouble of lining their computer cabinets with metal foil. Portable dual band j for hotel travelers, restricted apartment dwellers, or for.

Many people, including me, have passed around plans for a simple j pole. Install 70cm stubs on the 2m antenna to create a good uhf radiation pattern. A vhfuhf dualband jpole searching for an inexpensive, highperformance dualband base antenna for vhf and uhf. Posted on march 28, 2018 october 26, 2019 by cam w4xxv tips added at the end of the article below on 10262019.

The original contruction article by wb6iqn appeared in the february 2003 issue of qst magazine. Dual band j pole w measurements for 146mhz and 446mhz coarse thread 2part version title. J pole and super jpole antenna the jpole antenna fig. The antenna shown below is an inexpensive dual band j pole antenna dbj1 that has gain on 70cm.

Although it is scheduled to be published in tars talk in a future issue, i thought it would be a good idea to add it to the download page of the website before publication. Dbj2 ed fong 121420 16 of 24 stub shows a clear resonant at 445mhz. The basic j is reported to have 3db of gain over a. With the lead in coax, total length approaches 8ft. Improving gain of the super jpole antenna new the collinear jpole, often known as the super j, does improve the behavior over a regular jpole. A vhfuhf dual band j pole 662,851 bytes, pdf file feb 2003 qst searching for an inexpensive, highperformance dual band base antenna for vhf and uhf. Based on these fundamentals, a technique is introduced to extend these principles to achieve dual band operation. The portable or base 2m70cm copper pipe j antenna by.

Dual band jpole ham radio antenna, ham radio, ham radio kits. Just follow the instuctions like on the diagram and swrs should be good. Copper dual band super j pole antenna by ka0nan, april 1993. I mentioned a commercial swr meter, as many small vhfuhf meters tend to add currents to the antenna line that. Twometer antennas are small compared to those for the lower frequency bands, and the availability of repeaters on this band greatly extends the range of lightweight low power handhelds and mobile stations. Open 2m 70cm 300 ohm ladder line twin lead jpole because. We see many claims of dual band performance sold on the internet but when we purchased many of these antennas they are just vhf antennas that also resonate at uhf. Qst feb 2003 reprinted with permission of both edison fong and the arrl cq quarterly summer 2012.

Conclusion in this paper, the dual band monopole antenna is simulated and tested using network analyzer. Mar 01, 2017 figure 3 the original dbj1 dual band j pole. I built the dual band j pole antenna from the article in the september 1994 new ham companion an easy dual band vhfuhf antenna, page 61, but i just cant get it to work. Because the velocity factor for this ladder line is different from normal 300 ohm twin lead, the traditional dimensions will not provide a good match. The copper pipe j pole matching section would be exposed to the the dbj1. Dbj1 commercial dual band base antenna 152157 mhz and 460470 mhz. Modified aluminum dual band j pole arrow antenna for fiberglass body mini rv by kk6vlv. I built the dual band j pole antenna from the article in the september. The theory for a single band j pole is first described.

K4krw collinear j pole bob k9tmus slim jim variation on j pole dual band easily built from a piece of 450 ohm ladder line. Figure 5 dual band j pole with a 220 mhz copper pipe j pole attached at the bottom. In particular, a vhf and uhf antenna for the amateur bands. Mount the antenna on a pole about 6 feet long and fasten to a step ladder or some support with some rope or electrical tape. One of the most popular vhf and uhf base station antennas is the j pole. This is because on 2m its a half wave which has a nice low radiation pattern, but on 70cm the antenna may kind of work, but it wont be working as intended and will have a. Jan 14, 2017 here is a schematic drawing of the dual band jpole antenna plans click here word doc dimensions j pole pdf print instructions for this jpole. Building jpole amateur radio antennas category is a curation of 91 web resources on, the jpole antenna revisited yet again, j pole antenna for 6 meters, concealed dss jpole. Dbj2 ed fong 121420 15 of 24 here i am in my lab using the hp8753d 6 ghz network analyzer. I have tested single band j pole configurations constructed from copper pipe, 450. The portable or base 2m70cm copper pipe j antenna by n6jsx. Variation on j pole dual band easily built from a piece of 450 ohm ladder line. Sep 28, 2018 this pin was discovered by pedro lissette. Some dual band designs have poor 70cm performance, if you look at the radiation pattern, and not just the swr.

Nov 14, 2007 it is designed for good antenna patterns on both 2m and 70cm. This is a very easy and simple 2 meter70cm vertical antenna. On a wooden or metal pole on fiberglass or plastic vehicles motorhomes, trucks, boats mount it just about anywhere. This is my revised base 2m70cm copperpipe j, a howto diy with an optional method to make a portable dual band j for hotel travelers, restricted apartment dwellers, or for limited balconypatio use. A description is then given on how this dual band principal is applied to a fully portable roll up jpole antenna. Performance reference as compared to standard j pole link btw.

Don murray w9ve building a dual band antenna mentorfest 102304 16 an even better j pole electrically the gain is about 7. The dimensions given assume that the antenna is inserted into a 3. Kb9hgi cactus dual band j pole dual band cactus j pole this is a very easy and simple 2 meter70cm vertical antenna. Although it is scheduled to be published in tars talk in a future issue, i thought it would be a good idea to add it.

The simulated antenna operates at two frequencies 900 mhz gsm band and 2. A tri band antenna for 2 meters, 220 mhz, and 70cm. These are also cheap to make and was passed on to me from another ham and i thought i would pass. The di pole antenna is so called as the half wavelength antenna. Construction plans for a modified version of the arrow model. However, i have built more than six of these antennas and can attest to the great performance. This is an excellent performing j pole type antenna, constructed from readily available materials. Dualband vhfuhf twinlead oloop of nylon line to hang antenna j pole antenna by james a. A pdf of this article, and many more, can be found i. Solution develop plans for both 3824 rod and 3816 rod clubsorgs could stockpile the cb mounts and the doubleend studs cheaply and easily 4. Ahars lmarc j pole dual band antenna 2mtr 146 mhz and 70cm 432 mhz this antenna provides a dual band 2m 70cm antenna for base and portable application. Modified aluminum dual band j pole arrow antenna for. Williams 54inches standard flat 300 ohm twinlead cut out wire and insulation w 14 notch ant to get more range out of that handhcld transceiver that just can t quite make that distant re peater all your friends brag about. Other very good j antenna designs published in 73 magazine have been.

Two meter antennas are small compared to those for the lower frequency bands, and the availability of repeaters on this band greatly extends the range of. While all the designs performed well, each had shortcomings. Well, a dual band slim jim can be done, but its performance is massively compromised on the higher band 70cm. The antenna is en closed in uvresistant pvc pipe and can thus withstand the elements with.

A balun is necessary because a j pole antenna uses a balanced feed the. A commonly used antenna is the half wave di pole antenna. Note that the dimensions are slightly longer than those in figure 3 because it is not enclosed in a pvc. Williams 54inches standard flat 300 ohm twinlead cut out wire and insulation w 14 notch ant to get more range out of that. Swr should be dual band hand held radio as a signal source and a kenwood vhfuhf power and swr meter as a tuning indicator. Research uncovered that a dual stud converting between 3816 and 3824 is found in automotive applications, but they arent a stocked item either. Dualband jpole w measurements for 146mhz and 446mhz. Dual band j p01e searching for an inexpensive, highperformance dual band base antenna for vhf and uhf. Although traditional vhf j pole antennas will resonate at uhf, they suffer a 6db loss at uhf over a. Why settle for the performance your rubber duck offers. A tri band antenna for 2 meters, 220 mhz, and 70cm antenna.

Omnidirectional the osj146440 is a heavy duty antenna. Click here for an adobe acrobat file version of the first qst article. A pdf of this article, and many more, can be found in the files folder. Ahars lmarc jpole dual band antenna 2mtr 146 mhz and. I dont know the originator of this clever adaptation so i cannot provide any acknowledgement. Build this portable j pole and boost your signal for next to. I built one of these myself and seems to work quit well. The basic configuration of the ribbon j pole is shown in figure l. Not practical for implementation although triband operation is achieved. Uhf rubber duck standard vhf j pole dual band j pole 38. The first one of mfj1724b magnet mount mobile antenna burnedout the capacitor in the. The design is based on an article that appeared many years ago 1987 in cq magazine, a version is produced by arrow antennas in the usa.

Many commercial hf antennas use this technique to achieve good patterns on their multi band antennas. Dual band 144432mhz j pole antenna colin g4fcn after the construction night in january 2016 several members showed an interest in this antenna. Benefits ground plane independent simplicity built in triplexer effect 3 feed lines simultaneous transmission no bleed over between bands assumed gain. Kinsner, ve4wk j pole 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 j pole parts list procedure p2 m1. Before i built any homebrew mobile vhf antennas, the only vhf mobile antenna i had was an mfj1724b magnet mount mobile antenna.