This design is excellent for matching both long and short length wire antennas for multiband use. endobj 4 0 obj 35. 1 0 obj /ProcSet 7 0 R >> 35-43, 49-63, 70-85. Swr usually is all over the place and the tuner will just not do it's job. So is an essential piece of gear to have. , This is a partial reprint (with permission) of an excellent series of articles published by KV5R It is used for non-resonant verticals like 43 foot or 33 foot Or Wire antennas like an End-Fed 1/2 Wave Multiple Length Wire Antenna. 49:1 or other high ratio transformers are for resonant "cut to frequency" antennas like the traditional zepp/fuchs antenna. (Originally published February 22, 2021). The beauty of the halfwave antenna is it's a complete antenna in the sense it needs no counterpoise. The idea It is not a good choice for working lower bands from a too short wire, that is, if you have cut your wire to a 20m halfwave, it ain't much punkin' for 40m, 80m, or 160m. Solder a the 100pF capacitor between the center conductor wire and ground wires. Our newdesign isperfect for matching both long and short length wire antennas for multiband use. Electronics The short piece is for the primary winding of the transformer, and the long piece is for the secondary winding of the transformer. This is to avoid the antenna radiator from acting like a resistor, and thus instead of radiating radiofrequency energy produced by the transmitter, sending it back down the coax toward the transmitter. Balun Designs. When on the trail, at Field Day, or whenever a good antenna is x][~ XwiH:99gn`1-wz;n[VbW7JH4D]>}>y/D_^7,yyx}s*nveo>mn|6k7GMY4%" M)?O|'opw8o1\5JNe:9hTc5@Ik~aE%O^0$ 0E 'BX2?R!t&^E"3oqbW |${boEU>jU:]bQW?4, u1'^`oQ_4E 0~y L^'y}-RHV8L KSZ?mF4lTv'r^mF|":e}?VdTm7bGR]PchDpb*{*HGJ-m)bC!EX"iM%8L7O7-=jcn+D{_' I HH~v70J^9$.7m]knq)L(UQ%OrK:nn!8*EP Longer wire is always more 2 0 obj /BitsPerComponent 8 There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). It is important to use a counterpoise. This project assembles a 49:1 ferrite-core ("FT") type #43 transformer that matches 50 ohm input to 2500 ohm end fed antenna. The kit includes the parts needed to construct a 49:1 impedance matching network, which will transform the impedance to 50 Ohms, which will suit most transceivers. This is not exactly a 1/2 wavelength in free space, but works for wire as it has a different velocity factor than "air". Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. This is a 4:1 Current Balun.That means it can match a 200ohm antenna to a 50 feed line. Enclosure Height: 5.000 in. He knew that in order for the tuner to "see" a fairly low swr to work within it's range,that the antenna had to be NOT A HALF WAVE ON ANY FREQUENCY that we wanted to us, because a half wave will give us a very high impedance and the resultingswr into a 50 ohm transmitter! As an example, a 28-31 foot wire will typically allow 40 thru 10 meter coverage and a 43-50 foot wire will provide access to 80 thru 10 meters. these are the worst lengths and you want to be as far from colored Wire-Lengths-for-9-1-ununs.pdf Created Date: 12/12/2022 11:20:42 AM . 2 0 obj /Title (Wire-Lengths-for-9-1-ununs.pdf) The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. /XObject << /Im0 9 0 R >> Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. Links This is a followup video to #344 where I assembled the 49:1 UNUN kit from HF-Kits / ARRL. This transformer converts the impedance at the end . /Name /Im0 The 49:1 unun with 3000 ohms of resistance shows a VSWR under 10:1 from 160M to 15M, and less than 3:1 from 80M to 20M. Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. Clansman End Fed Long Wire Antenna Used. Shortwave Listening Continue twisting the entire length of the short wire. At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. 4 0 obj Update guys:made the unun,the antenna was extended to about 37m length,and I added a counterpoise which is about 10m.The whole thing is much higher in the air,compared to where it was before. Building on the original 1:1 design by Dr. Jerry Sevick, this balun has two (2) cores in a stacked Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW, Decrease Quantity of Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW, Increase Quantity of Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW. /CreationDate (D:20221212112042) For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, We have also installed an additionalstud which can be used for a separate counterpoise wire rather than forcing the use of the feedline's coax shield, ttaching a counterpoise wire to the common point of the auto-transformer, provides the antenna radiator something to push against rather than the coax shield. I have found this calculation to work well, however it depends on many factors such as wire used, location etc. The key to end fed antenna success is the matching network interface between the long wire antenna and the coax feed line and feed line choke at the transceiver. Theme: Newsup by Themeansar. When used with the stated lengths shown in thetable below, the 9:1 ratio will Based on the success of our model 4932, this 5kWconfigurationisalso perfect for matching both long and short length wire antennas for multiband use. endobj Here Is a 250 Watt Home-Brew That I Made In about an Hour. 2 0 obj I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. << tuner the colored bands below are the best lengths as long as your Computer Help 1 X FT240-43 Ferrite Toroid Core 43 Material(Mouser Electronics), 1 X SO-239 UHF PANEL JACK S/CUP SO-239(Mouser Electronics), No. I used the RigExpert Zoom AA-55 to test VSWR of the 49:1 unun impedance transformer. I took a literally random length of 14 gauge house wire and attached a banana plug to be shoved into the antenna port of the tuner. The length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). So you have the freq range of interest and the total length of the wire, figuring out wich balun will be a better match for 50ohm coax should be easy. Usually any wire length that is non resonant on the band or bands desired will work with the 4:1 ratio. If the choices are. In fact, the 9:1 unun that I built is actually an autotransformer. We hoisted the free end of the antenna wire approximately 30 feet into a tree. Random wire lengths you should and should not use! Turns 1 & 2 are primary windings (the short wire). . document.getElementById("copyright_year").innerHTML = new Date().getFullYear(); u?X`f0&/Ri;W0Tn_*TX:ug 40-30-20-17. /Resources << SWR will vary based on topography, wire orientation and use of ground or counterpoise. Let the now free end of the short wire hang down from the toroid. A 50 foot run of RG-8X coax connected the antenna into the LDG Z100-plus tuner and then a Yaesu FT-891A transceiver. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. This will be for an eyehook in order to provide strain relief for the radiator wire. 1863 1.49 swr 3915 2.50 7200 1.80 14.332 1.29 18.130 1.07 21.300 1.40 24.950 1.30 28.400 1.37 This is a great antenna that is . The random wire antenna is probably one of the least expensive, easiest and cheapest HF antennas to use if you have a tuner and you want to get the "most" out of a length of "random" wire without having to pull out that calculator, doing the math, getting the center insulator built orbought, running the feedline, and all the rest that goes with putting up a more elaborate antenna. SWR was good after cutting the wire to appropriate length. $1YacO5Q}YC\>qZ } Weight: 0.380 lbs. In theory, my LDG Z100 Plus autotuner should be capable of matching the impedance of this 49:1 transformer with a end-fed half wave length antenna radiator across all amateur HF bands. Theme designed by Papathemes. stream Product Reviews A small ring terminal for 14ga wire that fits these screws would be helpful too. (Note: I am not satisfied with this part of the project, so I will describe it here briefly. 35-45, 54-64, 67-77. % Cannon". Make sure the beginning few inches of twisted wire is not involved in the winding (i.e., just hanging down from the toroid). Again, the bands are USA, so change them A success! A few more comments about this 49:1 autotransformer EFHW design. One is for the top of the box so that it can be hung up. The other is to provide strain relief for the antenna wire). Ham Satellites [ /PDF /Text /ImageI ] Just add or subtract as needed a little at a time toget the best compromise. The fewer bands, the fewer high impedance regions to avoid. I sent him the link to the 49:1 unit to get his feedback. Well then you need to choose a wire length that is at least 1/4 on 40 meters, and doesn't fall on any of the 1/2 multiples for ALL the bands between 40 to 10 meters While you could certainly calculate the lengths to avoid using the standard formulas, and then make a chart, the section below may be what you are looking for. >> Q Step 1: Drill holes for and install the SO-239 or BNC connector, the stainless steel machine screw antenna connector and the ss machine screw ground connector. 9:1 or 49:1 unun for end-fed long/random wire? It is optimized for 3.5/7/10/14 MHz but will work reasonably well on all amateur bands from 80 meters thru 10 meters with a 135 foot length of wire and a short connection to ground. Advertising Info https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. You also want the antenna to be at least 1/4 wavelength long for each band you plan to use. Box cutter (for scraping enamel off of wire ends), (Helpful) Step drill bit for SO-239 connector, Paracord (for simulating and measuring lengths of windings on toroid), Antenna analyzer for HF frequencies (I use the RigExpert Zoom AA-55), Resistor(s) totaling about 3000 ohms (I used 1K and 2K ohm resistors in series). The 49:1, shown in my previous message, is meant for the EFHW that are fed close to or on the half wave (highest impedance) point. Wait a few minutes for glue to set. stream random wire should use 423/f. Support The Site This was 9m vertically metres up a fishing pole and then about 5.8m out. 32.00. Typically unbalanced = 50/75 ohms too unbalanced = 450/675 ohms. X:nzf4p:t;r }~_HOZcX:^$* J^XZuu|"nX/Wkw0hA>y1(z2+v_Xzu[/:^$*m*>hk_:+c{ Kj8~q7c? Just an FYI that I thought you might be interested in. Ham Hints Cut the ground wires (free twisted short and long wires) of the unun to the correct size, scrape the enamel insulation off of the free end with a box cutter, and add a ring terminal. Drill a hole in the top for an eyehook (to be used to secure the unun to whatever it is you want to hang it from.). Power handling is 100 watts CW / SSB & 25W Data modes. So, having nothing better to do one day, I re-did the calculations going out to 500 feet. https://www.kb6nu.com/playing-end-fed-wire-antennas-91-ununs/, http://www.hamuniverse.com/randomwireantennalengths.html, https://www.youtube.com/watch?v=sty7RlXQoJI, https://www.youtube.com/watch?v=WwJnXTVUrgI, Quote from: refmo on October 15, 2019, 2036 UTC, Quote from: joczo on October 16, 2019, 0815 UTC, http://www.w3pga.org/Antenna%20Books/Reflections%20III.pdf, http://www.arrl.org/files/file/Technology/tis/info/pdf/7007024.pdf, http://www.tasrt.ca/AntennaTips/AntennaTips.htm, http://www.wb2rcb.com/documents/balunlin.pdf. The "Super Bullet" End Fed Long Wire Antenna Matcher - 1500/3000 watt rated for Super-Punch of your signal! something as high as you can find. 33 ft #18 insulated copper wire (20m half wave), Counterpoise: 1 meter coax (0.05 x wavelength) connected between 64131 and Balun Designs 1115d Isolation /Choking balun, If you would like to use high power up to legal limit with a single end fed wire antenna (not necessarily a half wave) consider using our. IMG_2.jpg Step 2: Take the 6 feet of 18 gauge enameled copper wire, measure 11" from one end and fold it back. Figure 3 Wiring of the 9:1 voltage unun. Here Is a 250 Watt Home-Brew That I Made In about an Hour. When you're 1/2w long you're around 2k ohms or more where the balun won't under or over xform; as you approach 3/4w your z is going to drop to where a coax match can be made just by soldering the wire to the center conductor sans balun - more or less the principle of the windom and ocf dipole. 2. %PDF-1.4 are blocked out because an antenna should be at least that long. However, the list has been revised and is good for wires as long as 500 feet. 27.00 (27.00/Unit) Free Postage. . An excellent way to attach a long wire antenna to the Ham It Up, this 1:9 balun has an SMA output port and high-quality spring-type terminal block input for your coax. (Also note that here may be instances where the suggested lengths may not work exactly due to the many variables in the surroundings of the antenna, wire length variances, your tuner, it's height above ground, it's construction, etc. For calculating the length of a half wave in metres, I use 141 (MHz) for wire elements. I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. We are working every day to make sure our community is the best Radio Hobbyist's site. Site Map endobj An UNUN is needed to match the high impedance of an end fed antenna (2k-4k ohms range). It may not display this or other websites correctly. Lengths for Long-wire Antennas Jack - VE3EED Recommended lengths: 29 - 35.5 - 41 - 58 - 71 - 84 - 107 - 119 - 148 - 203 - 347 - 407 - 423 Not recommended lengths: 16 - 19 - 22 - 26 - 32 - 33 - 38 - 44 - 46 - 48 - 52 - 64 - 65 - 66 - 76 Prescott Hamfest 2023 Saturday - May 13, 2023 - 0800 to 1200 MST Granville Elementary School 5250 Stover Drive, Prescott Valley, AZ 86314 The 2023 Prescott Hamfest is co-sponsored by the Yavapai Amateur Radio Club (YARC) and the Amateur Radio Council of Arizona (ARCA). Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas. endobj Each winding is counted when the wire enters through the center hole of the toroid. wire lengths less than 1/4 wavelength of the lowest desired frequency For example, when adding a 1/4w tiger tail to a 2m ht with a halfwave for antenna will likely show no improvement at all in tx or rx strengths. Antenna Design You have to give up a band or two, like 60m and 6m, as 3 to31 MHz - up to 1kW intermittent (50% duty cycle). . Antenna Safety! If you would like to use high power up to legal limit with a single end fed wire antenna (not necessarily a half wave) consider using our Model 9135 along with one of the wire lengths shown in the Installation Notes. I'll get a 9:1 unun,and use a suggested random wire length to avoid half-wave and it's multiples then,that sounds like the best things I can get out of this setup. ", KiwiSDR Online Radio - 500 ft Northeast Beverage, KiwiSDR Online Radio - 400 ft South Beverage, KiwiSDR Online Radio - 10/11m dipole up 20 meters high. The major point of this message is to tell you that approximately 20 minutes after I connected the balun unit to the antenna, I made contact with a gentleman in Italy-my first European contact!! Anyway, an old friend mentioned 'MyAntenna.com' but they were closed for the summer. Drill a hole in one side for the antenna radiator wire mount (for a #8 bolt in my build). (The numbers aboveare a great start, thanks to Jack and Mike! Click to enlarge. The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. Use only the white gaps for your antenna lengths, and if UJM-49-1 $56.99 Save up to 6% when you buy more. 4 0 obj want the antenna to be at least 1/4 wavelength long for each band you which got me thinking. >> I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. The Nelson antenna 9 to 1 unun did the trick. After winding #2 is made and extends down the backside of the toroid, untwist the wires. >> License Study random wire page. I made just a touch over 100 QSOs today with the new unit. , Reprinted with permission of Hamuniverse, this is an excellent explanation of SWR and how to best me endobj The graph below shows lengths to avoid for different collections of bands. Use with other lengths can potentially damage the transformer depending on power level in use. There probably should be some holes for ventilation. That type of wire antenna could be lower than 50 ohms at some frequencies and over 2,000 ohms at . 3 0 obj (A t0 B) Fold over 6 to 8 inches and twist it together. stream For a better experience, please enable JavaScript in your browser before proceeding. shown in the column e. var sc_project=8077274; Midi Music (Also check out AB3AP'Swebsite and say thanks for sharing his skills. In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. For instance, to work 40m be sure the antenna is at least google_ad_slot = "1982258389"; EFHW unun Resonant Long Wire 49:1 Transformer With 67' Antenna Wire. /MediaBox [0 0 748 752] rig, often with no feedline, and the other end in the air attached to So for example 80m could range in length from 120 to 133 feet. but instead of the Jaycar core, we used an Amidon FT-240-43; anyhow, we also followed the UnUn with a 1:1 guanella choke and boxed everything, at that point, we . I connected the free untwisted end of the short wire to the center conductor of my homemade testing jig (see tools list) with an alligator clip. << Power Handling (CW/SSB): 100 W/200 W Enclosure Width: 2.500 in. an auto-tuner at the base vs. the same antenna fed a 4:1 balun wound with 75 ohm coax on two separate type 43 ferrite cores and a remotely sited tuner fed via 200ft of low loss LDF2-50 coax vs. a broadband antenna of the same element length. The ratio doesn't need to be 49:1 2,400 ohm either, other ratios will transform to other impedance. /Producer (XnView, http://www.xnview.com) Stacked coreswithwinding configured as 49:1auto transformer. The unun was floating at about 15 feet above ground. I have used the 49.2 ft (15 Meter) length of wire on vacation with both automatic tuners and an MFJ Model 16010 tuner with good results for 40, 20, 17, and 15 Meter operation. it is easy to pack and easy to install. /ModDate (D:20221212112042) A good place to start is the formula 468 / f (MHz) for a 1/2 wavelength wire antenna. Coverutilizes integralneoprene gasket for weatherproof integrity. I made one without doing this and it didn't work so well. Humor 31 you're using different ham bands than in these examples, modify and rerun This antenna, which works on 10, 15, 20, and 40 meters, has a very high impedance of around 2,500 Ohms. /Count 1 1936 article, however, fall in line with 468/f and so is used here. this 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA %PDF-1.5 % You will also need a half-wavelength length of wire (14 or 12 gauge typically) in order to construct an antenna radiator for whichever ham band you choose.
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