I have found this calculation to work well, however it depends on many factors such as wire used, location etc. [ /PDF /Text /ImageI ] 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. Hi guys,not really hfu related,but I tought I might ask here as I have my account. which got me thinking. For instance, to work 40m be sure the antenna is at least Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. BUILD INSTRUCTIONS FOR 49:1 UNUN IMPEDEDENCE TRANSFORMER: WX1MAR and I brought the DIY 49:1 unun with a borrowed antenna radiator wire cut for 20M half-wavelength to Ashland State Park K-2417 in Massachusetts for a Parks-on-the-Air (POTA) activation. The length should be calculated based on the lowest frequency to be worked. 3 0 obj Stacked coreswithwinding configured as 49:1auto transformer. Thanks for your answer,I will probably go with the 9:1 then. It uses an FT140-43 or FT240-43 toroid in a 49:1 impedance matching unit at the base and a 110 micro Henry (H) coil to act as a loading coil for 80m and a choke to stop higher frequencies using the last 2m of wire. Free Postage. "Just received my new 64131 yesterday and was anxious to see how well it performed. . 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. 49:1 UNUN Transformer 2 Kw 160 - 40 m - Wire Antennas The matching unit The impedance at the end of a half wave antenna is somewhere between 2000-5000 Ohms. 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA Midi Music That type of wire antenna could be lower than 50 ohms at some frequencies and over 2,000 ohms at . so that it is not a halfwave multiple of any frequency you want to use. Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. REVISED: 16 19 22 26 32 33 38 44 46 48 52 64 65 66 76 78 80 88 92 95 96 99 104 110 112 114 123 128 130 132 133 138 144 152 154 156 160 165 171 176 182 184 190 192 195 198 208 209 220 224 228 230 231 234 240 242 246 247 256 260 264 266 272 276 285 286 288 297 304 308 312 320 322 323 325 330 336 338 342 352 361 363 364 366 368 369 374 380 384 390 396 399 400 414 416 418 429 432 437 440 442 448 455 456 460 462 464 468 475 480 484 494 495 496. You have to give up a band or two, like 60m and 6m, as endobj ones How to Make a Balun or Unun : 3 Steps - Instructables Then verify it with your installed antenna and SWR measurements. So for example 80m could range in length from 120 to 133 feet. Advertising Info Repeater Builders presents an extremely high impedance to the tu The most common question I get asked is what is the correct length for my End Fed Long Wire Antenna? 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! In the first year using this unun with a random length endfed wire (Aluminum Elec fence wire at that) I managed to confirm WAS via LoTW on 10m, 15, 17, 20, 30, 40, 80. . tuner the colored bands below are the best lengths as long as your EFHW unun Resonant Long Wire 49:1 Transformer With 67' Antenna Wire. While I have not done so yet, I plan on gluing the test cap to the back of the junction box. $1YacO5Q}YC\>qZ } hb```YloD@(aKI V!}g@~}%Q/[[~_=Wy-:O)x[~hs/~SGeG _QE C6q %r HF Antenna Choice 9:1 vs 49:1 vs PAR - Antennas - SOTA Reflector /CreationDate (D:20221212112042) . The 30 day return period lapsed before I could get the antenna deployed to test it. Turns 1 through 14 are secondary windings (the long wire). (The numbers aboveare a great start, thanks to Jack and Mike! Moving the pot up and down gives a feel for the SWR versus antenna impedance sensitivity. Wire lengths for the 4:1 ratio in models 4932 and 4935. j#f5(fk0?P[polEo5b2-/oVZu1Qo-I6C/M@TbddPc#cdZZ|7+|o{}!F#?Go7ju|?wwgow/c2/W-m~~hn[S29OU}}r7lc]wsw[shS[#qbrrK[7*0,Xv{k+o {=*vo S__O~*=y/zk75O?yjCnXS{`~Ii'c_GxN. /Title (Wire-Lengths-for-9-1-ununs.pdf) % you're using different ham bands than in these examples, modify and rerun Any SWR measurement taken with the transformer at the feedpoint should not exceed 1.5:1withNOtuner in use. I made one without doing this and it didn't work so well. The fewer bands, the fewer high impedance regions to avoid. I made just a touch over 100 QSOs today with the new unit. Designed for those who want the maximum isolation and choking across the full HF spectrum. Quantity: Sold individually. Built with the same craftsmanship as all our other units, this new model will allow you to either replace your current matching unit or construct a new higher powerend fed half wave antenna. End-Fed Half-Wave Antenna Kit - American Radio Relay League What Is an End-Fed Half-Wave (EFHW) Antenna? - OnAllBands End Fed Antennas - Elgin Amateur Radio Society At multiples of half wavelengths of the For best results, use the Wire Length Feet 1.8 MHz 3.7 MHz 5.3 MHz 7.1 MHz 10.1 MHz 14.2 MHz 18.1 MHz 21.2 MHz 24.9 MHz 28.5 MHz 50.1 MHz End fed 49:1 60ft wire (using coax as the counter poise. /Name /Im0 My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! CQ-Calling All Hams! You can get good loading and low swr on sometimes 2 or 3 bands, but one or more of the bands thatyou want, just will not cooperate with an swr that can be adjusted with the "tuner". Modify bands and We'd really appreciate it! . stream Even easier than The unun was floating at about 15 feet above ground. it is easy to pack and easy to install. Start winding the Matching Auto Transformer, each pass through the center of the core equals one turn. "Here's the word on random-wire antennae.". I usually go with a 3.2k transformation wire winding ratio of 8:1 which is a final impedance conversion of 64:1 (50ohm * 64 = 3.2k ohm). The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. I actually did this first and before the connector was bolted to the box. Usually any wire length that is non resonant, like those shown above, will work with the 4:1 ratio. Vhf and Up V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT c=W>:sECXTkc=X JavaScript is disabled. The ratio doesn't need to be 49:1 2,400 ohm either, other ratios will transform to other impedance. Two pieces of 14 gauge enameled wire (e.g., Thermalese), one short piece (about 1 foot in length) and one long piece (about 7 feet in length). endobj Engineering the EFHW 49:1 Transformer and Antenna I included the tools I used to analyze the transformer as well; this is only necessary if you are interested in analyzing your project. Many hams have tried till they are blue in the face to install the random wire antenna that works on most; if not all of the HF bands with terrible results. 1 0 obj EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! PDF Construction Details 49:1 Un-Un For End-Fed Resonant HalfWave Antenna Cut the center conductor wire (free untwisted end of short wire) of the unun to the correct size, scrape the enamel insulation off of the free end with a box cutter, and solder it to the SO239 connector. NEMA rated 4x marine grade junction box for outdoor installations. The popular End-Fed Half-Wave (EFHW) Antenna is an easily portable, high-impedance (2,000-4,000 ohm) wire antenna that resonates on its fundamental frequency and all harmonics above. PDF Wire-Lengths-for-9-1-ununs - OM0ET End Fed Half Wave Antenna Coupler Schematic - 7-30MHz. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 7 0 obj The Nelson antenna 9 to 1 unun did the trick. Usually any wire length that is non resonant on the band or bands desired will work with the 4:1 ratio. /* Ad banner 160 x 600 */ N4UJW. I plotted the results for the U.S. CW band edges for use with my4 band Elecraft K1 qrp rig. all US ham bands. 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. q /ColorSpace 11 0 R What these lengths are depend on your tuner and also the wire's surroundings and also the ground system. One single wire, no solder connections,very simple.all the way from the tuner to the end support. Start winding the toroid with the twisted wires at loop #1 (see schematic below). You are using an out of date browser. /MediaBox [0 0 748 752] When do you use a 1:1, 9:1 or a 49:1 balun? X:nzf4p:t;r }~_HOZcX:^$* J^XZuu|"nX/Wkw0hA>y1(z2+v_Xzu[/:^$*m*>hk_:+c{ So is an essential piece of gear to have. Cut a 4 foot length of AWG #18 enameled wire. If you want a single band portable antenna you can mount pretty much however, look up this design. 2 eyehooks with washers and nuts (I used #8 diameter, but size is up to you.) uR5I5z G^u2`j[}+sy9 0$Ve For a better experience, please enable JavaScript in your browser before proceeding. 35-45, 54-64, 67-77. For example a 32 foot length is actually a half wave on 20m with an impedance of about 3500 ohms and requires a 50:1 balun. Caution: When used atfull power rating of 1kW, the antenna must have a low SWRon the band selected and be used on a 50% duty cycle. This may not be relevant to HF stuff, but the antenna I use for NDB reception has a 400:1 transformer (20:1) turns ratio. I swept the VSWR of the unun and resistors as described from <1 to 55MHz. NOTE: Rewording the previous paragraph, if you have a capable enough The Short Answer Would Be That an UnUn Is a "UN balanced to UN balanced" matching transformer. Here Is a 250 Watt Home-Brew That I Made In about an Hour. FCC Information This project assembles a 49:1 ferrite-core ("FT") type #43 transformer that matches 50 ohm input to 2500 ohm end fed antenna. Save program output in file named 'f', and use EFHW Antenna and 49:1 UnUn | WorldwideDX Radio Forum So for example 80m could range in length from 120 to 133 feet. End fed 9:1 58ft wire and 17ft counterpose wire touching ground. Enclosure Height: 5.000 in. endobj 9:1 Unun EF Random Long wire matching Transformer with BNC or SO-239. Nelson Antennas 9:1 balun - eHam.net The second smallest number I measured was 2.7pF, derived from the self resonance at 2.72 MHz with the magnetizing inductance (measured at 25.8 H) with the secondary open and the output wire folded to a small 1/2 length. InJack's own words. Cannon". I say run what you got and don't worry about it. While these lengths have been shown to work well on many bands, which To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- End Fed 9:1 Magic Wire Lengths | ve3ips 9:1 Unun 1.5-54MHz 2kW 9132S. Beginning from the 3rd band from the left, the vertical blue lines are: 160M, 80M, 60M, 40M, 30M, 20M, 17M, 15M, 12M, (11M), and 10M bands. I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. wire lengths less than 1/4 wavelength of the lowest desired frequency 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). Longer wire is always more PDF 33ft Verticals and 4:1 Ununs - G8JNJ SWR was good after cutting the wire to appropriate length. var sc_security="1df091cc". The Short Answer Would Be That an UnUn Is a UN balanced to UN balancedmatching transformer. Superior Essex Heavy build polyamideimide. x[q;`&z`uAlo#V@;hvOYt, @*Ys~_W_~W_aw_ p[N+}[t-^oLy}xz>7/~c|ZZt75;kN^=>Y+_~|b~"m*tw>xG=x6Qwz|xvz- When on the trail, at Field Day, or whenever a good antenna is SEARCH It is used fornon-resonant verticals like 43 foot or 33 foot Or Wire antennas like an End-Fed1/2 Wave Multiple Length Wire Antenna. endobj 1. endobj <> (Center fed is so appealing because you avoid this.). >> &nb Following the directions exactly as specified (0.47wl / 0.05wl matching counterpoise) and drilling two weep holes in the appropriate position, I had a 10 meter EFHW antenna up in less than ten minutes. SO-239 (UHF female) chassis mount with screws, nuts, lock washers.