End Fed Antennas. ", KiwiSDR Online Radio - 500 ft Northeast Beverage, KiwiSDR Online Radio - 400 ft South Beverage, KiwiSDR Online Radio - 10/11m dipole up 20 meters high. << Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. While I have not done so yet, I plan on gluing the test cap to the back of the junction box. (Originally published February 22, 2021). hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 Playing with end-fed wire antennas and 9:1 ununs X:nzf4p:t;r }~_HOZcX:^$* J^XZuu|"nX/Wkw0hA>y1(z2+v_Xzu[/:^$*m*>hk_:+c{ bands as possible. SEARCH This transformer is designed to be used with an end fed half wavelength of wire only. At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. /MediaBox [0 0 748 752] is that for a given ham band there are min and max frequencies which Its really an impedance transformer (9:1) to feed a high impedance, end fed (unbalanced) random wire which is likely to be a few hundred ohms, and transform it into something closer to a 50 (unbalanced) coaxial input, hence UnUn. 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. Picture Information. 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. When on the trail, at Field Day, or whenever a good antenna is 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. unavailable, a random wire can save the day, but it is important to (The numbers aboveare a great start, thanks to Jack and Mike! Enclosure Depth: 1.250 in. Technical specification : Type : 49:1 Unun Frequency : 1.8 MHz - 7.3 MHz Turns ratio: 1:7 Impedance ratio: 1:49 Input Impedance: 50 Output Impedance: 2450 Power Handling (CW/SSB/ Digital Modes) : 2Kw of peak power / DM Modes 500 watts Core Type : 3 x FT240-43 by Fair-rite Co. Wire type: Enamel copper wire 2.0 mm (AWG 12) Assembled and tested. SO-239 (UHF female) chassis mount with screws, nuts, lock washers. VSWR analysis of the antenna in the field showed that VSWRs between 3-5.5 from 40M to 10M. 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. Tune Around! 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. Part List: HF & Shortwave For typical tuners built into a rig, We'd really appreciate it! tuner the colored bands below are the best lengths as long as your Multiples are on C and Par EF 20 and par EF 40 (I realize for 17m I would prob just add that band to a 49:1 balun) That's that my question is. Kj8~q7c? I swept the VSWR of the unun and resistors as described from <1 to 55MHz. Re: 9:1 or 49:1 unun for end-fed long/random wire? He used 300 ohm twin-lead and a 4:1 UNUN, with a 1:1 current choke between the UNUN and the coax to the tuner and transceiver: The full-size "flimsy" (ref. (Also check out AB3AP'Swebsite and say thanks for sharing his skills. The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. Proudly powered by WordPress /&KWA7{L=D]g0Z!F9;V{zL[h-D,u(.9rg(RHI{f t*C/?? stream Even better would be shortening to 53'. Ham Radio End Fed Antenna with a 1:64 Matching Network 1 0 obj 9:1 Magnetic Longwire Balun / Unun - M0UKD - Amateur Radio Blog and leave the unun on the ground. Wire-Lengths-for-9-1-ununs.pdf Created Date: 12/12/2022 11:20:42 AM . 49:1 End Fed Half Wave Antenna 40-10M 100W Version Bands of operation 40,20,15 & 10m using 67 feet of our UV, Ozone resistant Antenna wire. In addition to multiples, This antenna, which works on 10, 15, 20, and 40 meters, has a very high impedance of around 2,500 Ohms. 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. End-Fed Half-Wave Antenna Kit - American Radio Relay League Just add or subtract as needed a little at a time toget the best compromise. Code Practice , Most matching problems occur when the antenna system To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- 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. ), Note that Jack, VE3EED,went SK several years agohe will be missed. The vertical (y-) axis shows the VSWR and the horizontal (x-) axis shows the frequencies. 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 endobj 9:1 Unun 1.5-54MHz 2kW 9132S - The DX Shop Limited The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. endobj uR5ucE`_aksLjYT=hzRa]JucX7d}|'}`XRa>X 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. Enclosure Height: 5.000 in. So I just wanna say thank-you!! Wire lengths for the 4:1 ratio in models 4932 and 4935. Let's have a look at a few details on how to build a 49:1 impedance . 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. You are using an out of date browser. here are values for CW portions of the USA endobj So those are the numbers above thatwe have to stay as far away from as possible when building a long-wire antenna. This homebrew 49:1 impedance transformer is the heart of any EFHW antenna you will build, most of the time. Anyway, an old friend mentioned 'MyAntenna.com' but they were closed for the summer. This is not exactly a 1/2 wavelength in free space, but works for wire as it has a different velocity factor than "air". Some important and helpful references I used for this work: https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. 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. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. These dimensions were derived from modelling the antenna in EZNEC. wire is at least 1/4 wavelength. End Fed Half Wave Antenna Coupler Schematic - 7-30MHz. In another life, I could have been a telephone engineer. HF Antenna Choice 9:1 vs 49:1 vs PAR - Antennas - SOTA Reflector PDF Wire Lengths for 4 and 9-1 Ununs - Balun Designs 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. The "9:1 UNUN" are for random length wire antennas fed at the end. 35. So, if you connect a length of wire that presents an impedance of about 450 to the input, you'll get an impedance of about 50 on the output. << 9:1 Unun EF Random Long wire matching Transformer with BNC or SO-239. 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. EFHW unun Resonant Long Wire 49:1 Transformer With 67' Antenna Wire. Any SWR measurement taken with the transformer at the feedpoint should not exceed 1.5:1withNOtuner in use. I'm not saying aliens are in the radio, but aliens definitely are in the radio. Advertising Info random wire should use 423/f. I sent him the link to the 49:1 unit to get his feedback. End Fed Half Wave 40-10 Wire Antenna - N6DOZ ones Antenna") is an 84' long end fed and a 17' long counterpoise (6.5' for 20m). For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. K1S Valentines Are (Almost) Out The Door! For instance, to work 40m be sure the antenna is at least Random wire lengths you should and should not use! Q Jack, VE3EED - SK. Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. In other When do you use a 1:1, 9:1 or a 49:1 balun? results. 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. Wait a few minutes for glue to set. Links In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. >> He had heard good things about 'Balun Designs' so he recommended you. 73. JACK, VE3EED 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. Jack, VE3EED, hopefully has solved a major headache we all have when we attempt to go thru the trial and error and frustration with getting the random wire to work where WE want it to work. I have not done this yet. At multiples of half wavelengths of the Our newdesign isperfect for matching both long and short length wire antennas for multiband use. All you need for a random wire antenna is some wire, your tuner, one or more supports up as high as you can get them to string the wire from the supports to the tuner, at least one or two insulatorsand a little time. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. 5 0 obj 3 0 obj understand its properties. %PDF-1.4 I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. Please note that I will not be describing the construction of the antenna wire radiator here. Just add or subtract as needed a little at a time to get the best compromise. The fewer bands, the fewer high impedance regions to avoid. 25 0 obj <> endobj Upon further research, I remade it tightly twisting those two separate wires together, just as it shows in archjeb's picture, and it worked surprisingly well. The WorldwideDX Radio Forum was originally established in 2001. The counterpoise wire, This transformer is designed to be used with an end fed, Approx. var sc_security="1df091cc". You have to give up a band or two, like 60m and 6m, as stream An Unun is used to match an unbalanced line to another unbalanced line. Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. //-->, The "Best" Random Wire Antenna Lengths ?7{*. PDF Construction Details 49:1 Un-Un For End-Fed Resonant HalfWave Antenna 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. Product Reviews 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 . To DB's point of a single band antenna, this 49:1 transformer is a good choice for a single band matcher. Modify bands and You can add your own wire or get the complete product from this link EFLW-3K antennas. InJack's own words. Work all bands from 80 through 10 on it. Hope it's clear now, if not. JC[ d8O[UKKQ{yZ{G 'Upno_*~8uo a@G`' zxUHXW&`}mEp`?i0 oE:N0-/t"t.-? Designed for use with single wire unbalanced antennas, this new addition is small, compact and perfect for quick portable/emergency installations. The table below represents half wave lengths and multiples that you DO NOT WANT TO USE! Gil Gruson 1 Campaign | Comines, France $0 USD 0 backers 0% of $3,450 Flexible Goal Follow Story FAQ Updates 0 Comments 0 Prototype The project team has a working demo, not the final product. How We Flew An End-Fed Half Wave (EFHW) Ham Radio Antenna On A - KM1NDY These are sometimes known as a Magnetic Longwire Balun. I have found this calculation to work well, however it depends on many factors such as wire used, location etc. 35. 40-30-20-17. End-fed wire antenna lengths - Amateur Radio Stack Exchange the program as I did, above, for my K1. You also want the antenna to be at least 1/4 wavelength long for each band you plan to use. The Short Answer Would Be That an UnUn Is a "UN balanced to UN balanced" matching transformer. There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). Make sure the beginning few inches of twisted wire is not involved in the winding (i.e., just hanging down from the toroid). google_ad_height = 600; , Reprinted with permission of Hamuniverse, this is an excellent explanation of SWR and how to best me excellent page for EFHW info - or, addressed below, to cut the wire The "Almost Random" Wire Antenna - KB6NU's Ham Radio Blog Ask Elmer I included the tools I used to analyze the transformer as well; this is only necessary if you are interested in analyzing your project. A standard recommendation (see QST, March 1936, p. 32, "An Unorthodox Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500/3000 Watts, End Fed Long good show chuck, you said ya picked up a 430, did i tell i fried the 0ne i got from you, can anyone point me in the direction of a 2 pill schem for the HG 2879? What Is an End-Fed Half-Wave (EFHW) Antenna? - OnAllBands If you plan on stringing up a dipole you use 2 equal lengths of wire with the Balun in the middle. doing the initial 468/f on C and D scales. #347: Quick test of the 40m Halfwave End-Fed antenna using a 49:1 49:1 Impedance Transformer for EFHW Antenna - DX Explorer installed, it is a compromise antenna but great for portable use because PDF Wire-Lengths-for-9-1-ununs - OM0ET I say run what you got and don't worry about it. They just saved you and I loads of time and frustration. >> The novel thing was that I only built it the day before and it uses a Coghlan camping washing line spool with the string taken off and about 21m of wire wound onto it. >> Each vertical blue line represents an amateur radio band. /Kids [ 4 0 R ] EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 Performance is ASTOUNDING, far exceeding my expectations. 0 Even easier than Hertz Antenna" shows in line 2 of the table that a similarly installed For instance, to work 40m be sure the antenna is at least 10m or 33' long. Turns 1 through 14 are secondary windings (the long wire). . I wrote a small C program that does just what Jack did, butI used the band edges. End fed 9:1 58ft wire and 17ft counterpose wire touching ground. 32.00. WwS`8o}=n,pjhzRa]Ju/Ru ni4=UvZ:u9*@ Xz+zZcXm}i[Z;Z>.u!*eQVjucXeqYZnSJu)U[n>>KXzZ.Lz sqxcGj]%q}i6=-?YTlnZXV6}=U >5`ZNxChzRa]JU.6TVr6a] Built with the same craftsmanship as all our other For those that enjoy endfed antennas but want to run more power, Balun Designs now offers an excellent alternative. %PDF-1.5 % 4 0 obj 49:1 vs. 9:1 Transformer for RX only? - RadioReference.com Forums Each winding is counted when the wire enters through the center hole of the toroid. u?X`f0&/Ri;W0Tn_*TX:ug 3 0 obj The length should be calculated based on the lowest frequency to be worked. However, the radio didn't tune up very well on 15 meters. 7 0 obj Change the program to use 423 if desired.) The transformer usually used with an end fed wire is a 9:1 transformer. 74 0 obj <>stream transmit frequency the impedance is so high that tuners in most rigs 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. >> wire lengths less than 1/4 wavelength of the lowest desired frequency An end fed half wave antenna is one of a specific length depending on the frequency that it is to be used on, for example, an end fed half wave antenna for 80 meters is about 130 long. x {avla[g#+yt]Mk"B` xp[AO8;c=\b}|8p4cSmzgU7be,+i5ci6uq.x T/s@9uk-oZX;u`=U >8rsIXW B:uUVr6a] <>/Metadata 239 0 R/ViewerPreferences 240 0 R>> (A t0 B) Fold over 6 to 8 inches and twist it together. The graph below shows lengths to avoid for different collections of bands. google_ad_width = 160; Generally an EFHW will be in the range of 2,000 to 5,000 ohms at the very end of the dipole when resonant. 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. %PDF-1.5 This type of antenna is very easy to install because there is no need . random wire page. 40-30-20 . The unun was floating at about 15 feet above ground.