The table below represents half wave lengths and multiples that you DO NOT WANT TO USE! Here are the final numbers (in my opinion) in green below that would be good for a long-wire antenna: (You may want to make a note of them), REVISED: 29 35.5 41 58 71 84 107 119 148 203 347 407 423, REVISION NOTE: We had a note from James, KB5YN, pointing out that one of my so-called GOOD numbers was 220 feet. This type of antenna is very easy to install because there is no need . In another life, I could have been a telephone engineer. For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. endobj 35-45, 54-64, 67-77. SO-239 connectors are silver plated with Teflon insulation. IMG_2.jpg Step 2: Take the 6 feet of 18 gauge enameled copper wire, measure 11" from one end and fold it back. Weight: 0.380 lbs. The counterpoise wire does not have to be similar in length to the main radiator wire and just a short wire is all that is needed, about 0.05 . /Im0 Do tuner the colored bands below are the best lengths as long as your A 49:1 would match 50 ohms to about 2,450 ohms and a 64:1 matches to 3,200 ohms, typical of a 1/2 wave end fed. Wait a few minutes for glue to set. << UJM-49-1 $56.99 Save up to 6% when you buy more. want the antenna to be at least 1/4 wavelength long for each band you hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 random wire should use 423/f. <>/Metadata 239 0 R/ViewerPreferences 240 0 R>> 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. If you plan on stringing up a dipole you use 2 equal lengths of wire with the Balun in the middle. Typically unbalanced = 50/75 ohms too unbalanced = 450/675 ohms. endobj Hope it's clear now, if not. 1936 article, however, fall in line with 468/f and so is used here. endobj Contact Make sure the beginning few inches of twisted wire is not involved in the winding (i.e., just hanging down from the toroid). wire to the UnUn "-" connector and then down to ground there it connects with the two other wires but neither the counterpoise nor the two other wires are connected to ground. You can take one of these 49:1 transformers and use the 468/freq (Mhz) formula to calculate the length you need in feet. Palomar Engineers employs a dual core matching system that offers wide bandwidth (1-61 MHz), 500 watt PEP rating, and a connection for a counterpoise or ground if desired. 1. 80m up, W3EDP's 84' antenna, 17' counterpoise is probably the way to go. 1 0 obj It's an efficient way to get all the multiples I used the RigExpert Zoom AA-55 to test VSWR of the 49:1 unun impedance transformer. A way of connecting the analyzer to the transformer. 4 0 obj I made just a touch over 100 QSOs today with the new unit. >> here are values for CW portions of the USA Just add or subtract as needed a little at a time toget the best compromise. 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. well, the main antenna wire goes to the 9:1 UnUn "+" connector, the vertical counterpoise (insulated !) JC[ d8O[UKKQ{yZ{G 'Upno_*~8uo a@G`' zxUHXW&`}mEp`?i0 oE:N0-/t"t.-? These are sometimes known as a Magnetic Longwire Balun. &nb Notice from column f that there is no length giving low impendance for VSWR analysis of the antenna in the field showed that VSWRs between 3-5.5 from 40M to 10M. I swept the VSWR of the unun and resistors as described from <1 to 55MHz. Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun /ColorSpace 11 0 R x {avla[g#+yt]Mk"B` xp[AO8;c=\b}|8p4cSmzgU7be,+i5ci6uq.x T/s@9uk-oZX;u`=U >8rsIXW B:uUVr6a] NOTE: Rewording the previous paragraph, if you have a capable enough Longer wire is always more The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. SSTV << endobj Odds are that most lengths are fine though, so the easiest solution is to pick a length based on something else (like, the room you have available) and if you get unlucky, roll the dice again. /Name /Im0 This calculates to 4.2 m or 14 ft for an 80m end-fed. Repeater Basics Dimensional Drawing of Standard Enclosure, 1:1 Common Mode Choke / Noise Suppression, Core Material Selecton for Baluns and Ununs, Antenna Matching Problems When Using Ladder Line or Open Wire Feedlines, Model 4932 - 4 & 9:1 Unun 1.5 - 54MHz - 2kW, Model 49130 - 49:1 - 80-10m EFHW - 200 watts, Model 64131e - 64:1 & 49:1 - 80-10m EFHW - Up to 1kW, Model 4116 - 4:1 Hybrid Balun 1.5 - 54MHz 3kW, Model 9130sw - QRP 9:1 Unun 1.5 - 54 MHz - 300 watts, Model 1115d - Max Choking 1:1 Balun, 1.5-54 MHz, 5kW. Jack, VE3EED - SK. 49:1 or other high ratio transformers are for resonant "cut to frequency" antennas like the traditional zepp/fuchs antenna. Because I'm more visually oriented I then plotted the many overlapping "red zones" and ended up with the page at: Lengths of a half-wave or multiple must be avoided. Anyway, an old friend mentioned 'MyAntenna.com' but they were closed for the summer. 3 0 obj 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. (Also check out AB3AP'Swebsite and say thanks for sharing his skills. 3. I used 2000 and 1000 ohm resistors in series connected to the proper unun wires with alligator clips for a total of 3000 ohms. //-->, The "Best" Random Wire Antenna Lengths The fewer bands, the fewer high impedance regions to avoid. (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. (Also note that here may be instances where the suggested lengths may not work exactly due tothe many variablesin the surroundings of the antenna, wire length variances,your tuner, it's height above ground, it's construction,etc. On our next windy free day, AA1F and . 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). When you're antenna (or radial) length's an odd multiple of the operating freq, you may not need a balun or even a transmatch. 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. Just an FYI that I thought you might be interested in. Cut the antenna radiator wire (free untwisted end of long wire) of the unun to the correct size, scrape the enamel insulation off of the free end with a box cutter, add a ring terminal, and secure to antenna radiator bolt with washers and lock washers. <>>> 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. 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. % The 9:1 may work best with that length wire and a tuner, but some say that length is undesirable for the hf HAM bands. Even better would be shortening to 53'. EFHW unun Resonant Long Wire 49:1 Transformer With 67' Antenna Wire. endstream endobj startxref Here Is a 250 Watt Home-Brew That I Made In about an Hour. Antenna") is an 84' long end fed and a 17' long counterpoise (6.5' for 20m). Antenna Safety! The free end of the untwisted portion of the long wire (past the 14th winding) will be secured to this bolt as well on the inside of the box, while the radiator will be secured to it on the outside. 1 0 obj << An Unun is used to match an unbalanced line to another unbalanced line. Each winding is counted when the wire enters through the center hole of the toroid. Figure 2 Schematic of the 9:1 voltage unun . which got me thinking. a more capable tuner - see AA5TB's That meant calculating all the way to 32 multiples of a half wave on 10 meters. 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. There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. all US ham bands. Designed for those who want the maximum isolation and choking across the full HF spectrum. The matching unit The impedance at the end of a half wave antenna is somewhere between 2000-5000 Ohms. endobj Do what works best! 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. plan to use. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! The trick, therefore, is either Lengths to avoid are not always the same as so that it is not a halfwave multiple of any frequency you want to use. You will note that when comparing my results with VE3EED that some of the results are a bit different. The length should be calculated based on the lowest frequency to be worked. So for 80 meters (say 3.525 MHz) this gives you about 133' of wire. ?7{*. Use with other lengths can potentially damage the transformer depending on power level in use. Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. Clansman End Fed Long Wire Antenna Used. The short piece is for the primary winding of the transformer, and the long piece is for the secondary winding of the transformer. While these lengths have been shown to work well on many bands, which these are the worst lengths and you want to be as far from colored Presented for your consideration by Jack, VE3EED. My commercial EFHW is 130 feet long for 80 and up, and my 40 meter homebrew antenna is about . this >> The fewer bands, the fewer high impedance regions to avoid. 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. The WSPR map is so dense it looks like the US and Europe are just big blobs of color. installed, it is a compromise antenna but great for portable use because So a 49:1 impedance transformer is needed to match the 50 ohms of the coax at the feed line. While I have not done so yet, I plan on gluing the test cap to the back of the junction box. However, the radio didn't tune up very well on 15 meters. "I received my third balun from Balun Designs this afternoon. stream Code Practice Alternate connectors and Mounting Options are available in the. >> it is easy to pack and easy to install. 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- 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. 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. 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. Because I had some spare Cu-Wire I wound another 1:49 Unun on a smaller FT-140-43 toroid and tried different capacitors between feedline and ground (to compensate for the 10m band). >> 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. /Title (Wire-Lengths-for-9-1-ununs.pdf) 32.00. Feeling a bit too lazy to calculate that by hand, however, I wrote a This will be for an eyehook in order to provide strain relief for the radiator wire. something as high as you can find. Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. The most important length is one that is non-resonant on any band. stream answers on D - one setting. /Creator (XnView) There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). Repeater Builders Q 35. End fed 9:1 58ft wire and 17ft counterpose wire touching ground. The "9:1 UNUN" are for random length wire antennas fed at the end. He was so impressed that he purchased a 9:1 unit from you, his will be delivered Saturday. 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. results. stream 27.00 (27.00/Unit) Free Postage. The Nelson antenna 9 to 1 unun did the trick. rig, often with no feedline, and the other end in the air attached to are easily converted to half wavelengths by the famous 468/f generally Site Map The 30 day return period lapsed before I could get the antenna deployed to test it. We do not encourage any radio operations contrary to regulations. is that for a given ham band there are min and max frequencies which 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. One is for the top of the box so that it can be hung up. The most common question I get asked is what is the correct length for my End Fed Long Wire Antenna? /Height 752 Hopefully these random wire length calculations will help us all make this "easy" antenna work better! The QRP End-Fed Half-Wave Antenna 49:1 Transformer Building a great impedance transformer for Ham Radio end-fed wire antennas. Usually any wire length that is non resonant on the band or bands desired will work with the 4:1 ratio. %PDF-1.5 7 0 obj Quantity: Sold individually. I'm not saying aliens are in the radio, but aliens definitely are in the radio. 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] 3 0 obj Thank you so much for such a great product! This design is excellent for matching both long and short length wire antennas for multiband use. Links STORE 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. presents an extremely high impedance to the tu 59 0 obj <>/Filter/FlateDecode/ID[<81C501BAF3AD19DF6B2122F37F15AF84>]/Index[25 50]/Info 24 0 R/Length 149/Prev 898971/Root 26 0 R/Size 75/Type/XRef/W[1 3 1]>>stream Both were on 20 meters at 97 watts, Icom 7300. Power handling is 100 watts CW / SSB & 25W Data modes. 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 I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. /Width 748 q I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. InJack's own words. Hertz Antenna" shows in line 2 of the table that a similarly installed << /&KWA7{L=D]g0Z!F9;V{zL[h-D,u(.9rg(RHI{f t*C/?? Our Ask An Elmer panel discuss this question - what's the difference between matching units?Please consider using. JavaScript is disabled. . x 2 in. A 50 foot run of RG-8X coax connected the antenna into the LDG Z100-plus tuner and then a Yaesu FT-891A transceiver. Shortwave Listening 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. . <> Performance is ASTOUNDING, far exceeding my expectations. Yes, with the recent surge in popularity of the end-fed half-wave antenna, the 49:1 balun has also become the defacto ratio for use with them. 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. I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. 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 . config file by typing gnuplot rw.gnu. /Filter [ /FlateDecode ] . Advertising Info Placing 3000 to 4000 ohms of resistance between the free end of the twisted portion of wires (the gound) and the free end of the long wire (the wire that connects with the antenna radiator after the 14th winding), can simulate adding an antenna radiator wire to the unun impedance transformer. Well, I didn't think it would make any difference at that many multiples. A couple hours later when I sat down to do some more DXing, I made contact with a gentleman in Slovenia-my second European contact. 35. Windings are inserted into Teflon tubes increasingtotal breakdown to 10,000 volts. FCC Information 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. I'm consistently pleased with the quality and ease of use of Balun Designs products and look forward to my next purchase in the future. A good place to start is the formula 468 / f (MHz) for a 1/2 wavelength wire antenna. 35-43, 49-63, 70-85. . Drill out holes in the designated bottom of the electrical junction box for the SO239 chassis mount.