1 0 obj SWR will vary based on topography, wire orientation and use of ground or counterpoise. 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). I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. >> << /Width 748 PVC Junction Box(Home Depot), 1 x 1/2 in. 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. $119.95. which got me thinking. To DB's point of a single band antenna, this 49:1 transformer is a good choice for a single band matcher. Free Postage. 9:1 Unun EF Random Long wire matching Transformer with BNC or SO-239. In other Lengths of a half-wave or multiple must be avoided. 6 0 obj Here's a list of recommended lengths of wire to use with a 9:1 unun. 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. /Producer (XnView, http://www.xnview.com) Turns 1 & 2 are primary windings (the short wire). Twist the short and long wires together starting at an end of each wire. The 49:1 impedance transformer will help you bring down the high impedance of your resonant EFHW antenna to almost 50 Ohm. endobj 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. Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. >> google_ad_height = 600; Even easier than >> Several ways exist to bring the wire's high impedance feedpoint closer to the desired 50 ohms, including use of a 49:1 or 64:1 unun, which eliminates the need . 32.00. Computer Help /Length 10 0 R Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. Hopefully these random wire length calculations will help us all make this "easy" antenna work better! 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. Vhf and Up Ultimately, this housing works fine, but it is heavy and clunky.). 25 0 obj <> endobj If you want all the bands from 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). endobj Multiples are on C and The unun was floating at about 15 feet above ground. Site Map x 2 in. 2 0 obj transmit frequency the impedance is so high that tuners in most rigs Superior Essex Heavy build polyamideimide. Even better would be shortening to 53'. One is for the top of the box so that it can be hung up. The fewer bands, the fewer high impedance regions to avoid. Again, the bands are USA, so change them 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. 3 0 obj Balun Designs. We hoisted the free end of the antenna wire approximately 30 feet into a tree. An Unun is used to match an unbalanced line to another unbalanced line. ), Note that Jack, VE3EED,went SK several years agohe will be missed. 22.00 + 5.00 Postage. Feeling a bit too lazy to calculate that by hand, however, I wrote a For typical tuners built into a rig, We recently found some good information about random wire lengths that you should and should not use. /&KWA7{L=D]g0Z!F9;V{zL[h-D,u(.9rg(RHI{f t*C/?? 4 x 4 x 2 electrical junction box (available at big box hardware stores), One PVC DWV Test Cap (available at big box hardware stores in plumbing). I will also find some sort of heat resistant packing material to help hold the transformer in place. I actually did this first and before the connector was bolted to the box. Thus a 1/4 wave for 20m@16ft, 40m@33ft as examples are not going to work. 9:1 or 49:1 unun for end-fed long/random wire? Antenna Design What these lengths are depend on your tuner and also the wire's surroundings and also the ground system. The length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). Note: My (A to B) length was 6 inches. License Study You also This will be for an eyehook in order to provide strain relief for the radiator wire. I did not want to put the transformer in the housing until I tested it. The magic lengths to use with the End Fed longwire is 29, 35.5, 41, 58, 71 and 84 feet I use a 29 foot wire with my PackTenna 9:1 balun for 40m-10m and then add a 28 foot length for better coverage on 80m when needed. In fact, the 9:1 unun that I built is actually an autotransformer. endobj 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. 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 . and experiment. =======================, More on Random Wire Lengths from Mike, AB3AP (06-29-2012), I was surfing around Hamuniverse.com and found thIs page on random wire antennas: Notice from column f that there is no length giving low impendance for The key is you want to stay at least 1/2w long but not near 3/4w for any band of interest. 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. Just add or subtract as needed a little at a time toget the best compromise. ?7{*. 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. Antenna Safety! understand its properties. This antenna, which works on 10, 15, 20, and 40 meters, has a very high impedance of around 2,500 Ohms. My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! That is the 10th multiple of a half wave on 15 meters. /CreationDate (D:20221212112042) x {avla[g#+yt]Mk"B` xp[AO8;c=\b}|8p4cSmzgU7be,+i5ci6uq.x T/s@9uk-oZX;u`=U >8rsIXW B:uUVr6a] stream The other is to provide strain relief for the antenna wire). 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.). , This is a partial reprint (with permission) of an excellent series of articles published by KV5R Continue twisting the entire length of the short wire. The goal of the impedance transformer is match the 50 ohm impedance of the feedline (coaxial cable) with the potential 3000 to 4000 ohm impedance expected from an end-fed half wave antenna wire radiator. I'm looking forward to getting off work and hitting 40 & 20 meters again!! q 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. Swr usually is all over the place and the tuner will just not do it's job. When on the trail, at Field Day, or whenever a good antenna is 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. google_ad_width = 160; Save program output in file named 'f', and use 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. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. It will be good for 15m, and 10m. Coverutilizes integralneoprene gasket for weatherproof integrity. plan to use. you're using different ham bands than in these examples, modify and rerun Then verify it with your installed antenna and SWR measurements. SO-239 (UHF female) chassis mount with screws, nuts, lock washers. Random wire lengths you should and should not use! The 30 day return period lapsed before I could get the antenna deployed to test it. Wire lengths for the 4:1 ratio in models 4932 and 4935. 20/40/17m. 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. 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. /Type /Page Thanks for your answer,I will probably go with the 9:1 then. <> This design is excellent for matching both long and short length wire antennas for multiband use. There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. 40-30-20-17. You have to stay away from a half wavelength on any frequency. Weight: 0.380 lbs. It's an efficient way to get all the multiples 1936 article, however, fall in line with 468/f and so is used here. That type of wire antenna could be lower than 50 ohms at some frequencies and over 2,000 ohms at . Theme: Newsup by Themeansar. 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!! 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. /Height 752 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. 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. First, it is important to understand the difference between the end fed half wave and a random wire (or "long wire") antenna: the random wire is just a piece of wire that is matched to 50 Ohm impedance using an antenna coupler, sometimes adding a 9:1 unun. Do what works best! I used the RigExpert Zoom AA-55 to test VSWR of the 49:1 unun impedance transformer. 3 to31 MHz - up to 1kW intermittent (50% duty cycle). End fed 9:1 58ft wire and 17ft counterpose wire touching ground. Downward impedance transformation by factor of 49. However, the radio didn't tune up very well on 15 meters. Cannon". 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. Start winding the toroid with the twisted wires at loop #1 (see schematic below). I made one without doing this and it didn't work so well. presents an extremely high impedance to the tu When do you use a 1:1, 9:1 or a 49:1 balun? Here Is a 250 Watt Home-Brew That I Made In about an Hour. here are values for CW portions of the USA 35. Liquidtight NM 90-Degree Connector(Home Depot). Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth. Windings are inserted into Teflon tubes increasingtotal breakdown to 10,000 volts. After winding #2 is made and extends down the backside of the toroid, untwist the wires. 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. InJack's own words. 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. 9:1 UnUn End Fed Long Wire Lengths - Pretty Simple. NOTE: Rewording the previous paragraph, if you have a capable enough >> The WSPR map is so dense it looks like the US and Europe are just big blobs of color. /Pages 3 0 R So after much frustration..down it comes and you go on to a totally different type of antenna.all that time just wasted inyour opinion..until now! The bandwidth where SWR was below 2:1 was about one MHz. About Batteries answers on D - one setting. endobj A small ring terminal for 14ga wire that fits these screws would be helpful too. are easily converted to half wavelengths by the famous 468/f generally I have found this calculation to work well, however it depends on many factors such as wire used, location etc. You'll want to have that wire up as high as you can get.. So, having nothing better to do one day, I re-did the calculations going out to 500 feet. . hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 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? 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. Jack, VE3EED - SK. This is a followup video to #344 where I assembled the 49:1 UNUN kit from HF-Kits / ARRL. 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] >> 35-45, 54-64, 67-77. 9 0 obj Presented for your consideration by Jack, VE3EED. for your country and favorite modes of operation. This transformer converts the impedance at the end . (QST, Oct 1926, "The Length of the Use with other lengths can potentially damage the transformer depending on power level in use. 31 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. Hope it's clear now, if not. 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. 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. Reading Room One single wire, no solder connections,very simple.all the way from the tuner to the end support. 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. I only used two screws instead of four. The "9:1 UNUN" are for random length wire antennas fed at the end. Repeater Builders Hertz Antenna" shows in line 2 of the table that a similarly installed This project assembles a 49:1 ferrite-core ("FT") type #43 transformer that matches 50 ohm input to 2500 ohm end fed antenna. 73, JC[ d8O[UKKQ{yZ{G 'Upno_*~8uo a@G`' zxUHXW&`}mEp`?i0 oE:N0-/t"t.-? Performance is ASTOUNDING, far exceeding my expectations. SSTV Tweak the antenna length if necessary and then maybe adjust the turns ratio again. 0$Ve FCC Information This type of antenna is very easy to install because there is no need . 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. Humor Drill out holes in the designated bottom of the electrical junction box for the SO239 chassis mount. /Type /XObject 3. 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. shown in the column e. var sc_project=8077274; 35. 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. Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. want the antenna to be at least 1/4 wavelength long for each band you 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. 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA /Title (Wire-Lengths-for-9-1-ununs.pdf) high the other 1.5m (4.5feet). The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. 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. /Im0 Do <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas. 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. 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. endstream /ColorSpace 11 0 R bands you're intested in in a vector like the example below, by typing. a more capable tuner - see AA5TB's bands as possible. V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT c=W>:sECXTkc=X (Originally published February 22, 2021). UJM-49-1 $56.99 Save up to 6% when you buy more. . endobj this Winding 1:64 Matching Auto Transformer on the FT240-43 core. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! /Resources << https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. Q 1 0 obj So a 49:1 impedance transformer is needed to match the 50 ohms of the coax at the feed line. For instance, to work 40m be sure the antenna is at least 10m or 33' long. Repeater Basics Designed for those who want the maximum isolation and choking across the full HF spectrum. I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. << 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. We do not encourage any radio operations contrary to regulations. SBULLET-9U-1500. 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 . The First Thing New Hams Often Ask:What Is An UnUn? June 8, 2022 at 9:17 am. End Fed Antennas. multiples, and of course different band combinations yield different "Here's the word on random-wire antennae.". A success! End fed 49:1 60ft wire (using coax as the counter poise. 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. Care to buy us a beer? So for example 80m could range in length from 120 to 133 feet. This design is excellent for matching both long and short length wire antennas for multiband use. 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. K1S Valentines Are (Almost) Out The Door! Ham Radio News! I imported my spools from the US, but I have seen them on Ebay in the UK. stream Enclosure Depth: 1.250 in. While I have not done so yet, I plan on gluing the test cap to the back of the junction box. Let's have a look at a few details on how to build a 49:1 impedance . 49:1 or other high ratio transformers are for resonant "cut to frequency" antennas like the traditional zepp/fuchs antenna. often can't match it. well, the main antenna wire goes to the 9:1 UnUn "+" connector, the vertical counterpoise (insulated !) endobj 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. Thank you so much for such a great product! u?X`f0&/Ri;W0Tn_*TX:ug 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. 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. , The "Best" Random Wire Antenna Lengths Here they are in order: Be sure to review the various lengths in the link below to obtain the lowest SWR across most if not all HF bands. (Center fed is so appealing because you avoid this.). Moving the pot up and down gives a feel for the SWR versus antenna impedance sensitivity. Please note that I will not be describing the construction of the antenna wire radiator here. %PDF-1.5 <>/Metadata 239 0 R/ViewerPreferences 240 0 R>> One end goes straight into the /CropBox [0 0 748 752] Tune Around! Antenna") is an 84' long end fed and a 17' long counterpoise (6.5' for 20m). Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun It may not display this or other websites correctly. Electronics Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. 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. 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.
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