stream 4 0 obj 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. Ham Satellites 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. Liquidtight NM 90-Degree Connector(Home Depot). Windings are inserted into Teflon tubes increasingtotal breakdown to 10,000 volts. Usually any wire length that is non resonant, like those shown above, will work with the 4:1 ratio. For instance, to work 40m be sure the antenna is at least This design is excellent for matching both long and short length wire antennas for multiband use. << End Fed Half Wave Antenna Coupler Schematic - 7-30MHz. SEARCH and experiment. 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. The graph below shows lengths to avoid for different collections of bands. 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. I say run what you got and don't worry about it. 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. While I have not done so yet, I plan on gluing the test cap to the back of the junction box. 22.00 + 5.00 Postage. /CropBox [0 0 748 752] 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. Even easier than 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". This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). Code Practice google_ad_client = "ca-pub-9377297764300878"; On our next windy free day, AA1F and . PVC Junction Box(Home Depot), 1 x 1/2 in. Superior Essex Heavy build polyamideimide. This type of antenna is very easy to install because there is no need . At multiples of half wavelengths of the Connect this ring terminal to one of the SO239 chassis bolts. (Center fed is so appealing because you avoid this.). Each winding is counted when the wire enters through the center hole of the toroid. 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. 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. Meet 'Balun One Nine', a small, cost-effective balun. This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. SWR will vary based on topography, wire orientation and use of ground or counterpoise. <> The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. You have to stay away from a half wavelength on any frequency. I have found this calculation to work well, however it depends on many factors such as wire used, location etc. plan to use. endobj 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. Twist the short and long wires together starting at an end of each wire. q 80m up, W3EDP's 84' antenna, 17' counterpoise is probably the way to go. I imported my spools from the US, but I have seen them on Ebay in the UK. %%EOF 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. 35-45, 54-64, 67-77. For typical tuners built into a rig, Here they are in order: 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. NOTE: Rewording the previous paragraph, if you have a capable enough hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 $1YacO5Q}YC\>qZ } I used the RigExpert Zoom AA-55 to test VSWR of the 49:1 unun impedance transformer. 40-30-20 . However, the list has been revised and is good for wires as long as 500 feet. 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. document.getElementById("copyright_year").innerHTML = new Date().getFullYear(); Note: My (A to B) length was 6 inches. transmit frequency the impedance is so high that tuners in most rigs 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. 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. https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. Save program output in file named 'f', and use doing the initial 468/f on C and D scales. Legal Stuff << 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA The trick, therefore, is either Alternate connectors and Mounting Options are available in 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 /Subtype /Image =======================, 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: stream %PDF-1.5 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). (A t0 B) Fold over 6 to 8 inches and twist it together. Ask Elmer 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. endobj One single wire, no solder connections,very simple.all the way from the tuner to the end support. You will note that when comparing my results with VE3EED that some of the results are a bit different. (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. 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). 9 0 obj 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. You can add your own wire or get the complete product from this link EFLW-3K antennas. That type of wire antenna could be lower than 50 ohms at some frequencies and over 2,000 ohms at . are blocked out because an antenna should be at least that long. Vacation Closure - See Homepage for Next Availability. N4UJW. Generally an EFHW will be in the range of 2,000 to 5,000 ohms at the very end of the dipole when resonant. Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. often can't match it. 40-30-20-15m bands for my 4 band Elecraft K1 qrp rig. <> 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. Tools The First Thing New Hams Often Ask:What Is An UnUn? 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. I attached the toroids to a PVC DWV test cap with 3 cable ties. The other is to provide strain relief for the antenna wire). 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] A Balun is used to match a balanced line to an unbalanced line. 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. http://udel.edu/~mm/ham/randomWire/. 3 0 obj The WorldwideDX Radio Forum was originally established in 2001. After winding #2 is made and extends down the backside of the toroid, untwist the wires. Quantity: Sold individually. ), Note that Jack, VE3EED,went SK several years agohe will be missed. However, the radio didn't tune up very well on 15 meters. Just add or subtract as needed a little at a time to get the best compromise. google_ad_slot = "1982258389"; Some important and helpful references I used for this work: https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. Power handling is 100 watts CW / SSB & 25W Data modes. Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. Hopefully these random wire length calculations will help us all make this "easy" antenna work better! 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. Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth. &nb endobj wire lengths less than 1/4 wavelength of the lowest desired frequency Here Is a 250 Watt Home-Brew That I Made In about an Hour. 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. 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. /&KWA7{L=D]g0Z!F9;V{zL[h-D,u(.9rg(RHI{f t*C/?? Part List: 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. 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 A way of connecting the analyzer to the transformer. To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- UNUN 9:1 or 4:1- 3kW ICAS This is is dual 9:1 and 4:1 UNUN used for popular "non-resonant" length END FED wire antennas or verticals like 27 or 43 feet. Let's have a look at a few details on how to build a 49:1 impedance . You have to give up a band or two, like 60m and 6m, as 1 0 obj Winding 1:64 Matching Auto Transformer on the FT240-43 core. Use with other lengths can potentially damage the transformer depending on power level in use. x 4 in. 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. Wait a few minutes for glue to set. It is important to use a counterpoise. 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. This article explains why the use of mix 43 for HF applications is almost always a mistake. gnuplot (QST, Oct 1926, "The Length of the Powered by BigCommerce. I did not want to put the transformer in the housing until I tested it. Change the program to use 423 if desired.) the program as I did, above, for my K1. . Hertz Antenna" shows in line 2 of the table that a similarly installed The matching unit The impedance at the end of a half wave antenna is somewhere between 2000-5000 Ohms. See the picture below. Some of these numbers are too close to squeeze in between them. The "Super Bullet" End Fed Long Wire Antenna Matcher - 1500/3000 watt rated for Super-Punch of your signal! Ham Hints "Just received my new 64131 yesterday and was anxious to see how well it performed. 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 used a homemade jig made of an SO239 chassis mount to bare wires, alligator clips, and a coax-jumper with PL259 (UHF male) ends; see picture below. One end goes straight into the 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. Thus a 1/4 wave for 20m@16ft, 40m@33ft as examples are not going to work. endobj /Im0 Do var sc_invisible=1; understand its properties. I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. Our newdesign isperfect for matching both long and short length wire antennas for multiband use. The length should be calculated based on the lowest frequency to be worked. The short piece is for the primary winding of the transformer, and the long piece is for the secondary winding of the transformer. config file by typing gnuplot rw.gnu. random wire should use 423/f. Wire lengths for the 4:1 ratio in models 4932 and 4935. Feeling a bit too lazy to calculate that by hand, however, I wrote a 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. /XObject << /Im0 9 0 R >> Reading Room Re: 9:1 or 49:1 unun for end-fed long/random wire? Superglue 2 toroids together. Experimenting by slightly changing the wire length (+ or-) is encouraged to provide best overall performance. The beauty of the halfwave antenna is it's a complete antenna in the sense it needs no counterpoise. 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. /Type /Page Moving the pot up and down gives a feel for the SWR versus antenna impedance sensitivity. So for example 80m could range in length from 120 to 133 feet. Both were on 20 meters at 97 watts, Icom 7300. The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. Jack, VE3EED - SK. Midi Music If you want all the bands from The length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). I'm looking forward to getting off work and hitting 40 & 20 meters again!! 1 0 obj Start winding the toroid with the twisted wires at loop #1 (see schematic below). Then verify it with your installed antenna and SWR measurements. . installed, it is a compromise antenna but great for portable use because 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. Longer wire is always more They just saved you and I loads of time and frustration. Here is an ARRL /* Ad banner 160 x 600 */ Do what works best! var sc_security="1df091cc". Repeater Basics 1 0 obj 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. Use with other lengths can potentially damage the transformer depending on power level in use. >> <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> unavailable, a random wire can save the day, but it is important to If you want a single band portable antenna you can mount pretty much however, look up this design. The idea The Short Answer Would Be That an UnUn Is a "UN balanced to UN balanced" matching transformer. The fewer bands, the fewer high impedance regions to avoid. here are values for CW portions of the USA 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). 4 0 obj (Originally published February 22, 2021).

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