49:1 unun wire lengths

Support The Site Wire-Lengths-for-9-1-ununs.pdf Created Date: 12/12/2022 11:20:42 AM . UJM-49-1 $56.99 Save up to 6% when you buy more. Turns 1 & 2 are primary windings (the short wire). My commercial EFHW is 130 feet long for 80 and up, and my 40 meter homebrew antenna is about . Antenna") is an 84' long end fed and a 17' long counterpoise (6.5' for 20m). /Width 748 Here Is a 250 Watt Home-Brew That I Made In about an Hour. Twist the short and long wires together starting at an end of each wire. So those are the numbers above thatwe have to stay as far away from as possible when building a long-wire antenna. Electronics Just add or subtract as needed a little at a time toget the best compromise. To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- PVC Junction Box(Home Depot), 1 x 1/2 in. For typical tuners built into a rig, google_ad_slot = "1982258389"; >> 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! ones "Here's the word on random-wire antennae.". 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. (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. I sent him the link to the 49:1 unit to get his feedback. What these lengths are depend on your tuner and also the wire's surroundings and also the ground system. 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). Thank you so much for such a great product! 2 0 obj 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. 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. Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. 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] %PDF-1.5 This transformer converts the impedance at the end . This transformer is designed to be used with an end fed half wavelength of wire only. A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. HF & Shortwave >> 73. JACK, VE3EED Turns 1 through 14 are secondary windings (the long wire). Kj8~q7c? Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun bands as possible. 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. . %PDF-1.7 << This calculates to 4.2 m or 14 ft for an 80m end-fed. Let the now free end of the short wire hang down from the toroid. 4 0 obj A level of 500-600 watts is the maximum with a further reduction onany band measuringabove 3:1. I connected it to a 33 wire running from my balcony, through the trees, and ran WSPR overnight to check things out. So for example 80m could range in length from 120 to 133 feet. 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). That is the 10th multiple of a half wave on 15 meters. After winding #2 is made and extends down the backside of the toroid, untwist the wires. Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. For instance, to work 40m be sure the antenna is at least A way of connecting the analyzer to the transformer. 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. At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. 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. google_ad_height = 600; <>>> (QST, Oct 1926, "The Length of the <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> Well, I didn't think it would make any difference at that many multiples. q We'd really appreciate it! Here I show finalizing the antenna, getting it in the air, and run. Having the option to switch rapidly between 49:1 and 64:1 should prove to be a really nice feature.. 9 0 obj CQ-Calling All Hams! I'm looking forward to getting off work and hitting 40 & 20 meters again!! 2. Each vertical blue line represents an amateur radio band. I have included a screenshot showing the stations that reported spotting my 200 mw beacon over the last 16 hours. NOTE: Rewording the previous paragraph, if you have a capable enough /Resources << x 4 in. ?7{*. program or two to do all the dirty work. AndWhat Is It Used For In Antennas? Windings are inserted into Teflon tubes increasingtotal breakdown to 10,000 volts. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. 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. End Fed Antennas. I only used two screws instead of four. Even easier than SBULLET-9U-1500. endobj 74 0 obj <>stream 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). Picture 1 of 9. endobj Experimenting by slightly changing the wire length (+ or-) is encouraged to provide best overall performance. 9:1 or 49:1 unun for end-fed long/random wire? Alternate connectors and Mounting Options are available in the. I used the RigExpert Zoom AA-55 to test VSWR of the 49:1 unun impedance transformer. ), Note that Jack, VE3EED,went SK several years agohe will be missed. 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. The First Thing New Hams Often Ask:What Is An UnUn? However, the radio didn't tune up very well on 15 meters. 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 transformer usually used with an end fed wire is a 9:1 transformer. For a better experience, please enable JavaScript in your browser before proceeding. This antenna, which works on 10, 15, 20, and 40 meters, has a very high impedance of around 2,500 Ohms. They just saved you and I loads of time and frustration. 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". The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. 35-45, 54-64, 67-77. google_ad_client = "ca-pub-9377297764300878"; This was 9m vertically metres up a fishing pole and then about 5.8m out. /Kids [ 4 0 R ] Any SWR measurement taken with the transformer at the feedpoint should not exceed 1.5:1withNOtuner in use. Designed for use with single wire unbalanced antennas, this new addition is small, compact and perfect for quick portable/emergency installations. <>/Metadata 239 0 R/ViewerPreferences 240 0 R>> 40-10m with a 49:1 Unun. Tune Around! all US ham bands. /Filter [ /FlateDecode ] 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. excellent page for EFHW info - or, addressed below, to cut the wire 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? Figure 3 Wiring of the 9:1 voltage unun. SO-239 (UHF female) chassis mount with screws, nuts, lock washers. endobj Super Bullet Features: - Uses proprietary broadband impedance transformer design for maximum bandwidth with SWR < 2 from 1.8-61 MHz for 1500 Watt model and 1.8-30 MHz for 3000 watt model The length should be calculated based on the lowest frequency to be worked. 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. . 0$Ve $119.95. Meet 'Balun One Nine', a small, cost-effective balun. So, having nothing better to do one day, I re-did the calculations going out to 500 feet. Just an FYI that I thought you might be interested in. <> If the choices are. /Height 752 installed, it is a compromise antenna but great for portable use because InJack's own words. 5 0 obj You will note that when comparing my results with VE3EED that some of the results are a bit different. Jack, VE3EED - SK. endobj Continue on winding the long wire through the toroid to complete loops 3 through 14 as shown in the schematic below. /Type /XObject The bandwidth where SWR was below 2:1 was about one MHz. /Title (Wire-Lengths-for-9-1-ununs.pdf) 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- My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! var sc_invisible=1; You can add your own wire or get the complete product from this link EFLW-3K antennas. One end goes straight into the 1 0 obj Be sure to review the various lengths in the link below to obtain the lowest SWR across most if not all HF bands. so that it is not a halfwave multiple of any frequency you want to use. 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. 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). We hoisted the free end of the antenna wire approximately 30 feet into a tree. Lengths of a half-wave or multiple must be avoided. Tools /ModDate (D:20221212112042) results. 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. Quantity: Sold individually. So for example 80m could range in length from 120 to 133 feet. The graph below shows lengths to avoid for different collections of bands. Each winding is counted when the wire enters through the center hole of the toroid. 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. It may not display this or other websites correctly. 6 0 obj 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. Connect this ring terminal to one of the SO239 chassis bolts. 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. presents an extremely high impedance to the tu 2 0 obj wire is at least 1/4 wavelength. Power Handling (CW/SSB): 100 W/200 W Enclosure Width: 2.500 in. << Solder a the 100pF capacitor between the center conductor wire and ground wires. 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. For reasons that I do not understand, adding a capacitor between the coax conductor wire (untwisted free end of short wire) and the ground (twisted free ends of long and short wire) can increase the functional bandwidth of the antenna on the higher HF frequencies. Repeater Basics << wire lengths less than 1/4 wavelength of the lowest desired frequency config file by typing gnuplot rw.gnu. 22.00 + 5.00 Postage. I included the tools I used to analyze the transformer as well; this is only necessary if you are interested in analyzing your project. Again, the bands are USA, so change them want the antenna to be at least 1/4 wavelength long for each band you x {avla[g#+yt]Mk"B` xp[AO8;c=\b}|8p4cSmzgU7be,+i5ci6uq.x T/s@9uk-oZX;u`=U >8rsIXW B:uUVr6a] Then verify it with your installed antenna and SWR measurements. are blocked out because an antenna should be at least that long. Change the program to use 423 if desired.) 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). var sc_security="1df091cc". 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. multiples, and of course different band combinations yield different gnuplot I swept the VSWR of the unun and resistors as described from <1 to 55MHz. Therefore, we came up with the following numbers to avoid (IN FEET): These lengths in the table beloware the culprits that cause all of the trouble when using random lengths. 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 . 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. 3. Technical specification : Type : 49:1 Unun Frequency : 1.81 MHz - 30MHz Impedance ratio: 1:49 Input Impedance: 50 Output Impedance: 2500 Power Handling (CW/SSB) : 250W Core Type : 1x FT240-43 by Fair-rite Co. Capacitor 100pF 3KV Assembled and tested. Both were on 20 meters at 97 watts, Icom 7300.

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