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. In another life, I could have been a telephone engineer. 74 0 obj <>stream I have used the 49.2 ft (15 Meter) length of wire on vacation with both automatic tuners and an MFJ Model 16010 tuner with good results for 40, 20, 17, and 15 Meter operation. q Attaching a counterpoise wire to the common point of the auto-transformer provides the antenna radiator something to push against rather than the coax shield. I made one without doing this and it didn't work so well. 40-30-20-17. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. >> "Can you please recommend schematics that are designed to tune setups like these? For instance, to work 40m be sure the antenna is at least 10m or 33' long. 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.). We hoisted the free end of the antenna wire approximately 30 feet into a tree. The graph below shows lengths to avoid for different collections of bands. 49:1 or other high ratio transformers are for resonant "cut to frequency" antennas like the traditional zepp/fuchs antenna. Thank you so much for such a great product! Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. For a better experience, please enable JavaScript in your browser before proceeding. 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. 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. Y &lD30. I say run what you got and don't worry about it. /Length 10 0 R As typically I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. 1 X FT240-43 Ferrite Toroid Core 43 Material(Mouser Electronics), 1 X SO-239 UHF PANEL JACK S/CUP SO-239(Mouser Electronics), No. Power Handling (CW/SSB): 100 W/200 W Enclosure Width: 2.500 in. The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Legal Stuff I included the tools I used to analyze the transformer as well; this is only necessary if you are interested in analyzing your project. ones 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. The most important length is one that is non-resonant on any band. The "Super Bullet" End Fed Long Wire Antenna Matcher - 1500/3000 watt rated for Super-Punch of your signal! 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. Picture 1 of 9. Midi Music So a 49:1 impedance transformer is needed to match the 50 ohms of the coax at the feed line. Please note that I will not be describing the construction of the antenna wire radiator here. 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. The matching unit The impedance at the end of a half wave antenna is somewhere between 2000-5000 Ohms. plan to use. uR5I5z G^u2`j[}+sy9 Contact The key is you want to stay at least 1/2w long but not near 3/4w for any band of interest. 3 to31 MHz - up to 1kW intermittent (50% duty cycle). 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). /Type /Pages Hope it's clear now, if not. 3 0 obj 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. I have found this calculation to work well, however it depends on many factors such as wire used, location etc. Turns 1 through 14 are secondary windings (the long wire). Well, I didn't think it would make any difference at that many multiples. endobj endobj V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT c=W>:sECXTkc=X 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. It is important to use a counterpoise. is that for a given ham band there are min and max frequencies which Winding 1:64 Matching Auto Transformer on the FT240-43 core. 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. The vertical (y-) axis shows the VSWR and the horizontal (x-) axis shows the frequencies. Drill out holes in the designated bottom of the electrical junction box for the SO239 chassis mount. JavaScript is disabled. Re: 9:1 or 49:1 unun for end-fed long/random wire? Balun Designs. When do you use a 1:1, 9:1 or a 49:1 balun? 9:1 Unun EF Random Long wire matching Transformer with BNC or SO-239. This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. A level of 500-600 watts is the maximum with a further reduction onany band measuringabove 3:1. Save program output in file named 'f', and use InJack's own words. 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 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 . /CreationDate (D:20221212112042) 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. I actually did this first and before the connector was bolted to the box. Weight: 0.380 lbs. Just add or subtract as needed a little at a time to get the best compromise. Experimenting by slightly changing the wire length (+ or-) is encouraged to provide best overall performance. Continue on winding the long wire through the toroid to complete loops 3 through 14 as shown in the schematic below. I imported my spools from the US, but I have seen them on Ebay in the UK. I'm not saying aliens are in the radio, but aliens definitely are in the radio. Here is an ARRL 1 0 obj Repeater Builders . 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. A Balun is used to match a balanced line to an unbalanced line. There probably should be some holes for ventilation. Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. 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. This article explains why the use of mix 43 for HF applications is almost always a mistake. 20/40/17m. endobj /Count 1 /Width 748 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. While these lengths have been shown to work well on many bands, which Thanks for your answer,I will probably go with the 9:1 then. <>>> << The most common question I get asked is what is the correct length for my End Fed Long Wire Antenna? /&KWA7{L=D]g0Z!F9;V{zL[h-D,u(.9rg(RHI{f t*C/?? This design is excellent for matching both long and short length wire antennas for multiband use. 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. This unit is a Balun Designs, in collaboration with Fair Rite products, has developed what we consider to be the best single core 1:1 feedline isolation balun available today. The WSPR map is so dense it looks like the US and Europe are just big blobs of color. (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. I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. something as high as you can find. On our next windy free day, AA1F and . However, the radio didn't tune up very well on 15 meters. >> 1 bolt for antenna hook up (with nuts, washers, lock washers, and possibly thumb screw; I used #8 diameter, about an inch or so in length.). 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 "Best" Random Wire Antenna Lengths 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. endstream endobj startxref The ratio doesn't need to be 49:1 2,400 ohm either, other ratios will transform to other impedance. google_ad_height = 600; wire lengths less than 1/4 wavelength of the lowest desired frequency <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> 748 0 0 752 0 0 cm (QST, Oct 1926, "The Length of the Coverutilizes integralneoprene gasket for weatherproof integrity. The 49:1 impedance transformer will help you bring down the high impedance of your resonant EFHW antenna to almost 50 Ohm. x 2 in. HF Underground wiki Radio Hobbyist technical blogHFU Discord EuroPirate ChatPropagation DataTeamspeak Server, TDK CXA-2090 LCD Inverter Module New Old Stock USA Seller $19.99, Shortwave Pirate Radio In North America And Around The World, And Other Signals That Go Bump In The Night, Login with username, password and session length. Then verify it with your installed antenna and SWR measurements. 2 0 obj I connected it to a 33 wire running from my balcony, through the trees, and ran WSPR overnight to check things out. I'm looking forward to getting off work and hitting 40 & 20 meters again!! 10C) for the 10-80 m bands, or even 6-160 m: 17 ft (5.2 m) of twin-lead and 68 ft (20.7 m) of antenna wire (i.e., standard dimensions). 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. Use only the white gaps for your antenna lengths, and if 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. Tune Around! 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. Building on the original 1:1 design by Dr. Jerry Sevick, this balun has two (2) cores in a stacked Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW, Decrease Quantity of Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW, Increase Quantity of Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW. Stacked coreswithwinding configured as 49:1auto transformer. understand its properties. You have to stay away from a half wavelength on any frequency. SSTV >> /Pages 3 0 R stream 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. PVC Junction Box(Home Depot), 1 x 1/2 in. 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. This Balun Designs unit is replacing an MFj 1982 HP EFHW balun that was DOA when it arrived last May. 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. SWR was good after cutting the wire to appropriate length. At multiples of half wavelengths of the Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth. and experiment. 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 9:1 may work best with that length wire and a tuner, but some say that length is undesirable for the hf HAM bands. /ColorSpace 11 0 R 35-45, 54-64, 67-77. hb```YloD@(aKI V!}g@~}%Q/[[~_=Wy-:O)x[~hs/~SGeG _QE C6q %r I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). I connected the free twisted end of the short and long wires (the ground) the chassis wire (ground) of my homemade testing jig with alligator clip. bands as possible. /Parent 3 0 R 40-30-20 . I used the RigExpert Zoom AA-55 to test VSWR of the 49:1 unun impedance transformer. 40-30-20-15m bands for my 4 band Elecraft K1 qrp rig. Wire lengths for the 4:1 ratio in models 4932 and 4935. A 50 foot run of RG-8X coax connected the antenna into the LDG Z100-plus tuner and then a Yaesu FT-891A transceiver. The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. Even easier than Cut a 4 foot length of AWG #18 enameled wire. That's it in a nutshell..or is it? For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. The 30 day return period lapsed before I could get the antenna deployed to test it. An end fed antenna consists of a wire fed on its end, the length of that wire is not resonant with any frequency or frequencies you will be using it on. Performance is ASTOUNDING, far exceeding my expectations. Powered by BigCommerce. SWR will vary based on topography, wire orientation and use of ground or counterpoise. installed, it is a compromise antenna but great for portable use because This project assembles a 49:1 ferrite-core ("FT") type #43 transformer that matches 50 ohm input to 2500 ohm end fed antenna. 73. JACK, VE3EED 0 Superior Essex Heavy build polyamideimide. presents an extremely high impedance to the tu 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA Again, the bands are USA, so change them A few more comments about this 49:1 autotransformer EFHW design.