49:1 unun wire lengths

Picture 1 of 9. 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). random wire page. At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. 35. endobj "I received my third balun from Balun Designs this afternoon. He had heard good things about 'Balun Designs' so he recommended you. 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. /Length 6 0 R hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 The "9:1 UNUN" are for random length wire antennas fed at the end. The 49:1 impedance transformer will help you bring down the high impedance of your resonant EFHW antenna to almost 50 Ohm. (Originally published February 22, 2021). Typically unbalanced = 50/75 ohms too unbalanced = 450/675 ohms. 1936 article, however, fall in line with 468/f and so is used here. Just a note, if you make one of these yourself, you need to twist together the first two wraps of the 14 winding wire with both wraps of the two winding wire. SSTV DIY 49:1 Unun Impedance Transformer For End-Fed Half Wave (EFWH Tools endobj >> x {avla[g#+yt]Mk"B` xp[AO8;c=\b}|8p4cSmzgU7be,+i5ci6uq.x T/s@9uk-oZX;u`=U >8rsIXW B:uUVr6a] /Producer (XnView, http://www.xnview.com) Tune Around! 40-30-20-15m bands for my 4 band Elecraft K1 qrp rig. . often can't match it. After winding #2 is made and extends down the backside of the toroid, untwist the wires. uR5I5z G^u2`j[}+sy9 //-->, The "Best" Random Wire Antenna Lengths 35-43, 49-63, 70-85. . Random Wire Antenna Lengths - University of Delaware 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. N4UJW. I did not want to put the transformer in the housing until I tested it. . %%EOF Hope it's clear now, if not. IMG_2.jpg Step 2: Take the 6 feet of 18 gauge enameled copper wire, measure 11" from one end and fold it back. When do you use a 1:1, 9:1 or a 49:1 balun? a more capable tuner - see AA5TB's This is not exactly a 1/2 wavelength in free space, but works for wire as it has a different velocity factor than "air". Well, I didn't think it would make any difference at that many multiples. 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. 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). If you plan on stringing up a dipole you use 2 equal lengths of wire with the Balun in the middle. 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. For instance, to work 40m be sure the antenna is at least 10m or 33' long. I'm not saying aliens are in the radio, but aliens definitely are in the radio. The Short Answer Would Be That an UnUn Is a UN balanced to UN balancedmatching transformer. I have included a screenshot showing the stations that reported spotting my 200 mw beacon over the last 16 hours. This transformer is designed to be used with an end fed half wavelength of wire only. >> var sc_security="1df091cc". >> I sent him the link to the 49:1 unit to get his feedback. This Balun Designs unit is replacing an MFj 1982 HP EFHW balun that was DOA when it arrived last May. 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. JavaScript is disabled. Meet 'Balun One Nine', a small, cost-effective balun. A small ring terminal for 14ga wire that fits these screws would be helpful too. understand its properties. 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. You will note that when comparing my results with VE3EED that some of the results are a bit different. 8 0 obj This type of antenna is very easy to install because there is no need . 9:1 UNUN - MyAntennas.com There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. Winding 1:64 Matching Auto Transformer on the FT240-43 core. In another life, I could have been a telephone engineer. So, having nothing better to do one day, I re-did the calculations going out to 500 feet. 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. endobj 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 QRP End-Fed Half-Wave Antenna 49:1 Transformer 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). endobj Recommended wire lengths for Unun Balun - Webclass.org Both were on 20 meters at 97 watts, Icom 7300. End Fed Antennas - Elgin Amateur Radio Society My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! Coverutilizes integralneoprene gasket for weatherproof integrity. Continue twisting the entire length of the short wire. ", KiwiSDR Online Radio - 500 ft Northeast Beverage, KiwiSDR Online Radio - 400 ft South Beverage, KiwiSDR Online Radio - 10/11m dipole up 20 meters high. End-fed wire antenna lengths - Amateur Radio Stack Exchange This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. 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. Some important and helpful references I used for this work: https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. This will be for an eyehook in order to provide strain relief for the radiator wire. /CreationDate (D:20221212112042) Feeling a bit too lazy to calculate that by hand, however, I wrote a This transformer converts the impedance at the end . Advertising Info Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. Hertz Antenna" shows in line 2 of the table that a similarly installed What these lengths are depend on your tuner and also the wire's surroundings and also the ground system. Weight: 0.380 lbs. Computer Help Thank you so much for such a great product! PVC Junction Box(Home Depot), 1 x 1/2 in. Ham Radio End Fed Antenna with a 1:64 Matching Network You'll want to have that wire up as high as you can get.. Hopefully these random wire length calculations will help us all make this "easy" antenna work better! http://udel.edu/~mm/ham/randomWire/. /Pages 3 0 R 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 length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). 4 0 obj 6 0 obj Antenna") is an 84' long end fed and a 17' long counterpoise (6.5' for 20m). Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth. << About Batteries I used 2000 and 1000 ohm resistors in series connected to the proper unun wires with alligator clips for a total of 3000 ohms. 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! 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. The counterpoise wire, This transformer is designed to be used with an end fed, Approx. If the transformer is used with an externaltuner in conjunction with a single wireantenna typically 130-135 feet in length, power should be reduced on those bands that show an SWR above 1.6 to2:5 withoutthe tuner. doing the initial 468/f on C and D scales. Privacy Policy There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). Click to enlarge. /Creator (XnView) Because I'm more visually oriented I then plotted the many overlapping "red zones" and ended up with the page at: 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. 9:1 Unun 1.5-54MHz 2kW 9132S - The DX Shop Limited The following wire connections do not need to be made in the order I described. This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). Figure 3 Wiring of the 9:1 voltage unun. /MediaBox [0 0 748 752] "Just received my new 64131 yesterday and was anxious to see how well it performed. 9:1 or 49:1 unun for end-fed long/random wire? Jack, VE3EED - SK. 6 Screws/ Nuts/ Washers/Wing Nuts And Ring Connectors, 1 X Mica Capacitors 100pF 500V 5%(Mouser Electronics), 1 x 4 in. 9:1 UnUn End Fed Long Wire Lengths - Pretty Simple | ve3ips STORE End Fed Half Wave Antenna Coupler (EFHW) - M0UKD Having the option to switch rapidly between 49:1 and 64:1 should prove to be a really nice feature.. Post Reviews answers on D - one setting. 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. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! This antenna, which works on 10, 15, 20, and 40 meters, has a very high impedance of around 2,500 Ohms. https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. NOTE: Rewording the previous paragraph, if you have a capable enough This is a followup video to #344 where I assembled the 49:1 UNUN kit from HF-Kits / ARRL. 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. 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. Random wire lengths you should and should not use! stream 1:64 vs 1:49 balun for an end fed?? : r/amateurradio - reddit Downward impedance transformation by factor of 49. I imported my spools from the US, but I have seen them on Ebay in the UK. 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. 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. END FED "RANDOM WIRE" HF DIPOLE 9:1 ANTENNA RELACEMENT ELEMENT ONLY $28.99 Save up to 6% when you buy more. Stacked coreswithwinding configured as 49:1auto transformer. Ham Satellites We recently found some good information about random wire lengths that you should and should not use. It will be good for 15m, and 10m. 35. Solder a the 100pF capacitor between the center conductor wire and ground wires. The fewer bands, the fewer high impedance regions to avoid. 0$Ve Thanks for your answer,I will probably go with the 9:1 then. ones 49:1 Impedance Transformer for EFHW Antenna - DX Explorer high the other 1.5m (4.5feet). If the choices are. 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. Turns 1 through 14 are secondary windings (the long wire). Engineering the EFHW 49:1 Transformer and Antenna Designed for use with single wire unbalanced antennas, this new addition is small, compact and perfect for quick portable/emergency installations. It is used for non-resonant verticals like 43 foot or 33 foot Or Wire antennas like an End-Fed 1/2 Wave Multiple Length Wire Antenna. 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. 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. I say run what you got and don't worry about it. Change the program to use 423 if desired.) 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!! We are working every day to make sure our community is the best Radio Hobbyist's site. 4 0 obj >> Please note that I will not be describing the construction of the antenna wire radiator here. Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW - Balun Designs We hoisted the free end of the antenna wire approximately 30 feet into a tree. 1 0 obj I attached the toroids to a PVC DWV test cap with 3 cable ties. % SBULLET-9U-1500. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. 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. So for 80 meters (say 3.525 MHz) this gives you about 133' of wire. Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. %PDF-1.5 used by hams for dipole lengths. Ham Radio Videos! is that for a given ham band there are min and max frequencies which all US ham bands. Experimenting with 1:64 and 1:49 end-fed antenna Ununs on - reddit 32.00. (Note: I am not satisfied with this part of the project, so I will describe it here briefly. . PDF Recommended wire lengths and Installation Notes for Unun models 4932 9:1 Unun 1.5-54MHz 2kW 9132S. /Type /Catalog 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. Just add or subtract as needed a little at a time to get the best compromise. x 4 in. Care to buy us a beer? This homebrew 49:1 impedance transformer is the heart of any EFHW antenna you will build, most of the time. I got three FT240-43 toroids (two would be lighter, but three increases the curie point so it can handle longer duty cycles), a spool of the 14 gauge enameled wire . Presented for your consideration by Jack, VE3EED. A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. 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.). 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. June 8, 2022 at 9:17 am. /ProcSet 7 0 R >> Enclosure Height: 5.000 in. Quantity: Sold individually. You are using an out of date browser. =======================, 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: We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. Be sure to review the various lengths in the link below to obtain the lowest SWR across most if not all HF bands. EFHW Antenna and 49:1 UnUn | WorldwideDX Radio Forum 31 SO-239 connectors are silver plated with Teflon insulation. W3EDP's results in the above referenced End Fed Half Wave Antennas - Elgin Amateur Radio Society A good place to start is the formula 468 / f (MHz) for a 1/2 wavelength wire antenna. For example, End Fed 9:1 Magic Wire Lengths | ve3ips Uber From Philadelphia Airport To 30th Street Station, Articles OTHER