49:1 unun wire lengths

Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. He was so impressed that he purchased a 9:1 unit from you, his will be delivered Saturday. 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. W3EDP's results in the above referenced N4UJW. See the picture below. One is for the top of the box so that it can be hung up. My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! Clansman End Fed Long Wire Antenna Used. 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!! 5 0 obj uR5ucE`_aksLjYT=hzRa]JucX7d}|'}`XRa>X The length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). These dimensions were derived from modelling the antenna in EZNEC. >> /Im0 Do Moving the pot up and down gives a feel for the SWR versus antenna impedance sensitivity. 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. Tune Around! 3 0 obj are blocked out because an antenna should be at least that long. %PDF-1.4 are easily converted to half wavelengths by the famous 468/f generally The short piece is for the primary winding of the transformer, and the long piece is for the secondary winding of the transformer. it is easy to pack and easy to install. 9 0 obj 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 . "Can you please recommend schematics that are designed to tune setups like these? In stock . http://udel.edu/~mm/ham/randomWire/. That meant calculating all the way to 32 multiples of a half wave on 10 meters. Antenna") is an 84' long end fed and a 17' long counterpoise (6.5' for 20m). I attached the toroids to a PVC DWV test cap with 3 cable ties. 2 0 obj Best SWR was . 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. for your country and favorite modes of operation. endobj 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. unavailable, a random wire can save the day, but it is important to The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. endobj (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. Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. 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. Click to enlarge. This antenna, which works on 10, 15, 20, and 40 meters, has a very high impedance of around 2,500 Ohms. transmit frequency the impedance is so high that tuners in most rigs We recently found some good information about random wire lengths that you should and should not use. 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. (The numbers aboveare a great start, thanks to Jack and Mike! endobj Shortwave Listening This article explains why the use of mix 43 for HF applications is almost always a mistake. This was 9m vertically metres up a fishing pole and then about 5.8m out. JavaScript is disabled. 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] Balun Designs. The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. 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. Vhf and Up Suggested wire lengths for 1-61 MHz operation (measured from Bullet wire point): Bands Covered (meters) Wire Length (feet) Minimum Coax Length (feet) 40-30-20-15. So for example 80m could range in length from 120 to 133 feet. $1YacO5Q}YC\>qZ } The second smallest number I measured was 2.7pF, derived from the self resonance at 2.72 MHz with the magnetizing inductance (measured at 25.8 H) with the secondary open and the output wire folded to a small 1/2 length. The trick, therefore, is either 27.00 (27.00/Unit) Free Postage. results. So, having nothing better to do one day, I re-did the calculations going out to 500 feet. Twist the short and long wires together starting at an end of each wire. google_ad_height = 600; It's an efficient way to get all the multiples Use with other lengths can potentially damage the transformer depending on power level in use. Picture 1 of 9. License Study 2 0 obj We do not encourage any radio operations contrary to regulations. The idea End fed 49:1 60ft wire (using coax as the counter poise. 40-10m with a 49:1 Unun. Here Is a 250 Watt Home-Brew That I Made In about an Hour. https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. This design is excellent for matching both long and short length wire antennas for multiband use. %PDF-1.7 It may not display this or other websites correctly. To DB's point of a single band antenna, this 49:1 transformer is a good choice for a single band matcher. Enclosure Depth: 1.250 in. 7 0 obj Then verify it with your installed antenna and SWR measurements. IMG_2.jpg Step 2: Take the 6 feet of 18 gauge enameled copper wire, measure 11" from one end and fold it back. Drill out holes in the designated bottom of the electrical junction box for the SO239 chassis mount. About Hamuniverse An Unun is used to match an unbalanced line to another unbalanced line. var sc_security="1df091cc". Repeater Builders (wlSR9dJ_x%+VHX4FRr 3>;g^x%g'wkJu,i~#Q"2|WGf[!_m]#&1$)R.{--" 'dGO;=_B$T}". /CreationDate (D:20221212112042) Privacy Policy There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). I imported my spools from the US, but I have seen them on Ebay in the UK. Ultimately, this housing works fine, but it is heavy and clunky.). Cut a 4 foot length of AWG #18 enameled wire. Links Support The Site [ /PDF /Text /ImageI ] Designed for use with single wire unbalanced antennas, this new addition is small, compact and perfect for quick portable/emergency installations. Code Practice a more capable tuner - see AA5TB's these are the worst lengths and you want to be as far from colored So is an essential piece of gear to have. 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. 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). frequencies for your country or favorite modes. AndWhat Is It Used For In Antennas? I plotted the results for the U.S. CW band edges for use with my4 band Elecraft K1 qrp rig. Start winding the Matching Auto Transformer, each pass through the center of the core equals one turn. stream All you need for a random wire antenna is some wire, your tuner, one or more supports up as high as you can get them to string the wire from the supports to the tuner, at least one or two insulatorsand a little time. (Center fed is so appealing because you avoid this.). /Kids [ 4 0 R ] 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. A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. 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). For calculating the length of a half wave in metres, I use 141 (MHz) for wire elements. recommended on VE3EED's page because I use all halfwave Advertising Info Antenna Design However, the list has been revised and is good for wires as long as 500 feet. Well then you need to choose a wire length that is at least 1/4 on 40 meters, and doesn't fall on any of the 1/2 multiples for ALL the bands between 40 to 10 meters While you could certainly calculate the lengths to avoid using the standard formulas, and then make a chart, the section below may be what you are looking for. "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. (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. So for example 80m could range in length from 120 to 133 feet. here are values for CW portions of the USA This is a 4:1 Current Balun.That means it can match a 200ohm antenna to a 50 feed line. InJack's own words. 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. /ModDate (D:20221212112042) 1 0 obj /Creator (XnView) /ColorSpace 11 0 R Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. 3 0 obj 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. Lengths for Long-wire Antennas Jack - VE3EED Recommended lengths: 29 - 35.5 - 41 - 58 - 71 - 84 - 107 - 119 - 148 - 203 - 347 - 407 - 423 Not recommended lengths: 16 - 19 - 22 - 26 - 32 - 33 - 38 - 44 - 46 - 48 - 52 - 64 - 65 - 66 - 76 EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! . I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. (Originally published February 22, 2021). A way of connecting the analyzer to the transformer. The unun was floating at about 15 feet above ground. answers on D - one setting. 9:1 Unun EF Random Long wire matching Transformer with BNC or SO-239. 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). 3. shown in the column e. var sc_project=8077274; Notice from column f that there is no length giving low impendance for 59 0 obj <>/Filter/FlateDecode/ID[<81C501BAF3AD19DF6B2122F37F15AF84>]/Index[25 50]/Info 24 0 R/Length 149/Prev 898971/Root 26 0 R/Size 75/Type/XRef/W[1 3 1]>>stream uR5I5z G^u2`j[}+sy9 So a 49:1 impedance transformer is needed to match the 50 ohms of the coax at the feed line. endobj /Type /Catalog The bandwidth where SWR was below 2:1 was about one MHz. PVC Junction Box(Home Depot), 1 x 1/2 in. the C code, in Matlab or Octave get a plot by simply putting the //-->, The "Best" Random Wire Antenna Lengths /Height 752 Use only the white gaps for your antenna lengths, and if /Subtype /Image Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. Save program output in file named 'f', and use It will be good for 15m, and 10m. Turns 1 through 14 are secondary windings (the long wire). 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. In fact, the 9:1 unun that I built is actually an autotransformer. You can take one of these 49:1 transformers and use the 468/freq (Mhz) formula to calculate the length you need in feet. One single wire, no solder connections,very simple.all the way from the tuner to the end support. the program as I did, above, for my K1. Well, I didn't think it would make any difference at that many multiples. Let's have a look at a few details on how to build a 49:1 impedance . When on the trail, at Field Day, or whenever a good antenna is RFI Tips and Tricks and experiment. /Resources << This transformer converts the impedance at the end . 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. You have to stay away from a half wavelength on any frequency. =======================, 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: 40-30-20-17. In theory, my LDG Z100 Plus autotuner should be capable of matching the impedance of this 49:1 transformer with a end-fed half wave length antenna radiator across all amateur HF bands. /Parent 3 0 R multiples, and of course different band combinations yield different Again, the bands are USA, so change them I included the tools I used to analyze the transformer as well; this is only necessary if you are interested in analyzing your project. The length should be calculated based on the lowest frequency to be worked. Both were on 20 meters at 97 watts, Icom 7300. 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. Just add or subtract as needed a little at a time to get the best compromise. Connect this ring terminal to one of the SO239 chassis bolts. Tools Windings are inserted into Teflon tubes increasingtotal breakdown to 10,000 volts. <>>> 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. Electronics So those are the numbers above thatwe have to stay as far away from as possible when building a long-wire antenna. Cannon". /XObject << /Im0 9 0 R >> I'm looking forward to getting off work and hitting 40 & 20 meters again!! 74 0 obj <>stream endobj 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 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. Just an FYI that I thought you might be interested in. Use a slide rule! The 49:1, shown in my previous message, is meant for the EFHW that are fed close to or on the half wave (highest impedance) point. The Short Answer Would Be That an UnUn Is a UN balanced to UN balancedmatching transformer. Swr usually is all over the place and the tuner will just not do it's job. I actually did this first and before the connector was bolted to the box. 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. I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. <> Stacked coreswithwinding configured as 49:1auto transformer. <> config file by typing gnuplot rw.gnu. /Contents 5 0 R 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. Hertz Antenna" shows in line 2 of the table that a similarly installed Turns 1 & 2 are primary windings (the short wire). Part List: 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- The other is to provide strain relief for the antenna wire). random wire page. bands as possible. Ham Radio Videos! A standard recommendation (see QST, March 1936, p. 32, "An Unorthodox 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. This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). The graph below shows lengths to avoid for different collections of bands. /Type /XObject Here is an ARRL 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. The WSPR map is so dense it looks like the US and Europe are just big blobs of color. Antenna Safety! Continue twisting the entire length of the short wire. For instance, to work 40m be sure the antenna is at least 10m or 33' long. . endobj 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. /MediaBox [0 0 748 752] % Q gnuplot 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. 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. 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. EFHW unun Resonant Long Wire 49:1 Transformer With 67' Antenna Wire. 3 0 obj (Also check out AB3AP'Swebsite and say thanks for sharing his skills. 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). 40-30-20 . << 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. SSTV Wire lengths for the 4:1 ratio in models 4932 and 4935. 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. I used 2000 and 1000 ohm resistors in series connected to the proper unun wires with alligator clips for a total of 3000 ohms. For typical tuners built into a rig, Anyway, an old friend mentioned 'MyAntenna.com' but they were closed for the summer. I connected it to a 33 wire running from my balcony, through the trees, and ran WSPR overnight to check things out. JC[ d8O[UKKQ{yZ{G 'Upno_*~8uo a@G`' zxUHXW&`}mEp`?i0 oE:N0-/t"t.-? <> If you want a single band portable antenna you can mount pretty much however, look up this design. The First Thing New Hams Often Ask:What Is An UnUn? You have to give up a band or two, like 60m and 6m, as google_ad_client = "ca-pub-9377297764300878"; 73, The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. 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. 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. When do you use a 1:1, 9:1 or a 49:1 balun? Coverutilizes integralneoprene gasket for weatherproof integrity. In other If the choices are. Longer wire is always more I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. >> /Name /Im0 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. 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? SO-239 connectors are silver plated with Teflon insulation. 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 This calculates to 4.2 m or 14 ft for an 80m end-fed. Change the program to use 423 if desired.) Work all bands from 80 through 10 on it. endobj I use this 8010 EFHW at home, too. 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. However, the radio didn't tune up very well on 15 meters. You also This transformer is designed to be used with an end fed half wavelength of wire only. You are using an out of date browser. excellent page for EFHW info - or, addressed below, to cut the wire Please note that I will not be describing the construction of the antenna wire radiator here. 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. Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas.

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