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. A png image named g.png will be created. "Just received my new 64131 yesterday and was anxious to see how well it performed. //-->, The "Best" Random Wire Antenna Lengths Again, the bands are USA, so change them endobj and leave the unun on the ground. 2 0 obj , Reprinted with permission of Hamuniverse, this is an excellent explanation of SWR and how to best me I have not done this yet. Q 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. Having the option to switch rapidly between 49:1 and 64:1 should prove to be a really nice feature.. is that for a given ham band there are min and max frequencies which 9:1 or 49:1 unun for end-fed long/random wire? a more capable tuner - see AA5TB's Generally an EFHW will be in the range of 2,000 to 5,000 ohms at the very end of the dipole when resonant. Enclosure Depth: 1.250 in. I included the tools I used to analyze the transformer as well; this is only necessary if you are interested in analyzing your project. There probably should be some holes for ventilation. The table below represents half wave lengths and multiples that you DO NOT WANT TO USE! Coverutilizes integralneoprene gasket for weatherproof integrity. This Balun Designs unit is replacing an MFj 1982 HP EFHW balun that was DOA when it arrived last May. 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. I connected it to a 33 wire running from my balcony, through the trees, and ran WSPR overnight to check things out. . In other Y &lD30. ones "I received my third balun from Balun Designs this afternoon. << As typically We'd really appreciate it! So those are the numbers above thatwe have to stay as far away from as possible when building a long-wire antenna. June 8, 2022 at 9:17 am. 4 0 obj Thanks for your answer,I will probably go with the 9:1 then. endstream Just add or subtract as needed a little at a time toget the best compromise. <> 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. 9:1 UnUn End Fed Long Wire Lengths - Pretty Simple. NEMA rated 4x marine grade junction box for outdoor installations. 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. << One end goes straight into the Wire-Lengths-for-9-1-ununs.pdf Created Date: 12/12/2022 11:20:42 AM . However, the list has been revised and is good for wires as long as 500 feet. 27.00 (27.00/Unit) Free Postage. 5 0 obj all US ham bands. This antenna, which works on 10, 15, 20, and 40 meters, has a very high impedance of around 2,500 Ohms. (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. Electronics 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. Re: 9:1 or 49:1 unun for end-fed long/random wire? In stock . Reading Room 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 The counterpoise wire, This transformer is designed to be used with an end fed, Approx. When used with the stated Balun Designsis now offering a low power alternative for those who want to use an End Fed Half Wave for portable or temporary installations. /Name /Im0 35. What these lengths are depend on your tuner and also the wire's surroundings and also the ground system. thank you. is helpful if you're in a hurry to get on the air, read up on the topic 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. (Also check out AB3AP'Swebsite and say thanks for sharing his skills. There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. I only used two screws instead of four. (Originally published February 22, 2021). <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> For example, This transformer is designed to be used with an end fed half wavelength of wire only. 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA 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. Use only the white gaps for your antenna lengths, and if (The numbers aboveare a great start, thanks to Jack and Mike! these are the worst lengths and you want to be as far from colored SWR was good after cutting the wire to appropriate length. bands as possible. 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. << Solder a the 100pF capacitor between the center conductor wire and ground wires. 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 . Superglue 2 toroids together. /Title (Wire-Lengths-for-9-1-ununs.pdf) Just add or subtract as needed a little at a time to get the best compromise. 49:1 or other high ratio transformers are for resonant "cut to frequency" antennas like the traditional zepp/fuchs antenna. 73. JACK, VE3EED (QST, Oct 1926, "The Length of the 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. It may not display this or other websites correctly. config file by typing gnuplot rw.gnu. The WorldwideDX Radio Forum was originally established in 2001. ), Note that Jack, VE3EED,went SK several years agohe will be missed. In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. 3. | >> Computer Help The other is to provide strain relief for the antenna wire). Care to buy us a beer? It will be good for 15m, and 10m. I sent him the link to the 49:1 unit to get his feedback. /BitsPerComponent 8 program or two to do all the dirty work. The vertical (y-) axis shows the VSWR and the horizontal (x-) axis shows the frequencies. >> This design is excellent for matching both long and short length wire antennas for multiband use. high the other 1.5m (4.5feet). /Parent 3 0 R Then verify it with your installed antenna and SWR measurements. I imported my spools from the US, but I have seen them on Ebay in the UK. Powered by BigCommerce. Do what works best! 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 While I have not done so yet, I plan on gluing the test cap to the back of the junction box. When on the trail, at Field Day, or whenever a good antenna is We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. 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. This is not exactly a 1/2 wavelength in free space, but works for wire as it has a different velocity factor than "air". One single wire, no solder connections,very simple.all the way from the tuner to the end support. x 2 in. For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. 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. We are working every day to make sure our community is the best Radio Hobbyist's site. j#f5(fk0?P[polEo5b2-/oVZu1Qo-I6C/M@TbddPc#cdZZ|7+|o{}!F#?Go7ju|?wwgow/c2/W-m~~hn[S29OU}}r7lc]wsw[shS[#qbrrK[7*0,Xv{k+o {=*vo S__O~*=y/zk75O?yjCnXS{`~Ii'c_GxN. 31 Just an FYI that I thought you might be interested in. Continue twisting the entire length of the short wire. endobj uR5I5z G^u2`j[}+sy9 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. Work all bands from 80 through 10 on it. << %PDF-1.4 %PDF-1.5 % One is for the top of the box so that it can be hung up. Some important and helpful references I used for this work: https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. The length should be calculated based on the lowest frequency to be worked. 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. 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? End fed 9:1 58ft wire and 17ft counterpose wire touching ground. A standard recommendation (see QST, March 1936, p. 32, "An Unorthodox Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. This transformer is designed to be used with an end fed half wavelength of wire only. Typically unbalanced = 50/75 ohms too unbalanced = 450/675 ohms. The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Best SWR was . the C code, in Matlab or Octave get a plot by simply putting the A success! /Type /Catalog Here I show finalizing the antenna, getting it in the air, and run. Lengths to avoid are not always the same as Here Is a 250 Watt Home-Brew That I Made In about an Hour. 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. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! >> I swept the VSWR of the unun and resistors as described from <1 to 55MHz. Change the program to use 423 if desired.) I have included a screenshot showing the stations that reported spotting my 200 mw beacon over the last 16 hours. The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. The ratio doesn't need to be 49:1 2,400 ohm either, other ratios will transform to other impedance. You also You can add your own wire or get the complete product from this link EFLW-3K antennas. << Midi Music are easily converted to half wavelengths by the famous 468/f generally I'm looking forward to getting off work and hitting 40 & 20 meters again!! 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. Drill another hole in the same side as the antenna radiator wire mount hole. <>>> it is easy to pack and easy to install. 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. var sc_security="1df091cc". Ham Hints plan to use. Our Ask An Elmer panel discuss this question - what's the difference between matching units?Please consider using. 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). Privacy Policy The bandwidth where SWR was below 2:1 was about one MHz. 2. 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. the program as I did, above, for my K1. Weight: 0.380 lbs. Turns 1 through 14 are secondary windings (the long wire). A level of 500-600 watts is the maximum with a further reduction onany band measuringabove 3:1. frequencies for your country or favorite modes. Tweak the antenna length if necessary and then maybe adjust the turns ratio again. Figure 2 Schematic of the 9:1 voltage unun . 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). Tune Around! A Balun is used to match a balanced line to an unbalanced line. Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. 35-45, 54-64, 67-77. Cannon". CQ-Calling All Hams! They just saved you and I loads of time and frustration. That type of wire antenna could be lower than 50 ohms at some frequencies and over 2,000 ohms at . for your country and favorite modes of operation. I'm not saying aliens are in the radio, but aliens definitely are in the radio. Even easier than I did not want to put the transformer in the housing until I tested it. Multiples are on C and So I just wanna say thank-you!! >> 10m or 33' long. If you want all the bands from IMG_2.jpg Step 2: Take the 6 feet of 18 gauge enameled copper wire, measure 11" from one end and fold it back. If the choices are. 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. 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.). excellent page for EFHW info - or, addressed below, to cut the wire Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. Balun Designs. gnuplot /Contents 5 0 R The transformer usually used with an end fed wire is a 9:1 transformer. In fact, the 9:1 unun that I built is actually an autotransformer. endobj Code Practice We do not encourage any radio operations contrary to regulations. ?7{*. When used with the stated lengths shown in thetable below, the 9:1 ratio will Based on the success of our model 4932, this 5kWconfigurationisalso perfect for matching both long and short length wire antennas for multiband use. Here's a list of recommended lengths of wire to use with a 9:1 unun. 40-30-20-15m bands for my 4 band Elecraft K1 qrp rig. 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. N4UJW. 748 0 0 752 0 0 cm (wlSR9dJ_x%+VHX4FRr 3>;g^x%g'wkJu,i~#Q"2|WGf[!_m]#&1$)R.{--" 'dGO;=_B$T}". so that it is not a halfwave multiple of any frequency you want to use. X:nzf4p:t;r }~_HOZcX:^$* J^XZuu|"nX/Wkw0hA>y1(z2+v_Xzu[/:^$*m*>hk_:+c{ /Length 10 0 R 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. Gil Gruson 1 Campaign | Comines, France $0 USD 0 backers 0% of $3,450 Flexible Goal Follow Story FAQ Updates 0 Comments 0 Prototype The project team has a working demo, not the final product. You can take one of these 49:1 transformers and use the 468/freq (Mhz) formula to calculate the length you need in feet. Continue on winding the long wire through the toroid to complete loops 3 through 14 as shown in the schematic below. <> x][~ XwiH:99gn`1-wz;n[VbW7JH4D]>}>y/D_^7,yyx}s*nveo>mn|6k7GMY4%" M)?O|'opw8o1\5JNe:9hTc5@Ik~aE%O^0$ 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 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). Product Reviews understand its properties. (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. results. This is considered a random wire end fed antenna, not to be confused with a half wave end fed antenna which uses a 49:1 or 64:1 unun and a wire that is a half wave length.

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