This is a followup video to #344 where I assembled the 49:1 UNUN kit from HF-Kits / ARRL. /Width 748 hb```YloD@(aKI V!}g@~}%Q/[[~_=Wy-:O)x[~hs/~SGeG _QE C6q %r An excellent way to attach a long wire antenna to the Ham It Up, this 1:9 balun has an SMA output port and high-quality spring-type terminal block input for your coax. (Originally published February 22, 2021). A png image named g.png will be created. <>/Metadata 239 0 R/ViewerPreferences 240 0 R>> 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. For instance, to work 40m be sure the antenna is at least 10m or 33' long. wire is at least 1/4 wavelength. 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. /Parent 3 0 R I wrote a small C program that does just what Jack did, butI used the band edges. x@ 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. Drill another hole in the same side as the antenna radiator wire mount hole. When you're antenna (or radial) length's an odd multiple of the operating freq, you may not need a balun or even a transmatch. (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. =======================, 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: V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT c=W>:sECXTkc=X The counterpoise wire, This transformer is designed to be used with an end fed, Approx. /ColorSpace 11 0 R Generally an EFHW will be in the range of 2,000 to 5,000 ohms at the very end of the dipole when resonant. I use this 8010 EFHW at home, too. recommended on VE3EED's page because I use all halfwave >> Built with the same craftsmanship as all our other For those that enjoy endfed antennas but want to run more power, Balun Designs now offers an excellent alternative. 8 0 obj 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- 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. If you want all the bands from Superior Essex Heavy build polyamideimide. Picture 1 of 9. So I just wanna say thank-you!! Y &lD30. 7 0 obj 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!! Ham Satellites << 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. endobj Hi guys,not really hfu related,but I tought I might ask here as I have my account. Here's a list of recommended lengths of wire to use with a 9:1 unun. A good place to start is the formula 468 / f (MHz) for a 1/2 wavelength wire antenna. The Short Answer Would Be That an UnUn Is a UN balanced to UN balancedmatching transformer. Repeater Basics 25 0 obj <> endobj <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> This was 9m vertically metres up a fishing pole and then about 5.8m out. 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA 2 eyehooks with washers and nuts (I used #8 diameter, but size is up to you.) 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. 35. % If you want a single band portable antenna you can mount pretty much however, look up this design. 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. I plotted the results for the U.S. CW band edges for use with my4 band Elecraft K1 qrp rig. the C code, in Matlab or Octave get a plot by simply putting the http://udel.edu/~mm/ham/randomWire/. Here Is a 250 Watt Home-Brew That I Made In about an Hour. The following wire connections do not need to be made in the order I described. << 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. Hopefully these random wire length calculations will help us all make this "easy" antenna work better! This will be for an eyehook in order to provide strain relief for the radiator wire. Antenna") is an 84' long end fed and a 17' long counterpoise (6.5' for 20m). << 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 . STORE Performance is ASTOUNDING, far exceeding my expectations. Jack, VE3EED - SK. This transformer is designed to be used with an end fed half wavelength of wire only. answers on D - one setting. 3 0 obj He knew that in order for the tuner to "see" a fairly low swr to work within it's range,that the antenna had to be NOT A HALF WAVE ON ANY FREQUENCY that we wanted to us, because a half wave will give us a very high impedance and the resultingswr into a 50 ohm transmitter! 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. (The numbers aboveare a great start, thanks to Jack and Mike! and experiment. (A t0 B) Fold over 6 to 8 inches and twist it together. , Reprinted with permission of Hamuniverse, this is an excellent explanation of SWR and how to best me 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? The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. 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. So, having nothing better to do one day, I re-did the calculations going out to 500 feet. 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. /MediaBox [0 0 748 752] . 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. So those are the numbers above thatwe have to stay as far away from as possible when building a long-wire antenna. 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. 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. 6 0 obj Modify bands and /Height 752 A standard recommendation (see QST, March 1936, p. 32, "An Unorthodox /Kids [ 4 0 R ] Hope it's clear now, if not. a more capable tuner - see AA5TB's So for 80 meters (say 3.525 MHz) this gives you about 133' of wire. SBULLET-9U-1500. /ProcSet 7 0 R >> The other is to provide strain relief for the antenna wire). Any SWR measurement taken with the transformer at the feedpoint should not exceed 1.5:1withNOtuner in use. Moving the pot up and down gives a feel for the SWR versus antenna impedance sensitivity. uR5ucE`_aksLjYT=hzRa]JucX7d}|'}`XRa>X 9:1 Unun 1.5-54MHz 2kW 9132S. 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. 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. That meant calculating all the way to 32 multiples of a half wave on 10 meters. You also want the antenna to be at least 1/4 wavelength long for each band you plan to use. About Hamuniverse This calculates to 4.2 m or 14 ft for an 80m end-fed. >> 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've made contact with several folks across North America in my 6 months as an amateur but getting to Europe flipped a switch and I'm afraid this amateur radio thing is going to be addicting. Electronics /* Ad banner 160 x 600 */ x 2 in. 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. which got me thinking. An UNUN is needed to match the high impedance of an end fed antenna (2k-4k ohms range). 74 0 obj <>stream /Resources << 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! The graph below shows lengths to avoid for different collections of bands. Then verify it with your installed antenna and SWR measurements. , Most matching problems occur when the antenna system This project assembles a 49:1 ferrite-core ("FT") type #43 transformer that matches 50 ohm input to 2500 ohm end fed antenna. transmit frequency the impedance is so high that tuners in most rigs These dimensions were derived from modelling the antenna in EZNEC. Wire lengths for the 4:1 ratio in models 4932 and 4935. 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. AndWhat Is It Used For In Antennas? want the antenna to be at least 1/4 wavelength long for each band you Because I'm more visually oriented I then plotted the many overlapping "red zones" and ended up with the page at: << Just add or subtract as needed a little at a time to get the best compromise. x 4 in. program or two to do all the dirty work. /&KWA7{L=D]g0Z!F9;V{zL[h-D,u(.9rg(RHI{f t*C/?? N4UJW. << A level of 500-600 watts is the maximum with a further reduction onany band measuringabove 3:1. /Type /Catalog Ham Hints "Here's the word on random-wire antennae.". /BitsPerComponent 8 I used a homemade jig made of an SO239 chassis mount to bare wires, alligator clips, and a coax-jumper with PL259 (UHF male) ends; see picture below. >> 35-43, 49-63, 70-85. Ham Radio Videos! You also endobj You can add your own wire or get the complete product from this link EFLW-3K antennas. Presented for your consideration by Jack, VE3EED. . 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. One is for the top of the box so that it can be hung up. 0 Quantity: Sold individually. Ultimately, this housing works fine, but it is heavy and clunky.). . Code Practice Both were on 20 meters at 97 watts, Icom 7300. Connect this ring terminal to one of the SO239 chassis bolts. Here Is a 250 Watt Home-Brew That I Made In about an Hour. In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. 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. multiples, and of course different band combinations yield different 2. Cut a 4 foot length of AWG #18 enameled wire. %PDF-1.7 Swr usually is all over the place and the tuner will just not do it's job. /Type /Page <> 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. /Name /Im0 https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. these are the worst lengths and you want to be as far from colored Weight: 0.380 lbs. I will also find some sort of heat resistant packing material to help hold the transformer in place. Privacy Policy Usually any wire length that is non resonant, like those shown above, will work with the 4:1 ratio. After winding #2 is made and extends down the backside of the toroid, untwist the wires. I connected it to a 33 wire running from my balcony, through the trees, and ran WSPR overnight to check things out. Jack, VE3EED, used center frequencies of thebands described in the article above, and I thought it would be nice to use band edges. Antenna Safety! The First Thing New Hams Often Ask:What Is An UnUn? ?7{*. While I have not done so yet, I plan on gluing the test cap to the back of the junction box. A small ring terminal for 14ga wire that fits these screws would be helpful too. 5 0 obj , This is a partial reprint (with permission) of an excellent series of articles published by KV5R Some of these numbers are too close to squeeze in between them. Balun Designs. However, the radio didn't tune up very well on 15 meters. While these lengths have been shown to work well on many bands, which My commercial EFHW is 130 feet long for 80 and up, and my 40 meter homebrew antenna is about . so that it is not a halfwave multiple of any frequency you want to use. stream Feeling a bit too lazy to calculate that by hand, however, I wrote a In stock . 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). At multiples of half wavelengths of the Powered by BigCommerce. /XObject << /Im0 9 0 R >> Click to enlarge. Solder a the 100pF capacitor between the center conductor wire and ground wires. This article explains why the use of mix 43 for HF applications is almost always a mistake. The bandwidth where SWR was below 2:1 was about one MHz. At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. They just saved you and I loads of time and frustration. endobj 1863 1.49 swr 3915 2.50 7200 1.80 14.332 1.29 18.130 1.07 21.300 1.40 24.950 1.30 28.400 1.37 This is a great antenna that is . Do what works best! ones For calculating the length of a half wave in metres, I use 141 (MHz) for wire elements. /Filter [ /FlateDecode ] This design is excellent for matching both long and short length wire antennas for multiband use. 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. 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. The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. 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. You have to give up a band or two, like 60m and 6m, as This article details the construction of the transformer. Wait a few minutes for glue to set. 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. Update guys:made the unun,the antenna was extended to about 37m length,and I added a counterpoise which is about 10m.The whole thing is much higher in the air,compared to where it was before. End Fed Antennas. %PDF-1.5 % Even easier than SO-239 (UHF female) chassis mount with screws, nuts, lock washers. Power Handling (CW/SSB): 100 W/200 W Enclosure Width: 2.500 in. Drill a hole in one side for the antenna radiator wire mount (for a #8 bolt in my build). A 50 foot run of RG-8X coax connected the antenna into the LDG Z100-plus tuner and then a Yaesu FT-891A transceiver. Advertising Info 3. 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 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. 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. For typical tuners built into a rig, Use with other lengths can potentially damage the transformer depending on power level in use. 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. google_ad_slot = "1982258389"; Liquidtight NM 90-Degree Connector(Home Depot). &nb Start winding the Matching Auto Transformer, each pass through the center of the core equals one turn. thank you. 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. Use with other lengths can potentially damage the transformer depending on power level in use. something as high as you can find. [ /PDF /Text /ImageI ] Just add or subtract as needed a little at a time toget the best compromise. unavailable, a random wire can save the day, but it is important to This is a 4:1 Current Balun.That means it can match a 200ohm antenna to a 50 feed line. Start winding the toroid with the twisted wires at loop #1 (see schematic below). Typically unbalanced = 50/75 ohms too unbalanced = 450/675 ohms. are easily converted to half wavelengths by the famous 468/f generally As typically In another life, I could have been a telephone engineer. stream I made one without doing this and it didn't work so well. Best SWR was . 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. In fact, the 9:1 unun that I built is actually an autotransformer. Proudly powered by WordPress If the choices are. 22.00 + 5.00 Postage. 27.00 (27.00/Unit) Free Postage. Meet 'Balun One Nine', a small, cost-effective balun. 4 0 obj ), Note that Jack, VE3EED,went SK several years agohe will be missed. 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. Let the now free end of the short wire hang down from the toroid. Let's have a look at a few details on how to build a 49:1 impedance . I only used two screws instead of four. 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. Downward impedance transformation by factor of 49. The key is you want to stay at least 1/2w long but not near 3/4w for any band of interest. When on the trail, at Field Day, or whenever a good antenna is For best results, use the Wire Length Feet 1.8 MHz 3.7 MHz 5.3 MHz 7.1 MHz 10.1 MHz 14.2 MHz 18.1 MHz 21.2 MHz 24.9 MHz 28.5 MHz 50.1 MHz Anyway, an old friend mentioned 'MyAntenna.com' but they were closed for the summer. /ModDate (D:20221212112042) /CreationDate (D:20221212112042) The vertical (y-) axis shows the VSWR and the horizontal (x-) axis shows the frequencies.
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