Usually any wire length that is non resonant, like those shown above, will work with the 4:1 ratio. Figure 2 Schematic of the 9:1 voltage unun . 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. Free Postage. Here Is a 250 Watt Home-Brew That I Made In about an Hour. 49:1 or other high ratio transformers are for resonant "cut to frequency" antennas like the traditional zepp/fuchs antenna. <> , Most matching problems occur when the antenna system Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. June 8, 2022 at 9:17 am. 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. An Unun is used to match an unbalanced line to another unbalanced line. Vhf and Up endstream endobj startxref A success! The transformer usually used with an end fed wire is a 9:1 transformer. 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. SEARCH Swr usually is all over the place and the tuner will just not do it's job. 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. License Study I made just a touch over 100 QSOs today with the new unit. . I have included a screenshot showing the stations that reported spotting my 200 mw beacon over the last 16 hours. it is easy to pack and easy to install. 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 The QRP End-Fed Half-Wave Antenna 49:1 Transformer Building a great impedance transformer for Ham Radio end-fed wire antennas. used by hams for dipole lengths. This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> 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 Clansman End Fed Long Wire Antenna Used. Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. results. 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. "I received my third balun from Balun Designs this afternoon. Use a slide rule! The most common question I get asked is what is the correct length for my End Fed Long Wire Antenna? You can take one of these 49:1 transformers and use the 468/freq (Mhz) formula to calculate the length you need in feet. Ham Hints When do you use a 1:1, 9:1 or a 49:1 balun? You can add your own wire or get the complete product from this link EFLW-3K antennas. endobj As typically For calculating the length of a half wave in metres, I use 141 (MHz) for wire elements. To DB's point of a single band antenna, this 49:1 transformer is a good choice for a single band matcher. program or two to do all the dirty work. /&KWA7{L=D]g0Z!F9;V{zL[h-D,u(.9rg(RHI{f t*C/?? We'd really appreciate it! After winding #2 is made and extends down the backside of the toroid, untwist the wires. Thanks for your answer,I will probably go with the 9:1 then. 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. I wrote a small C program that does just what Jack did, butI used the band edges. I attached the toroids to a PVC DWV test cap with 3 cable ties. I only used two screws instead of four. 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. 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. /Subtype /Image In other Meet 'Balun One Nine', a small, cost-effective balun. Connect this ring terminal to one of the SO239 chassis bolts. 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. The following wire connections do not need to be made in the order I described. 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. Wire-Lengths-for-9-1-ununs.pdf Created Date: 12/12/2022 11:20:42 AM . The length of enamelled copper wire per winding for the T-200-2 powdered iron toroid core is determined by length per winding = 50mm per turn plus 250mm tails. hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 /Im0 Do want the antenna to be at least 1/4 wavelength long for each band you Repeater Basics 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. You also random wire should use 423/f. The unun was floating at about 15 feet above ground. 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 . stream Lengths of a half-wave or multiple must be avoided. is that for a given ham band there are min and max frequencies which Weight: 0.380 lbs. 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 for 80 meters (say 3.525 MHz) this gives you about 133' of wire. 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. I sent him the link to the 49:1 unit to get his feedback. 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. 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. Care to buy us a beer? While I have not done so yet, I plan on gluing the test cap to the back of the junction box. , Reprinted with permission of Hamuniverse, this is an excellent explanation of SWR and how to best me I swept the VSWR of the unun and resistors as described from <1 to 55MHz. Random wire lengths you should and should not use! endobj Solder a the 100pF capacitor between the center conductor wire and ground wires. There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). <> 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. Coverutilizes integralneoprene gasket for weatherproof integrity. Tweak the antenna length if necessary and then maybe adjust the turns ratio again. 74 0 obj <>stream Even better would be shortening to 53'. For instance, to work 40m be sure the antenna is at least Just add or subtract as needed a little at a time to get the best compromise. Work all bands from 80 through 10 on it. Hertz Antenna" shows in line 2 of the table that a similarly installed 7 0 obj Post Reviews Our Ask An Elmer panel discuss this question - what's the difference between matching units?Please consider using. /Type /Page This was 9m vertically metres up a fishing pole and then about 5.8m out. 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). transmit frequency the impedance is so high that tuners in most rigs 9:1 Unun 1.5-54MHz 2kW 9132S. He had heard good things about 'Balun Designs' so he recommended you. 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). /Pages 3 0 R In stock . endobj 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. Some important and helpful references I used for this work: https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. SO-239 connectors are silver plated with Teflon insulation. (QST, Oct 1926, "The Length of the Alternate connectors and Mounting Options are available in the. The idea Quantity: Sold individually. STORE /MediaBox [0 0 748 752] >> "Just received my new 64131 yesterday and was anxious to see how well it performed. 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. HF & Shortwave IMG_2.jpg Step 2: Take the 6 feet of 18 gauge enameled copper wire, measure 11" from one end and fold it back. What these lengths are depend on your tuner and also the wire's surroundings and also the ground system. 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 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. /Type /XObject Designed for those who want the maximum isolation and choking across the full HF spectrum. 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. &nb 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 VSWR analysis of the antenna in the field showed that VSWRs between 3-5.5 from 40M to 10M. The Short Answer Would Be That an UnUn Is a "UN balanced to UN balanced" matching transformer. This homebrew 49:1 impedance transformer is the heart of any EFHW antenna you will build, most of the time. /Contents 5 0 R However, the list has been revised and is good for wires as long as 500 feet. The 30 day return period lapsed before I could get the antenna deployed to test it. >> The most important length is one that is non-resonant on any band. Wire lengths for the 4:1 ratio in models 4932 and 4935. 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 . 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. shown in the column e. var sc_project=8077274; The length should be calculated based on the lowest frequency to be worked. You are using an out of date browser. Continue on winding the long wire through the toroid to complete loops 3 through 14 as shown in the schematic below. << 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. you're using different ham bands than in these examples, modify and rerun 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. The WorldwideDX Radio Forum was originally established in 2001. 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. google_ad_client = "ca-pub-9377297764300878"; =======================, 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: The beauty of the halfwave antenna is it's a complete antenna in the sense it needs no counterpoise. %PDF-1.4 unavailable, a random wire can save the day, but it is important to We do not encourage any radio operations contrary to regulations. The popular End-Fed Half-Wave (EFHW) Antenna is an easily portable, high-impedance (2,000-4,000 ohm) wire antenna that resonates on its fundamental frequency and all harmonics above. For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. Click to enlarge. are easily converted to half wavelengths by the famous 468/f generally 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. I connected the free untwisted end of the short wire to the center conductor of my homemade testing jig (see tools list) with an alligator clip. 748 0 0 752 0 0 cm 1 0 obj N4UJW. (A t0 B) Fold over 6 to 8 inches and twist it together. <> 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! I have not done this yet. Ask Elmer /Type /Pages /Creator (XnView) 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- /Length 6 0 R 5 0 obj Moving the pot up and down gives a feel for the SWR versus antenna impedance sensitivity. 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). Note: My (A to B) length was 6 inches. 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. In fact, the 9:1 unun that I built is actually an autotransformer. Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas. Y &lD30. Tools 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. 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. gnuplot 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.). About Hamuniverse /ColorSpace 11 0 R Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> AndWhat Is It Used For In Antennas? In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. Ham Radio News! 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. multiples, and of course different band combinations yield different 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. /Title (Wire-Lengths-for-9-1-ununs.pdf) 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. Lengths to avoid are not always the same as 20/40/17m. A VSWR sweep of the unun after adding a 100pF capacitor shows an SWR <5:1 from 160M to 10M. One is for the top of the box so that it can be hung up. There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. Generally an EFHW will be in the range of 2,000 to 5,000 ohms at the very end of the dipole when resonant. Superglue 2 toroids together. This article details the construction of the transformer. Our newdesign isperfect for matching both long and short length wire antennas for multiband use. NEMA rated 4x marine grade junction box for outdoor installations. We hoisted the free end of the antenna wire approximately 30 feet into a tree. The bandwidth where SWR was below 2:1 was about one MHz. 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). 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. The "Super Bullet" End Fed Long Wire Antenna Matcher - 1500/3000 watt rated for Super-Punch of your signal! 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. I did not want to put the transformer in the housing until I tested it. Hopefully these random wire length calculations will help us all make this "easy" antenna work better! %PDF-1.5 % So, having nothing better to do one day, I re-did the calculations going out to 500 feet. . 73, 3 0 obj random wire page. The other is to provide strain relief for the antenna wire). JC[ d8O[UKKQ{yZ{G 'Upno_*~8uo a@G`' zxUHXW&`}mEp`?i0 oE:N0-/t"t.-? google_ad_width = 160; See the picture below. these are the worst lengths and you want to be as far from colored 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. | % %PDF-1.7 Typically unbalanced = 50/75 ohms too unbalanced = 450/675 ohms. Well, I didn't think it would make any difference at that many multiples. 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. These are sometimes known as a Magnetic Longwire Balun. /ModDate (D:20221212112042) End Fed Antennas. I plotted the results for the U.S. CW band edges for use with my4 band Elecraft K1 qrp rig. We are working every day to make sure our community is the best Radio Hobbyist's site. Each winding is counted when the wire enters through the center hole of the toroid. (wlSR9dJ_x%+VHX4FRr 3>;g^x%g'wkJu,i~#Q"2|WGf[!_m]#&1$)R.{--" 'dGO;=_B$T}". 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 Model 9135 along with one of the wire lengths shown in the Installation Notes. SSTV config file by typing gnuplot rw.gnu. Start winding the Matching Auto Transformer, each pass through the center of the core equals one turn.
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