Ham Satellites This is a 4:1 Current Balun.That means it can match a 200ohm antenna to a 50 feed line. ones multiples, and of course different band combinations yield different Alternate connectors and Mounting Options are available in the. the program as I did, above, for my K1. When on the trail, at Field Day, or whenever a good antenna is 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. /Subtype /Image End fed 49:1 60ft wire (using coax as the counter poise. 35-43, 49-63, 70-85. http://udel.edu/~mm/ham/randomWire/. We do not encourage any radio operations contrary to regulations. Click to enlarge. Just add or subtract as needed a little at a time to get the best compromise. 9:1 or 49:1 unun for end-fed long/random wire? Thus a 1/4 wave for 20m@16ft, 40m@33ft as examples are not going to work. %PDF-1.4 So for 80 meters (say 3.525 MHz) this gives you about 133' of wire. 49:1 or other high ratio transformers are for resonant "cut to frequency" antennas like the traditional zepp/fuchs antenna. STORE Ultimately, this housing works fine, but it is heavy and clunky.). UJM-49-1 $56.99 Save up to 6% when you buy more. hb```YloD@(aKI V!}g@~}%Q/[[~_=Wy-:O)x[~hs/~SGeG _QE C6q %r He had heard good things about 'Balun Designs' so he recommended you. "Can you please recommend schematics that are designed to tune setups like these? 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. Jack, VE3EED, used center frequencies of thebands described in the article above, and I thought it would be nice to use band edges. 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. Feeling a bit too lazy to calculate that by hand, however, I wrote a 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 That's it in a nutshell..or is it? are easily converted to half wavelengths by the famous 468/f generally (Center fed is so appealing because you avoid this.). Tune Around! installed, it is a compromise antenna but great for portable use because Again, the bands are USA, so change them Hi guys,not really hfu related,but I tought I might ask here as I have my account. If the choices are. 3 0 obj The idea 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. << config file by typing gnuplot rw.gnu. 7 0 obj $1YacO5Q}YC\>qZ } and leave the unun on the ground. Picture 1 of 9. So I just wanna say thank-you!! In addition to multiples, Vhf and Up 40-10m with a 49:1 Unun. HF & Shortwave thank you. 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. Just add or subtract as needed a little at a time toget the best compromise. you're using different ham bands than in these examples, modify and rerun SWR will vary based on topography, wire orientation and use of ground or counterpoise. Continue on winding the long wire through the toroid to complete loops 3 through 14 as shown in the schematic below. Typically unbalanced = 50/75 ohms too unbalanced = 450/675 ohms. The short piece is for the primary winding of the transformer, and the long piece is for the secondary winding of the transformer. This project assembles a 49:1 ferrite-core ("FT") type #43 transformer that matches 50 ohm input to 2500 ohm end fed antenna. The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. Vacation Closure - See Homepage for Next Availability. Then verify it with your installed antenna and SWR measurements. here are values for CW portions of the USA (The numbers aboveare a great start, thanks to Jack and Mike! 1. AndWhat Is It Used For In Antennas? 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. Cannon". For example, It may not display this or other websites correctly. About Batteries Use only the white gaps for your antenna lengths, and if That meant calculating all the way to 32 multiples of a half wave on 10 meters. The unun was floating at about 15 feet above ground. Theme designed by Papathemes. "I received my third balun from Balun Designs this afternoon. The length should be calculated based on the lowest frequency to be worked. I sent him the link to the 49:1 unit to get his feedback. Tools We hoisted the free end of the antenna wire approximately 30 feet into a tree. Hertz Antenna" shows in line 2 of the table that a similarly installed 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. random wire page. If you want all the bands from Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. Electronics 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). 1936 article, however, fall in line with 468/f and so is used here. You have to stay away from a half wavelength on any frequency. An Unun is used to match an unbalanced line to another unbalanced line. Advertising Info 3 to31 MHz - up to 1kW intermittent (50% duty cycle). tuner the colored bands below are the best lengths as long as your So for example 80m could range in length from 120 to 133 feet. << <> /Type /Catalog For a better experience, please enable JavaScript in your browser before proceeding. Free Postage. Modify bands and In another life, I could have been a telephone engineer. Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. Wire lengths for the 4:1 ratio in models 4932 and 4935. Midi Music 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. 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. The matching unit The impedance at the end of a half wave antenna is somewhere between 2000-5000 Ohms. Drill out holes in the designated bottom of the electrical junction box for the SO239 chassis mount. Winding 1:64 Matching Auto Transformer on the FT240-43 core. 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. Start winding the toroid with the twisted wires at loop #1 (see schematic below). My commercial EFHW is 130 feet long for 80 and up, and my 40 meter homebrew antenna is about . At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. Designed for those who want the maximum isolation and choking across the full HF spectrum. Random wire lengths you should and should not use! For calculating the length of a half wave in metres, I use 141 (MHz) for wire elements. A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. /Creator (XnView) . stream The length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). google_ad_slot = "1982258389"; /CropBox [0 0 748 752] The fewer bands, the fewer high impedance regions to avoid. /Filter [ /FlateDecode ] 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. You also 2 0 obj Longer wire is always more Here Is a 250 Watt Home-Brew That I Made In about an Hour. 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). Clansman End Fed Long Wire Antenna Used. This will be for an eyehook in order to provide strain relief for the radiator wire. x {avla[g#+yt]Mk"B` xp[AO8;c=\b}|8p4cSmzgU7be,+i5ci6uq.x T/s@9uk-oZX;u`=U >8rsIXW B:uUVr6a] %PDF-1.5 % Ham Radio Videos! 2 eyehooks with washers and nuts (I used #8 diameter, but size is up to you.) endobj 32.00. /* Ad banner 160 x 600 */ 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. 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! 31 . This is not exactly a 1/2 wavelength in free space, but works for wire as it has a different velocity factor than "air". Just an FYI that I thought you might be interested in. SSTV <> endobj For instance, to work 40m be sure the antenna is at least 10m or 33' long. Anyway, an old friend mentioned 'MyAntenna.com' but they were closed for the summer. A success! Superior Essex Heavy build polyamideimide. So is an essential piece of gear to have. We recently found some good information about random wire lengths that you should and should not use. 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. which got me thinking. One single wire, no solder connections,very simple.all the way from the tuner to the end support. Privacy Policy VSWR analysis of the antenna in the field showed that VSWRs between 3-5.5 from 40M to 10M. You can get good loading and low swr on sometimes 2 or 3 bands, but one or more of the bands thatyou want, just will not cooperate with an swr that can be adjusted with the "tuner". Power Handling (CW/SSB): 100 W/200 W Enclosure Width: 2.500 in. 0$Ve Here's a list of recommended lengths of wire to use with a 9:1 unun. (QST, Oct 1926, "The Length of the Superglue 2 toroids together. The counterpoise wire does not have to be similar in length to the main radiator wire and just a short wire is all that is needed, about 0.05 . I say run what you got and don't worry about it. The length should be calculated based on the lowest frequency to be worked. Reading Room it is easy to pack and easy to install. endobj He was so impressed that he purchased a 9:1 unit from you, his will be delivered Saturday. >> SBULLET-9U-1500. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. 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. 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. 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. The beauty of the halfwave antenna is it's a complete antenna in the sense it needs no counterpoise. 35. 9 0 obj Re: 9:1 or 49:1 unun for end-fed long/random wire? There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. 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. something as high as you can find. bands you're intested in in a vector like the example below, by typing. 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. Liquidtight NM 90-Degree Connector(Home Depot). recommended on VE3EED's page because I use all halfwave This calculates to 4.2 m or 14 ft for an 80m end-fed. wire lengths less than 1/4 wavelength of the lowest desired frequency 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. There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). 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- ?7{*. Part List: NEMA rated 4x marine grade junction box for outdoor installations. 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. I use this 8010 EFHW at home, too. JC[ d8O[UKKQ{yZ{G 'Upno_*~8uo a@G`' zxUHXW&`}mEp`?i0 oE:N0-/t"t.-? I made just a touch over 100 QSOs today with the new unit. They just saved you and I loads of time and frustration. 40-30-20 . The QRP End-Fed Half-Wave Antenna 49:1 Transformer Building a great impedance transformer for Ham Radio end-fed wire antennas. /Producer (XnView, http://www.xnview.com) q Swr usually is all over the place and the tuner will just not do it's job. /Length 10 0 R So, having nothing better to do one day, I re-did the calculations going out to 500 feet. 1 0 obj 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 1 0 obj https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth. Some of these numbers are too close to squeeze in between them. The transformer usually used with an end fed wire is a 9:1 transformer. You also want the antenna to be at least 1/4 wavelength long for each band you plan to use. , Most matching problems occur when the antenna system Twist the short and long wires together starting at an end of each wire. I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. /MediaBox [0 0 748 752] /&KWA7{L=D]g0Z!F9;V{zL[h-D,u(.9rg(RHI{f t*C/?? excellent page for EFHW info - or, addressed below, to cut the wire This design is excellent for matching both long and short length wire antennas for multiband use. Any SWR measurement taken with the transformer at the feedpoint should not exceed 1.5:1withNOtuner in use. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! Wire-Lengths-for-9-1-ununs.pdf Created Date: 12/12/2022 11:20:42 AM . A 50 foot run of RG-8X coax connected the antenna into the LDG Z100-plus tuner and then a Yaesu FT-891A transceiver. (Also check out AB3AP'Swebsite and say thanks for sharing his skills. 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. Drill another hole in the same side as the antenna radiator wire mount hole. In fact, the 9:1 unun that I built is actually an autotransformer. End fed 9:1 58ft wire and 17ft counterpose wire touching ground. Power handling is 100 watts CW / SSB & 25W Data modes. frequencies for your country or favorite modes. 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 [ /PDF /Text /ImageI ] You have to give up a band or two, like 60m and 6m, as 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? 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! 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. 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. %PDF-1.5 Humor This antenna, which works on 10, 15, 20, and 40 meters, has a very high impedance of around 2,500 Ohms. Use a slide rule! There probably should be some holes for ventilation. An UNUN is needed to match the high impedance of an end fed antenna (2k-4k ohms range). 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. Theme: Newsup by Themeansar. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. 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. %PDF-1.7 About Hamuniverse One end goes straight into the endobj I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. Enclosure Depth: 1.250 in. Quantity: Sold individually. 74 0 obj <>stream 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. It will be good for 15m, and 10m. Figure 2 Schematic of the 9:1 voltage unun . This Balun Designs unit is replacing an MFj 1982 HP EFHW balun that was DOA when it arrived last May. 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. endobj x@ A png image named g.png will be created. plan to use. hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 (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. presents an extremely high impedance to the tu 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. 9:1 Unun 1.5-54MHz 2kW 9132S. 2 0 obj Best SWR was . The vertical (y-) axis shows the VSWR and the horizontal (x-) axis shows the frequencies. I'm looking forward to getting off work and hitting 40 & 20 meters again!! << Links stream The graph below shows lengths to avoid for different collections of bands. 748 0 0 752 0 0 cm /XObject << /Im0 9 0 R >> stream To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- are blocked out because an antenna should be at least that long. I connected it to a 33 wire running from my balcony, through the trees, and ran WSPR overnight to check things out. endobj FCC Information and experiment. The trick, therefore, is either Antenna Safety! Notice from column f that there is no length giving low impendance for This is a followup video to #344 where I assembled the 49:1 UNUN kit from HF-Kits / ARRL. I plotted the results for the U.S. CW band edges for use with my4 band Elecraft K1 qrp rig. The 49:1 impedance transformer will help you bring down the high impedance of your resonant EFHW antenna to almost 50 Ohm. A 9:1 matches 50 ohms to 450 ohms and that turns out to be an ok compromise for feeding 50-100ft of wire for general purpose SW receive. Turns 1 & 2 are primary windings (the short wire). /Height 752 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. 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. 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 table below represents half wave lengths and multiples that you DO NOT WANT TO USE! 4 0 obj Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas. Thanks for your answer,I will probably go with the 9:1 then. It's an efficient way to get all the multiples 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. /Im0 Do Hope it's clear now, if not. I'll get a 9:1 unun,and use a suggested random wire length to avoid half-wave and it's multiples then,that sounds like the best things I can get out of this setup.