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. Theme: Newsup by Themeansar. <> % In stock . I swept the VSWR of the unun and resistors as described from <1 to 55MHz. This type of antenna is very easy to install because there is no need . Drill a hole in one side for the antenna radiator wire mount (for a #8 bolt in my build). 35-45, 54-64, 67-77. 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). program or two to do all the dirty work. Windings are inserted into Teflon tubes increasingtotal breakdown to 10,000 volts. Tools When on the trail, at Field Day, or whenever a good antenna is 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. 80m up, W3EDP's 84' antenna, 17' counterpoise is probably the way to go. google_ad_client = "ca-pub-9377297764300878"; 1936 article, however, fall in line with 468/f and so is used here. You'll want to have that wire up as high as you can get.. Picture Information. Each vertical blue line represents an amateur radio band. Lengths of a half-wave or multiple must be avoided. Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. Performance is ASTOUNDING, far exceeding my expectations. Continue on winding the long wire through the toroid to complete loops 3 through 14 as shown in the schematic below. /Subtype /Image V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT c=W>:sECXTkc=X wire lengths less than 1/4 wavelength of the lowest desired frequency 35-43, 49-63, 70-85. &nb Quantity: Sold individually. /MediaBox [0 0 748 752] One end goes straight into the Note: My (A to B) length was 6 inches. . This will be for an eyehook in order to provide strain relief for the radiator wire. Reading Room . /ColorSpace 11 0 R understand its properties. FCC Information >> Here Is a 250 Watt Home-Brew That I Made In about an Hour. 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. This antenna, which works on 10, 15, 20, and 40 meters, has a very high impedance of around 2,500 Ohms. "Here's the word on random-wire antennae.". There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). 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. %%EOF You can take one of these 49:1 transformers and use the 468/freq (Mhz) formula to calculate the length you need in feet. Product Reviews Just add or subtract as needed a little at a time toget the best compromise. Technical specification : Type : 49:1 Unun Frequency : 1.8 MHz - 7.3 MHz Turns ratio: 1:7 Impedance ratio: 1:49 Input Impedance: 50 Output Impedance: 2450 Power Handling (CW/SSB/ Digital Modes) : 2Kw of peak power / DM Modes 500 watts Core Type : 3 x FT240-43 by Fair-rite Co. Wire type: Enamel copper wire 2.0 mm (AWG 12) Assembled and tested. My commercial EFHW is 130 feet long for 80 and up, and my 40 meter homebrew antenna is about . Part List: AndWhat Is It Used For In Antennas? The unun was floating at about 15 feet above ground. About Hamuniverse http://udel.edu/~mm/ham/randomWire/. 7 0 obj 20/40/17m. Having the option to switch rapidly between 49:1 and 64:1 should prove to be a really nice feature.. The graph below shows lengths to avoid for different collections of bands. /Type /Catalog That is the 10th multiple of a half wave on 15 meters. 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!! A success! . frequencies for your country or favorite modes. Privacy Policy document.getElementById("copyright_year").innerHTML = new Date().getFullYear(); q Re: 9:1 or 49:1 unun for end-fed long/random wire? /Creator (XnView) This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. uR5ucE`_aksLjYT=hzRa]JucX7d}|'}`XRa>X In addition to multiples, ?7{*. Here's a list of recommended lengths of wire to use with a 9:1 unun. /Type /Pages Cannon". /XObject << /Im0 9 0 R >> Thus a 1/4 wave for 20m@16ft, 40m@33ft as examples are not going to work. you're using different ham bands than in these examples, modify and rerun I only used two screws instead of four. endobj That meant calculating all the way to 32 multiples of a half wave on 10 meters. Ask Elmer 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. So those are the numbers above thatwe have to stay as far away from as possible when building a long-wire antenna. To DB's point of a single band antenna, this 49:1 transformer is a good choice for a single band matcher. I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. 32.00. endstream endobj startxref >> NEMA rated 4x marine grade junction box for outdoor installations. (A t0 B) Fold over 6 to 8 inches and twist it together. 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. . It will be good for 15m, and 10m. Ham Radio News! /ModDate (D:20221212112042) SBULLET-9U-1500. << A way of connecting the analyzer to the transformer. (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. X:nzf4p:t;r }~_HOZcX:^$* J^XZuu|"nX/Wkw0hA>y1(z2+v_Xzu[/:^$*m*>hk_:+c{ 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. Cut a 4 foot length of AWG #18 enameled wire. InJack's own words. One is for the top of the box so that it can be hung up. 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. On our next windy free day, AA1F and . Downward impedance transformation by factor of 49. In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. 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. 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. The Nelson antenna 9 to 1 unun did the trick. Moving the pot up and down gives a feel for the SWR versus antenna impedance sensitivity. 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. endobj If the choices are. So is an essential piece of gear to have. A so-called random wire antenna is an end fed antenna. 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). 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- Just add or subtract as needed a little at a time to get the best compromise. SSTV Multiples are on C and Well, I didn't think it would make any difference at that many multiples. /Count 1 << The WSPR map is so dense it looks like the US and Europe are just big blobs of color. Enclosure Height: 5.000 in. Hope it's clear now, if not. My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! so that it is not a halfwave multiple of any frequency you want to use. "Can you please recommend schematics that are designed to tune setups like these? 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. N4UJW. ), Note that Jack, VE3EED,went SK several years agohe will be missed. Power handling is 100 watts CW / SSB & 25W Data modes. << Continue twisting the entire length of the short wire. 9:1 Unun 1.5-54MHz 2kW 9132S. About Batteries ", KiwiSDR Online Radio - 500 ft Northeast Beverage, KiwiSDR Online Radio - 400 ft South Beverage, KiwiSDR Online Radio - 10/11m dipole up 20 meters high. The table below represents half wave lengths and multiples that you DO NOT WANT TO USE! answers on D - one setting. I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. Care to buy us a beer? Each winding is counted when the wire enters through the center hole of the toroid. /Type /Page 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. While I have not done so yet, I plan on gluing the test cap to the back of the junction box. I have found this calculation to work well, however it depends on many factors such as wire used, location etc. I made just a touch over 100 QSOs today with the new unit. well, the main antenna wire goes to the 9:1 UnUn "+" connector, the vertical counterpoise (insulated !) uR5I5z G^u2`j[}+sy9 A 49:1 would match 50 ohms to about 2,450 ohms and a 64:1 matches to 3,200 ohms, typical of a 1/2 wave end fed. The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. However, the radio didn't tune up very well on 15 meters. //-->, The "Best" Random Wire Antenna Lengths 3 to31 MHz - up to 1kW intermittent (50% duty cycle). This design is excellent for matching both long and short length wire antennas for multiband use. Swr usually is all over the place and the tuner will just not do it's job. For instance, to work 40m be sure the antenna is at least 0$Ve 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). %PDF-1.5 % 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 Advertising Info these are the worst lengths and you want to be as far from colored End Fed Antennas. Even easier than stream Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun 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! Please note that I will not be describing the construction of the antenna wire radiator here. I imported my spools from the US, but I have seen them on Ebay in the UK. I'm consistently pleased with the quality and ease of use of Balun Designs products and look forward to my next purchase in the future. and experiment. 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. $1YacO5Q}YC\>qZ } The bandwidth where SWR was below 2:1 was about one MHz. You also /Height 752 stream /Pages 3 0 R At multiples of half wavelengths of the If you plan on stringing up a dipole you use 2 equal lengths of wire with the Balun in the middle. At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. Meet 'Balun One Nine', a small, cost-effective balun. Antenna Design We hoisted the free end of the antenna wire approximately 30 feet into a tree. JC[ d8O[UKKQ{yZ{G 'Upno_*~8uo a@G`' zxUHXW&`}mEp`?i0 oE:N0-/t"t.-? IMG_2.jpg Step 2: Take the 6 feet of 18 gauge enameled copper wire, measure 11" from one end and fold it back. Hertz Antenna" shows in line 2 of the table that a similarly installed (wlSR9dJ_x%+VHX4FRr 3>;g^x%g'wkJu,i~#Q"2|WGf[!_m]#&1$)R.{--" 'dGO;=_B$T}". something as high as you can find. 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. 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. That's it in a nutshell..or is it? 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. This is not exactly a 1/2 wavelength in free space, but works for wire as it has a different velocity factor than "air". hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 Proudly powered by WordPress /Length 6 0 R A 50 foot run of RG-8X coax connected the antenna into the LDG Z100-plus tuner and then a Yaesu FT-891A transceiver. You are using an out of date browser. Here is an ARRL I included the tools I used to analyze the transformer as well; this is only necessary if you are interested in analyzing your project. 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. << STORE Electronics endobj Ham Hints Twist the short and long wires together starting at an end of each wire. 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! Turns 1 & 2 are primary windings (the short wire). Ham Radio Videos! the program as I did, above, for my K1. I wrote a small C program that does just what Jack did, butI used the band edges. Solder a the 100pF capacitor between the center conductor wire and ground wires. The beauty of the halfwave antenna is it's a complete antenna in the sense it needs no counterpoise. This was 9m vertically metres up a fishing pole and then about 5.8m out. SWR will vary based on topography, wire orientation and use of ground or counterpoise. is helpful if you're in a hurry to get on the air, read up on the topic endobj Be sure to review the various lengths in the link below to obtain the lowest SWR across most if not all HF bands. Click to enlarge. Usually any wire length that is non resonant on the band or bands desired will work with the 4:1 ratio. Links (Note: I am not satisfied with this part of the project, so I will describe it here briefly. 74 0 obj <>stream >> Thanks for your answer,I will probably go with the 9:1 then. Connect this ring terminal to one of the SO239 chassis bolts. transmit frequency the impedance is so high that tuners in most rigs This article explains why the use of mix 43 for HF applications is almost always a mistake. gnuplot You will note that when comparing my results with VE3EED that some of the results are a bit different. , This is a partial reprint (with permission) of an excellent series of articles published by KV5R I made one without doing this and it didn't work so well. Repeater Basics 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. 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. Y &lD30. all US ham bands. You have to stay away from a half wavelength on any frequency. This transformer is designed to be used with an end fed half wavelength of wire only. UJM-49-1 $56.99 Save up to 6% when you buy more. 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. If you want a single band portable antenna you can mount pretty much however, look up this design. The ratio doesn't need to be 49:1 2,400 ohm either, other ratios will transform to other impedance. He had heard good things about 'Balun Designs' so he recommended you. The other is to provide strain relief for the antenna wire). 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. Use with other lengths can potentially damage the transformer depending on power level in use. Stacked coreswithwinding configured as 49:1auto transformer. To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- The length should be calculated based on the lowest frequency to be worked. 9:1 Unun EF Random Long wire matching Transformer with BNC or SO-239. The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. x@ PVC Junction Box(Home Depot), 1 x 1/2 in. You need to use these lengths and the longer ones . After winding #2 is made and extends down the backside of the toroid, untwist the wires. This Balun Designs unit is replacing an MFj 1982 HP EFHW balun that was DOA when it arrived last May. In the first year using this unun with a random length endfed wire (Aluminum Elec fence wire at that) I managed to confirm WAS via LoTW on 10m, 15, 17, 20, 30, 40, 80. . 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. 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 The length should be calculated based on the lowest frequency to be worked. stream He was so impressed that he purchased a 9:1 unit from you, his will be delivered Saturday. 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. It is important to use a counterpoise. >> So for example 80m could range in length from 120 to 133 feet. Jack, VE3EED, used center frequencies of thebands described in the article above, and I thought it would be nice to use band edges. /Im0 Do I used the RigExpert Zoom AA-55 to test VSWR of the 49:1 unun impedance transformer. For calculating the length of a half wave in metres, I use 141 (MHz) for wire elements. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. high the other 1.5m (4.5feet). The "9:1 UNUN" are for random length wire antennas fed at the end. Vhf and Up <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> | /BitsPerComponent 8 Antenna Safety! here are values for CW portions of the USA for your country and favorite modes of operation. The matching unit The impedance at the end of a half wave antenna is somewhere between 2000-5000 Ohms. 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. endstream For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. "I received my third balun from Balun Designs this afternoon. Midi Music /Kids [ 4 0 R ] a more capable tuner - see AA5TB's These are sometimes known as a Magnetic Longwire Balun. /Parent 3 0 R So, having nothing better to do one day, I re-did the calculations going out to 500 feet. 4 0 obj The transformer usually used with an end fed wire is a 9:1 transformer. is that for a given ham band there are min and max frequencies which endobj 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 . RFI Tips and Tricks Anyway, an old friend mentioned 'MyAntenna.com' but they were closed for the summer. I say run what you got and don't worry about it. 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. Some of these numbers are too close to squeeze in between them. /Contents 5 0 R Start winding the toroid with the twisted wires at loop #1 (see schematic below). <> 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". 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 Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth. rig, often with no feedline, and the other end in the air attached to /Name /Im0 Vacation Closure - See Homepage for Next Availability. << and leave the unun on the ground. For a better experience, please enable JavaScript in your browser before proceeding. So I just wanna say thank-you!! 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 . are easily converted to half wavelengths by the famous 468/f generally I attached the toroids to a PVC DWV test cap with 3 cable ties. The short piece is for the primary winding of the transformer, and the long piece is for the secondary winding of the transformer. I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. 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. End Fed Half Wave Antenna Coupler Schematic - 7-30MHz. The 49:1 impedance transformer will help you bring down the high impedance of your resonant EFHW antenna to almost 50 Ohm.
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