. program or two to do all the dirty work. 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. Vacation Closure - See Homepage for Next Availability. For calculating the length of a half wave in metres, I use 141 (MHz) for wire elements. For example, endobj /Creator (XnView) google_ad_slot = "1982258389"; Let's have a look at a few details on how to build a 49:1 impedance . This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. Many hams have tried till they are blue in the face to install the random wire antenna that works on most; if not all of the HF bands with terrible results. Prescott Hamfest 2023 Saturday - May 13, 2023 - 0800 to 1200 MST Granville Elementary School 5250 Stover Drive, Prescott Valley, AZ 86314 The 2023 Prescott Hamfest is co-sponsored by the Yavapai Amateur Radio Club (YARC) and the Amateur Radio Council of Arizona (ARCA). 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. In other After winding #2 is made and extends down the backside of the toroid, untwist the wires. rig, often with no feedline, and the other end in the air attached to 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). Electronics Clansman End Fed Long Wire Antenna Used. Best SWR was . I connected it to a 33 wire running from my balcony, through the trees, and ran WSPR overnight to check things out. Wire lengths for the 4:1 ratio in models 4932 and 4935. Then verify it with your installed antenna and SWR measurements. 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). thank you. 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!! To DB's point of a single band antenna, this 49:1 transformer is a good choice for a single band matcher. AndWhat Is It Used For In Antennas? Support The Site HF & Shortwave bands as possible. Repeater Basics In another life, I could have been a telephone engineer. VSWR analysis of the antenna in the field showed that VSWRs between 3-5.5 from 40M to 10M. %PDF-1.5 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. Please note that I will not be describing the construction of the antenna wire radiator here. recommended on VE3EED's page because I use all halfwave /Resources << 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. The trick, therefore, is either The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. 22.00 + 5.00 Postage. I attached the toroids to a PVC DWV test cap with 3 cable ties. However, the radio didn't tune up very well on 15 meters. One end goes straight into the Here Is a 250 Watt Home-Brew That I Made In about an Hour. This Balun Designs unit is replacing an MFj 1982 HP EFHW balun that was DOA when it arrived last May. A success! Thank you so much for such a great product! Jack, VE3EED - SK. /Im0 Do Do what works best! /XObject << /Im0 9 0 R >> ones STORE 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. 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 . The random wire antenna is probably one of the least expensive, easiest and cheapest HF antennas to use if you have a tuner and you want to get the "most" out of a length of "random" wire without having to pull out that calculator, doing the math, getting the center insulator built orbought, running the feedline, and all the rest that goes with putting up a more elaborate antenna. This transformer is designed to be used with an end fed half wavelength of wire only. 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). endobj Lengths of a half-wave or multiple must be avoided. Swr usually is all over the place and the tuner will just not do it's job. The graph below shows lengths to avoid for different collections of bands. 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. 27.00 (27.00/Unit) Free Postage. JC[ d8O[UKKQ{yZ{G 'Upno_*~8uo a@G`' zxUHXW&`}mEp`?i0 oE:N0-/t"t.-? 0$Ve I will also find some sort of heat resistant packing material to help hold the transformer in place. This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). Some of these numbers are too close to squeeze in between them. 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. (A t0 B) Fold over 6 to 8 inches and twist it together. My commercial EFHW is 130 feet long for 80 and up, and my 40 meter homebrew antenna is about . random wire should use 423/f. Legal Stuff (The numbers aboveare a great start, thanks to Jack and Mike! Alternate connectors and Mounting Options are available in the. Site Map 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. NOTE: Rewording the previous paragraph, if you have a capable enough is helpful if you're in a hurry to get on the air, read up on the topic 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. The following wire connections do not need to be made in the order I described. Step 1: Drill holes for and install the SO-239 or BNC connector, the stainless steel machine screw antenna connector and the ss machine screw ground connector. Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. 9:1 UnUn End Fed Long Wire Lengths - Pretty Simple. gnuplot Winding 1:64 Matching Auto Transformer on the FT240-43 core. SEARCH 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. Wait a few minutes for glue to set. Advertising Info Kj8~q7c? 20/40/17m. are blocked out because an antenna should be at least that long. wire lengths less than 1/4 wavelength of the lowest desired frequency "Here's the word on random-wire antennae.". x 4 in. (Center fed is so appealing because you avoid this.). 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. (wlSR9dJ_x%+VHX4FRr 3>;g^x%g'wkJu,i~#Q"2|WGf[!_m]#&1$)R.{--" 'dGO;=_B$T}". 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). /Contents 5 0 R 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. 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. Just add or subtract as needed a little at a time to get the best compromise. At multiples of half wavelengths of the I swept the VSWR of the unun and resistors as described from <1 to 55MHz. I made just a touch over 100 QSOs today with the new unit. 2. the C code, in Matlab or Octave get a plot by simply putting the While these lengths have been shown to work well on many bands, which If you want all the bands from 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. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. stream 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. stream Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. 2 0 obj , This is a partial reprint (with permission) of an excellent series of articles published by KV5R I included the tools I used to analyze the transformer as well; this is only necessary if you are interested in analyzing your project. You are using an out of date browser. 1. A way of connecting the analyzer to the transformer. Y &lD30. This is not exactly a 1/2 wavelength in free space, but works for wire as it has a different velocity factor than "air". 40-10m with a 49:1 Unun. 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. I wrote a small C program that does just what Jack did, butI used the band edges. 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. Longer wire is always more An UNUN is needed to match the high impedance of an end fed antenna (2k-4k ohms range). "I received my third balun from Balun Designs this afternoon. installed, it is a compromise antenna but great for portable use because In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. results. 3 0 obj >> /Type /Page Par EF 20 and par EF 40 (I realize for 17m I would prob just add that band to a 49:1 balun) That's that my question is. 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. <> Ham Radio News! google_ad_client = "ca-pub-9377297764300878"; Thus a 1/4 wave for 20m@16ft, 40m@33ft as examples are not going to work. /CropBox [0 0 748 752] I use this 8010 EFHW at home, too. End Fed Antennas. A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. so that it is not a halfwave multiple of any frequency you want to use. u?X`f0&/Ri;W0Tn_*TX:ug We recently found some good information about random wire lengths that you should and should not use. The length should be calculated based on the lowest frequency to be worked. 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. That's it in a nutshell..or is it? See the picture below. Notice from column f that there is no length giving low impendance for Just add or subtract as needed a little at a time toget the best compromise. Antenna Design multiples, and of course different band combinations yield different End fed 9:1 58ft wire and 17ft counterpose wire touching ground. /ColorSpace 11 0 R This design is excellent for matching both long and short length wire antennas for multiband use. 49:1 or other high ratio transformers are for resonant "cut to frequency" antennas like the traditional zepp/fuchs antenna. here are values for CW portions of the USA the program as I did, above, for my K1. You can take one of these 49:1 transformers and use the 468/freq (Mhz) formula to calculate the length you need in feet. 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. Both were on 20 meters at 97 watts, Icom 7300. 2 0 obj The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. << q The transformer usually used with an end fed wire is a 9:1 transformer. Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. random wire page. Multiples are on C and END FED "RANDOM WIRE" HF DIPOLE 9:1 ANTENNA RELACEMENT ELEMENT ONLY $28.99 Save up to 6% when you buy more. 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! End fed 49:1 60ft wire (using coax as the counter poise. Use only the white gaps for your antenna lengths, and if and experiment. Power handling is 100 watts CW / SSB & 25W Data modes. I plotted the results for the U.S. CW band edges for use with my4 band Elecraft K1 qrp rig. Ham Radio Videos! SO-239 (UHF female) chassis mount with screws, nuts, lock washers. These dimensions were derived from modelling the antenna in EZNEC. 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. /Type /Pages 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 management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. 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. understand its properties. You also want the antenna to be at least 1/4 wavelength long for each band you plan to use. Hi guys,not really hfu related,but I tought I might ask here as I have my account. <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> endobj Just an FYI that I thought you might be interested in. hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 /Subtype /Image 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. 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. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! is that for a given ham band there are min and max frequencies which endobj 4 0 obj which got me thinking. 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 . Q This antenna, which works on 10, 15, 20, and 40 meters, has a very high impedance of around 2,500 Ohms. Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. bands you're intested in in a vector like the example below, by typing. Our newdesign isperfect for matching both long and short length wire antennas for multiband use. Here they are in order: 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 Work all bands from 80 through 10 on it. 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. Here is an ARRL Hopefully these random wire length calculations will help us all make this "easy" antenna work better! The counterpoise wire, This transformer is designed to be used with an end fed, Approx. 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. <>/Metadata 239 0 R/ViewerPreferences 240 0 R>> SSTV SBULLET-9U-1500. 6 Screws/ Nuts/ Washers/Wing Nuts And Ring Connectors, 1 X Mica Capacitors 100pF 500V 5%(Mouser Electronics), 1 x 4 in. A good place to start is the formula 468 / f (MHz) for a 1/2 wavelength wire antenna. I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. 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. We are working every day to make sure our community is the best Radio Hobbyist's site. We do not encourage any radio operations contrary to regulations. Product Reviews << Enclosure Depth: 1.250 in. 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. You also I imported my spools from the US, but I have seen them on Ebay in the UK. 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 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. Anyway, an old friend mentioned 'MyAntenna.com' but they were closed for the summer. 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.). 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. (Also check out AB3AP'Swebsite and say thanks for sharing his skills. The WorldwideDX Radio Forum was originally established in 2001. 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. ), Note that Jack, VE3EED,went SK several years agohe will be missed. Some important and helpful references I used for this work: https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. This was 9m vertically metres up a fishing pole and then about 5.8m out. x@ 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. 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. Well, I didn't think it would make any difference at that many multiples. Shortwave Listening <>>> endstream endobj startxref 2 0 obj So for example 80m could range in length from 120 to 133 feet. Let the now free end of the short wire hang down from the toroid. Because I'm more visually oriented I then plotted the many overlapping "red zones" and ended up with the page at: Hope it's clear now, if not. I have included a screenshot showing the stations that reported spotting my 200 mw beacon over the last 16 hours. Part List: /Length 6 0 R Be sure to review the various lengths in the link below to obtain the lowest SWR across most if not all HF bands. That is the 10th multiple of a half wave on 15 meters. /Length 10 0 R I'm looking forward to getting off work and hitting 40 & 20 meters again!! 9 0 obj high the other 1.5m (4.5feet). These are sometimes known as a Magnetic Longwire Balun. The key is you want to stay at least 1/2w long but not near 3/4w for any band of interest. Contact I did not want to put the transformer in the housing until I tested it. shown in the column e. var sc_project=8077274; About Batteries (Originally published February 22, 2021). 2 eyehooks with washers and nuts (I used #8 diameter, but size is up to you.) //-->, The "Best" Random Wire Antenna Lengths Use with other lengths can potentially damage the transformer depending on power level in use. 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. config file by typing gnuplot rw.gnu. The WSPR map is so dense it looks like the US and Europe are just big blobs of color. plan to use. One is for the top of the box so that it can be hung up. 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 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. 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). Superior Essex Heavy build polyamideimide. hb```YloD@(aKI V!}g@~}%Q/[[~_=Wy-:O)x[~hs/~SGeG _QE C6q %r wire is at least 1/4 wavelength. endobj <> The bandwidth where SWR was below 2:1 was about one MHz. So is an essential piece of gear to have. endobj PVC Junction Box(Home Depot), 1 x 1/2 in. This article explains why the use of mix 43 for HF applications is almost always a mistake. End Fed Half Wave Antenna Coupler Schematic - 7-30MHz. NEMA rated 4x marine grade junction box for outdoor installations. Theme: Newsup by Themeansar. Computer Help Even easier than >> Drill a hole in one side for the antenna radiator wire mount (for a #8 bolt in my build). It's an efficient way to get all the multiples Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth. Turns 1 through 14 are secondary windings (the long wire). for your country and favorite modes of operation.

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