49:1 unun wire lengths49:1 unun wire lengths

SEARCH <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> Ask Elmer Start winding the toroid with the twisted wires at loop #1 (see schematic below). 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. are blocked out because an antenna should be at least that long. 31 The 9:1 may work best with that length wire and a tuner, but some say that length is undesirable for the hf HAM bands. This is a 4:1 Current Balun.That means it can match a 200ohm antenna to a 50 feed line. is helpful if you're in a hurry to get on the air, read up on the topic So is an essential piece of gear to have. 35. << /Type /Pages /CreationDate (D:20221212112042) Tools Drill out holes in the designated bottom of the electrical junction box for the SO239 chassis mount. Do what works best! config file by typing gnuplot rw.gnu. Use with other lengths can potentially damage the transformer depending on power level in 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. I have not done this yet. About Batteries Code Practice I connected it to a 33 wire running from my balcony, through the trees, and ran WSPR overnight to check things out. So for example 80m could range in length from 120 to 133 feet. Some of these numbers are too close to squeeze in between them. Save program output in file named 'f', and use (QST, Oct 1926, "The Length of the They just saved you and I loads of time and frustration. I did not want to put the transformer in the housing until I tested it. I actually did this first and before the connector was bolted to the box. In fact, the 9:1 unun that I built is actually an autotransformer. Continue twisting the entire length of the short wire. wire lengths less than 1/4 wavelength of the lowest desired frequency 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 748 0 0 752 0 0 cm This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. EFHW unun Resonant Long Wire 49:1 Transformer With 67' Antenna Wire. Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. 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. 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. CQ-Calling All Hams! 6 0 obj doing the initial 468/f on C and D scales. /BitsPerComponent 8 =======================, 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: N4UJW. 4 0 obj 7 0 obj 6 Screws/ Nuts/ Washers/Wing Nuts And Ring Connectors, 1 X Mica Capacitors 100pF 500V 5%(Mouser Electronics), 1 x 4 in. I have found this calculation to work well, however it depends on many factors such as wire used, location etc. This transformer is designed to be used with an end fed half wavelength of wire only. 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. , This is a partial reprint (with permission) of an excellent series of articles published by KV5R endstream endobj startxref and experiment. The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. I made one without doing this and it didn't work so well. The counterpoise wire, This transformer is designed to be used with an end fed, Approx. UJM-49-1 $56.99 Save up to 6% when you buy more. Just add or subtract as needed a little at a time to get the best compromise. google_ad_width = 160; 1 0 obj A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. Here Is a 250 Watt Home-Brew That I Made In about an Hour. 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 . 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. 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. Be sure to review the various lengths in the link below to obtain the lowest SWR across most if not all HF bands. 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). Theme: Newsup by Themeansar. Thanks for your answer,I will probably go with the 9:1 then. 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. 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. V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT c=W>:sECXTkc=X Moving the pot up and down gives a feel for the SWR versus antenna impedance sensitivity. 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. uR5I5z G^u2`j[}+sy9 1 bolt for antenna hook up (with nuts, washers, lock washers, and possibly thumb screw; I used #8 diameter, about an inch or so in length.). 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 . I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. google_ad_height = 600; The 30 day return period lapsed before I could get the antenna deployed to test it. The "9:1 UNUN" are for random length wire antennas fed at the end. results. 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 The key is you want to stay at least 1/2w long but not near 3/4w for any band of interest. Designed for those who want the maximum isolation and choking across the full HF spectrum. The 49:1 impedance transformer will help you bring down the high impedance of your resonant EFHW antenna to almost 50 Ohm. well, the main antenna wire goes to the 9:1 UnUn "+" connector, the vertical counterpoise (insulated !) plan to use. 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. 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. "Here's the word on random-wire antennae.". 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. The most important length is one that is non-resonant on any band. This is not exactly a 1/2 wavelength in free space, but works for wire as it has a different velocity factor than "air". 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. it is easy to pack and easy to install. Advertising Info 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. This transformer is designed to be used with an end fed half wavelength of wire only. wire is at least 1/4 wavelength. Jack, VE3EED, used center frequencies of thebands described in the article above, and I thought it would be nice to use band edges. However, the list has been revised and is good for wires as long as 500 feet. The bandwidth where SWR was below 2:1 was about one MHz. 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). Enclosure Height: 5.000 in. A Balun is used to match a balanced line to an unbalanced line. 9:1 Unun EF Random Long wire matching Transformer with BNC or SO-239. STORE Ham Hints You are using an out of date browser. I attached the toroids to a PVC DWV test cap with 3 cable ties. You can take one of these 49:1 transformers and use the 468/freq (Mhz) formula to calculate the length you need in feet. 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 In theory, my LDG Z100 Plus autotuner should be capable of matching the impedance of this 49:1 transformer with a end-fed half wave length antenna radiator across all amateur HF bands. To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- 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!! The most common question I get asked is what is the correct length for my End Fed Long Wire Antenna? The beauty of the halfwave antenna is it's a complete antenna in the sense it needs no counterpoise. 1. stream Here they are in order: 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 . Change the program to use 423 if desired.) << Well, I didn't think it would make any difference at that many multiples. endobj 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. Reading Room That is the 10th multiple of a half wave on 15 meters. However, the radio didn't tune up very well on 15 meters. /CropBox [0 0 748 752] This article details the construction of the transformer. At multiples of half wavelengths of the Usually any wire length that is non resonant, like those shown above, will work with the 4:1 ratio. These are sometimes known as a Magnetic Longwire Balun. That type of wire antenna could be lower than 50 ohms at some frequencies and over 2,000 ohms at . The graph below shows lengths to avoid for different collections of bands. /Width 748 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. Each winding is counted when the wire enters through the center hole of the toroid. 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 1 0 obj /XObject << /Im0 9 0 R >> ?7{*. About Hamuniverse 73, 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. 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. 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. 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. >> (Note: I am not satisfied with this part of the project, so I will describe it here briefly. For instance, to work 40m be sure the antenna is at least Picture 1 of 9. 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA He was so impressed that he purchased a 9:1 unit from you, his will be delivered Saturday. (wlSR9dJ_x%+VHX4FRr 3>;g^x%g'wkJu,i~#Q"2|WGf[!_m]#&1$)R.{--" 'dGO;=_B$T}". /Creator (XnView) 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. (Center fed is so appealing because you avoid this.). "I received my third balun from Balun Designs this afternoon. Use a slide rule! endobj Connect this ring terminal to one of the SO239 chassis bolts. endobj Use with other lengths can potentially damage the transformer depending on power level in use. As typically Wire lengths for the 4:1 ratio in models 4932 and 4935. Anyway, an old friend mentioned 'MyAntenna.com' but they were closed for the summer. 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). Just add or subtract as needed a little at a time toget the best compromise. %PDF-1.5 35-45, 54-64, 67-77. 20/40/17m. At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. I included the tools I used to analyze the transformer as well; this is only necessary if you are interested in analyzing your project. stream 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. "Just received my new 64131 yesterday and was anxious to see how well it performed. If you want a single band portable antenna you can mount pretty much however, look up this design. Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. unavailable, a random wire can save the day, but it is important to Use only the white gaps for your antenna lengths, and if NEMA rated 4x marine grade junction box for outdoor installations. Product Reviews 4 0 obj If the choices are. VSWR analysis of the antenna in the field showed that VSWRs between 3-5.5 from 40M to 10M. There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). /Type /XObject You also want the antenna to be at least 1/4 wavelength long for each band you plan to use. 8 0 obj gnuplot SBULLET-9U-1500. 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. the program as I did, above, for my K1. Enclosure Depth: 1.250 in. answers on D - one setting. Tweak the antenna length if necessary and then maybe adjust the turns ratio again. . It will be good for 15m, and 10m. 0 something as high as you can find. << Thank you so much for such a great product! An Unun is used to match an unbalanced line to another unbalanced line. A VSWR sweep of the unun after adding a 100pF capacitor shows an SWR <5:1 from 160M to 10M. Presented for your consideration by Jack, VE3EED. I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. Make sure the beginning few inches of twisted wire is not involved in the winding (i.e., just hanging down from the toroid). This design is excellent for matching both long and short length wire antennas for multiband use. End Fed Half Wave Antenna Coupler Schematic - 7-30MHz. 35-43, 49-63, 70-85. 40-30-20 . The idea 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. << Solder a the 100pF capacitor between the center conductor wire and ground wires. 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. is that for a given ham band there are min and max frequencies which 2 eyehooks with washers and nuts (I used #8 diameter, but size is up to you.) Ham Radio News! here are values for CW portions of the USA This is a followup video to #344 where I assembled the 49:1 UNUN kit from HF-Kits / ARRL. Then verify it with your installed antenna and SWR measurements. For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. We are working every day to make sure our community is the best Radio Hobbyist's site. Y &lD30. 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. Care to buy us a beer? Here I show finalizing the antenna, getting it in the air, and run. 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. 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 . https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. A few more comments about this 49:1 autotransformer EFHW design. <> I imported my spools from the US, but I have seen them on Ebay in the UK. Notice from column f that there is no length giving low impendance for Legal Stuff HF & Shortwave Figure 2 Schematic of the 9:1 voltage unun . Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas. You need to use these lengths and the longer ones . Generally an EFHW will be in the range of 2,000 to 5,000 ohms at the very end of the dipole when resonant. uR5ucE`_aksLjYT=hzRa]JucX7d}|'}`XRa>X Part List: //-->, The "Best" Random Wire Antenna Lengths These dimensions were derived from modelling the antenna in EZNEC. Repeater Builders 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. ), Note that Jack, VE3EED,went SK several years agohe will be missed. The Short Answer Would Be That an UnUn Is a UN balanced to UN balancedmatching transformer. /Length 10 0 R a more capable tuner - see AA5TB's 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. x@ 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. So, if you connect a length of wire that presents an impedance of about 450 to the input, you'll get an impedance of about 50 on the output. The WSPR map is so dense it looks like the US and Europe are just big blobs of color. Vacation Closure - See Homepage for Next Availability. Click to enlarge. A success! Meet 'Balun One Nine', a small, cost-effective balun. this Lengths to avoid are not always the same as