Work all bands from 80 through 10 on it. STORE 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. There probably should be some holes for ventilation. JavaScript is disabled. Hope it's clear now, if not. is that for a given ham band there are min and max frequencies which /Type /Pages Windings are inserted into Teflon tubes increasingtotal breakdown to 10,000 volts. stream Antenna Design FCC Information . Feeling a bit too lazy to calculate that by hand, however, I wrote a This design is excellent for matching both long and short length wire antennas for multiband use. Kj8~q7c? x {avla[g#+yt]Mk"B` xp[AO8;c=\b}|8p4cSmzgU7be,+i5ci6uq.x T/s@9uk-oZX;u`=U >8rsIXW B:uUVr6a] Balun Designs. 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. A Balun is used to match a balanced line to an unbalanced line. Longer wire is always more 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. 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. << Notice from column f that there is no length giving low impendance for /BitsPerComponent 8 <> 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. var sc_invisible=1; To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- 35-45, 54-64, 67-77. q 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. While I have not done so yet, I plan on gluing the test cap to the back of the junction box. So for example 80m could range in length from 120 to 133 feet. Contact That meant calculating all the way to 32 multiples of a half wave on 10 meters. The beauty of the halfwave antenna is it's a complete antenna in the sense it needs no counterpoise. ", KiwiSDR Online Radio - 500 ft Northeast Beverage, KiwiSDR Online Radio - 400 ft South Beverage, KiwiSDR Online Radio - 10/11m dipole up 20 meters high. 35. . >> This transformer converts the impedance at the end . 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). So those are the numbers above thatwe have to stay as far away from as possible when building a long-wire antenna. http://udel.edu/~mm/ham/randomWire/. I sent him the link to the 49:1 unit to get his feedback. A level of 500-600 watts is the maximum with a further reduction onany band measuringabove 3:1. stream I have included a screenshot showing the stations that reported spotting my 200 mw beacon over the last 16 hours. However, the list has been revised and is good for wires as long as 500 feet. One end goes straight into the I have not done this yet. NOTE: Rewording the previous paragraph, if you have a capable enough I only used two screws instead of four. 3 to31 MHz - up to 1kW intermittent (50% duty cycle). 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. 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. << InJack's own words. here are values for CW portions of the USA 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. Hopefully these random wire length calculations will help us all make this "easy" antenna work better! A so-called random wire antenna is an end fed antenna. Weight: 0.380 lbs. endobj 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. 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. 4 0 obj This will be for an eyehook in order to provide strain relief for the radiator wire. Typically unbalanced = 50/75 ohms too unbalanced = 450/675 ohms. google_ad_slot = "1982258389"; The WSPR map is so dense it looks like the US and Europe are just big blobs of color. (Note: I am not satisfied with this part of the project, so I will describe it here briefly. 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. <> I actually did this first and before the connector was bolted to the box. WwS`8o}=n,pjhzRa]Ju/Ru ni4=UvZ:u9*@ Xz+zZcXm}i[Z;Z>.u!*eQVjucXeqYZnSJu)U[n>>KXzZ.Lz sqxcGj]%q}i6=-?YTlnZXV6}=U >5`ZNxChzRa]JU.6TVr6a] 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. Let's have a look at a few details on how to build a 49:1 impedance . Drill out holes in the designated bottom of the electrical junction box for the SO239 chassis mount. Drill a hole in one side for the antenna radiator wire mount (for a #8 bolt in my build). gnuplot (wlSR9dJ_x%+VHX4FRr 3>;g^x%g'wkJu,i~#Q"2|WGf[!_m]#&1$)R.{--" 'dGO;=_B$T}". Theme designed by Papathemes. Power handling is 100 watts CW / SSB & 25W Data modes. EFHW unun Resonant Long Wire 49:1 Transformer With 67' Antenna Wire. In another life, I could have been a telephone engineer. 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. Having the option to switch rapidly between 49:1 and 64:1 should prove to be a really nice feature.. 2. endobj for your country and favorite modes of operation. END FED "RANDOM WIRE" HF DIPOLE 9:1 ANTENNA RELACEMENT ELEMENT ONLY $28.99 Save up to 6% when you buy more. all US ham bands. This article explains why the use of mix 43 for HF applications is almost always a mistake. We'd really appreciate it! Wire lengths for the 4:1 ratio in models 4932 and 4935. 27.00 (27.00/Unit) Free Postage. Advertising Info The magic lengths to use with the End Fed longwire is 29, 35.5, 41, 58, 71 and 84 feet I use a 29 foot wire with my PackTenna 9:1 balun for 40m-10m and then add a 28 foot length for better coverage on 80m when needed. X:nzf4p:t;r }~_HOZcX:^$* J^XZuu|"nX/Wkw0hA>y1(z2+v_Xzu[/:^$*m*>hk_:+c{ 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? google_ad_client = "ca-pub-9377297764300878"; 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 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!! Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. After winding #2 is made and extends down the backside of the toroid, untwist the wires. these are the worst lengths and you want to be as far from colored You also want the antenna to be at least 1/4 wavelength long for each band you plan to use. endobj Thanks for your answer,I will probably go with the 9:1 then. Multiples are on C and NEMA rated 4x marine grade junction box for outdoor installations. For example, it is easy to pack and easy to install. SWR was good after cutting the wire to appropriate length. HF & Shortwave (A t0 B) Fold over 6 to 8 inches and twist it together. Re: 9:1 or 49:1 unun for end-fed long/random wire? program or two to do all the dirty work. 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. Figure 3 Wiring of the 9:1 voltage unun. There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). End Fed Antennas. Usually any wire length that is non resonant, like those shown above, will work with the 4:1 ratio. 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! 40-30-20-17. One is for the top of the box so that it can be hung up. 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. 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. These dimensions were derived from modelling the antenna in EZNEC. 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. 1 0 obj If the choices are. Legal Stuff Downward impedance transformation by factor of 49. endobj The graph below shows lengths to avoid for different collections of bands. multiples, and of course different band combinations yield different 9:1 Unun EF Random Long wire matching Transformer with BNC or SO-239. 3. I did not want to put the transformer in the housing until I tested it. bands you're intested in in a vector like the example below, by typing. Powered by BigCommerce. /Filter [ /FlateDecode ] 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). >> https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. For calculating the length of a half wave in metres, I use 141 (MHz) for wire elements. Site Map <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> 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. [ /PDF /Text /ImageI ] "Here's the word on random-wire antennae.". 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. This is to avoid the antenna radiator from acting like a resistor, and thus instead of radiating radiofrequency energy produced by the transmitter, sending it back down the coax toward the transmitter. You'll want to have that wire up as high as you can get.. Repeater Basics 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. SO-239 connectors are silver plated with Teflon insulation. This Balun Designs unit is replacing an MFj 1982 HP EFHW balun that was DOA when it arrived last May. Drill another hole in the same side as the antenna radiator wire mount hole. used by hams for dipole lengths. and experiment. 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 . unavailable, a random wire can save the day, but it is important to You will note that when comparing my results with VE3EED that some of the results are a bit different. /XObject << /Im0 9 0 R >> Ham Radio Videos! Random wire lengths you should and should not use! Enclosure Height: 5.000 in. Use with other lengths can potentially damage the transformer depending on power level in use. endstream What these lengths are depend on your tuner and also the wire's surroundings and also the ground system. 2 eyehooks with washers and nuts (I used #8 diameter, but size is up to you.) document.getElementById("copyright_year").innerHTML = new Date().getFullYear(); As typically (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. Technical specification : Type : 49:1 Unun Frequency : 1.81 MHz - 30MHz Impedance ratio: 1:49 Input Impedance: 50 Output Impedance: 2500 Power Handling (CW/SSB) : 250W Core Type : 1x FT240-43 by Fair-rite Co. Capacitor 100pF 3KV Assembled and tested. 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA Figure 2 Schematic of the 9:1 voltage unun . %PDF-1.5 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. 0 Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. We recently found some good information about random wire lengths that you should and should not use. That's it in a nutshell..or is it? Here they are in order: Note: My (A to B) length was 6 inches. This transformer is designed to be used with an end fed half wavelength of wire only. Do what works best! 5 0 obj and leave the unun on the ground. << You can add your own wire or get the complete product from this link EFLW-3K antennas. Thank you so much for such a great product! 6 Screws/ Nuts/ Washers/Wing Nuts And Ring Connectors, 1 X Mica Capacitors 100pF 500V 5%(Mouser Electronics), 1 x 4 in. often can't match it. 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. We hoisted the free end of the antenna wire approximately 30 feet into a tree. %PDF-1.7 Here is an ARRL If you plan on stringing up a dipole you use 2 equal lengths of wire with the Balun in the middle. 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. % /ModDate (D:20221212112042) In addition to multiples, A VSWR sweep of the unun after adding a 100pF capacitor shows an SWR <5:1 from 160M to 10M. 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. . This calculates to 4.2 m or 14 ft for an 80m end-fed. The Short Answer Would Be That an UnUn Is a "UN balanced to UN balanced" matching transformer. It will be good for 15m, and 10m. google_ad_height = 600; The length should be calculated based on the lowest frequency to be worked. (Also check out AB3AP'Swebsite and say thanks for sharing his skills. Post Reviews A png image named g.png will be created. The short piece is for the primary winding of the transformer, and the long piece is for the secondary winding of the transformer. If you want all the bands from Continue twisting the entire length of the short wire. My commercial EFHW is 130 feet long for 80 and up, and my 40 meter homebrew antenna is about . We do not encourage any radio operations contrary to regulations. I'm looking forward to getting off work and hitting 40 & 20 meters again!! Here I show finalizing the antenna, getting it in the air, and run. 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 . So is an essential piece of gear to have. Tools "Just received my new 64131 yesterday and was anxious to see how well it performed. 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. I made just a touch over 100 QSOs today with the new unit. 1 0 obj 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. high the other 1.5m (4.5feet). He was so impressed that he purchased a 9:1 unit from you, his will be delivered Saturday. Superglue 2 toroids together. 2 0 obj You also Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas. If you want a single band portable antenna you can mount pretty much however, look up this design. Start winding the toroid with the twisted wires at loop #1 (see schematic below). My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! Support The Site which got me thinking. VSWR analysis of the antenna in the field showed that VSWRs between 3-5.5 from 40M to 10M. Some important and helpful references I used for this work: https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. 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. 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. 1936 article, however, fall in line with 468/f and so is used here. I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. wire is at least 1/4 wavelength. I imported my spools from the US, but I have seen them on Ebay in the UK. 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 I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. Just add or subtract as needed a little at a time toget the best compromise. So you have the freq range of interest and the total length of the wire, figuring out wich balun will be a better match for 50ohm coax should be easy. 9:1 UnUn End Fed Long Wire Lengths - Pretty Simple. Some of these numbers are too close to squeeze in between them. 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). 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 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. You are using an out of date browser. $119.95. 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. Tune Around! I swept the VSWR of the unun and resistors as described from <1 to 55MHz. CQ-Calling All Hams! endobj At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. Picture 1 of 9. Use a slide rule! Free Postage. 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. About Batteries %%EOF W3EDP's results in the above referenced This article details the construction of the transformer. It may not display this or other websites correctly. For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. endobj a more capable tuner - see AA5TB's rig, often with no feedline, and the other end in the air attached to Alternate connectors and Mounting Options are available in the. Product Reviews <> The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. This design is excellent for matching both long and short length wire antennas for multiband use. The bandwidth where SWR was below 2:1 was about one MHz. . Stacked coreswithwinding configured as 49:1auto transformer. (The numbers aboveare a great start, thanks to Jack and Mike! Liquidtight NM 90-Degree Connector(Home Depot). >> The length should be calculated based on the lowest frequency to be worked. A way of connecting the analyzer to the transformer. Part List: For instance, to work 40m be sure the antenna is at least 10m or 33' long. Wait a few minutes for glue to set. 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. A success! Make sure the beginning few inches of twisted wire is not involved in the winding (i.e., just hanging down from the toroid). endobj 748 0 0 752 0 0 cm /Resources << Repeater Builders 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. <> 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. Moving the pot up and down gives a feel for the SWR versus antenna impedance sensitivity. uR5I5z G^u2`j[}+sy9 hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 u?X`f0&/Ri;W0Tn_*TX:ug For a better experience, please enable JavaScript in your browser before proceeding. Quantity: Sold individually. Use with other lengths can potentially damage the transformer depending on power level in use.