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you're using different ham bands than in these examples, modify and rerun thank you. (Note: I am not satisfied with this part of the project, so I will describe it here briefly. Then verify it with your installed antenna and SWR measurements. RFI Tips and Tricks Each winding is counted when the wire enters through the center hole of the toroid. 5 0 obj They just saved you and I loads of time and frustration. 8 0 obj This calculates to 4.2 m or 14 ft for an 80m end-fed. <> /Producer (XnView, http://www.xnview.com) Do what works best! u?X`f0&/Ri;W0Tn_*TX:ug want the antenna to be at least 1/4 wavelength long for each band you 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! endobj We recently found some good information about random wire lengths that you should and should not use. Solder a the 100pF capacitor between the center conductor wire and ground wires. //-->, The "Best" Random Wire Antenna Lengths The most important length is one that is non-resonant on any band. >> Just add or subtract as needed a little at a time toget the best compromise. (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. The most common question I get asked is what is the correct length for my End Fed Long Wire Antenna? Turns 1 & 2 are primary windings (the short wire). 3 0 obj (Center fed is so appealing because you avoid this.). 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. 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. Humor It may not display this or other websites correctly. Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. 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. 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. 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 Drill out holes in the designated bottom of the electrical junction box for the SO239 chassis mount. 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. This design is excellent for matching both long and short length wire antennas for multiband use. CQ-Calling All Hams! 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. Best SWR was . ", KiwiSDR Online Radio - 500 ft Northeast Beverage, KiwiSDR Online Radio - 400 ft South Beverage, KiwiSDR Online Radio - 10/11m dipole up 20 meters high. 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. At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. Hi guys,not really hfu related,but I tought I might ask here as I have my account. The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. 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. I imported my spools from the US, but I have seen them on Ebay in the UK. Winding 1:64 Matching Auto Transformer on the FT240-43 core. I have not done this yet. Having the option to switch rapidly between 49:1 and 64:1 should prove to be a really nice feature.. 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. The length should be calculated based on the lowest frequency to be worked. https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. However, the list has been revised and is good for wires as long as 500 feet. 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? 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. 4 0 obj 4 0 obj 40-30-20-17. <>/Metadata 239 0 R/ViewerPreferences 240 0 R>> The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA I attached the toroids to a PVC DWV test cap with 3 cable ties. 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.). On our next windy free day, AA1F and . This design is excellent for matching both long and short length wire antennas for multiband use. It is important to use a counterpoise. The First Thing New Hams Often Ask:What Is An UnUn? stream Here I show finalizing the antenna, getting it in the air, and run. <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> 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. This type of antenna is very easy to install because there is no need . The table below represents half wave lengths and multiples that you DO NOT WANT TO USE! 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. $119.95. Care to buy us a beer? In stock . 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- 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. I use this 8010 EFHW at home, too. 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. Electronics endobj EFHW unun Resonant Long Wire 49:1 Transformer With 67' Antenna Wire. is that for a given ham band there are min and max frequencies which To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- You'll want to have that wire up as high as you can get.. /Contents 5 0 R This is not exactly a 1/2 wavelength in free space, but works for wire as it has a different velocity factor than "air". SWR was good after cutting the wire to appropriate length. https://www.kb6nu.com/playing-end-fed-wire-antennas-91-ununs/, http://www.hamuniverse.com/randomwireantennalengths.html, https://www.youtube.com/watch?v=sty7RlXQoJI, https://www.youtube.com/watch?v=WwJnXTVUrgI, Quote from: refmo on October 15, 2019, 2036 UTC, Quote from: joczo on October 16, 2019, 0815 UTC, http://www.w3pga.org/Antenna%20Books/Reflections%20III.pdf, http://www.arrl.org/files/file/Technology/tis/info/pdf/7007024.pdf, http://www.tasrt.ca/AntennaTips/AntennaTips.htm, http://www.wb2rcb.com/documents/balunlin.pdf. 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. W3EDP's results in the above referenced The beauty of the halfwave antenna is it's a complete antenna in the sense it needs no counterpoise. The "Super Bullet" End Fed Long Wire Antenna Matcher - 1500/3000 watt rated for Super-Punch of your signal! Site Map You are using an out of date browser. 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. Repeater Builders I sent him the link to the 49:1 unit to get his feedback. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. shown in the column e. var sc_project=8077274; The unun was floating at about 15 feet above ground. | JC[ d8O[UKKQ{yZ{G 'Upno_*~8uo a@G`' zxUHXW&`}mEp`?i0 oE:N0-/t"t.-? /Im0 Do Generally an EFHW will be in the range of 2,000 to 5,000 ohms at the very end of the dipole when resonant. V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT c=W>:sECXTkc=X End fed 49:1 60ft wire (using coax as the counter poise. the program as I did, above, for my K1. Tools Weight: 0.380 lbs. I used 2000 and 1000 ohm resistors in series connected to the proper unun wires with alligator clips for a total of 3000 ohms. 32.00. config file by typing gnuplot rw.gnu. When do you use a 1:1, 9:1 or a 49:1 balun? Tweak the antenna length if necessary and then maybe adjust the turns ratio again. So, having nothing better to do one day, I re-did the calculations going out to 500 feet. for your country and favorite modes of operation. $1YacO5Q}YC\>qZ } A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. Cut a 4 foot length of AWG #18 enameled wire. There probably should be some holes for ventilation. The vertical (y-) axis shows the VSWR and the horizontal (x-) axis shows the frequencies. I have included a screenshot showing the stations that reported spotting my 200 mw beacon over the last 16 hours. Here they are in order: In fact, the 9:1 unun that I built is actually an autotransformer. Legal Stuff stream 35-45, 54-64, 67-77. >> var sc_invisible=1; stream 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. 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. 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. x {avla[g#+yt]Mk"B` xp[AO8;c=\b}|8p4cSmzgU7be,+i5ci6uq.x T/s@9uk-oZX;u`=U >8rsIXW B:uUVr6a] (Also check out AB3AP'Swebsite and say thanks for sharing his skills. 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 . I will also find some sort of heat resistant packing material to help hold the transformer in place. So for 80 meters (say 3.525 MHz) this gives you about 133' of wire. Each vertical blue line represents an amateur radio band. endobj A success! When you're 1/2w long you're around 2k ohms or more where the balun won't under or over xform; as you approach 3/4w your z is going to drop to where a coax match can be made just by soldering the wire to the center conductor sans balun - more or less the principle of the windom and ocf dipole. I'm looking forward to getting off work and hitting 40 & 20 meters again!! I wrote a small C program that does just what Jack did, butI used the band edges. 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. Meet 'Balun One Nine', a small, cost-effective balun. I used the RigExpert Zoom AA-55 to test VSWR of the 49:1 unun impedance transformer. So is an essential piece of gear to have. About Batteries 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 . understand its properties. Windings are inserted into Teflon tubes increasingtotal breakdown to 10,000 volts. 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). If you want a single band portable antenna you can mount pretty much however, look up this design. Powered by BigCommerce. A way of connecting the analyzer to the transformer. 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. . wire to the UnUn "-" connector and then down to ground there it connects with the two other wires but neither the counterpoise nor the two other wires are connected to ground. tuner the colored bands below are the best lengths as long as your This is considered a random wire end fed antenna, not to be confused with a half wave end fed antenna which uses a 49:1 or 64:1 unun and a wire that is a half wave length. 9:1 or 49:1 unun for end-fed long/random wire? The bandwidth where SWR was below 2:1 was about one MHz. 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. 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. 1 0 obj x@ For typical tuners built into a rig, << 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. , Reprinted with permission of Hamuniverse, this is an excellent explanation of SWR and how to best me /Subtype /Image 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 . There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). We'd really appreciate it! Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun Y &lD30. That meant calculating all the way to 32 multiples of a half wave on 10 meters. /Width 748 Vacation Closure - See Homepage for Next Availability. /Length 6 0 R 35. <> 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. 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. 1 0 obj The fewer bands, the fewer high impedance regions to avoid. Q 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. Re: 9:1 or 49:1 unun for end-fed long/random wire? I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. Hopefully these random wire length calculations will help us all make this "easy" antenna work better! (wlSR9dJ_x%+VHX4FRr 3>;g^x%g'wkJu,i~#Q"2|WGf[!_m]#&1$)R.{--" 'dGO;=_B$T}". , This is a partial reprint (with permission) of an excellent series of articles published by KV5R /ProcSet 7 0 R >> Experimenting by slightly changing the wire length (+ or-) is encouraged to provide best overall performance. 3 0 obj 0 So a 49:1 impedance transformer is needed to match the 50 ohms of the coax at the feed line. Balun Designs. The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. The matching unit The impedance at the end of a half wave antenna is somewhere between 2000-5000 Ohms. /Type /XObject As typically EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). 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).