June 8, 2022 at 9:17 am. doing the initial 468/f on C and D scales. REVISED: 16 19 22 26 32 33 38 44 46 48 52 64 65 66 76 78 80 88 92 95 96 99 104 110 112 114 123 128 130 132 133 138 144 152 154 156 160 165 171 176 182 184 190 192 195 198 208 209 220 224 228 230 231 234 240 242 246 247 256 260 264 266 272 276 285 286 288 297 304 308 312 320 322 323 325 330 336 338 342 352 361 363 364 366 368 369 374 380 384 390 396 399 400 414 416 418 429 432 437 440 442 448 455 456 460 462 464 468 475 480 484 494 495 496. 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 . Privacy Policy You are using an out of date browser. The 30 day return period lapsed before I could get the antenna deployed to test it. This article explains why the use of mix 43 for HF applications is almost always a mistake. stream It is used for non-resonant verticals like 43 foot or 33 foot Or Wire antennas like an End-Fed 1/2 Wave Multiple Length Wire Antenna. it is easy to pack and easy to install. a more capable tuner - see AA5TB's For typical tuners built into a rig, 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. Product Reviews When on the trail, at Field Day, or whenever a good antenna is 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. Do what works best! A success! So, having nothing better to do one day, I re-did the calculations going out to 500 feet. Repeater Builders SSTV At multiples of half wavelengths of the Start winding the toroid with the twisted wires at loop #1 (see schematic below). We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. 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). The unun was floating at about 15 feet above ground. &nb 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. 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. I attached the toroids to a PVC DWV test cap with 3 cable ties. 6 Screws/ Nuts/ Washers/Wing Nuts And Ring Connectors, 1 X Mica Capacitors 100pF 500V 5%(Mouser Electronics), 1 x 4 in. Turns 1 through 14 are secondary windings (the long wire). We do not encourage any radio operations contrary to regulations. >> $119.95. 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. 25 0 obj
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Performance is ASTOUNDING, far exceeding my expectations. /CropBox [0 0 748 752] 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. Twist the short and long wires together starting at an end of each wire. The key is you want to stay at least 1/2w long but not near 3/4w for any band of interest. /Type /XObject Vhf and Up This will be for an eyehook in order to provide strain relief for the radiator wire. Each winding is counted when the wire enters through the center hole of the toroid. >> Cannon". google_ad_client = "ca-pub-9377297764300878"; A VSWR sweep of the unun after adding a 100pF capacitor shows an SWR <5:1 from 160M to 10M. 33 ft #18 insulated copper wire (20m half wave), Counterpoise: 1 meter coax (0.05 x wavelength) connected between 64131 and Balun Designs 1115d Isolation /Choking balun, 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. The Nelson antenna 9 to 1 unun did the trick. Continue twisting the entire length of the short wire. Figure 2 Schematic of the 9:1 voltage unun . 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 . you're using different ham bands than in these examples, modify and rerun Turns 1 & 2 are primary windings (the short wire). 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. 20/40/17m. So those are the numbers above thatwe have to stay as far away from as possible when building a long-wire antenna. Even better would be shortening to 53'. For example, The most common question I get asked is what is the correct length for my End Fed Long Wire Antenna? Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. Theme: Newsup by Themeansar. , Reprinted with permission of Hamuniverse, this is an excellent explanation of SWR and how to best me q A few more comments about this 49:1 autotransformer EFHW design. Let's have a look at a few details on how to build a 49:1 impedance . See the picture below. 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. 1 0 obj
NOTE: Rewording the previous paragraph, if you have a capable enough stream
x@ 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. 3 0 obj
This homebrew 49:1 impedance transformer is the heart of any EFHW antenna you will build, most of the time. Free Postage. Picture Information. So for 80 meters (say 3.525 MHz) this gives you about 133' of wire. You also want the antenna to be at least 1/4 wavelength long for each band you plan to use. 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. We recently found some good information about random wire lengths that you should and should not use. Balun Designs. RFI Tips and Tricks At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. 7 0 obj 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. 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. Any SWR measurement taken with the transformer at the feedpoint should not exceed 1.5:1withNOtuner in use. var sc_security="1df091cc". 2 0 obj
Connect this ring terminal to one of the SO239 chassis bolts. If the choices are. 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. "Can you please recommend schematics that are designed to tune setups like these? %PDF-1.5
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End fed 49:1 60ft wire (using coax as the counter poise. something as high as you can find. 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!! var sc_invisible=1; %%EOF
END FED "RANDOM WIRE" HF DIPOLE 9:1 ANTENNA RELACEMENT ELEMENT ONLY $28.99 Save up to 6% when you buy more. Anyway, an old friend mentioned 'MyAntenna.com' but they were closed for the summer. Re: 9:1 or 49:1 unun for end-fed long/random wire? This was 9m vertically metres up a fishing pole and then about 5.8m out. "Just received my new 64131 yesterday and was anxious to see how well it performed. 8 0 obj 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. I plotted the results for the U.S. CW band edges for use with my4 band Elecraft K1 qrp rig. I used 2000 and 1000 ohm resistors in series connected to the proper unun wires with alligator clips for a total of 3000 ohms. 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. 35. 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. 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. 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). 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. endobj
Jack, VE3EED - SK. 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. 9:1 Unun 1.5-54MHz 2kW 9132S. 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). End Fed Antennas. 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. /* Ad banner 160 x 600 */ Random wire lengths you should and should not use! "I received my third balun from Balun Designs this afternoon. I have included a screenshot showing the stations that reported spotting my 200 mw beacon over the last 16 hours. 1 0 obj However, the list has been revised and is good for wires as long as 500 feet. This design is excellent for matching both long and short length wire antennas for multiband use. x
{avla[g#+yt]Mk"B` xp[AO8;c=\b}|8p4cSmzgU7be,+i5ci6uq.x T/s@9uk-oZX;u`=U >8rsIXW B:uUVr6a] The "9:1 UNUN" are for random length wire antennas fed at the end. A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. wire is at least 1/4 wavelength. /BitsPerComponent 8 Note: My (A to B) length was 6 inches. << Hopefully these random wire length calculations will help us all make this "easy" antenna work better! Swr usually is all over the place and the tuner will just not do it's job. The fewer bands, the fewer high impedance regions to avoid. 40-30-20-15m bands for my 4 band Elecraft K1 qrp rig. A png image named g.png will be created. uR5I5z G^u2`j[}+sy9 endstream
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Drill out holes in the designated bottom of the electrical junction box for the SO239 chassis mount. The most important length is one that is non-resonant on any band. 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 . << answers on D - one setting. google_ad_width = 160; SO-239 (UHF female) chassis mount with screws, nuts, lock washers. 3 0 obj
However, the radio didn't tune up very well on 15 meters. understand its properties. 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? I have found this calculation to work well, however it depends on many factors such as wire used, location etc. If you want a single band portable antenna you can mount pretty much however, look up this design. << endobj
all US ham bands. The bandwidth where SWR was below 2:1 was about one MHz. Vacation Closure - See Homepage for Next Availability. ?7{*. I used a homemade jig made of an SO239 chassis mount to bare wires, alligator clips, and a coax-jumper with PL259 (UHF male) ends; see picture below. Here they are in order: I actually did this first and before the connector was bolted to the box. You have to give up a band or two, like 60m and 6m, as /Parent 3 0 R 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.). 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. hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i
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Some important and helpful references I used for this work: https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. Click to enlarge. 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.). This type of antenna is very easy to install because there is no need . Best SWR was . 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. FCC Information /MediaBox [0 0 748 752] Clansman End Fed Long Wire Antenna Used. He was so impressed that he purchased a 9:1 unit from you, his will be delivered Saturday. are easily converted to half wavelengths by the famous 468/f generally //-->, The "Best" Random Wire Antenna Lengths this Wire lengths for the 4:1 ratio in models 4932 and 4935. /XObject << /Im0 9 0 R >> 40-30-20-17. random wire page. Hertz Antenna" shows in line 2 of the table that a similarly installed InJack's own words. u?X`f0&/Ri;W0Tn_*TX:ug Feeling a bit too lazy to calculate that by hand, however, I wrote a 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. << $1YacO5Q}YC\>qZ } 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. ones This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). 74 0 obj
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, This is a partial reprint (with permission) of an excellent series of articles published by KV5R There probably should be some holes for ventilation. Well, I didn't think it would make any difference at that many multiples. Save program output in file named 'f', and use N4UJW. (Originally published February 22, 2021). There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). Again, the bands are USA, so change them In another life, I could have been a telephone engineer. well, the main antenna wire goes to the 9:1 UnUn "+" connector, the vertical counterpoise (insulated !) This design is excellent for matching both long and short length wire antennas for multiband use. << An Unun is used to match an unbalanced line to another unbalanced line. Ham Radio News! <>
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Stacked coreswithwinding configured as 49:1auto transformer. Electronics 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. %PDF-1.7
1. End Fed Half Wave Antenna Coupler Schematic - 7-30MHz. Thus a 1/4 wave for 20m@16ft, 40m@33ft as examples are not going to work. I say run what you got and don't worry about it. It's an efficient way to get all the multiples Legal Stuff
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". Links 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. 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. , Most matching problems occur when the antenna system
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. 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. This antenna, which works on 10, 15, 20, and 40 meters, has a very high impedance of around 2,500 Ohms. You'll want to have that wire up as high as you can get.. Both were on 20 meters at 97 watts, Icom 7300. I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. I'm looking forward to getting off work and hitting 40 & 20 meters again!! End fed 9:1 58ft wire and 17ft counterpose wire touching ground. << Enclosure Height: 5.000 in. Liquidtight NM 90-Degree Connector(Home Depot). The WSPR map is so dense it looks like the US and Europe are just big blobs of color. 0$Ve This transformer is designed to be used with an end fed half wavelength of wire only. bands as possible. K1S Valentines Are (Almost) Out The Door! Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. 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. 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). HF Underground wiki Radio Hobbyist technical blogHFU Discord EuroPirate ChatPropagation DataTeamspeak Server, TDK CXA-2090 LCD Inverter Module New Old Stock USA Seller $19.99, Shortwave Pirate Radio In North America And Around The World, And Other Signals That Go Bump In The Night, Login with username, password and session length. Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. VSWR analysis of the antenna in the field showed that VSWRs between 3-5.5 from 40M to 10M. high the other 1.5m (4.5feet). endobj
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Tune Around! 73, ), Note that Jack, VE3EED,went SK several years agohe will be missed. 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! SO-239 connectors are silver plated with Teflon insulation. transmit frequency the impedance is so high that tuners in most rigs 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'm consistently pleased with the quality and ease of use of Balun Designs products and look forward to my next purchase in the future. /Title (Wire-Lengths-for-9-1-ununs.pdf) Tweak the antenna length if necessary and then maybe adjust the turns ratio again. The 49:1 impedance transformer will help you bring down the high impedance of your resonant EFHW antenna to almost 50 Ohm. /Height 752 PVC Junction Box(Home Depot), 1 x 1/2 in. You have to stay away from a half wavelength on any frequency. 9 0 obj The short piece is for the primary winding of the transformer, and the long piece is for the secondary winding of the transformer. Drill a hole in one side for the antenna radiator wire mount (for a #8 bolt in my build). installed, it is a compromise antenna but great for portable use because W3EDP's results in the above referenced config file by typing gnuplot rw.gnu. Please note that I will not be describing the construction of the antenna wire radiator here. 1936 article, however, fall in line with 468/f and so is used here. 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. endobj 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. frequencies for your country or favorite modes. %PDF-1.5
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. 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. Proudly powered by WordPress 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. We hoisted the free end of the antenna wire approximately 30 feet into a tree. 35-43, 49-63, 70-85. /CreationDate (D:20221212112042) 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. 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.
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