(The numbers aboveare a great start, thanks to Jack and Mike! and leave the unun on the ground. >> I made just a touch over 100 QSOs today with the new unit. Drill a hole in one side for the antenna radiator wire mount (for a #8 bolt in my build). >> << used by hams for dipole lengths. google_ad_slot = "1982258389"; endobj In stock . Privacy Policy Hope it's clear now, if not. 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. 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. DIY 49:1 Unun Impedance Transformer For End-Fed Half Wave (EFWH Here is an ARRL The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. It will be good for 15m, and 10m. The Short Answer Would Be That an UnUn Is a UN balanced to UN balancedmatching transformer. stream 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. Following the directions exactly as specified (0.47wl / 0.05wl matching counterpoise) and drilling two weep holes in the appropriate position, I had a 10 meter EFHW antenna up in less than ten minutes. Modify bands and Y &lD30. 4 0 obj #347: Quick test of the 40m Halfwave End-Fed antenna using a 49:1 PDF 33ft Verticals and 4:1 Ununs - G8JNJ For calculating the length of a half wave in metres, I use 141 (MHz) for wire elements. 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. . 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. A standard recommendation (see QST, March 1936, p. 32, "An Unorthodox 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. I attached the toroids to a PVC DWV test cap with 3 cable ties. If the choices are. 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. The unun was floating at about 15 feet above ground. Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth. This article details the construction of the transformer. Code Practice 9:1 Magnetic Longwire Balun / Unun - M0UKD - Amateur Radio Blog 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. results. << Experimenting by slightly changing the wire length (+ or-) is encouraged to provide best overall performance. Tweak the antenna length if necessary and then maybe adjust the turns ratio again. 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/. /Count 1 1 0 obj Continue twisting the entire length of the short wire. bands as possible. 49:1 impedance transformer UNUN - Wire Antennas One end goes straight into the You have to give up a band or two, like 60m and 6m, as There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). here are values for CW portions of the USA Antenna") is an 84' long end fed and a 17' long counterpoise (6.5' for 20m). The First Thing New Hams Often Ask:What Is An UnUn? /&KWA7{L=D]g0Z!F9;V{zL[h-D,u(.9rg(RHI{f t*C/?? Drill another hole in the same side as the antenna radiator wire mount hole. x@ An end fed half wave antenna is one of a specific length depending on the frequency that it is to be used on, for example, an end fed half wave antenna for 80 meters is about 130 long. So, having nothing better to do one day, I re-did the calculations going out to 500 feet. 9:1 Unun EF Random Long wire matching Transformer with BNC or SO-239. While I have not done so yet, I plan on gluing the test cap to the back of the junction box. 0 /Name /Im0 6 Screws/ Nuts/ Washers/Wing Nuts And Ring Connectors, 1 X Mica Capacitors 100pF 500V 5%(Mouser Electronics), 1 x 4 in. End Fed 9:1 Magic Wire Lengths | ve3ips . End Fed Half Wave 40-10 Wire Antenna - N6DOZ Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 How to Make a Balun or Unun : 3 Steps - Instructables 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. Repeater Basics June 8, 2022 at 9:17 am. Then verify it with your installed antenna and SWR measurements. google_ad_height = 600; Balun Designs. Ham Satellites An Unun is used to match an unbalanced line to another unbalanced line. Playing with end-fed wire antennas and 9:1 ununs 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. The "9:1 UNUN" are for random length wire antennas fed at the end. Random wire lengths you should and should not use! 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. 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 You are using an out of date browser. Thanks for your answer,I will probably go with the 9:1 then. The beauty of the halfwave antenna is it's a complete antenna in the sense it needs no counterpoise. To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- 3. A small ring terminal for 14ga wire that fits these screws would be helpful too. Kj8~q7c? (Center fed is so appealing because you avoid this.). InJack's own words. Downward impedance transformation by factor of 49. 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). 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. <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> However, the list has been revised and is good for wires as long as 500 feet. 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. NEMA rated 4x marine grade junction box for outdoor installations. Ham Radio Videos! (Also check out AB3AP'Swebsite and say thanks for sharing his skills. If you want all the bands from I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. These dimensions were derived from modelling the antenna in EZNEC. SWR was good after cutting the wire to appropriate length. 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. Make sure the beginning few inches of twisted wire is not involved in the winding (i.e., just hanging down from the toroid). /CropBox [0 0 748 752] Presented for your consideration by Jack, VE3EED. I have included a screenshot showing the stations that reported spotting my 200 mw beacon over the last 16 hours. << Click to enlarge. Ham Radio End Fed Antenna with a 1:64 Matching Network Vacation Closure - See Homepage for Next Availability. <>/Metadata 239 0 R/ViewerPreferences 240 0 R>> The "Almost Random" Wire Antenna - KB6NU's Ham Radio Blog stream End Fed Antennas - Elgin Amateur Radio Society To DB's point of a single band antenna, this 49:1 transformer is a good choice for a single band matcher. /XObject << /Im0 9 0 R >> Jack, VE3EED, used center frequencies of thebands described in the article above, and I thought it would be nice to use band edges. The second smallest number I measured was 2.7pF, derived from the self resonance at 2.72 MHz with the magnetizing inductance (measured at 25.8 H) with the secondary open and the output wire folded to a small 1/2 length. 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). Connect this ring terminal to one of the SO239 chassis bolts. (Also note that here may be instances where the suggested lengths may not work exactly due to the many variables in the surroundings of the antenna, wire length variances, your tuner, it's height above ground, it's construction, etc. I swept the VSWR of the unun and resistors as described from <1 to 55MHz. 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 . 40-30-20-15m bands for my 4 band Elecraft K1 qrp rig. Because I'm more visually oriented I then plotted the many overlapping "red zones" and ended up with the page at: The vertical (y-) axis shows the VSWR and the horizontal (x-) axis shows the frequencies. PVC Junction Box(Home Depot), 1 x 1/2 in. 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. END FED "RANDOM WIRE" HF DIPOLE 9:1 ANTENNA RELACEMENT ELEMENT ONLY $28.99 Save up to 6% when you buy more. SSTV (wlSR9dJ_x%+VHX4FRr 3>;g^x%g'wkJu,i~#Q"2|WGf[!_m]#&1$)R.{--" 'dGO;=_B$T}". Random Wire Antennas - Best Lengths To Use For Random Wire . This Balun Designs unit is replacing an MFj 1982 HP EFHW balun that was DOA when it arrived last May. Do what works best! Wire Lengths For 9-1 Ununs | PDF | Electricity - Scribd Post Reviews 33 ft #18 insulated copper wire (20m half wave), Counterpoise: 1 meter coax (0.05 x wavelength) connected between 64131 and Balun Designs 1115d Isolation /Choking balun, If you would like to use high power up to legal limit with a single end fed wire antenna (not necessarily a half wave) consider using our. I connected the free twisted end of the short and long wires (the ground) the chassis wire (ground) of my homemade testing jig with alligator clip. [ /PDF /Text /ImageI ] Vhf and Up Picture 1 of 9. something as high as you can find. So those are the numbers above thatwe have to stay as far away from as possible when building a long-wire antenna. config file by typing gnuplot rw.gnu. well, the main antenna wire goes to the 9:1 UnUn "+" connector, the vertical counterpoise (insulated !) 2 0 obj Legal Stuff The kit includes the parts needed to construct a 49:1 impedance matching network, which will transform the impedance to 50 Ohms, which will suit most transceivers. /Subtype /Image You have to stay away from a half wavelength on any frequency. 4 0 obj Solder a the 100pF capacitor between the center conductor wire and ground wires. Best SWR was . /Length 6 0 R It is important to use a counterpoise. This design is excellent for matching both long and short length wire antennas for multiband use. 0$Ve Single Wire/End Fed Antenna - K7MEM Some important and helpful references I used for this work: https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. Tune Around! Turns 1 through 14 are secondary windings (the long wire). Theme: Newsup by Themeansar. The counterpoise wire, This transformer is designed to be used with an end fed, Approx. Just add or subtract as needed a little at a time to get the best compromise. I imported my spools from the US, but I have seen them on Ebay in the UK. Each winding is counted when the wire enters through the center hole of the toroid. 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). Our Ask An Elmer panel discuss this question - what's the difference between matching units?Please consider using. Lengths to avoid are not always the same as 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. This calculates to 4.2 m or 14 ft for an 80m end-fed. endstream Engineering the EFHW 49:1 Transformer and Antenna | 9:1 Unun 1.5-54MHz 2kW 9132S. hb```YloD@(aKI V!}g@~}%Q/[[~_=Wy-:O)x[~hs/~SGeG _QE C6q %r 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. /Length 10 0 R 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. I say run what you got and don't worry about it. 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. Power handling is 100 watts CW / SSB & 25W Data modes. 1:64 vs 1:49 balun for an end fed?? : r/amateurradio - reddit My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! 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. I made one without doing this and it didn't work so well. Enclosure Depth: 1.250 in. 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 /Im0 Do excellent page for EFHW info - or, addressed below, to cut the wire A so-called random wire antenna is an end fed antenna. Hopefully these random wire length calculations will help us all make this "easy" antenna work better! Prescott Hamfest - W7YRC 7 0 obj 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. 9:1 UnUn End Fed Long Wire Lengths - Pretty Simple | ve3ips q 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. http://udel.edu/~mm/ham/randomWire/. Ham Radio News! Power Handling (CW/SSB): 100 W/200 W Enclosure Width: 2.500 in. End Fed Half Wave Wire Antennas | N6CC The "Super Bullet" End Fed Long Wire Antenna Matcher - 1500/3000 watt rated for Super-Punch of your signal! 49:1 Impedance Transformer for EFHW Antenna - DX Explorer 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. The trick, therefore, is either Both were on 20 meters at 97 watts, Icom 7300. This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. SO-239 (UHF female) chassis mount with screws, nuts, lock washers. unavailable, a random wire can save the day, but it is important to The graph below shows lengths to avoid for different collections of bands. However, the radio didn't tune up very well on 15 meters. which got me thinking. Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas Windings are inserted into Teflon tubes increasingtotal breakdown to 10,000 volts. 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. 9:1 UNUN - MyAntennas.com

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