You will note that when comparing my results with VE3EED that some of the results are a bit different. Support The Site unavailable, a random wire can save the day, but it is important to 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". multiples, and of course different band combinations yield different In another life, I could have been a telephone engineer. You also want the antenna to be at least 1/4 wavelength long for each band you plan to use. VSWR analysis of the antenna in the field showed that VSWRs between 3-5.5 from 40M to 10M. SBULLET-9U-1500. the program as I did, above, for my K1. Antenna") is an 84' long end fed and a 17' long counterpoise (6.5' for 20m). The most important length is one that is non-resonant on any band. Each winding is counted when the wire enters through the center hole of the toroid. Here Is a 250 Watt Home-Brew That I Made In about an Hour. END FED "RANDOM WIRE" HF DIPOLE 9:1 ANTENNA RELACEMENT ELEMENT ONLY $28.99 Save up to 6% when you buy more. /ProcSet 7 0 R >> (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. Picture Information. This transformer is designed to be used with an end fed half wavelength of wire only. 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). gnuplot 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 , Reprinted with permission of Hamuniverse, this is an excellent explanation of SWR and how to best me 1. Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun 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. Proudly powered by WordPress 4 0 obj The "Super Bullet" End Fed Long Wire Antenna Matcher - 1500/3000 watt rated for Super-Punch of your signal! endobj x {avla[g#+yt]Mk"B` xp[AO8;c=\b}|8p4cSmzgU7be,+i5ci6uq.x T/s@9uk-oZX;u`=U >8rsIXW B:uUVr6a] $1YacO5Q}YC\>qZ } often can't match it. 22.00 + 5.00 Postage. FCC Information q endobj 40-30-20-17. it is easy to pack and easy to install. STORE 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. 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. Theme: Newsup by Themeansar. Start winding the Matching Auto Transformer, each pass through the center of the core equals one turn. Designed for use with single wire unbalanced antennas, this new addition is small, compact and perfect for quick portable/emergency installations. Jack, VE3EED, used center frequencies of thebands described in the article above, and I thought it would be nice to use band edges. 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? 32.00. Ham Radio Videos! Let's have a look at a few details on how to build a 49:1 impedance . Here Is a 250 Watt Home-Brew That I Made In about an Hour. Click to enlarge. Reading Room Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. Figure 3 Wiring of the 9:1 voltage unun. Antenna Safety! I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. Experimenting by slightly changing the wire length (+ or-) is encouraged to provide best overall performance. UJM-49-1 $56.99 Save up to 6% when you buy more. The graph below shows lengths to avoid for different collections of bands. Twist the short and long wires together starting at an end of each wire. InJack's own words. A success! 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. /ColorSpace 11 0 R EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! Liquidtight NM 90-Degree Connector(Home Depot). I swept the VSWR of the unun and resistors as described from <1 to 55MHz. 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. Kj8~q7c? Here is an ARRL On our next windy free day, AA1F and . installed, it is a compromise antenna but great for portable use because Humor << %PDF-1.7 Thank you so much for such a great product! Weight: 0.380 lbs. /BitsPerComponent 8 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. /CreationDate (D:20221212112042) The fewer bands, the fewer high impedance regions to avoid. 6 Screws/ Nuts/ Washers/Wing Nuts And Ring Connectors, 1 X Mica Capacitors 100pF 500V 5%(Mouser Electronics), 1 x 4 in. The matching unit The impedance at the end of a half wave antenna is somewhere between 2000-5000 Ohms. Repeater Basics 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 That is the 10th multiple of a half wave on 15 meters. << If you plan on stringing up a dipole you use 2 equal lengths of wire with the Balun in the middle. /Producer (XnView, http://www.xnview.com) 1 0 obj Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. 2 0 obj About Batteries A few more comments about this 49:1 autotransformer EFHW design. /MediaBox [0 0 748 752] transmit frequency the impedance is so high that tuners in most rigs 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). The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. <> >> End Fed Antennas. , This is a partial reprint (with permission) of an excellent series of articles published by KV5R
Comments are closed.