Home-brew End-Fed 49:1 UnUn. - KA9QJG Repeaters x 2 in. The First Thing New Hams Often Ask:What Is An UnUn? This design is excellent for matching both long and short length wire antennas for multiband use. So is an essential piece of gear to have. /CreationDate (D:20221212112042) Then verify it with your installed antenna and SWR measurements. 40-30-20-17. 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. 2 0 obj 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 . 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. "Can you please recommend schematics that are designed to tune setups like these? Free Postage. 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA 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. 35-43, 49-63, 70-85. x 4 in. 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. Wire lengths for the 4:1 ratio in models 4932 and 4935. 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. Prescott Hamfest - W7YRC Vhf and Up endstream endobj startxref This is a 4:1 Current Balun.That means it can match a 200ohm antenna to a 50 feed line. 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. "Just received my new 64131 yesterday and was anxious to see how well it performed. PDF Wire-Lengths-for-9-1-ununs - OM0ET He had heard good things about 'Balun Designs' so he recommended you. June 8, 2022 at 9:17 am. The goal of the impedance transformer is match the 50 ohm impedance of the feedline (coaxial cable) with the potential 3000 to 4000 ohm impedance expected from an end-fed half wave antenna wire radiator. Even better would be shortening to 53'. << hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. $119.95. My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! N4UJW. Drill a hole in one side for the antenna radiator wire mount (for a #8 bolt in my build). Thank you so much for such a great product! Our newdesign isperfect for matching both long and short length wire antennas for multiband use. Save program output in file named 'f', and use 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. often can't match it. 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. 2 eyehooks with washers and nuts (I used #8 diameter, but size is up to you.) /Creator (XnView) PDF Wire Lengths for 4 and 9-1 Ununs - Balun Designs InJack's own words. 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. q 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. recommended on VE3EED's page because I use all halfwave The length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. The "Almost Random" Wire Antenna - KB6NU's Ham Radio Blog You also The 30 day return period lapsed before I could get the antenna deployed to test it. A way of connecting the analyzer to the transformer. are easily converted to half wavelengths by the famous 468/f generally When on the trail, at Field Day, or whenever a good antenna is high the other 1.5m (4.5feet). endobj 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. 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.). The WSPR map is so dense it looks like the US and Europe are just big blobs of color. 2 0 obj Single Wire/End Fed Antenna - K7MEM Wire Lengths For 9-1 Ununs | PDF | Electricity - Scribd The "9:1 UNUN" are for random length wire antennas fed at the end. | Drill another hole in the same side as the antenna radiator wire mount hole. The following wire connections do not need to be made in the order I described. 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 . About Batteries Start winding the toroid with the twisted wires at loop #1 (see schematic below). I have found this calculation to work well, however it depends on many factors such as wire used, location etc. Wire-Lengths-for-9-1-ununs.pdf Created Date: 12/12/2022 11:20:42 AM . We recently found some good information about random wire lengths that you should and should not use. ", KiwiSDR Online Radio - 500 ft Northeast Beverage, KiwiSDR Online Radio - 400 ft South Beverage, KiwiSDR Online Radio - 10/11m dipole up 20 meters high. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! 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). I won't bore you with all that so the first portion of this still only shows up to the 4th multiple.