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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. var sc_security="1df091cc". UJM-49-1 $56.99 Save up to 6% when you buy more. Do what works best! I have used the 49.2 ft (15 Meter) length of wire on vacation with both automatic tuners and an MFJ Model 16010 tuner with good results for 40, 20, 17, and 15 Meter operation. endobj << A 50 foot run of RG-8X coax connected the antenna into the LDG Z100-plus tuner and then a Yaesu FT-891A transceiver. 22.00 + 5.00 Postage. 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. K1S Valentines Are (Almost) Out The Door! [ /PDF /Text /ImageI ] 1 0 obj wire lengths less than 1/4 wavelength of the lowest desired frequency Site Map are blocked out because an antenna should be at least that long. 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. The graph below shows lengths to avoid for different collections of bands. Quantity: Sold individually. 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. . Here is an ARRL The unun was floating at about 15 feet above ground. When do you use a 1:1, 9:1 or a 49:1 balun? I say run what you got and don't worry about it. 3 0 obj /Creator (XnView) Let the now free end of the short wire hang down from the toroid. Designed for those who want the maximum isolation and choking across the full HF spectrum. Work all bands from 80 through 10 on it. You also want the antenna to be at least 1/4 wavelength long for each band you plan to use. Cut a 4 foot length of AWG #18 enameled wire. We'd really appreciate it! /XObject << /Im0 9 0 R >> 9 0 obj Power Handling (CW/SSB): 100 W/200 W Enclosure Width: 2.500 in. Re: 9:1 or 49:1 unun for end-fed long/random wire? I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. Dimensional Drawing of Standard Enclosure, 1:1 Common Mode Choke / Noise Suppression, Core Material Selecton for Baluns and Ununs, Antenna Matching Problems When Using Ladder Line or Open Wire Feedlines, Model 4932 - 4 & 9:1 Unun 1.5 - 54MHz - 2kW, Model 49130 - 49:1 - 80-10m EFHW - 200 watts, Model 64131e - 64:1 & 49:1 - 80-10m EFHW - Up to 1kW, Model 4116 - 4:1 Hybrid Balun 1.5 - 54MHz 3kW, Model 9130sw - QRP 9:1 Unun 1.5 - 54 MHz - 300 watts, Model 1115d - Max Choking 1:1 Balun, 1.5-54 MHz, 5kW. /CropBox [0 0 748 752] After winding #2 is made and extends down the backside of the toroid, untwist the wires. The table below represents half wave lengths and multiples that you DO NOT WANT TO USE! Post Reviews Let's have a look at a few details on how to build a 49:1 impedance . This unit is a Balun Designs, in collaboration with Fair Rite products, has developed what we consider to be the best single core 1:1 feedline isolation balun available today. Electronics /Length 6 0 R Because I'm more visually oriented I then plotted the many overlapping "red zones" and ended up with the page at: Ham Radio Videos! A so-called random wire antenna is an end fed antenna. bands you're intested in in a vector like the example below, by typing. 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! For a better experience, please enable JavaScript in your browser before proceeding. 9:1 or 49:1 unun for end-fed long/random wire? tuner the colored bands below are the best lengths as long as your Experimenting by slightly changing the wire length (+ or-) is encouraged to provide best overall performance. The counterpoise wire, This transformer is designed to be used with an end fed, Approx. 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). I swept the VSWR of the unun and resistors as described from <1 to 55MHz. Even better would be shortening to 53'. Again, the bands are USA, so change them 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. here are values for CW portions of the USA Meet 'Balun One Nine', a small, cost-effective balun. 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. SWR was good after cutting the wire to appropriate length. It is used fornon-resonant verticals like 43 foot or 33 foot Or Wire antennas like an End-Fed1/2 Wave Multiple Length Wire Antenna. The fewer bands, the fewer high impedance regions to avoid. Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun Here Is a 250 Watt Home-Brew That I Made In about an Hour. Connect this ring terminal to one of the SO239 chassis bolts. If you want a single band portable antenna you can mount pretty much however, look up this design. /Im0 Do >> unavailable, a random wire can save the day, but it is important to (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. The Short Answer Would Be That an UnUn Is a UN balanced to UN balancedmatching transformer. 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. endobj hb```YloD@(aKI V!}g@~}%Q/[[~_=Wy-:O)x[~hs/~SGeG _QE C6q %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". 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. Some of these numbers are too close to squeeze in between them. 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". At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. The short piece is for the primary winding of the transformer, and the long piece is for the secondary winding of the transformer. When on the trail, at Field Day, or whenever a good antenna is 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.
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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. The most important length is one that is non-resonant on any band. An UNUN is needed to match the high impedance of an end fed antenna (2k-4k ohms range). I only used two screws instead of four. To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- Picture 1 of 9. 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 . The novel thing was that I only built it the day before and it uses a Coghlan camping washing line spool with the string taken off and about 21m of wire wound onto it. Ultimately, this housing works fine, but it is heavy and clunky.). Just an FYI that I thought you might be interested in. 10m or 33' long. random wire should use 423/f. 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. For example, This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. and experiment. 3. <>
uR5ucE`_aksLjYT=hzRa]JucX7d}|'}`XRa>X results. AndWhat Is It Used For In Antennas? I attached the toroids to a PVC DWV test cap with 3 cable ties. you're using different ham bands than in these examples, modify and rerun 7 0 obj Use only the white gaps for your antenna lengths, and if Coverutilizes integralneoprene gasket for weatherproof integrity. endstream 73. JACK, VE3EED In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. 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. The trick, therefore, is either /Resources << these are the worst lengths and you want to be as far from colored /Producer (XnView, http://www.xnview.com) Click to enlarge. 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 plan to use. is that for a given ham band there are min and max frequencies which . . 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. 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. Tweak the antenna length if necessary and then maybe adjust the turns ratio again. This type of antenna is very easy to install because there is no need . endobj /Filter [ /FlateDecode ] For instance, to work 40m be sure the antenna is at least 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). document.getElementById("copyright_year").innerHTML = new Date().getFullYear(); I made one without doing this and it didn't work so well. Best SWR was . End fed 9:1 58ft wire and 17ft counterpose wire touching ground. 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. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. I have found this calculation to work well, however it depends on many factors such as wire used, location etc. 5 0 obj This article details the construction of the transformer. This calculates to 4.2 m or 14 ft for an 80m end-fed. endobj
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. A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. google_ad_width = 160; endobj
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. /Width 748 Each vertical blue line represents an amateur radio band. 2 0 obj This design is excellent for matching both long and short length wire antennas for multiband use. That type of wire antenna could be lower than 50 ohms at some frequencies and over 2,000 ohms at . 9:1 Unun 1.5-54MHz 2kW 9132S. This transformer converts the impedance at the end . 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. Turns 1 & 2 are primary windings (the short wire). There probably should be some holes for ventilation. My commercial EFHW is 130 feet long for 80 and up, and my 40 meter homebrew antenna is about . The length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). The ratio doesn't need to be 49:1 2,400 ohm either, other ratios will transform to other impedance. Ham Satellites Free Postage. 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. something as high as you can find. 80m up, W3EDP's 84' antenna, 17' counterpoise is probably the way to go. Privacy Policy A VSWR sweep of the unun after adding a 100pF capacitor shows an SWR <5:1 from 160M to 10M. What these lengths are depend on your tuner and also the wire's surroundings and also the ground system. Just a note, if you make one of these yourself, you need to twist together the first two wraps of the 14 winding wire with both wraps of the two winding wire. He was so impressed that he purchased a 9:1 unit from you, his will be delivered Saturday. %PDF-1.7
Part List: Start winding the toroid with the twisted wires at loop #1 (see schematic below). 35-43, 49-63, 70-85. 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. Designed for use with single wire unbalanced antennas, this new addition is small, compact and perfect for quick portable/emergency installations. You also ?7{*. In another life, I could have been a telephone engineer.