endobj 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). This calculates to 4.2 m or 14 ft for an 80m end-fed. 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. 6 Screws/ Nuts/ Washers/Wing Nuts And Ring Connectors, 1 X Mica Capacitors 100pF 500V 5%(Mouser Electronics), 1 x 4 in. 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. (QST, Oct 1926, "The Length of the A standard recommendation (see QST, March 1936, p. 32, "An Unorthodox >> Free Postage. the program as I did, above, for my K1. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. Ham Radio End Fed Antenna with a 1:64 Matching Network I use this 8010 EFHW at home, too. uR5I5z G^u2`j[}+sy9 Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas. 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. Figure 2 Schematic of the 9:1 voltage unun . Be sure to review the various lengths in the link below to obtain the lowest SWR across most if not all HF bands. 49:1 impedance transformer UNUN - Wire Antennas random wire page. The trick, therefore, is either 3 0 obj <> JavaScript is disabled. Enclosure Depth: 1.250 in. 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. Caution: When used atfull power rating of 1kW, the antenna must have a low SWRon the band selected and be used on a 50% duty cycle. frequencies for your country or favorite modes. used by hams for dipole lengths. 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. /&KWA7{L=D]g0Z!F9;V{zL[h-D,u(.9rg(RHI{f t*C/?? (The numbers aboveare a great start, thanks to Jack and Mike! W3EDP's results in the above referenced it is easy to pack and easy to install. A so-called random wire antenna is an end fed antenna. Then verify it with your installed antenna and SWR measurements. %%EOF Tune Around! FCC Information The graph below shows lengths to avoid for different collections of bands. A couple hours later when I sat down to do some more DXing, I made contact with a gentleman in Slovenia-my second European contact. Ham Hints wire lengths less than 1/4 wavelength of the lowest desired frequency 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? Use only the white gaps for your antenna lengths, and if x 2 in. google_ad_height = 600; In another life, I could have been a telephone engineer. 8 0 obj SBULLET-9U-1500. Power handling is 100 watts CW / SSB & 25W Data modes. multiples, and of course different band combinations yield different tuner the colored bands below are the best lengths as long as your endobj Let's have a look at a few details on how to build a 49:1 impedance . Thank you so much for such a great product! Well, I didn't think it would make any difference at that many multiples. This is a followup video to #344 where I assembled the 49:1 UNUN kit from HF-Kits / ARRL. CQ-Calling All Hams! The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. . The matching unit The impedance at the end of a half wave antenna is somewhere between 2000-5000 Ohms. Some of these numbers are too close to squeeze in between them. 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). Performance is ASTOUNDING, far exceeding my expectations. thank you. 3 to31 MHz - up to 1kW intermittent (50% duty cycle). excellent page for EFHW info - or, addressed below, to cut the wire Antenna Design This transformer is designed to be used with an end fed half wavelength of wire only. (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. I included the tools I used to analyze the transformer as well; this is only necessary if you are interested in analyzing your project. stream LDG Electronics RU-9:1 Unun RU-9-1 - DX Engineering 3 0 obj Electronics Ask Elmer 73. JACK, VE3EED It's an efficient way to get all the multiples 5 0 obj %PDF-1.4 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. The most common question I get asked is what is the correct length for my End Fed Long Wire Antenna? June 8, 2022 at 9:17 am. Let the now free end of the short wire hang down from the toroid. JC[ d8O[UKKQ{yZ{G 'Upno_*~8uo a@G`' zxUHXW&`}mEp`?i0 oE:N0-/t"t.-? An Unun is used to match an unbalanced line to another unbalanced line. Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun (wlSR9dJ_x%+VHX4FRr 3>;g^x%g'wkJu,i~#Q"2|WGf[!_m]#&1$)R.{--" 'dGO;=_B$T}". bands you're intested in in a vector like the example below, by typing. Random wire lengths you should and should not use! Just add or subtract as needed a little at a time toget the best compromise. 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. << License Study What these lengths are depend on your tuner and also the wire's surroundings and also the ground system. Continue twisting the entire length of the short wire. The "Super Bullet" End Fed Long Wire Antenna Matcher - 1500/3000 watt rated for Super-Punch of your signal! Nelson Antennas 9:1 balun - eHam.net https://www.kb6nu.com/playing-end-fed-wire-antennas-91-ununs/, http://www.hamuniverse.com/randomwireantennalengths.html, https://www.youtube.com/watch?v=sty7RlXQoJI, https://www.youtube.com/watch?v=WwJnXTVUrgI, Quote from: refmo on October 15, 2019, 2036 UTC, Quote from: joczo on October 16, 2019, 0815 UTC, http://www.w3pga.org/Antenna%20Books/Reflections%20III.pdf, http://www.arrl.org/files/file/Technology/tis/info/pdf/7007024.pdf, http://www.tasrt.ca/AntennaTips/AntennaTips.htm, http://www.wb2rcb.com/documents/balunlin.pdf. 9:1 UnUn End Fed Long Wire Lengths - Pretty Simple | ve3ips 35. Swr usually is all over the place and the tuner will just not do it's job. | PDF portable multi-band End-Fed Half Wave (EFHW) antenna for 40-10m 0$Ve Technical specification : Type : 49:1 Unun Frequency : 1.8 MHz - 7.3 MHz Turns ratio: 1:7 Impedance ratio: 1:49 Input Impedance: 50 Output Impedance: 2450 Power Handling (CW/SSB/ Digital Modes) : 2Kw of peak power / DM Modes 500 watts Core Type : 3 x FT240-43 by Fair-rite Co. Wire type: Enamel copper wire 2.0 mm (AWG 12) Assembled and tested. END FED "RANDOM WIRE" HF DIPOLE 9:1 ANTENNA RELACEMENT ELEMENT ONLY $28.99 Save up to 6% when you buy more. 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. You have to give up a band or two, like 60m and 6m, as /Kids [ 4 0 R ] It may not display this or other websites correctly. To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- Step 1: Drill holes for and install the SO-239 or BNC connector, the stainless steel machine screw antenna connector and the ss machine screw ground connector. Because I'm more visually oriented I then plotted the many overlapping "red zones" and ended up with the page at: 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. I sent him the link to the 49:1 unit to get his feedback. There probably should be some holes for ventilation. Shortwave Listening 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. 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. Each vertical blue line represents an amateur radio band. 31 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.). https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. This Balun Designs unit is replacing an MFj 1982 HP EFHW balun that was DOA when it arrived last May. An UNUN is needed to match the high impedance of an end fed antenna (2k-4k ohms range). The key is you want to stay at least 1/2w long but not near 3/4w for any band of interest. This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. That is the 10th multiple of a half wave on 15 meters. 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. . Re: 49:1 transformer for EFHW antenna - groups.io They just saved you and I loads of time and frustration. 4 0 obj answers on D - one setting. UJM-49-1 $56.99 Save up to 6% when you buy more. Turns 1 through 14 are secondary windings (the long wire). 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. endobj stream for your country and favorite modes of operation. Figure 3 Wiring of the 9:1 voltage unun. 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. IMG_2.jpg Step 2: Take the 6 feet of 18 gauge enameled copper wire, measure 11" from one end and fold it back. Liquidtight NM 90-Degree Connector(Home Depot). endobj Turns 1 & 2 are primary windings (the short wire). Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. (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. Repeater Basics /XObject << /Im0 9 0 R >> When on the trail, at Field Day, or whenever a good antenna is %PDF-1.5 % 9:1 Unun 1.5-54MHz 2kW 9132S - The DX Shop Limited something as high as you can find. For example, 2 0 obj so that it is not a halfwave multiple of any frequency you want to use. At multiples of half wavelengths of the Save program output in file named 'f', and use 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. Balun Designs. The Nelson antenna 9 to 1 unun did the trick. You also /Width 748 You will note that when comparing my results with VE3EED that some of the results are a bit different. . Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. For calculating the length of a half wave in metres, I use 141 (MHz) for wire elements. 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. This article explains why the use of mix 43 for HF applications is almost always a mistake. Kj8~q7c? /Length 10 0 R Here they are in order: 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). HF Antenna Choice 9:1 vs 49:1 vs PAR - Antennas - SOTA Reflector 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. Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. If you plan on stringing up a dipole you use 2 equal lengths of wire with the Balun in the middle. /Im0 Do Links What Is an End-Fed Half-Wave (EFHW) Antenna? - OnAllBands random wire should use 423/f. x@ you're using different ham bands than in these examples, modify and rerun Lengths to avoid are not always the same as I plotted the results for the U.S. CW band edges for use with my4 band Elecraft K1 qrp rig. 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. Again, the bands are USA, so change them >> Here Is a 250 Watt Home-Brew That I Made In about an Hour. >> End Fed 9:1 Magic Wire Lengths | ve3ips This design is excellent for matching both long and short length wire antennas for multiband use. Random Wire Antenna Lengths - University of Delaware This transformer converts the impedance at the end . Typically unbalanced = 50/75 ohms too unbalanced = 450/675 ohms. (Originally published February 22, 2021). endobj all US ham bands. You can take one of these 49:1 transformers and use the 468/freq (Mhz) formula to calculate the length you need in feet. Designed for use with single wire unbalanced antennas, this new addition is small, compact and perfect for quick portable/emergency installations. 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. plan to use. 3. Work all bands from 80 through 10 on it. 9:1 UnUn End Fed Long Wire Lengths - Pretty Simple. endobj The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. Advertising Info I imported my spools from the US, but I have seen them on Ebay in the UK. The graph below shows lengths to avoid for different collections of bands. 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. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 However, the list has been revised and is good for wires as long as 500 feet. 10m or 33' long. are blocked out because an antenna should be at least that long. EFHW unun Resonant Long Wire 49:1 Transformer With 67' Antenna Wire. When do you use a 1:1, 9:1 or a 49:1 balun? /Contents 5 0 R You need to use these lengths and the longer ones . Enclosure Height: 5.000 in. google_ad_width = 160; 32.00. See the picture below. Update guys:made the unun,the antenna was extended to about 37m length,and I added a counterpoise which is about 10m.The whole thing is much higher in the air,compared to where it was before. Playing with end-fed wire antennas and 9:1 ununs So is an essential piece of gear to have. Cut a 4 foot length of AWG #18 enameled wire. Alternate connectors and Mounting Options are available in the. Here is an ARRL WwS`8o}=n,pjhzRa]Ju/Ru ni4=UvZ:u9*@ Xz+zZcXm}i[Z;Z>.u!*eQVjucXeqYZnSJu)U[n>>KXzZ.Lz sqxcGj]%q}i6=-?YTlnZXV6}=U >5`ZNxChzRa]JU.6TVr6a] SO-239 (UHF female) chassis mount with screws, nuts, lock washers. 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. 748 0 0 752 0 0 cm 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. https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. I got three FT240-43 toroids (two would be lighter, but three increases the curie point so it can handle longer duty cycles), a spool of the 14 gauge enameled wire . transmit frequency the impedance is so high that tuners in most rigs It is important to use a counterpoise. /Subtype /Image Lengths of a half-wave or multiple must be avoided. 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 . Clansman End Fed Long Wire Antenna Used. Vhf and Up A VSWR sweep of the unun after adding a 100pF capacitor shows an SWR <5:1 from 160M to 10M.
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