Y &lD30. 1936 article, however, fall in line with 468/f and so is used here. For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. understand its properties. 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. Re: 9:1 or 49:1 unun for end-fed long/random wire? June 8, 2022 at 9:17 am. Hi guys,not really hfu related,but I tought I might ask here as I have my account. PDF Construction Details 49:1 Un-Un For End-Fed Resonant HalfWave Antenna The 49:1, shown in my previous message, is meant for the EFHW that are fed close to or on the half wave (highest impedance) point. Wire lengths for the 4:1 ratio in models 4932 and 4935. /XObject << /Im0 9 0 R >> 35-43, 49-63, 70-85. Typically unbalanced = 50/75 ohms too unbalanced = 450/675 ohms. This calculates to 4.2 m or 14 ft for an 80m end-fed. It will be good for 15m, and 10m. PVC Junction Box(Home Depot), 1 x 1/2 in. SEARCH 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. However, the radio didn't tune up very well on 15 meters. Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun Generally an EFHW will be in the range of 2,000 to 5,000 ohms at the very end of the dipole when resonant. 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. Par EF 20 and par EF 40 (I realize for 17m I would prob just add that band to a 49:1 balun) That's that my question is. % You can add your own wire or get the complete product from this link EFLW-3K antennas. hb```YloD@(aKI V!}g@~}%Q/[[~_=Wy-:O)x[~hs/~SGeG _QE C6q %r 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. SWR was good after cutting the wire to appropriate length. NEMA rated 4x marine grade junction box for outdoor installations. 9:1 Magnetic Longwire Balun / Unun - M0UKD - Amateur Radio Blog If you want all the bands from Tune Around! excellent page for EFHW info - or, addressed below, to cut the wire There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. So is an essential piece of gear to have. I imported my spools from the US, but I have seen them on Ebay in the UK. Superglue 2 toroids together. stream 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. Palomar Engineers employs a dual core matching system that offers wide bandwidth (1-61 MHz), 500 watt PEP rating, and a connection for a counterpoise or ground if desired. The 9:1 may work best with that length wire and a tuner, but some say that length is undesirable for the hf HAM bands. 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. Contact /Type /Pages /CropBox [0 0 748 752] This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. the program as I did, above, for my K1. The length should be calculated based on the lowest frequency to be worked. AndWhat Is It Used For In Antennas? Figure 2 Schematic of the 9:1 voltage unun . Here Is a 250 Watt Home-Brew That I Made In about an Hour. 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. Many hams have tried till they are blue in the face to install the random wire antenna that works on most; if not all of the HF bands with terrible results. The First Thing New Hams Often Ask:What Is An UnUn? Multi-band end-fed - Nonstop Systems << hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 &nb I plotted the results for the U.S. CW band edges for use with my4 band Elecraft K1 qrp rig. Wait a few minutes for glue to set. 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 random wire antenna is probably one of the least expensive, easiest and cheapest HF antennas to use if you have a tuner and you want to get the "most" out of a length of "random" wire without having to pull out that calculator, doing the math, getting the center insulator built orbought, running the feedline, and all the rest that goes with putting up a more elaborate antenna. Experimenting by slightly changing the wire length (+ or-) is encouraged to provide best overall performance. 748 0 0 752 0 0 cm 9 0 obj 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. This may not be relevant to HF stuff, but the antenna I use for NDB reception has a 400:1 transformer (20:1) turns ratio. endobj endobj multiples, and of course different band combinations yield different Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. Having the option to switch rapidly between 49:1 and 64:1 should prove to be a really nice feature.. google_ad_width = 160; 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. . This homebrew 49:1 impedance transformer is the heart of any EFHW antenna you will build, most of the time. >> At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. If the choices are. Random wire length for 9:1 unun - fairlawnarc.groups.io installed, it is a compromise antenna but great for portable use because Jack, VE3EED, hopefully has solved a major headache we all have when we attempt to go thru the trial and error and frustration with getting the random wire to work where WE want it to work. I have included a screenshot showing the stations that reported spotting my 200 mw beacon over the last 16 hours. Click to enlarge. Balun One Nine v1 - Tiny Low-Cost 1:9 HF Antenna Balun and Unun with End Fed Long Wire Antennas - Palomar Engineers 9:1 or 49:1 unun for end-fed long/random wire? See the picture below. In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. I have not done this yet. stream %PDF-1.7 bands as possible. a more capable tuner - see AA5TB's Downward impedance transformation by factor of 49. << >> Enclosure Depth: 1.250 in. %%EOF 74 0 obj <>stream For reasons that I do not understand, adding a capacitor between the coax conductor wire (untwisted free end of short wire) and the ground (twisted free ends of long and short wire) can increase the functional bandwidth of the antenna on the higher HF frequencies. Shortwave Listening 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. 3 to31 MHz - up to 1kW intermittent (50% duty cycle). 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. 49:1 UNUN Transformer 2 Kw 160 - 40 m - Wire Antennas When do you use a 1:1, 9:1 or a 49:1 balun? [ /PDF /Text /ImageI ] ?7{*. It is optimized for 3.5/7/10/14 MHz but will work reasonably well on all amateur bands from 80 meters thru 10 meters with a 135 foot length of wire and a short connection to ground. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! http://udel.edu/~mm/ham/randomWire/. I made one without doing this and it didn't work so well. 5 0 obj 49:1 Impedance Transformer for EFHW Antenna - DX Explorer Just add or subtract as needed a little at a time to get the best compromise. 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. Lengths to avoid are not always the same as So, having nothing better to do one day, I re-did the calculations going out to 500 feet. /CreationDate (D:20221212112042) 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. We'd really appreciate it! /Type /Catalog << 10m or 33' long. 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. END FED "RANDOM WIRE" HF DIPOLE 9:1 ANTENNA RELACEMENT ELEMENT ONLY $28.99 Save up to 6% when you buy more. A small ring terminal for 14ga wire that fits these screws would be helpful too. often can't match it. JavaScript is disabled. https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. Longer wire is always more If you plan on stringing up a dipole you use 2 equal lengths of wire with the Balun in the middle. Picture Information. The Short Answer Would Be That an UnUn Is a UN balanced to UN balancedmatching transformer. I'm looking forward to getting off work and hitting 40 & 20 meters again!! Usually any wire length that is non resonant on the band or bands desired will work with the 4:1 ratio. Usually any wire length that is non resonant, like those shown above, will work with the 4:1 ratio. Re: 49:1 transformer for EFHW antenna - groups.io The transformer usually used with an end fed wire is a 9:1 transformer. Theme: Newsup by Themeansar. endstream all US ham bands. The other is to provide strain relief for the antenna wire). 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. Gil Gruson 1 Campaign | Comines, France $0 USD 0 backers 0% of $3,450 Flexible Goal Follow Story FAQ Updates 0 Comments 0 Prototype The project team has a working demo, not the final product. google_ad_height = 600; Feeling a bit too lazy to calculate that by hand, however, I wrote a You can take one of these 49:1 transformers and use the 468/freq (Mhz) formula to calculate the length you need in feet. While I have not done so yet, I plan on gluing the test cap to the back of the junction box. For instance, to work 40m be sure the antenna is at least Here are the final numbers (in my opinion) in green below that would be good for a long-wire antenna: (You may want to make a note of them), REVISED: 29 35.5 41 58 71 84 107 119 148 203 347 407 423, REVISION NOTE: We had a note from James, KB5YN, pointing out that one of my so-called GOOD numbers was 220 feet. RFI Tips and Tricks Presented for your consideration by Jack, VE3EED. here are values for CW portions of the USA So I just wanna say thank-you!! , Most matching problems occur when the antenna system An Unun is used to match an unbalanced line to another unbalanced line. About Batteries There probably should be some holes for ventilation. Moving the pot up and down gives a feel for the SWR versus antenna impedance sensitivity. Privacy Policy is that for a given ham band there are min and max frequencies which 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. I say run what you got and don't worry about it. The unun was floating at about 15 feet above ground. 73. JACK, VE3EED /Resources << I did not want to put the transformer in the housing until I tested it. IMG_2.jpg Step 2: Take the 6 feet of 18 gauge enameled copper wire, measure 11" from one end and fold it back. 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). <> Nelson Antennas 9:1 balun - eHam.net 2 0 obj 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. Use only the white gaps for your antenna lengths, and if A Balun is used to match a balanced line to an unbalanced line. Drill out holes in the designated bottom of the electrical junction box for the SO239 chassis mount. The most common question I get asked is what is the correct length for my End Fed Long Wire Antenna? 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. I used the RigExpert Zoom AA-55 to test VSWR of the 49:1 unun impedance transformer. Figure 3 Wiring of the 9:1 voltage unun. SBULLET-9U-1500. 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 . is helpful if you're in a hurry to get on the air, read up on the topic Here I show finalizing the antenna, getting it in the air, and run. EFHW unun Resonant Long Wire 49:1 Transformer With 67' Antenna Wire. VSWR analysis of the antenna in the field showed that VSWRs between 3-5.5 from 40M to 10M. 40-30-20 . "I received my third balun from Balun Designs this afternoon. A 50 foot run of RG-8X coax connected the antenna into the LDG Z100-plus tuner and then a Yaesu FT-891A transceiver. V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT c=W>:sECXTkc=X In another life, I could have been a telephone engineer. 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. Start winding the Matching Auto Transformer, each pass through the center of the core equals one turn. Modify bands and 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. Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas 9:1 Unun EF Random Long wire matching Transformer with BNC or SO-239. thank you. The table below represents half wave lengths and multiples that you DO NOT WANT TO USE! Kj8~q7c? Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. Prescott Hamfest - W7YRC 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. 0$Ve /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. 9:1 UNUN - MyAntennas.com CQ-Calling All Hams! /Pages 3 0 R random wire page. I used 2000 and 1000 ohm resistors in series connected to the proper unun wires with alligator clips for a total of 3000 ohms. are easily converted to half wavelengths by the famous 468/f generally Then verify it with your installed antenna and SWR measurements. Antenna") is an 84' long end fed and a 17' long counterpoise (6.5' for 20m). PDF Recommended wire lengths and Installation Notes for Unun models 4932 So a 49:1 impedance transformer is needed to match the 50 ohms of the coax at the feed line. The vertical (y-) axis shows the VSWR and the horizontal (x-) axis shows the frequencies. PDF 33ft Verticals and 4:1 Ununs - G8JNJ Advertising Info answers on D - one setting. endobj 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. 1:1, 9:1, 49:1 Matching Units - What's the difference? - YouTube Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. I only used two screws instead of four. 9:1 UnUn End Fed Long Wire Lengths - Pretty Simple | ve3ips Computer Help I wrote a small C program that does just what Jack did, butI used the band edges. 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. To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- Ask Elmer The length of enamelled copper wire per winding for the T-200-2 powdered iron toroid core is determined by length per winding = 50mm per turn plus 250mm tails. shown in the column e. var sc_project=8077274; "Here's the word on random-wire antennae.". Let the now free end of the short wire hang down from the toroid. which got me thinking. To DB's point of a single band antenna, this 49:1 transformer is a good choice for a single band matcher. 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. << This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). We do not encourage any radio operations contrary to regulations. 1. Weight: 0.380 lbs. Two pieces of 14 gauge enameled wire (e.g., Thermalese), one short piece (about 1 foot in length) and one long piece (about 7 feet in length). Hopefully these random wire length calculations will help us all make this "easy" antenna work better! When on the trail, at Field Day, or whenever a good antenna is You have to give up a band or two, like 60m and 6m, as First, it is important to understand the difference between the end fed half wave and a random wire (or "long wire") antenna: the random wire is just a piece of wire that is matched to 50 Ohm impedance using an antenna coupler, sometimes adding a 9:1 unun. u?X`f0&/Ri;W0Tn_*TX:ug frequencies for your country or favorite modes. Playing with end-fed wire antennas and 9:1 ununs This article explains why the use of mix 43 for HF applications is almost always a mistake. /Length 6 0 R Tools Unun 9:1 - VK6YSF - Home Page Turns 1 through 14 are secondary windings (the long wire). The length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). "Just received my new 64131 yesterday and was anxious to see how well it performed. 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA 80m up, W3EDP's 84' antenna, 17' counterpoise is probably the way to go. Thank you so much for such a great product! This will be for an eyehook in order to provide strain relief for the radiator wire. All you need for a random wire antenna is some wire, your tuner, one or more supports up as high as you can get them to string the wire from the supports to the tuner, at least one or two insulatorsand a little time. 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. ), Note that Jack, VE3EED,went SK several years agohe will be missed. Proudly powered by WordPress For calculating the length of a half wave in metres, I use 141 (MHz) for wire elements. << 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. 9:1 Unun 1.5-54MHz 2kW 9132S. The 30 day return period lapsed before I could get the antenna deployed to test it. endobj endobj . Multiples are on C and 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. Home-brew End-Fed 49:1 UnUn. - KA9QJG Repeaters Support The Site In other The ratio doesn't need to be 49:1 2,400 ohm either, other ratios will transform to other impedance. We recently found some good information about random wire lengths that you should and should not use. SO-239 connectors are silver plated with Teflon insulation. 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. If the transformer is used with an externaltuner in conjunction with a single wireantenna typically 130-135 feet in length, power should be reduced on those bands that show an SWR above 1.6 to2:5 withoutthe tuner. 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. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 LDG Electronics RU-9:1 Unun RU-9-1 - DX Engineering Use with other lengths can potentially damage the transformer depending on power level in use. They just saved you and I loads of time and frustration. 20/40/17m. Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. Ham Radio Videos! wire is at least 1/4 wavelength. Reading Room After winding #2 is made and extends down the backside of the toroid, untwist the wires. A standard recommendation (see QST, March 1936, p. 32, "An Unorthodox you're using different ham bands than in these examples, modify and rerun Legal Stuff Because I'm more visually oriented I then plotted the many overlapping "red zones" and ended up with the page at: End Fed Half Wave 40-10 Wire Antenna - N6DOZ Liquidtight NM 90-Degree Connector(Home Depot). A way of connecting the analyzer to the transformer.