preferably layman terms. Working in the forward direction a 1 to 1 is 50 in 50 out. terminal in the UNUN goes to the COLD side of both the input and the output. 9:1 BALUN / UNUN *** TO BUY WITH CONFIDENCE, YOU ARE GETTING PAYPAL PROTECTION ! Recommended Wire Lengths for 9:1 ratio (in feet) for Coverage of 160m through 10m 53 59 72 88.5 98.5 124.5 146 162 175 Values in color are best overall lengths to use for optimum HF spectrum coverage. 9:1 UnUn; 1-5-54 MHz; 2kW power handling; Insertion loss <0.2dB; Studs on sides with wingnuts; Silver plated SO239 connector; Price excl VAT: £ 72.95 incl VAT: £ 87.54. Requiring a balun to feed a balanced antenna from an un-balanced load with an impedance step up from 50ohms to 450ohms, a 1:9 Voltage balun design using an L15 ferrite toroid cores was selected. Windings are inserted into Teflon tubes increasing total breakdown to 10,000 volts. In this two-part tutorial, Paul (OM0ET) show us his new design of a compact 9:1 UnUn for portable QRP Random Wire Antennas. been doing a lot of reading on the subject, but nothing is telling me the difference appearance wise or component wise, just explaining how they work(a balun works with a balanced and unbalanced and a unun works with unbalanced and unbalanced, ect). Delta Loop Antennas (10) Double Bazooka (6) End-Fed Wire Antenna 9:1 Non Resonant (5) G5RV Antenna (2) Half Wave End Fed (19) Marconi Inverted L G7FEK (3) OCF Dipoles (Windom) (2) ZS6BKW (3) 2M (3) 4M (3) 6M (8) 10M (32) 12M (29) 15M (32) 17M (31) 20M (38) 30M (29) 40M (39) 60M (8) 11 M (CB) (7) 80M … Kevlar; HF. for a 9:1 UNUN its better to choose a "random length". There was quite a discussion on the 49:1 transformer for the EFHW antenna a few weeks ago. 49:1 or other high ratio transformers are for resonant "cut to frequency" antennas like the traditional zepp/fuchs antenna. Add to Cart. 49:1 impedance transformer UNUN +44 (0) 7753225261. 49:1 IMPEDANCE TRANSFORMERThe End Fed antenna is very popular especially for field work. This is why popular unun designs like the EARCHI 9:1 use low loss material such as Type 2. In this configuration, the coax shield will act as your counterpoise . 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. There is a Magnetic Longwire Balun. We do not encourage any radio operations contrary to regulations. Would it be noticeable in the field? Are you sure you wish to delete this message from the message archives of antennas@groups.io? The coax is connected to the SO-239 and fed to your radio. Add to Cart. The key is you want to stay at least 1/2w long but not near 3/4w for any band of interest. The SWR varied from a low of 5.9:1 on 10m to a high of 49:1 on 30m. The DX Shop are distributors for Balun Designs. I'm not saying aliens are in the radio, but aliens definitely are in the radio. They reduce or eliminate currents on the outside of your feedline allowing you to hear and to be heard much better. Top of unit has connector for antenna wire, half wave in lenght for coverage from 160 to 10 meter. ", KiwiSDR Online Radio - 500 ft Northeast Beverage, KiwiSDR Online Radio - 400 ft South Beverage. Cette impédance est divisée par 9 dans le MLB. 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 say run what you got and don't worry about it. HF Underground wiki  Radio Hobbyist technical blogHFU Rocket Chat EuroPirate ChatPropagation DataTeamspeak Server, Shortwave Pirate Radio In North America And Around The World, And Other Things That Go Bump In The Night, Login with username, password and session length. 9:1 Unun 1.5-54MHz 2kW 9132S quantity. The green bars show the performance with the feed coax connected directly to the vertical; no UnUn was used, there was no connection to any ground system, and no RF choke was used. With that big FT240 core, probably at least 25w but even 10 or 15w may work but require a bit more time. R. E. Klaus #187 . 5Kw / 2Kw. 49:1, 1/2 wave unun, built for base antenna and tower. Ideal for high power Windom design antenna . These are sometimes known as a Magnetic Longwire Balun. 9:1 random wire antenna (typically requires a tuner but can work easily on multi bands) 49:1 resonant end fed (does not require a tuner usually but mono band) Which of the above would be more "efficient"? Subject of the new topic: There was quite a discussion on the 49:1 transformer for the EFHW antenna a few weeks ago. 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 W1SFR End Fed 35’ Random Wire Antenna with 9:1 UnUn What is a random wire antenna and how does it work? There is virtually no difference in cost or complexity making a 9:1 vs 64:1 transformer, so I and many others are puzzled why people still bother to make a 9:1 type when the resonant EFHW with a 64:1 or 49:1 type transformer is so far superior on the air. In this video I show you this small home made QRP UnUn and I do quick impedance test. The term “random” infers that you can use any length of wire you want as an antenna, while that basic fact is true, there are some practical considerations. Constructed with two 240/43 cores and wound with 12 awg high temp magnet wire. 49:1 or other high ratio transformers are for resonant "cut to frequency" antennas like the traditional zepp/fuchs antenna. Introducing DX Engineering "Maxi-Core® 20" Baluns and Feedline Chokes. 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. Hi guys,not really hfu related,but I tought I might ask here as I have my account. 4:1 Voltage Balun At the feedpoint of an off-centre-fed Dipole, eg: Windom. This may explain the impedance transformation disparity you're observing. I've used a 9:1 End fed in the past with success, however it would be nice to not have to carry a tuner. 49:1 UNUN Transformer 2 Kw. You can also use the unun with no counterpoise or ground if your feedline is at least 25+ feet long. To celebrate our 20th Anniversary in the year 2020 we have developed a new line of Baluns and Feedline Chokes. Requiring a unun to feed a long wire antenna ideally without a tuner a 9:1 voltage unun design using a T200-2 Toroid core was selected. I think this violates the Terms of Service. One website wants you to add some coax on the unun without any chokes to create a counterpoise. Generally, a bit of “random” wire presents a high impedance, so the 9:1 transformation makes life easier on whatever antenna matching unit you have. One or more copper rods or pipes driven, at least, 4 feet into the earth near the dwelling entry point (2 or 3, is better, being spaced about 4 feet apart). Au départ, il était conseillé de prendre un fil de 20 m. Réfléchissons. Coax connection point is SO239 silver teflon. More. Install November 2016. The LDG Electronics RU-9:1 Unun was designed to allow easy interface of random length vertical and end fed antennas to the LDG line of Automatic Antenna Tuners. I think this message isn't appropriate for our Group. SWR will vary based on topography, proximity of nearby structures, configuration of the antenna wire and choice of ground or counterpoise. The beauty of the halfwave antenna is it's a complete antenna in the sense it needs no counterpoise. When we say a Balun or UNUN is a 4 to 1 device it will work just as well backwards. Add to basket. It is an impedance 9:1 transformer 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 ohm (unbalanced) coaxial input, hence UnUn. SWR for all lengths should typically be under 2.2:1 and in most cases will be under 1.8:1 for 160-10m allowing onboard tuners to *** There is a Magnetic Longwire Balun. A 4 to1 balun can also match 50 Ohm to 12 Ohms, and a 9 to 1 can match 50 Ohm to 5 ohms. Ça nous fai… "Can you please recommend schematics that are designed to tune setups like these? In another life, I could have been a telephone engineer. Thanks R.E. 450 ohms to 50 ohms. 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. It is an impedance 9:1 transformer 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 ohm (unbalanced) coaxial input, hence UnUn. Description Description. All hardware is stainless steel and housing has ground connector for ground rod or grounding to mast or tower. Here are some of Paul's observations: "This is my new design of the small 9:1 UnUn for portable QRP Random Wire Antenna. 9:1 UnUn Feeding a random/long wire or at the base of a multi-band vertical. Installation of the 9:1 balun/unun: The End-Fed is connected to one terminal of the "high" winding and the other terminal is connected to a good "EARTH" ground. Stacked cores with trifilar winding configured as 9:1 unun Downward impedance transformation by factor of 9. i.e. 9:1 or 49:1 unun for end-fed long/random wire? The new topic will begin with this message. The resonant EFHW types do not light up the coax with RF unless you operate them way out of band. Are you sure you wish to repost this message? Ça nous fait 4 Ω vus par le TX !!! 0; 0; Toggle navigation. Put a dummy load or an antenna that shows a good match to it, and put some power through the unun. My question is the 9:1 unun used with a random wire antenna considered to be as lossy as the 49:1 transfomer? It may be used with many of your antenna projects where a 4:1 Unun is typically recommended. This transf.. £95.00 Ex Tax: £95.00. There are many lengths of wires used with a 9:1 unun but most fall in between 30 to 40 feet. Re: 9:1 or 49:1 unun for end-fed long/random wire? To feed a balanced feed line ( antenna) with an un-bala.. £67.00 Ex Tax: £67.00. My question is the 9:1 unun used with a random wire antenna considered to be as lossy as the 49:1 transfomer? Et le courant qui l’accompagne. With the view to establish a quick and easy multi-band antenna deployment for portable and camping operations a simple long wire antenna with an earth or earth plus counterpoise arrangement with a 9:1 voltage unun is one possible solution.. 20 m, c’est un quart d’onde sur 80 m. L’extrémité présente donc, lorsque le fil est bien accordé, une impédance de 36 Ω (fois 2 pour un dipôle = 72 Ω). 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. The tuner was connected directly to the transceiver, and all cables were kept the same during the series of tests. Is a 9:1 unun considered to be as lossy as a 49:1 transformer? 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. Winding Material : 14 gauge Superior Essex Heavy build polyamideimide Allex 240 Winding Wire. Install November 2016. D’où un ROS de 50 : 4 = 12,5 => 12,5:1 ! After buying a couple of 9:1 UnUn's, I decided to try to make my own. Given that no ground system was used we might wonder what forms "the other half of the antenna": 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. 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 50Ω (unbalanced) coaxial input, hence UnUn. All Messages By This Member; ajparent1/kb1gmx #188 . It can however also be used as a balun … 4:1 CURRENT Transformer 1. 9:1 Voltage balun. The "9:1 UNUN" are for random length wire antennas fed at the end. its design is in its 49:1 impedance matching transformer, or unun (connects an unbalanced feed line to an unbalanced radiating element,) where much of this DIY is focused. I look up images and some 9:1 ununs look identical to a 1:1 balun or 4.1 balun.....help? 4:1 impedance transformer UNUN 1 Kw PEP. a 49:1 transformer with a bit of capacitance will help you more. Uses a ferrite toroidal core or cores (usually Type 43 or type 52 material). So I chose to model a 35 foot piece of wire and a 15 foot piece of #12 to simulate the shield of a piece of coax. This is Hi-Power QRO 9:1 Balun / Unun. Recommended wire lengths and Installation Notes for Unun models 4932, 4935, 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. It wasn't as hard as I thought it would be. Like: 29 35.5 41 58 71 84 107 119 148 all in feet! The 132-foot half-wave radiating element presents about an 1800 ohm (at 10 meters) to 5000 ohm (at 80 meters) impedance to an end-fed feed point. And I’m going to keep this VERY simple because there are scores of books dedicated to antenna design and efficiency. This 200 watt Unun also operates "stand alone" meaning that it does not necessarily require a tuner for use on certain antenna. It is a conventional transformer. 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. This includes: harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing. Thanks for your answer,I will probably go with the 9:1 then. I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. The "9:1 UNUN" are for random length wire antennas fed at the end. 250 Unun, my improved version of the Comet the G8JNJ 5:1 Unun and finally a 4:1 Unun fed with an auto-tuner at the far end of the 62m (200ft) LDF2-50 coax feed cable. 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. The present-day DX Engineering was launched in the year 2000. The Group moderators are responsible for maintaining their community and can address these issues. Sur 40 m, l’antenne résonne en demi-­onde. Typically, performance is better with no ground at the antenna, but you can try both ways. The UNUN has a high impedance ratio (49:1 to 64:1) – not feasible to use transmission line transformers whose practical limit is about 16:1.
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