The first one, wound f. ( 6 ) Estimated Ship Date: Monday 6/6/2022. May 5. alun-unun/ With the same set up, you could ad three wire terminals: 1:4 1:9 1:16 to give more length / band flexibility . If the choices are. However, depending on the capability of your tuner you may be able to attach the radiator and counterpoise directly to the tuner and avoid the unun. CLASS DIMENSION_SCALE NAME lat . 9:1 voltage unun using a L15 ferrite core. 2010 49. [ Hits: 1416 | Votes . This system is generally good on 80, 40, 20, 15 and 12 meters. With that big FT240 core, probably at least 25w but even 10 or 15w may work but require a bit more time. It is a 10meters piece of wire with a 9:1 toroidal transformer and a coax feed line of 25 meters . A . Thread Auto-transformers vs transformers and some mathy questions . Installation of the 9:1 balun/unun: . This system is generally good on 80, 40, 20, 15 and 12 meters. End fed 49:1 60ft wire (using coax as the counter poise. 80-10 meter coverage It is not a good choice for working lower bands from a too short wire, that is, if you have cut your wire to a 20m halfwave, it ain't much punkin' for 40m, 80m, or 160m. End fed 9:1 58ft wire and 17ft counterpose wire touching ground. The paperwork that comes with this little unit says that it can be used for power levels up to 150W but so far I have only used it pretty much for PSK31 and low power SSB (50W or less). Video content is allowed to be shared publicly by Youtube. 2/2 (4) element 7/10MHz Yagi (3.9m) Force12 Antennas. 49 pm Thanks rgood123!!! My focus is on power loss as I run QRP on batteries. Building a 9:1 UNUN With FT-140-43 Toroid. At this point, I've only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. Force12 Antennas - A super-compact dualband 7/10MHz WARC band Yagi with single feedpoint The 4-LFAR-40/30, an . The average insertion losses are unmatched by any other similar transformer on the market proving our worldwide leadership in . It will be good for 15m, and 10m. The bottom line is that you have to treat the antenna system as a whole in order to minimise losses. Put a dummy load or an antenna that shows a good match to it, and put some power through the unun. To DB's point of a single band antenna, this 49:1 transformer is a good choice for a single band matcher. Welcome to Link Mi! This 9:1 unun does NOT have a terminal for a ground; just a bolt and nut to connect a random wire antenna and an SO-239 socket on the side. The End-Fed Half-Wave (EFHW) antenna often uses a transformer with a transformation ratio of 49:1 (a turns ratio of 7). A feed line choke is a 1:1 impedance transformer with equal input and output impedance (usually 50 or 75 ohms in/out). Ideal: Sloper configuration with one counterpoise but several different length counterpoises is better. This one used a T240-43 toroid in a 49:1 impedance matching unit at the base and a choke on the coax about 12 feet away from the feedpoint to a) help the coax act as a counterpoise and b) stop RF getting . The EFHW UnUn---Homebrew yourself 49:1 UnUn autotransformer 2 turns primary to 14 turns secondary with a turns ratio of 7. You can also feed the antenna remotely through an unun (either a 4:1 or 9:1 unbalanced-unbalanced transformer). A tuner will help with that but introduces even more losses. 9%) While the most common birthplace for those born overseas remains England (15% of the overseas-born population), there has been an increase between the 2011 and 2016 Censuses in the proportion of people born in China (6. Most 1:4 and 1:9 transmission line UNUNs use powdered metal 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. #1 a Ferrite Rod that doubles as the L inductance and the Antenna. The balun must be a high quality current balun, not an unun or voltage balun. Keep the coax between the UnUn and tuner as short as possible. 9:1 Voltage Unun - A 9:1 voltage unun using a T-200-2 powdered iron toroid core to feed a long wire multiband antenna. #2 a Standard Loop antenna again the same L inductance and is also the antenna. figure 1. 9:1 voltage unun using a T-200-2 powdered iron toroid core. A 64:1 or 49:1 transformer is used to match the impedance (2500..3200 Ohm) of the feed line. PTFE insulation, 1.85mm outer dia (CPC part number CB10433) wound on FT240-61 core.. Having the option to switch rapidly between 49:1 and 64:1 should prove to be a really nice feature.. Building 49:1 impedance transformers for half-wave end-fed antennas, single or even multi-band with certain wire lengths, 134 or 67ft. Tools. April 4. This was 9m vertically metres up a fishing pole and then about 5.8m out. General. Requiring a unun to feed a long wire antenna . March 3. It should be a 1:1 ratio with high common mode impedance and high voltage breakdown. November 9. Part of the feed line is commonly used as a counterpoise. Impedance transformers in the Palomar Engineers' product line have input/output ratios either less than 1:1 (like 50 ohm input to 25 ohm output) or greater than 1:1 (like 50 ohm input to 200 ohm output). Uses a ferrite toroidal core or cores (usually Type 43 or type 52 material). 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. If changing the number of turns on one (or more) winding changes the the voltage, it is a voltage balun. Sometimes simple approach is the best one. 80m yagi OH8LQ. 1:49 Transformer - This 1:49 transformer is used with wires any multiple of 1/2 wavelength. The legend tells that antenna supposed work on multiple bands (1 lambda, 1.5 lambda, etc). So what does this mean to you? The 1:1 impedance transformation is achieved by making the impedance of each winding the same. Vertical or Horizontal Loop: The best balun for operation moderately far from resonance or on harmonics is a 4:1 ratio current Tuner . Installing a 1:1 choke balun at or near the unun will not allow the coax shield of the feed line to be used as a counterpoise. 9:1 voltage unun using a T-200-2 powdered iron toroid core. Thank you so much for such a great product! End fed 49:1 60ft wire (using coax as the counter poise. In fact, the 9:1 unun that I built is actually an autotransformer. The plots above show with a DX Engineering 4:1 balun and reasonably good coaxial cable, you can operate a loop over most of 80 and all of 40 meters. 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. 9:1 Baluns are useful between 450 ohm balanced lines for center fed Zepps and G5RV antennas where the impedance at the end of the feedline is 450 ohms (1/2 wavelength feedline), or high impedance feeds for log periodic beams. December 6. I have tried quite a few combinations before - with . I.e., a turns ratio of about 1:7 to 1:8. This configuration has a reduced upper frequency limit in comparison to the same transformer when being used to feed a balanced load. Random wire antennas are good antennas if you use a 9:1 UnUn to match the high antenna impedance of the wire to the low impedance of your transceiver. Installing a 1:1 choke balun at or near the unun will not allow the coax shield of the feed line to be used as a counterpoise. September 3. In doing some reading I've come to 2 conclusions regarding using End Feds for SOTA. A model of the W2DU 1:1 choke balun. Drill and drill bits (1/8 to in step bit, inch bit, 13/64 inch bit, 9/64 inch bit) Pliers; Wire cutter The 49:1 Unun Impedance Transformer secured in electrical junction box with all proper connections assembled. Similar to the 4:1 unun, but this was even more difficult to get working. Balun One Nine v1 - Tiny Low-Cost 1:9 HF Antenna Balun and Unun with Antenna Input Protection for Ham It Up, RTL-SDR, HackRF and Other HF-Capable Radios. $\endgroup$ 49 1.5 1.3 1.4 2.4 2.4 1.3 1.6 1.6 1.4 1.7 1.5 44 1.2 1.5 2.1 2.1 1.7 1.3 1.7 1.6 1.1 1.2 . DX Engineering DXE-MC20-V4-1 - DX Engineering Maxi-Core 20 Baluns and Feedline Chokes. Anything higher like 9:1 or 49:1 the core is wound as an UnUn for use with random and half wave wire antennas where a ground or counterpoise isn't as critical. Use a piece of bare pc board material and a 2" . Notes on making the W2DU choke balun by placing several . Title: Microsoft Word - BalunUnun Manual_DK2.docx Author: Dwayne XPS Created Date: 4/6/2019 3:06:31 PM End fed 9:1 58ft wire and 17ft counterpose wire touching ground. 9:1 Voltage Unun - FT240-61. Flux-coupled transformers with transformation ratios of 2:1, 4:1, 6:1, 9:1, and 16:1 are used for feeding beams and wire antennas such as the popular Off-Center-Fed Dipole (OCFD). A balun is designed to match an unbalanced source to a balanced load thus the name - BAL/UN BALanced to UNbalanced. 9:1 Baluns/Ununs. In the worst case with a bad set of parameters you can lose 10dB or more. The 9:1 UNUN is design to balance 450 ohm line to match a 50 ohm Unbalance coaxial cable. Maxi-Core 20 Voltage Balun, 4:1, 5 kW, Use on High Impedance Applications, Each. Almost any combination of turns can be used. Note: A 50 ohm balun can be tested using a pair of 25-ohm low-inductance resistors in place of the 100-ohm resistors used in the 4:1 test. 2/2 (4) element 7/10MHz Yagi (3.9m) Force12 Antennas. These are ~49:1, 56:1 75:1, or 81: ratio (~2500, 2800, 3750, or 4050:50 Ohms) UNUN transformers for EFHW antennas (End Fed Half Wave), just pick one and add half-wave long wire for the frequency of interest. February 19, 2020 No comments Read more . Balun and UNUN are being design with high quality materials to obtain the best performance for all conditions. The plots above show with a DX Engineering 4:1 balun and reasonably good coaxial cable, you can operate a loop over most of 80 and all of 40 meters. A voltage transformer type balun uses magnetic transfer ( transfomer action) to produce a balanced signal at the output. Except for the EFHW a . 49:1 Unun. If the choices are. Generally the 9:1 has far more loss as the transformer/core takes on heat to make the non-resonant antenna be of any use across wide bandwidths and are often deaf across some range of frequencies because of the nature of a random length of wire. The secret to an effective EFHW antenna is the 49:1 transformer which matches the impedance of your transceiver to the extremely high impedance of the antenna itself. Connections of the three wires A, B & C are as follows, In similar fashion, a 9:1 would use 225-ohm (220-ohm is perfectly good) low inductance carbon or metal resistors for R1 and R2. 80m yagi OH8LQ. In this case the feed line is separated from the rest of the coax with a 1:1 balun. The resonance is nearly flat throughout the entire HF ham amateur bans 1-30MHz. Here's a video that talks a little bit . . June 6. Ideally put the tuner next to the UnUn, or better still, use the tuner instead of the UnUn, at the feedpoint of the inverted V! Testing the 9:1 balun/unun: Properly designed and constructed toroid transformers are not lossey!!! Working in the forward direction a 1 to 1 is 50 in 50 out. 20/40/17m. This project assembles a 49:1 ferrite-core ("FT") type #43 transformer that matches 50 ohm input to 2500 ohm end fed antenna. 55 11 99270-9895 sac@kidsfashionwear.com.br Rua Jorge Rizzo, 89 - Pinheiros - SP CEP 05424-060 - So Paulo 1 SO-239 connector MFJ-7721 $1.49 1 1:4 1.5KW unun MFJ 10-10989D or build $29.95 1 Ceramic Feedthru MFJ 606-1006 $3.95 2 1N4003 diode Mouser 512-1N4003 $0.07 . Manual 1:1 BalUn 800 Watt, for dipole antennas; Manual 1:2 BalUn 600 Watts for Delta-loop & Quad-loop antennas; Manual 1:9 UnUn 600 Watts for long-wire antennas; Manual Common mode choke; Antenna trap kit building instructions; Manual 1:49 UnUn for End Fed antenna's 100 Watt; Manual 1:49 UnUn for End Fed antenna's 250 Watt 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. The half wave Endfed Antenna 49:1 will give you the best SWR in a few amateur bands, if you are okay with a little bit of higher SWR then it is possible to cover most of the amateur bands. 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 Figure 20: Nominal dimensions of the multi-band end-fed antenna. A '4 to 1' will convert the 50 ohms of your coax to 200 ohms ' ie 4 times' , P w 6FSSE - R v/ FSSE g HSFSSE X 3FSSE/ T "|FSSE 5 U { FHDB+4 Cm CLASS DIMENSION_SCALE NAME lon _Netcdf4Dimid long_name Longitude standard_name longitude units degrees_east actual_range CpC axis X t REFERENCE_LIST dataset dimension FHDB. . In this video, "Tech Minds" shows us how to build a basic 49:1 UnUn which will protect your transceiver as well as deliver maximum efficiency for the antenna. Squaring the ratio gives the transformation of 49:1 FT240-43 200 watts 14 gauge wire and a 100-200 PF cap helping with 15 and 10 meter resonance canceling some reactance. It is a conventional transformer. This particular UNUN is use for the most part on the "non-resonant length END FEED wire antenna", this balun is usually use with End Fed (Unbalance) random wire where the impedance at the end is about 450 . 9. And a UNUN is designed to match an unbalanced source to and unbalanced load - UNbalanced to UNbalanced and what you show here is simply a UNUN. August 4. Documentation. . This allows you to position the unun away from the house and then feed the antenna with coax. Force12 Antennas - A super-compact dualband 7/10MHz WARC band Yagi with single feedpoint The 4-LFAR-40/30, an . 20/40/17m. July 7. The efficiency is 98 percent. SOTA End Fed Antenna 9:1 or 49:1. Terence, 2E0IPK, asks "What makes a 49:1 unun and what does 49:1 actually mean? Let it sit key down for a minute or two and check the core. A 4 to1 balun can also match 50 Ohm to 12 Ohms, and a 9 to 1 can match 50 Ohm to 5 ohms. 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) $53.95 Designed for use with single wire . On the test bench with a 52 Ohm source and a 450 Ohm load the transformer shows a loss of no more than 0.6 dB with about 0.45 dB being average, and the low reading of 0.2 dB. Thread by: K5LIF, Jan 15, 2022, 9 replies, in forum: General Technical Questions and Answers. Using a vectorial network analyzer, I measured the CMRR on both chokes obtaining the following results: Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW Model 9130sw - QRP 9:1 Unun 1. O ptimised with 6 trifilar turns of 18AWG silver plated stranded wire. EFHW-xfrms. 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. So an impedance transformation ratio of about 1:50 to 1:60 is needed to get down to 50 . The benefit is that the radiating element is away from the shack and less likely to cause EMC problems. A End-fed random length or half wave antenna has a high impedance at the feed point, By connecting 50 ohm coax at that point without any matching device, I would expect that you are losing signals both on receive and transmit - so contrary to what others have said here, I would recommend you to add an UNUN at the point where you want to connect the coax to the antenna - a 9:1 ratio is . You'll see why this is important later. Ideal: . The input to any radio will have a tuned circuit consisting of a tuner and an Inductance or L. The L/C on a broadcast band receiver needs to tune from 530 khz to 1700 khz. Transformer is a 1:49 or 1:64 UnUn (not 1:4 or 1:9 used on random wire antennas) 50 Ohm Coax from transformer to station Multi-Band (works on all harmonics) Deploy it horizontal, sloping, inverted-L, inverted-V Commercial example: MyAntennas EFHW-8010-2K Pass it around (I want it back!) Show more Show less . I was directed here by another ham that was confused by the term "BALUN/UNUN". Mount the 1:4 unun, SO-239 connector, DC jack, terminal strip and coil ground terminal & screw as shown in Figures 3, 4 and 5. Again, with a good ground, no choke will be necessary and the antenna can perform at its best. Any of the units can be installed three different ways. Terence, 2E0IPK, asks "What makes a 49:1 unun and what does 49:1 actually mean? most I have read show the secondary windings after the pigtail wound consecutively around the. Most include 4:1, 9:1, 49:1 or other transformer, balun or unun attached between the antenna and a coax feedline which in turn goes to a tuner or directly to the radio. I finally got good performance from 1.8 to 30MHz, with less than 0.5dB loss over most of the range up to 30MHz, . Vertical or Horizontal Loop: The best balun for operation moderately far from resonance or on harmonics is a 4:1 ratio current Tuner . Any of the 913x units can be installed using three different methods. This article details the construction of the transformer. The other part is pick any value and then draw the 1.5:1 or 2:1 circle and see how much it can vary. For a 1:49 transformer that's about 1250ohms or 3800 ohms for the 2:1 circle so small errors like accurate to two significant digits is likely good enough and easily small enough as variation is height or nearby objects will easily exceed that. October 2. 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. Using a 4:1 balun and remote coax fed tuner typically adds about 1.5 to 2dB of loss in the best case, compared to a coax fed ATU at the base of the antenna with no Unun. The heart and engineering of 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. Iron powder vs. ferrite. Model 9130sw - QRP 9:1 Unun 1.5 - 54 MHz - 300 watts. Antenna. A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. Good luck, John. I have read several articles on winding 49:1 ununs. 9:1 Ununs are useful between coax and long wires with load impedances near 450 ohms. A current balun isolates the ground path from the counterpoise to the shack. The antenna generally has a high impedance (several thousand ohm) on most bands. The coaxial feed line, since it operates at high SWR, should be high quality and as short as possible. 100pF 15kVDC capacitor soldered at center conductor of SO239 connector and twisted ground wires. In parallel I checked on Google about the correct toroid etc so I found 2-3 pages with designs. Simple HF Baluns for 50/75 ohm coax. This is not a matching network, it's a wideband transformer and it has some advantages compared to LC matching . 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. The benefits are: One matching unit could feed a range of elements that were just simple wires (or could be multi-band with links or traps) The matching unit was low to the ground in an inverted V configuration and hence could be fed with a short coax. construction of 4:1 Unbalanced to Unbalanced, Ruthroff voltage transformers (UnUn), where one end of the windings are connected to ground and the centre connection is used as the 50 ohm feed point. 40-10m with a 49:1 Unun. Part Number: DXE-MC20-V4-1. Show diagrams, winding methods and tables of some 1:1 and 4:1 baluns for 1.8 - 30 MHz suitable for use up to 200W (400W peak) on systems using 50 or 75 ohm coaxial cable input where SWR should not exceed 1.6:1. February 19, 2020 No comments Read more . Back-to-back unun spectrum analyzer measurements suggest losses in the 1-2 dB range; but high power tests that barely got In order to evaluate the choking characteristics of the "red" toroids, I prepared two chokes by winding 12 coils of RG-58 on a iron powder T200-2 toroid and a ferrite FT240-43 one.