presents an extremely high impedance to the tu 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 Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. The most common question I get asked is what is the correct length for my End Fed Long Wire Antenna? is helpful if you're in a hurry to get on the air, read up on the topic endobj Alternate connectors and Mounting Options are available in the. He knew that in order for the tuner to "see" a fairly low swr to work within it's range,that the antenna had to be NOT A HALF WAVE ON ANY FREQUENCY that we wanted to us, because a half wave will give us a very high impedance and the resultingswr into a 50 ohm transmitter! Stacked coreswithwinding configured as 49:1auto transformer. <>/Metadata 239 0 R/ViewerPreferences 240 0 R>> endobj 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. (QST, Oct 1926, "The Length of the My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! all US ham bands. 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. I usually go with a 3.2k transformation wire winding ratio of 8:1 which is a final impedance conversion of 64:1 (50ohm * 64 = 3.2k ohm). Here's a list of recommended lengths of wire to use with a 9:1 unun. /BitsPerComponent 8 I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. Start winding the Matching Auto Transformer, each pass through the center of the core equals one turn. 40-30-20-15m bands for my 4 band Elecraft K1 qrp rig. 748 0 0 752 0 0 cm END FED "RANDOM WIRE" HF DIPOLE 9:1 ANTENNA RELACEMENT ELEMENT ONLY $28.99 Save up to 6% when you buy more. This design is excellent for matching both long and short length wire antennas for multiband use. https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. A so-called random wire antenna is an end fed antenna. Just an FYI that I thought you might be interested in. gnuplot Experimenting by slightly changing the wire length (+ or-) is encouraged to provide best overall performance. 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. For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. This is considered a random wire end fed antenna, not to be confused with a half wave end fed antenna which uses a 49:1 or 64:1 unun and a wire that is a half wave length. $1YacO5Q}YC\>qZ } <> %PDF-1.5 % STORE SBULLET-9U-1500. 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. 4 0 obj results. Product Reviews PVC Junction Box(Home Depot), 1 x 1/2 in. %PDF-1.7 He was so impressed that he purchased a 9:1 unit from you, his will be delivered Saturday. Hi guys,not really hfu related,but I tought I might ask here as I have my account. RFI Tips and Tricks "Here's the word on random-wire antennae.". 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. 0 /Length 6 0 R The Short Answer Would Be That an UnUn Is a "UN balanced to UN balanced" matching transformer. It may not display this or other websites correctly. &nb These are sometimes known as a Magnetic Longwire Balun. recommended on VE3EED's page because I use all halfwave Well, I didn't think it would make any difference at that many multiples. /ModDate (D:20221212112042) 1. Kj8~q7c? For calculating the length of a half wave in metres, I use 141 (MHz) for wire elements. Liquidtight NM 90-Degree Connector(Home Depot). 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. Let's have a look at a few details on how to build a 49:1 impedance . We'd really appreciate it! You need to use these lengths and the longer ones . 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. The First Thing New Hams Often Ask:What Is An UnUn? 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. I've made contact with several folks across North America in my 6 months as an amateur but getting to Europe flipped a switch and I'm afraid this amateur radio thing is going to be addicting. I'm not saying aliens are in the radio, but aliens definitely are in the radio. The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. A Balun is used to match a balanced line to an unbalanced line. 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). 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. Solder a the 100pF capacitor between the center conductor wire and ground wires. Our Ask An Elmer panel discuss this question - what's the difference between matching units?Please consider using. I have found this calculation to work well, however it depends on many factors such as wire used, location etc. Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun Vacation Closure - See Homepage for Next Availability. For example, 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. google_ad_slot = "1982258389"; Our newdesign isperfect for matching both long and short length wire antennas for multiband use. So for example 80m could range in length from 120 to 133 feet. program or two to do all the dirty work. A png image named g.png will be created. Best SWR was . X:nzf4p:t;r }~_HOZcX:^$* J^XZuu|"nX/Wkw0hA>y1(z2+v_Xzu[/:^$*m*>hk_:+c{ 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. an auto-tuner at the base vs. the same antenna fed a 4:1 balun wound with 75 ohm coax on two separate type 43 ferrite cores and a remotely sited tuner fed via 200ft of low loss LDF2-50 coax vs. a broadband antenna of the same element length. For instance, to work 40m be sure the antenna is at least 40-30-20 . Modify bands and Designed for those who want the maximum isolation and choking across the full HF spectrum. 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. 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. "Just received my new 64131 yesterday and was anxious to see how well it performed. Q Jack, VE3EED - SK. "I received my third balun from Balun Designs this afternoon. /Pages 3 0 R Hope it's clear now, if not. The Short Answer Would Be That an UnUn Is a UN balanced to UN balancedmatching transformer. Because I had some spare Cu-Wire I wound another 1:49 Unun on a smaller FT-140-43 toroid and tried different capacitors between feedline and ground (to compensate for the 10m band). When used with the stated lengths shown in thetable below, the 9:1 ratio will Based on the success of our model 4932, this 5kWconfigurationisalso perfect for matching both long and short length wire antennas for multiband use. A small ring terminal for 14ga wire that fits these screws would be helpful too. 9 0 obj This project assembles a 49:1 ferrite-core ("FT") type #43 transformer that matches 50 ohm input to 2500 ohm end fed antenna. 22.00 + 5.00 Postage. Ultimately, this housing works fine, but it is heavy and clunky.). Ask Elmer There probably should be some holes for ventilation. I made just a touch over 100 QSOs today with the new unit. End Fed Half Wave Antenna Coupler Schematic - 7-30MHz. //-->, The "Best" Random Wire Antenna Lengths and experiment. Even better would be shortening to 53'. Tools Make sure the beginning few inches of twisted wire is not involved in the winding (i.e., just hanging down from the toroid). Usually any wire length that is non resonant, like those shown above, will work with the 4:1 ratio. End Fed Antennas. I sent him the link to the 49:1 unit to get his feedback. /Filter [ /FlateDecode ] var sc_security="1df091cc". Figure 2 Schematic of the 9:1 voltage unun . This is a 4:1 Current Balun.That means it can match a 200ohm antenna to a 50 feed line. We have also installed an additionalstud which can be used for a separate counterpoise wire rather than forcing the use of the feedline's coax shield. This will be for an eyehook in order to provide strain relief for the radiator wire. /MediaBox [0 0 748 752] Generally an EFHW will be in the range of 2,000 to 5,000 ohms at the very end of the dipole when resonant. That meant calculating all the way to 32 multiples of a half wave on 10 meters. (wlSR9dJ_x%+VHX4FRr 3>;g^x%g'wkJu,i~#Q"2|WGf[!_m]#&1$)R.{--" 'dGO;=_B$T}". 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. This transformer is designed to be used with an end fed half wavelength of wire only. End fed 49:1 60ft wire (using coax as the counter poise. stream Drill a hole in the top for an eyehook (to be used to secure the unun to whatever it is you want to hang it from.). I only used two screws instead of four. Ham Satellites 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. Some of these numbers are too close to squeeze in between them. config file by typing gnuplot rw.gnu. 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. Change the program to use 423 if desired.) this Legal Stuff 2 eyehooks with washers and nuts (I used #8 diameter, but size is up to you.) I attached the toroids to a PVC DWV test cap with 3 cable ties.