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. 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. 9 0 obj We recently found some good information about random wire lengths that you should and should not use. The fewer bands, the fewer high impedance regions to avoid. installed, it is a compromise antenna but great for portable use because Hope it's clear now, if not. So for example 80m could range in length from 120 to 133 feet. x@ , Most matching problems occur when the antenna system Q 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. I attached the toroids to a PVC DWV test cap with 3 cable ties. /Resources << Support The Site Even better would be shortening to 53'. hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 What these lengths are depend on your tuner and also the wire's surroundings and also the ground system. (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. InJack's own words. (Center fed is so appealing because you avoid this.). Figure 3 Wiring of the 9:1 voltage unun. shown in the column e. var sc_project=8077274; 2 0 obj /Producer (XnView, http://www.xnview.com) /CreationDate (D:20221212112042) The WSPR map is so dense it looks like the US and Europe are just big blobs of color. 22.00 + 5.00 Postage. (A t0 B) Fold over 6 to 8 inches and twist it together. However, the radio didn't tune up very well on 15 meters. excellent page for EFHW info - or, addressed below, to cut the wire /Type /XObject 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. This article explains why the use of mix 43 for HF applications is almost always a mistake. the C code, in Matlab or Octave get a plot by simply putting the 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. Use with other lengths can potentially damage the transformer depending on power level in use. 4 0 obj End Fed Half Wave Antenna Coupler Schematic - 7-30MHz. Notice from column f that there is no length giving low impendance for Let's have a look at a few details on how to build a 49:1 impedance . So I just wanna say thank-you!! 33 ft #18 insulated copper wire (20m half wave), Counterpoise: 1 meter coax (0.05 x wavelength) connected between 64131 and Balun Designs 1115d Isolation /Choking balun, If you would like to use high power up to legal limit with a single end fed wire antenna (not necessarily a half wave) consider using our. Therefore, we came up with the following numbers to avoid (IN FEET): These lengths in the table beloware the culprits that cause all of the trouble when using random lengths. HF & Shortwave Upon further research, I remade it tightly twisting those two separate wires together, just as it shows in archjeb's picture, and it worked surprisingly well. Repeater Basics This project assembles a 49:1 ferrite-core ("FT") type #43 transformer that matches 50 ohm input to 2500 ohm end fed antenna. 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. 3 0 obj A Balun is used to match a balanced line to an unbalanced line. For typical tuners built into a rig, These are sometimes known as a Magnetic Longwire Balun. uR5ucE`_aksLjYT=hzRa]JucX7d}|'}`XRa>X <>>> To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. The unun was floating at about 15 feet above ground. Just add or subtract as needed a little at a time toget the best compromise. (Also check out AB3AP'Swebsite and say thanks for sharing his skills. Continue on winding the long wire through the toroid to complete loops 3 through 14 as shown in the schematic below. 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. These dimensions were derived from modelling the antenna in EZNEC. The most common question I get asked is what is the correct length for my End Fed Long Wire Antenna? /XObject << /Im0 9 0 R >> Picture Information. endobj Feeling a bit too lazy to calculate that by hand, however, I wrote a Moving the pot up and down gives a feel for the SWR versus antenna impedance sensitivity. Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. Drill out holes in the designated bottom of the electrical junction box for the SO239 chassis mount. stream 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? The trick, therefore, is either In addition to multiples, Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas. The major point of this message is to tell you that approximately 20 minutes after I connected the balun unit to the antenna, I made contact with a gentleman in Italy-my first European contact!! The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. You'll want to have that wire up as high as you can get.. 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. 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. 4 0 obj I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. 1936 article, however, fall in line with 468/f and so is used here. 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). I swept the VSWR of the unun and resistors as described from <1 to 55MHz. So for example 80m could range in length from 120 to 133 feet. To DB's point of a single band antenna, this 49:1 transformer is a good choice for a single band matcher. , Reprinted with permission of Hamuniverse, this is an excellent explanation of SWR and how to best me Ultimately, this housing works fine, but it is heavy and clunky.). [ /PDF /Text /ImageI ] Here Is a 250 Watt Home-Brew That I Made In about an Hour. For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. >> The beauty of the halfwave antenna is it's a complete antenna in the sense it needs no counterpoise. Electronics >> Start winding the toroid with the twisted wires at loop #1 (see schematic below). A so-called random wire antenna is an end fed antenna. In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. Antenna Safety! In fact, the 9:1 unun that I built is actually an autotransformer. endstream One single wire, no solder connections,very simple.all the way from the tuner to the end support. 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. /Width 748 program or two to do all the dirty work. This transformer is designed to be used with an end fed half wavelength of wire only. So those are the numbers above thatwe have to stay as far away from as possible when building a long-wire antenna. You need to use these lengths and the longer ones . Solder a the 100pF capacitor between the center conductor wire and ground wires. Kj8~q7c? are blocked out because an antenna should be at least that long. About Hamuniverse SWR will vary based on topography, wire orientation and use of ground or counterpoise. 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 . On our next windy free day, AA1F and . 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. Presented for your consideration by Jack, VE3EED. u?X`f0&/Ri;W0Tn_*TX:ug 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). 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). This is a followup video to #344 where I assembled the 49:1 UNUN kit from HF-Kits / ARRL. 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. =======================, More on Random Wire Lengths from Mike, AB3AP (06-29-2012), I was surfing around Hamuniverse.com and found thIs page on random wire antennas: The length should be calculated based on the lowest frequency to be worked. 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. 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. . for your country and favorite modes of operation. /Kids [ 4 0 R ] 2 0 obj Clansman End Fed Long Wire Antenna Used. Part List: 35. You have to give up a band or two, like 60m and 6m, as We do not encourage any radio operations contrary to regulations. so that it is not a halfwave multiple of any frequency you want to use. The table below represents half wave lengths and multiples that you DO NOT WANT TO USE! Weight: 0.380 lbs. The Nelson antenna 9 to 1 unun did the trick. but instead of the Jaycar core, we used an Amidon FT-240-43; anyhow, we also followed the UnUn with a 1:1 guanella choke and boxed everything, at that point, we . <> Cut the center conductor wire (free untwisted end of short wire) of the unun to the correct size, scrape the enamel insulation off of the free end with a box cutter, and solder it to the SO239 connector. 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. The 30 day return period lapsed before I could get the antenna deployed to test it. I connected the free twisted end of the short and long wires (the ground) the chassis wire (ground) of my homemade testing jig with alligator clip. The length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). I actually did this first and before the connector was bolted to the box. The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun They just saved you and I loads of time and frustration. ", KiwiSDR Online Radio - 500 ft Northeast Beverage, KiwiSDR Online Radio - 400 ft South Beverage, KiwiSDR Online Radio - 10/11m dipole up 20 meters high. The "9:1 UNUN" are for random length wire antennas fed at the end. endobj endobj Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. One end goes straight into the 2. /Pages 3 0 R (QST, Oct 1926, "The Length of the Repeater Builders 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. 74 0 obj <>stream Hi guys,not really hfu related,but I tought I might ask here as I have my account. A good place to start is the formula 468 / f (MHz) for a 1/2 wavelength wire antenna. Use only the white gaps for your antenna lengths, and if There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. 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. If you plan on stringing up a dipole you use 2 equal lengths of wire with the Balun in the middle. << June 8, 2022 at 9:17 am. You have to stay away from a half wavelength on any frequency. 9:1 Unun EF Random Long wire matching Transformer with BNC or SO-239. /BitsPerComponent 8 /ModDate (D:20221212112042) Turns 1 & 2 are primary windings (the short wire). 0$Ve I used 2000 and 1000 ohm resistors in series connected to the proper unun wires with alligator clips for a total of 3000 ohms. N4UJW. I wrote a small C program that does just what Jack did, butI used the band edges. I sent him the link to the 49:1 unit to get his feedback. This article details the construction of the transformer. Start winding the Matching Auto Transformer, each pass through the center of the core equals one turn. Turns 1 through 14 are secondary windings (the long wire). Theme: Newsup by Themeansar. It will be good for 15m, and 10m. A png image named g.png will be created. /Type /Page 1 0 obj IMG_2.jpg Step 2: Take the 6 feet of 18 gauge enameled copper wire, measure 11" from one end and fold it back. Note: My (A to B) length was 6 inches. "I received my third balun from Balun Designs this afternoon. Building on the original 1:1 design by Dr. Jerry Sevick, this balun has two (2) cores in a stacked Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW, Decrease Quantity of Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW, Increase Quantity of Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW. 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. % 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. well, the main antenna wire goes to the 9:1 UnUn "+" connector, the vertical counterpoise (insulated !) The ratio doesn't need to be 49:1 2,400 ohm either, other ratios will transform to other impedance. Let the now free end of the short wire hang down from the toroid. Just an FYI that I thought you might be interested in. End fed 49:1 60ft wire (using coax as the counter poise. 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. The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. 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. and leave the unun on the ground. 3. EFHW unun Resonant Long Wire 49:1 Transformer With 67' Antenna Wire. 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. The second smallest number I measured was 2.7pF, derived from the self resonance at 2.72 MHz with the magnetizing inductance (measured at 25.8 H) with the secondary open and the output wire folded to a small 1/2 length. 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 doing the initial 468/f on C and D scales. which got me thinking. Hertz Antenna" shows in line 2 of the table that a similarly installed This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). We hoisted the free end of the antenna wire approximately 30 feet into a tree. This design is excellent for matching both long and short length wire antennas for multiband use. The following wire connections do not need to be made in the order I described. /ProcSet 7 0 R >> However, the list has been revised and is good for wires as long as 500 feet. /Length 6 0 R Code Practice The Short Answer Would Be That an UnUn Is a UN balanced to UN balancedmatching transformer. Tools 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. See the picture below. 10C) for the 10-80 m bands, or even 6-160 m: 17 ft (5.2 m) of twin-lead and 68 ft (20.7 m) of antenna wire (i.e., standard dimensions). A 50 foot run of RG-8X coax connected the antenna into the LDG Z100-plus tuner and then a Yaesu FT-891A transceiver. it is easy to pack and easy to install. hb```YloD@(aKI V!}g@~}%Q/[[~_=Wy-:O)x[~hs/~SGeG _QE C6q %r 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). 35. Each vertical blue line represents an amateur radio band. high the other 1.5m (4.5feet). 3 to31 MHz - up to 1kW intermittent (50% duty cycle). http://udel.edu/~mm/ham/randomWire/. So is an essential piece of gear to have. 35-45, 54-64, 67-77. This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. 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. 27.00 (27.00/Unit) Free Postage. You are using an out of date browser. A success! One is for the top of the box so that it can be hung up. 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. Best SWR was . 1. V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT c=W>:sECXTkc=X you're using different ham bands than in these examples, modify and rerun Thank you so much for such a great product! I made one without doing this and it didn't work so well. google_ad_slot = "1982258389"; My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! (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. 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.