There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. unavailable, a random wire can save the day, but it is important to 59 0 obj <>/Filter/FlateDecode/ID[<81C501BAF3AD19DF6B2122F37F15AF84>]/Index[25 50]/Info 24 0 R/Length 149/Prev 898971/Root 26 0 R/Size 75/Type/XRef/W[1 3 1]>>stream A way of connecting the analyzer to the transformer. 4 0 obj //-->, The "Best" Random Wire Antenna Lengths bands you're intested in in a vector like the example below, by typing. I wrote a small C program that does just what Jack did, butI used the band edges. So for 80 meters (say 3.525 MHz) this gives you about 133' of wire. frequencies for your country or favorite modes. endobj That is the 10th multiple of a half wave on 15 meters. END FED "RANDOM WIRE" HF DIPOLE 9:1 ANTENNA RELACEMENT ELEMENT ONLY $28.99 Save up to 6% when you buy more. . In another life, I could have been a telephone engineer. I have not done this yet. (wlSR9dJ_x%+VHX4FRr 3>;g^x%g'wkJu,i~#Q"2|WGf[!_m]#&1$)R.{--" 'dGO;=_B$T}". In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. SO-239 connectors are silver plated with Teflon insulation. Just add or subtract as needed a little at a time to get the best compromise. I'm looking forward to getting off work and hitting 40 & 20 meters again!! <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> As typically 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. About Hamuniverse A small ring terminal for 14ga wire that fits these screws would be helpful too. Continue on winding the long wire through the toroid to complete loops 3 through 14 as shown in the schematic below. A 9:1 matches 50 ohms to 450 ohms and that turns out to be an ok compromise for feeding 50-100ft of wire for general purpose SW receive. Generally an EFHW will be in the range of 2,000 to 5,000 ohms at the very end of the dipole when resonant. 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. 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. 5 0 obj Quantity: Sold individually. We hoisted the free end of the antenna wire approximately 30 feet into a tree. Figure 3 Wiring of the 9:1 voltage unun. 31 I made one without doing this and it didn't work so well. Performance is ASTOUNDING, far exceeding my expectations. Kj8~q7c? <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> Care to buy us a beer? 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. The Short Answer Would Be That an UnUn Is a UN balanced to UN balancedmatching transformer. Well, I didn't think it would make any difference at that many multiples. are blocked out because an antenna should be at least that long. excellent page for EFHW info - or, addressed below, to cut the wire Weight: 0.380 lbs. This is a 4:1 Current Balun.That means it can match a 200ohm antenna to a 50 feed line. 40-10m with a 49:1 Unun. Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. Reading Room I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. endobj Please note that I will not be describing the construction of the antenna wire radiator here. google_ad_client = "ca-pub-9377297764300878"; 1. Electronics endstream A png image named g.png will be created. >> You have to stay away from a half wavelength on any frequency. 3 0 obj all US ham bands. For example, Clansman End Fed Long Wire Antenna Used. %PDF-1.7 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. 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). endobj Vhf and Up (Center fed is so appealing because you avoid this.). 0 Superglue 2 toroids together. 9:1 or 49:1 unun for end-fed long/random wire? >> JC[ d8O[UKKQ{yZ{G 'Upno_*~8uo a@G`' zxUHXW&`}mEp`?i0 oE:N0-/t"t.-? . 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. I have included a screenshot showing the stations that reported spotting my 200 mw beacon over the last 16 hours. /Count 1 REVISED: 16 19 22 26 32 33 38 44 46 48 52 64 65 66 76 78 80 88 92 95 96 99 104 110 112 114 123 128 130 132 133 138 144 152 154 156 160 165 171 176 182 184 190 192 195 198 208 209 220 224 228 230 231 234 240 242 246 247 256 260 264 266 272 276 285 286 288 297 304 308 312 320 322 323 325 330 336 338 342 352 361 363 364 366 368 369 374 380 384 390 396 399 400 414 416 418 429 432 437 440 442 448 455 456 460 462 464 468 475 480 484 494 495 496. gnuplot 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. . Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. In other W3EDP's results in the above referenced /Resources << See the picture below. The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Proudly powered by WordPress My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! I made just a touch over 100 QSOs today with the new unit. My commercial EFHW is 130 feet long for 80 and up, and my 40 meter homebrew antenna is about . wire is at least 1/4 wavelength. 27.00 (27.00/Unit) Free Postage. I have never tried to transmit through it, but it proved the optimal ratio for receiving with my setup. j#f5(fk0?P[polEo5b2-/oVZu1Qo-I6C/M@TbddPc#cdZZ|7+|o{}!F#?Go7ju|?wwgow/c2/W-m~~hn[S29OU}}r7lc]wsw[shS[#qbrrK[7*0,Xv{k+o {=*vo S__O~*=y/zk75O?yjCnXS{`~Ii'c_GxN. Step 1: Drill holes for and install the SO-239 or BNC connector, the stainless steel machine screw antenna connector and the ss machine screw ground connector. 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! Our newdesign isperfect for matching both long and short length wire antennas for multiband use. endobj Use only the white gaps for your antenna lengths, and if endobj V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT c=W>:sECXTkc=X Jack, VE3EED - SK. I swept the VSWR of the unun and resistors as described from <1 to 55MHz. something as high as you can find. This type of antenna is very easy to install because there is no need . random wire should use 423/f. This transformer is designed to be used with an end fed half wavelength of wire only. 40-30-20-15m bands for my 4 band Elecraft K1 qrp rig. Odds are that most lengths are fine though, so the easiest solution is to pick a length based on something else (like, the room you have available) and if you get unlucky, roll the dice again. I actually did this first and before the connector was bolted to the box. 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). In stock . Experimenting by slightly changing the wire length (+ or-) is encouraged to provide best overall performance. Best SWR was . I only used two screws instead of four. This is a followup video to #344 where I assembled the 49:1 UNUN kit from HF-Kits / ARRL. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. These dimensions were derived from modelling the antenna in EZNEC. Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. 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. 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. Swr usually is all over the place and the tuner will just not do it's job. It's an efficient way to get all the multiples So those are the numbers above thatwe have to stay as far away from as possible when building a long-wire antenna. This transformer converts the impedance at the end . K1S Valentines Are (Almost) Out The Door! stream << endobj When do you use a 1:1, 9:1 or a 49:1 balun? 74 0 obj <>stream x][~ XwiH:99gn`1-wz;n[VbW7JH4D]>}>y/D_^7,yyx}s*nveo>mn|6k7GMY4%" M)?O|'opw8o1\5JNe:9hTc5@Ik~aE%O^0$ 0E 'BX2?R!t&^E"3oqbW |${boEU>jU:]bQW?4, u1'^`oQ_4E 0~y L^'y}-RHV8L KSZ?mF4lTv'r^mF|":e}?VdTm7bGR]PchDpb*{*HGJ-m)bC!EX"iM%8L7O7-=jcn+D{_' I HH~v70J^9$.7m]knq)L(UQ%OrK:nn!8*EP the C code, in Matlab or Octave get a plot by simply putting the 2 0 obj So, having nothing better to do one day, I re-did the calculations going out to 500 feet. Lengths for Long-wire Antennas Jack - VE3EED Recommended lengths: 29 - 35.5 - 41 - 58 - 71 - 84 - 107 - 119 - 148 - 203 - 347 - 407 - 423 Not recommended lengths: 16 - 19 - 22 - 26 - 32 - 33 - 38 - 44 - 46 - 48 - 52 - 64 - 65 - 66 - 76 Repeater Builders AndWhat Is It Used For In Antennas? SBULLET-9U-1500. One end goes straight into the /Creator (XnView) Thus a 1/4 wave for 20m@16ft, 40m@33ft as examples are not going to work. 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. /Contents 5 0 R recommended on VE3EED's page because I use all halfwave You are using an out of date browser. Solder a the 100pF capacitor between the center conductor wire and ground wires. HF & Shortwave Here Is a 250 Watt Home-Brew That I Made In about an Hour. Cannon". For best results, use the Wire Length Feet 1.8 MHz 3.7 MHz 5.3 MHz 7.1 MHz 10.1 MHz 14.2 MHz 18.1 MHz 21.2 MHz 24.9 MHz 28.5 MHz 50.1 MHz 40-30-20-17. Here Is a 250 Watt Home-Brew That I Made In about an Hour. ), Note that Jack, VE3EED,went SK several years agohe will be missed. 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. high the other 1.5m (4.5feet). 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. Privacy Policy Ham Radio Videos! 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. The graph below shows lengths to avoid for different collections of bands. He had heard good things about 'Balun Designs' so he recommended you. For typical tuners built into a rig, rig, often with no feedline, and the other end in the air attached to it is easy to pack and easy to install. It is used for non-resonant verticals like 43 foot or 33 foot Or Wire antennas like an End-Fed 1/2 Wave Multiple Length Wire Antenna. 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. In addition to multiples, 2 0 obj /Title (Wire-Lengths-for-9-1-ununs.pdf) Because I'm more visually oriented I then plotted the many overlapping "red zones" and ended up with the page at: At multiples of half wavelengths of the Enclosure Depth: 1.250 in. google_ad_height = 600; %PDF-1.5 This article explains why the use of mix 43 for HF applications is almost always a mistake. 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. They just saved you and I loads of time and frustration. Here I show finalizing the antenna, getting it in the air, and run. NOTE: Rewording the previous paragraph, if you have a capable enough <> used by hams for dipole lengths. /Type /Pages Hi guys,not really hfu related,but I tought I might ask here as I have my account. 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. 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. stream 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. 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.