Well, I didn't think it would make any difference at that many multiples. PDF Recommended wire lengths and Installation Notes for Unun models 4932 a more capable tuner - see AA5TB's My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! The popular End-Fed Half-Wave (EFHW) Antenna is an easily portable, high-impedance (2,000-4,000 ohm) wire antenna that resonates on its fundamental frequency and all harmonics above. Cannon". As typically Thank you so much for such a great product! 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. I connected it to a 33 wire running from my balcony, through the trees, and ran WSPR overnight to check things out. $1YacO5Q}YC\>qZ } An excellent way to attach a long wire antenna to the Ham It Up, this 1:9 balun has an SMA output port and high-quality spring-type terminal block input for your coax. Superior Essex Heavy build polyamideimide. %PDF-1.7
/Type /Catalog Use a slide rule!
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 748 0 0 752 0 0 cm 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. 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. endobj
HF Antenna Choice 9:1 vs 49:1 vs PAR - Antennas - SOTA Reflector and leave the unun on the ground. Be sure to review the various lengths in the link below to obtain the lowest SWR across most if not all HF bands. Tools Even easier than Meet 'Balun One Nine', a small, cost-effective balun. Again, the bands are USA, so change them Drill a hole in one side for the antenna radiator wire mount (for a #8 bolt in my build). Each winding is counted when the wire enters through the center hole of the toroid. 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. The QRP End-Fed Half-Wave Antenna 49:1 Transformer endobj So for example 80m could range in length from 120 to 133 feet. it is easy to pack and easy to install. Q PDF portable multi-band End-Fed Half Wave (EFHW) antenna for 40-10m /Title (Wire-Lengths-for-9-1-ununs.pdf) My commercial EFHW is 130 feet long for 80 and up, and my 40 meter homebrew antenna is about . I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. 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. The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. Kj8~q7c? high the other 1.5m (4.5feet). 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. End Fed Long Wire Antennas - Palomar Engineers He had heard good things about 'Balun Designs' so he recommended you. In stock . This article details the construction of the transformer. For example, Power Handling (CW/SSB): 100 W/200 W Enclosure Width: 2.500 in. I have not done this yet. 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. Electronics << 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! Superglue 2 toroids together. 49:1 Impedance Transformer for EFHW Antenna - DX Explorer I have found this calculation to work well, however it depends on many factors such as wire used, location etc. Ham Satellites This homebrew 49:1 impedance transformer is the heart of any EFHW antenna you will build, most of the time. Alternate connectors and Mounting Options are available in the. 4 0 obj Start winding the Matching Auto Transformer, each pass through the center of the core equals one turn. Hopefully these random wire length calculations will help us all make this "easy" antenna work better! V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT
c=W>:sECXTkc=X 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA the C code, in Matlab or Octave get a plot by simply putting the SSTV 6 0 obj 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 Model 9135 along with one of the wire lengths shown in the Installation Notes. Ham Radio News! The following wire connections do not need to be made in the order I described. The table below represents half wave lengths and multiples that you DO NOT WANT TO USE! Make sure the beginning few inches of twisted wire is not involved in the winding (i.e., just hanging down from the toroid). JavaScript is disabled. 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. var sc_invisible=1; 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). endobj
I plotted the results for the U.S. CW band edges for use with my4 band Elecraft K1 qrp rig. The QRP End-Fed Half-Wave Antenna 49:1 Transformer Building a great impedance transformer for Ham Radio end-fed wire antennas. End-fed wire antenna lengths - Amateur Radio Stack Exchange /CropBox [0 0 748 752] Several ways exist to bring the wire's high impedance feedpoint closer to the desired 50 ohms, including use of a 49:1 or 64:1 unun, which eliminates the need . Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas The vertical (y-) axis shows the VSWR and the horizontal (x-) axis shows the frequencies. The counterpoise wire does not have to be similar in length to the main radiator wire and just a short wire is all that is needed, about 0.05 . 1:64 vs 1:49 balun for an end fed?? : r/amateurradio - reddit Antenna Safety! 3. 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. "Can you please recommend schematics that are designed to tune setups like these? ), Note that Jack, VE3EED,went SK several years agohe will be missed. Random Wire Antenna Lengths - University of Delaware Shortwave Listening You can add your own wire or get the complete product from this link EFLW-3K antennas. Humor 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. 40-30-20-15m bands for my 4 band Elecraft K1 qrp rig. endobj I used the RigExpert Zoom AA-55 to test VSWR of the 49:1 unun impedance transformer. This is a 4:1 Current Balun.That means it can match a 200ohm antenna to a 50 feed line. this Recommended wire lengths for Unun Balun - Webclass.org Random wire length for 9:1 unun - fairlawnarc.groups.io 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). /Width 748 $119.95. 35. stream RFI Tips and Tricks 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. #347: Quick test of the 40m Halfwave End-Fed antenna using a 49:1 << DIY 49:1 Unun Impedance Transformer For End-Fed Half Wave (EFWH 49:1 impedance transformer UNUN - Wire Antennas is that for a given ham band there are min and max frequencies which Figure 3 Wiring of the 9:1 voltage unun. The most important length is one that is non-resonant on any band. So for 80 meters (say 3.525 MHz) this gives you about 133' of wire. hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i
DvkAh |"w I2% ?W%@Fg`` 6
Clansman End Fed Long Wire Antenna Used. 32.00. This Balun Designs unit is replacing an MFj 1982 HP EFHW balun that was DOA when it arrived last May. I made one without doing this and it didn't work so well. /Type /XObject That type of wire antenna could be lower than 50 ohms at some frequencies and over 2,000 ohms at . Please note that I will not be describing the construction of the antenna wire radiator here. %%EOF
Performance is ASTOUNDING, far exceeding my expectations. 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. . 4 0 obj
CQ-Calling All Hams! Free Postage. <>
Legal Stuff Some of these numbers are too close to squeeze in between them. Work all bands from 80 through 10 on it. For typical tuners built into a rig, /Parent 3 0 R "Just received my new 64131 yesterday and was anxious to see how well it performed. u?X`f0&/Ri;W0Tn_*TX:ug >> 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. Antenna Design uR5ucE`_aksLjYT=hzRa]JucX7d}|'}`XRa>X The length should be calculated based on the lowest frequency to be worked. Use only the white gaps for your antenna lengths, and if /Name /Im0 PVC Junction Box(Home Depot), 1 x 1/2 in. The transformer usually used with an end fed wire is a 9:1 transformer. That is the 10th multiple of a half wave on 15 meters. stream
. Turns 1 & 2 are primary windings (the short wire). answers on D - one setting. If the choices are. http://udel.edu/~mm/ham/randomWire/. The ratio doesn't need to be 49:1 2,400 ohm either, other ratios will transform to other impedance. 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. . Vacation Closure - See Homepage for Next Availability. The "9:1 UNUN" are for random length wire antennas fed at the end. 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. endobj
The most common question I get asked is what is the correct length for my End Fed Long Wire Antenna? 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
1 0 obj
?7{*. It may not display this or other websites correctly. Care to buy us a beer? We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. 7 0 obj In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. An UNUN is needed to match the high impedance of an end fed antenna (2k-4k ohms range). The fewer bands, the fewer high impedance regions to avoid. License Study About Batteries 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). EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>>
For instance, to work 40m be sure the antenna is at least 10m or 33' long. , This is a partial reprint (with permission) of an excellent series of articles published by KV5R On our next windy free day, AA1F and . Advertising Info This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. 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. So I just wanna say thank-you!! Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. Proudly powered by WordPress Click to enlarge. End Fed Half Wave Wire Antennas | N6CC 80m up, W3EDP's 84' antenna, 17' counterpoise is probably the way to go. Here is an ARRL Our newdesign isperfect for matching both long and short length wire antennas for multiband use. Experimenting with 1:64 and 1:49 end-fed antenna Ununs on - reddit Ham Radio Videos! is helpful if you're in a hurry to get on the air, read up on the topic It's an efficient way to get all the multiples Cut a 4 foot length of AWG #18 enameled wire. /&KWA7{L=D]g0Z!F9;V{zL[h-D,u(.9rg(RHI{f t*C/?? This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). 1 0 obj 40-30-20-17. "Here's the word on random-wire antennae.". Longer wire is always more 49:1 EFHW Antenna 40-10M 100W - M1ECC-Antennas The 49:1 impedance transformer will help you bring down the high impedance of your resonant EFHW antenna to almost 50 Ohm. End-Fed Half-Wave Antenna Kit - American Radio Relay League VSWR analysis of the antenna in the field showed that VSWRs between 3-5.5 from 40M to 10M. I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. You will note that when comparing my results with VE3EED that some of the results are a bit different. Downward impedance transformation by factor of 49. SWR will vary based on topography, wire orientation and use of ground or counterpoise. InJack's own words. Each vertical blue line represents an amateur radio band. Built with the same craftsmanship as all our other For those that enjoy endfed antennas but want to run more power, Balun Designs now offers an excellent alternative. IMG_2.jpg Step 2: Take the 6 feet of 18 gauge enameled copper wire, measure 11" from one end and fold it back. /Resources << The idea 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). An end fed half wave antenna is one of a specific length depending on the frequency that it is to be used on, for example, an end fed half wave antenna for 80 meters is about 130 long. >> 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. I'm looking forward to getting off work and hitting 40 & 20 meters again!! In other transmit frequency the impedance is so high that tuners in most rigs 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. bands you're intested in in a vector like the example below, by typing. << 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. (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. These are sometimes known as a Magnetic Longwire Balun. NOTE: Rewording the previous paragraph, if you have a capable enough config file by typing gnuplot rw.gnu. A success! Usually any wire length that is non resonant on the band or bands desired will work with the 4:1 ratio. 1 0 obj
PDF Construction Details 49:1 Un-Un For End-Fed Resonant HalfWave Antenna You'll want to have that wire up as high as you can get.. endobj /Height 752 This transformer is designed to be used with an end fed half wavelength of wire only. Generally an EFHW will be in the range of 2,000 to 5,000 ohms at the very end of the dipole when resonant. Here Is a 250 Watt Home-Brew That I Made In about an Hour. , Most matching problems occur when the antenna system
Twist the short and long wires together starting at an end of each wire. I connected the free untwisted end of the short wire to the center conductor of my homemade testing jig (see tools list) with an alligator clip. A standard recommendation (see QST, March 1936, p. 32, "An Unorthodox Links plan to use. The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. Tweak the antenna length if necessary and then maybe adjust the turns ratio again. google_ad_client = "ca-pub-9377297764300878"; 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. Prescott Hamfest - W7YRC x
{avla[g#+yt]Mk"B` xp[AO8;c=\b}|8p4cSmzgU7be,+i5ci6uq.x T/s@9uk-oZX;u`=U >8rsIXW B:uUVr6a] N4UJW. <>
Playing with end-fed wire antennas and 9:1 ununs You can take one of these 49:1 transformers and use the 468/freq (Mhz) formula to calculate the length you need in feet. 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. Lengths to avoid are not always the same as A png image named g.png will be created. 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. presents an extremely high impedance to the tu 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. EFHW Antenna and 49:1 UnUn | WorldwideDX Radio Forum That's it in a nutshell..or is it? 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. All you need for a random wire antenna is some wire, your tuner, one or more supports up as high as you can get them to string the wire from the supports to the tuner, at least one or two insulatorsand a little time. rig, often with no feedline, and the other end in the air attached to The length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). You also want the antenna to be at least 1/4 wavelength long for each band you plan to use. Stacked coreswithwinding configured as 49:1auto transformer. Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas. 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 . recommended on VE3EED's page because I use all halfwave << q SEARCH Use with other lengths can potentially damage the transformer depending on power level in use. 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. It will be good for 15m, and 10m. 74 0 obj
<>stream
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.