Here are the final numbers (in my opinion) in green below that would be good for a long-wire antenna: (You may want to make a note of them), REVISED: 29 35.5 41 58 71 84 107 119 148 203 347 407 423, REVISION NOTE: We had a note from James, KB5YN, pointing out that one of my so-called GOOD numbers was 220 feet. 3 to31 MHz - up to 1kW intermittent (50% duty cycle). 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. Cut a 4 foot length of AWG #18 enameled wire. | The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. 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. /Producer (XnView, http://www.xnview.com) A so-called random wire antenna is an end fed antenna. /CropBox [0 0 748 752] You need to use these lengths and the longer ones . This transformer converts the impedance at the end . 27.00 (27.00/Unit) Free Postage. endobj 0 This transformer is designed to be used with an end fed half wavelength of wire only. BUILD INSTRUCTIONS FOR 49:1 UNUN IMPEDEDENCE TRANSFORMER: WX1MAR and I brought the DIY 49:1 unun with a borrowed antenna radiator wire cut for 20M half-wavelength to Ashland State Park K-2417 in Massachusetts for a Parks-on-the-Air (POTA) activation. 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. Tune Around! It may not display this or other websites correctly. Wait a few minutes for glue to set. Free Postage. /Type /XObject You have to give up a band or two, like 60m and 6m, as 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. 1 0 obj Continue on winding the long wire through the toroid to complete loops 3 through 14 as shown in the schematic below. <>/Metadata 239 0 R/ViewerPreferences 240 0 R>> Enclosure Depth: 1.250 in. Post Reviews See the picture below. &nb u?X`f0&/Ri;W0Tn_*TX:ug Please note that I will not be describing the construction of the antenna wire radiator here. 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. FCC Information endstream I used a homemade jig made of an SO239 chassis mount to bare wires, alligator clips, and a coax-jumper with PL259 (UHF male) ends; see picture below. He was so impressed that he purchased a 9:1 unit from you, his will be delivered Saturday. An end fed antenna consists of a wire fed on its end, the length of that wire is not resonant with any frequency or frequencies you will be using it on. Contact This design is excellent for matching both long and short length wire antennas for multiband use. 1 bolt for antenna hook up (with nuts, washers, lock washers, and possibly thumb screw; I used #8 diameter, about an inch or so in length.). Ultimately, this housing works fine, but it is heavy and clunky.). Re: 9:1 or 49:1 unun for end-fed long/random wire? transmit frequency the impedance is so high that tuners in most rigs A 50 foot run of RG-8X coax connected the antenna into the LDG Z100-plus tuner and then a Yaesu FT-891A transceiver. frequencies for your country or favorite modes. This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). These dimensions were derived from modelling the antenna in EZNEC. This is to avoid the antenna radiator from acting like a resistor, and thus instead of radiating radiofrequency energy produced by the transmitter, sending it back down the coax toward the transmitter. answers on D - one setting. stream program or two to do all the dirty work. Proudly powered by WordPress 32.00. 1 X FT240-43 Ferrite Toroid Core 43 Material(Mouser Electronics), 1 X SO-239 UHF PANEL JACK S/CUP SO-239(Mouser Electronics), No. Jack, VE3EED, hopefully has solved a major headache we all have when we attempt to go thru the trial and error and frustration with getting the random wire to work where WE want it to work. q 9:1 Unun 1.5-54MHz 2kW 9132S. The other is to provide strain relief for the antenna wire). /Type /Page /ModDate (D:20221212112042) Theme designed by Papathemes. 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 . (QST, Oct 1926, "The Length of the 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. /Subtype /Image /ProcSet 7 0 R >> A VSWR sweep of the unun after adding a 100pF capacitor shows an SWR <5:1 from 160M to 10M. 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. If you want a single band portable antenna you can mount pretty much however, look up this design. 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 endobj installed, it is a compromise antenna but great for portable use because The length should be calculated based on the lowest frequency to be worked. The QRP End-Fed Half-Wave Antenna 49:1 Transformer Building a great impedance transformer for Ham Radio end-fed wire antennas. Y &lD30. =======================, 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: recommended on VE3EED's page because I use all halfwave Because I'm more visually oriented I then plotted the many overlapping "red zones" and ended up with the page at: 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. 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. /Creator (XnView) One single wire, no solder connections,very simple.all the way from the tuner to the end support. (A t0 B) Fold over 6 to 8 inches and twist it together. 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. plan to use. This transformer is designed to be used with an end fed half wavelength of wire only. The length of a half wave antenna is calculated using the following formula: L (ft) = 468 / f (freq in mhz). The bandwidth where SWR was below 2:1 was about one MHz. "Can you please recommend schematics that are designed to tune setups like these? here are values for CW portions of the USA The short piece is for the primary winding of the transformer, and the long piece is for the secondary winding of the transformer. 1. 22.00 + 5.00 Postage. 25 0 obj <> endobj This project assembles a 49:1 ferrite-core ("FT") type #43 transformer that matches 50 ohm input to 2500 ohm end fed antenna. 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. $119.95. <>>> I imported my spools from the US, but I have seen them on Ebay in the UK. In stock . , Reprinted with permission of Hamuniverse, this is an excellent explanation of SWR and how to best me Computer Help In fact, the 9:1 unun that I built is actually an autotransformer. You will note that when comparing my results with VE3EED that some of the results are a bit different. bands you're intested in in a vector like the example below, by typing. Cannon". google_ad_client = "ca-pub-9377297764300878"; stream is helpful if you're in a hurry to get on the air, read up on the topic endobj Each vertical blue line represents an amateur radio band. endobj Use a slide rule! The key is you want to stay at least 1/2w long but not near 3/4w for any band of interest. I use this 8010 EFHW at home, too. 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. So those are the numbers above thatwe have to stay as far away from as possible when building a long-wire antenna. You have to stay away from a half wavelength on any frequency. A small ring terminal for 14ga wire that fits these screws would be helpful too. 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. Superglue 2 toroids together. Here is an ARRL 74 0 obj <>stream The graph below shows lengths to avoid for different collections of bands. Designed for use with single wire unbalanced antennas, this new addition is small, compact and perfect for quick portable/emergency installations. x {avla[g#+yt]Mk"B` xp[AO8;c=\b}|8p4cSmzgU7be,+i5ci6uq.x T/s@9uk-oZX;u`=U >8rsIXW B:uUVr6a] Experimenting by slightly changing the wire length (+ or-) is encouraged to provide best overall performance. << 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 %PDF-1.7 An UNUN is needed to match the high impedance of an end fed antenna (2k-4k ohms range). They just saved you and I loads of time and frustration. Click to enlarge. Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. so that it is not a halfwave multiple of any frequency you want to use. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! A 49:1 would match 50 ohms to about 2,450 ohms and a 64:1 matches to 3,200 ohms, typical of a 1/2 wave end fed. End fed 9:1 58ft wire and 17ft counterpose wire touching ground. On our next windy free day, AA1F and . Use only the white gaps for your antenna lengths, and if /CreationDate (D:20221212112042) 40-30-20-17. If you want all the bands from are blocked out because an antenna should be at least that long. 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). 8 0 obj 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? /Height 752 Winding 1:64 Matching Auto Transformer on the FT240-43 core. 2 eyehooks with washers and nuts (I used #8 diameter, but size is up to you.) google_ad_width = 160; 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. Best SWR was . The 49:1 impedance transformer will help you bring down the high impedance of your resonant EFHW antenna to almost 50 Ohm. Power handling is 100 watts CW / SSB & 25W Data modes. 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). The transformer usually used with an end fed wire is a 9:1 transformer. SO-239 connectors are silver plated with Teflon insulation. 7 0 obj We recently found some good information about random wire lengths that you should and should not 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. I attached the toroids to a PVC DWV test cap with 3 cable ties. 3 0 obj /Im0 Do This calculates to 4.2 m or 14 ft for an 80m end-fed. The most important length is one that is non-resonant on any band. AndWhat Is It Used For In Antennas? >> While I have not done so yet, I plan on gluing the test cap to the back of the junction box. Presented for your consideration by Jack, VE3EED. 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 following wire connections do not need to be made in the order I described. In other Some important and helpful references I used for this work: https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. Windings are inserted into Teflon tubes increasingtotal breakdown to 10,000 volts. and leave the unun on the ground. You can take one of these 49:1 transformers and use the 468/freq (Mhz) formula to calculate the length you need in feet. We are working every day to make sure our community is the best Radio Hobbyist's site. understand its properties. If you plan on stringing up a dipole you use 2 equal lengths of wire with the Balun in the middle. 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. want the antenna to be at least 1/4 wavelength long for each band you Kj8~q7c? I actually did this first and before the connector was bolted to the box. SWR will vary based on topography, wire orientation and use of ground or counterpoise. 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. License Study Then verify it with your installed antenna and SWR measurements. Liquidtight NM 90-Degree Connector(Home Depot). Palomar Engineers employs a dual core matching system that offers wide bandwidth (1-61 MHz), 500 watt PEP rating, and a connection for a counterpoise or ground if desired. The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. "I received my third balun from Balun Designs this afternoon. /Kids [ 4 0 R ] So for example 80m could range in length from 120 to 133 feet. Here's a list of recommended lengths of wire to use with a 9:1 unun. I'm looking forward to getting off work and hitting 40 & 20 meters again!! K1S Valentines Are (Almost) Out The Door! 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. Modify bands and Privacy Policy 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. 1863 1.49 swr 3915 2.50 7200 1.80 14.332 1.29 18.130 1.07 21.300 1.40 24.950 1.30 28.400 1.37 This is a great antenna that is . If the choices are. something as high as you can find. V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT c=W>:sECXTkc=X (The numbers aboveare a great start, thanks to Jack and Mike! This type of antenna is very easy to install because there is no need . /Resources << NOTE: Rewording the previous paragraph, if you have a capable enough 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! Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. Multiples are on C and Quantity: Sold individually. We do not encourage any radio operations contrary to regulations. 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). 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. Powered by BigCommerce. So a 49:1 impedance transformer is needed to match the 50 ohms of the coax at the feed line. 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. Make sure the beginning few inches of twisted wire is not involved in the winding (i.e., just hanging down from the toroid). 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. 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. At this point, Ive only used the 49:1 tap, but plan to take the 64131 whenever I operate portable. endobj 9:1 or 49:1 unun for end-fed long/random wire? Lengths of a half-wave or multiple must be avoided. $1YacO5Q}YC\>qZ } x 2 in. var sc_invisible=1; Coverutilizes integralneoprene gasket for weatherproof integrity. Do what works best! A png image named g.png will be created. The matching unit The impedance at the end of a half wave antenna is somewhere between 2000-5000 Ohms. End Fed Antennas. 20/40/17m. Picture 1 of 9. Power Handling (CW/SSB): 100 W/200 W Enclosure Width: 2.500 in. I have found this calculation to work well, however it depends on many factors such as wire used, location etc. This design is excellent for matching both long and short length wire antennas for multiband use. A Balun is used to match a balanced line to an unbalanced line. Antenna Safety! 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. Performance is ASTOUNDING, far exceeding my expectations. UJM-49-1 $56.99 Save up to 6% when you buy more. One end goes straight into the Tweak the antenna length if necessary and then maybe adjust the turns ratio again. which got me thinking. You can add your own wire or get the complete product from this link EFLW-3K antennas. Hi guys,not really hfu related,but I tought I might ask here as I have my account. At multiples of half wavelengths of the It's an efficient way to get all the multiples Cut the antenna radiator wire (free untwisted end of long wire) of the unun to the correct size, scrape the enamel insulation off of the free end with a box cutter, add a ring terminal, and secure to antenna radiator bolt with washers and lock washers. /Length 10 0 R That's it in a nutshell..or is it? SBULLET-9U-1500. tuner the colored bands below are the best lengths as long as your It will be good for 15m, and 10m. IMG_2.jpg Step 2: Take the 6 feet of 18 gauge enameled copper wire, measure 11" from one end and fold it back. That type of wire antenna could be lower than 50 ohms at some frequencies and over 2,000 ohms at . 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. . >> 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. /Type /Catalog << . 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. 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA Tools This homebrew 49:1 impedance transformer is the heart of any EFHW antenna you will build, most of the time. Picture Information. endobj Even better would be shortening to 53'. 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 There are numerous configurations available online that will accomplish this on multiple bands (Google search "end fed half wave antennas"). is that for a given ham band there are min and max frequencies which Some of these numbers are too close to squeeze in between them. bands as possible. (Center fed is so appealing because you avoid this.). 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. Twist the short and long wires together starting at an end of each wire. To summarise the results WRT to reference antenna consisting of 30ft wire vertical fed with auto- A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. Meet 'Balun One Nine', a small, cost-effective balun. Let's have a look at a few details on how to build a 49:1 impedance . 2 0 obj Any SWR measurement taken with the transformer at the feedpoint should not exceed 1.5:1withNOtuner in use. Again, the bands are USA, so change them The length should be calculated based on the lowest frequency to be worked. Turns 1 through 14 are secondary windings (the long wire). When used with the stated Balun Designsis now offering a low power alternative for those who want to use an End Fed Half Wave for portable or temporary installations. This will be for an eyehook in order to provide strain relief for the radiator wire. endobj a more capable tuner - see AA5TB's An Unun is used to match an unbalanced line to another unbalanced line. /ColorSpace 11 0 R Theme: Newsup by Themeansar. , This is a partial reprint (with permission) of an excellent series of articles published by KV5R Notice from column f that there is no length giving low impendance for I did not want to put the transformer in the housing until I tested it.
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49:1 unun wire lengths