49:1 unun wire lengths

understand its properties. 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. Having the option to switch rapidly between 49:1 and 64:1 should prove to be a really nice feature.. . 1 0 obj I have not done this yet. This was 9m vertically metres up a fishing pole and then about 5.8m out. Balun Designs. UJM-49-1 $56.99 Save up to 6% when you buy more. Winding 1:64 Matching Auto Transformer on the FT240-43 core. Hopefully these random wire length calculations will help us all make this "easy" antenna work better! var sc_security="1df091cc". Do what works best! In total 29 contacts were made from British Columbia to Texas to Florida in 40 minutes on 20M. Stacked coreswithwinding configured as 49:1auto transformer. InJack's own words. CQ-Calling All Hams! 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. 35-43, 49-63, 70-85. 49:1 End Fed Half Wave Antenna 40-10M 100W Version Bands of operation 40,20,15 & 10m using 67 feet of our UV, Ozone resistant Antenna wire. Humor I'm looking forward to getting off work and hitting 40 & 20 meters again!! /Length 10 0 R End fed 9:1 58ft wire and 17ft counterpose wire touching ground. Longer wire is always more This transformer is designed to be used with an end fed half wavelength of wire only. Site Map Please note that I will not be describing the construction of the antenna wire radiator here. Usually any wire length that is non resonant, like those shown above, will work with the 4:1 ratio. It is important to use a counterpoise. In other Care to buy us a beer? document.getElementById("copyright_year").innerHTML = new Date().getFullYear(); /Type /Pages endobj The transformer usually used with an end fed wire is a 9:1 transformer. FCC Information 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. Drill a hole in one side for the antenna radiator wire mount (for a #8 bolt in my build). This transformer converts the impedance at the end . 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA 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. /Count 1 Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. Here they are in order: multiples, and of course different band combinations yield different To DB's point of a single band antenna, this 49:1 transformer is a good choice for a single band matcher. One end goes straight into the That's it in a nutshell..or is it? Allows the internal tuner of most rigs to tune remotely mounted single wire antennas. /CreationDate (D:20221212112042) SO-239 connectors are silver plated with Teflon insulation. I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. I actually did this first and before the connector was bolted to the box. 9:1 or 49:1 unun for end-fed long/random wire? /Type /Catalog 27.00 (27.00/Unit) Free Postage. 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 . $119.95. /XObject << /Im0 9 0 R >> It may not display this or other websites correctly. We do not encourage any radio operations contrary to regulations. Because I'm more visually oriented I then plotted the many overlapping "red zones" and ended up with the page at: He had heard good things about 'Balun Designs' so he recommended you. Start winding the Matching Auto Transformer, each pass through the center of the core equals one turn. The Nelson antenna 9 to 1 unun did the trick. Each winding is counted when the wire enters through the center hole of the toroid. x 2 in. wire is at least 1/4 wavelength. (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. 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. hbbd```b``^ "Cs;D2 I*`0D;+EVUHy`qml0{YVw`b0i DvkAh |"w I2% ?W%@Fg`` 6 PVC Junction Box(Home Depot), 1 x 1/2 in. config file by typing gnuplot rw.gnu. Continue on winding the long wire through the toroid to complete loops 3 through 14 as shown in the schematic below. Re: 9:1 or 49:1 unun for end-fed long/random wire? %PDF-1.5 % /Parent 3 0 R <>>> Tune Around! You will note that when comparing my results with VE3EED that some of the results are a bit different. That meant calculating all the way to 32 multiples of a half wave on 10 meters. Continue twisting the entire length of the short wire. Connect this ring terminal to one of the SO239 chassis bolts. uR5ucE`_aksLjYT=hzRa]JucX7d}|'}`XRa>X <> shown in the column e. var sc_project=8077274; A VSWR sweep of the unun after adding a 100pF capacitor shows an SWR <5:1 from 160M to 10M. A success! I only used two screws instead of four. 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. 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. Antenna Design At multiples of half wavelengths of the x[q;`&z`uAlo#V@;hvOYt, @*Ys~_W_~W_aw_ p[N+}[t-^oLy}xz>7/~c|ZZt75;kN^=>Y+_~|b~"m*tw>xG=x6Qwz|xvz- Ham Hints So I just wanna say thank-you!! Wire lengths for the 4:1 ratio in models 4932 and 4935. 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). I imported my spools from the US, but I have seen them on Ebay in the UK. endobj So for example 80m could range in length from 120 to 133 feet. The WSPR map is so dense it looks like the US and Europe are just big blobs of color. %PDF-1.4 Here is an ARRL Q /Subtype /Image 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 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. I used the RigExpert Zoom AA-55 to test VSWR of the 49:1 unun impedance transformer. 49:1 UNUN IMPEDANCE XFORMER FOR END FED HALF WAVE ANTENNA. hb```YloD@(aKI V!}g@~}%Q/[[~_=Wy-:O)x[~hs/~SGeG _QE C6q %r Suggested wire lengths for 1-61 MHz operation (measured from Bullet wire point): Bands Covered (meters) Wire Length (feet) Minimum Coax Length (feet) 40-30-20-15. 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. JavaScript is disabled. /Type /Page 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. (A t0 B) Fold over 6 to 8 inches and twist it together. 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. 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. VSWR analysis of the antenna in the field showed that VSWRs between 3-5.5 from 40M to 10M. Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun 10m or 33' long. This is the latest and greatest transformer design for End Fed Half Wave (EFHW) antennas. WwS`8o}=n,pjhzRa]Ju/Ru ni4=UvZ:u9*@ Xz+zZcXm}i[Z;Z>.u!*eQVjucXeqYZnSJu)U[n>>KXzZ.Lz sqxcGj]%q}i6=-?YTlnZXV6}=U >5`ZNxChzRa]JU.6TVr6a] You can take one of these 49:1 transformers and use the 468/freq (Mhz) formula to calculate the length you need in feet. Y &lD30. 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. endobj Coverutilizes integralneoprene gasket for weatherproof integrity. EFHW unun Resonant Long Wire 49:1 Transformer With 67' Antenna Wire. &nb Solder a the 100pF capacitor between the center conductor wire and ground wires. N4UJW. Kj8~q7c? V#X~[Z?\ZcX:-Y?&Y?IqTnayZ{jTZOub}=UTWu1G>o.,RaT c=W>:sECXTkc=X all US ham bands. Drill out holes in the designated bottom of the electrical junction box for the SO239 chassis mount. 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. 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. So for example 80m could range in length from 120 to 133 feet. I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. and experiment. The graph below shows lengths to avoid for different collections of bands. W3EDP's results in the above referenced Twist the short and long wires together starting at an end of each wire. A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. A standard recommendation (see QST, March 1936, p. 32, "An Unorthodox The Short Answer Would Be That an UnUn Is a "UN balanced to UN balanced" matching transformer. Cut a 4 foot length of AWG #18 enameled wire. The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. X:nzf4p:t;r }~_HOZcX:^$* J^XZuu|"nX/Wkw0hA>y1(z2+v_Xzu[/:^$*m*>hk_:+c{ 31 >> For example a 32 foot length is actually a half wave on 20m with an impedance of about 3500 ohms and requires a 50:1 balun. 7 0 obj While these lengths have been shown to work well on many bands, which In stock . 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. Use with other lengths can potentially damage the transformer depending on power level in use. "I received my third balun from Balun Designs this afternoon. 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. 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. Links 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. You'll want to have that wire up as high as you can get.. 73, 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. Meet 'Balun One Nine', a small, cost-effective balun. Both were on 20 meters at 97 watts, Icom 7300.

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