RANDOM WIRE ANTENNA with 9:1 UnUn home made (part 1) 

To clear up some confusion in the comments...It is clear to see that you have 5 turns on the core. Each time the wire passes through the center of the core it is counted as one turn. Even though the drawing we see in the video has 10 turns the 5 turn toroid as built will work but more turns are preferred. The fact that it is a tri-filar winding, no matter how many turns, will result in a 1:3 turns ratio which also results in a 9:1 impedance ratio. This could be made with just 3 turns but, again, more turns are preferred. 10 turns would be much better. No matter how many turns it will always be 9:1 impedance ratio because of the 3 conductors in the windings and the way they are terminated. A ground or at least a length of counterpoise wire is important to achieve a satisfactory SWR.

Amazingly informative and concise. Perfect video! Thank you!

Thank you so very much for this very wonderful, well put together and explained with hands on construction, I am saving this to my favorites because I also want to build this, you are very good at making instruction videos! with your explanation and showing step by step, it couldn't be any easier. God bless and have a wonderful day!

Beautifully done! And another excellent video as well. Some wonderful results. Cheers!

Very good project - Well done - Thank you for sharing !

Paul, thank you for sharing your project. I learned a lot about a simple longwire antenna. Your construction was very clean and well laid out. Watching you go through the field testing was icing on the cake. I'm going to try building this antenna. I live in a hole so this would be the perfect antenna for me to run right down the edge of my property through a tree line.

Congratulations for such a neat video and for your hands-on experience. Loved it, I will surely try to make it. Thanks for making this video available, it's very easy for even a kid to follow your instructions.

This is inspiring! I need to build this antenna! Thank you so much. Brilliant presentation! New ham here!

Absolutely stunning vid, congrats.

Muy bueno el vídeo que realizó muy bien explicado y fácil de entender le agradezco su tiempo dar para enseñar a la que estamos aprendiendo de los que saben mas. 73

Thank you for sharing this video. Cheers and 73!

Nice antenna build. Works very well!!

Very nice project that’s on my list to make. Thank you 😊 73🍺🎙

Great presentation Paul, many thanks for sharing.

SUPERB DEMONSTATIONS, VERY HAPPY WITH YOUR 9.1 UNUN , 73S

Really interestig vid. Thanks! I wanted a simple piece of wire for 80.. and hopefully 160. I was just SHOCKED what a low end fed wire can do! It's crazy. It's noisy, yes, but easy to put up. And other than the UNUN, its a simple piece of wire. I use it on all bands from 80 to 10. If anyone wants to see my experience, look for '80 EFHW & Multi tap UNUN. I'm not a youtuber tho... and don't really know what I'm doing. I'm just a simple QRPer in Michigan you see.... 73 OM!

Love this video lots of information easy to under stand thank you in spring will build one like the link 73

Paľo išlo Ti to super. Gratulujem. 73!

Excelente e obrigado pela aula. Muito didática. Perfeita!. 73 Hugo Ruas front Brazil.

great workmanship,well done.

Excellent content. Thanks and 73 from Osasco, Sao Paulo, Brazil.

Good video, very clear with both the construction and operation of the Antenna

SWR 1.1 across the band. Unbelieveable. You said it!

Excellent! I have most of the parts needed. Just going to order the T15 toroid and build one of those myself. A very good video, thanks for making it and you earned my subscription. The built in SWR plot on your transceiver is very nice. 73's!!

Enjoyed you making the 9:1 yellow balun and 20 meter long wire antenna. Yes, it worked well. 73

Excellent build Paul, you always make it look so easy. Happy the swr was so low across the bands. 73 my friend & good DX

That is the coolest drill bit I have ever seen ;)

Another great video! Thank you and 73!

You did a wonderful job awesome a true person who knows technical things you have the right tools to work with really really looks great and it's working fantastic awesome job my friend thank you for sharing from Atlanta Georgia

Thanks for the video!

Thank you for a great video - very instructive - will be making one!

Great video. I tried this with 8 turns and it works well. I used a NEMA (waterproof) box and put rubber behind the SO239 to help make it water resistant. It's a fun antenna to use at my weekend house. I'll eventually put up something more permanent, but it's a nice, easy antenna to deploy and get on the air. Thanks and 73

Great video. for sharing. I built mine as per your U tube and it works just fantastic. .By adjusting the CP and the angel of the antenna wire I can get the SWR below 1,5-to -1 Thanks for sharing BOB AF2DX

Espectacular!!!, intentaré hacer una... Gracias por la aportación a los colegas radioaficionados, OA4Y... 73!

Great video! Thank you!

very nice! excellent workmanship, also!

great results thanks so much

Wow, Paul that has got to be the best build vid I have ever seen, I’ve seen good ones but had to watch again and again to catch the odd connection and the like. Your camera work and the attention to detail you give your viewers is very impressive this is the standard everyone should try to master. Great SWR results off the bat. OM0ET , I salute you and your Awesome vid👍🏼👍🏼👍🏼Regards 26CT3250. 73

brilliant work Paul (y)

well thought out process and details

God bless and have a wonderful day!

Been looking for a convenient antenna for field use, will give this one a go. Many thanks for this. M0KPK

Thanks for the great information Paul. Hope to hear you on the band. Roll on cycle 25

Thanks you for contribution..............

Thanks for the great video, but I notice that you use a type t 6 toroid, do you think make the same thing with a FT toroid? Thank you, best '73's de IU7FKX

Nice work greats 73s from TI5WNF in Costa Rica

Good step-by-step guide and very impressive results on QRP. 73 de SP2DMZ

Great build and video. Are you able to make available the plans for this UNUN? The link in your description is offline now. Thanks

Thanks for the video and I did subscribe. I found and bought that 9:1 unun on eBay and bought one. One question I have why did you put the puller above your cement and bar? Do you think when wind blows or ice it will raise. Also, are you concerned about it being cover up with snow. Looking for ideas. Thanks

Very nice craftsmanship and a professional looking video. I now feel confident in building this 9:1 UnUn for my longwire antenna. Thanks and 73!

Love your videos thank you

hacia muchos años que no veia un video sencillo explicado y montaje de los componentes,.juan cx3et.

One of best videos i seen De a71br

Very good antenna. Did you try with ground/counterpoise? What was the length of the radiating wire?

I am new to antenna construction and grounding. During your demonstration using your tuner with the finished antenna, what would the ground have been connected to if you had used it? A stake in the earth?

Paul great work. Im new amateur. I watch your video like and learn something.sorry for my English. Thanks for video.73.

Great video, thanks, 73 W2DWL

Very nice and informative video. I will try this one! Gongrats!

Hi Paul. Thank you very much for your work and for your excellent videos. After I saw this video, I made myself a 9:1 UnUn with a toroide from an hold PC power source. With a 20m wire and 11,5m counterpoise wire, the antenna its working on 160, 40, 20, 17, 15, 12 and 19 meters band's. On 80m the swr it's very high. I am trying to figure out what is going on with this. But this is a very simple to made and a very good antenna for QRP. Keep the good work. 73 from CT2JAW

Hello Paul, Thank you for your nice video. Just to avoid any misunderstanding, the measured good SWR is without using any internal ATU in your X5105, right ? Thanks - 73's. Stephane.

Beautifuul work and good response in R.O.S. SWR 1.1:1....fantastic de in3ufw

Did you get the 1.0 SWR without engaging the auto-tuner or was it engaged?

It is probably obvious to the majority of viewers, but it should be stated that the building of any balun or even a unUN requires the use of enameled or specially coated wire (sometimes called "magnet wire"). The use of enameled wire is so that the wires don't touch each other and short out the circuitry of the windings. There can be NO SHORTING OUT between these wires. Take some care not to scratch the enamel of the wire down to the bare copper surface ( except where soldering of the end of the wire needs to take place--- and this requires a complete removal of the coating for effective soldering purposes). If physical separation of the wires can be guaranteed for the life of this project, magnet wire may not be necessary, and uncoated wire may be used, but not recommended.

Paul, great video. I really enjoyed many of your assembly techniques. I am curious why you didn’t attach a ground or counterpoise.

thank you very good video

Dobrá inspirace vyrobím a vyzkouším. Akorád to bude od vrchu dolu jako sloper. Pozemek mám asi těch 20 metrů.

Excellent build video Paul. 73 wd4dda

Always love me some antenna videos, and testing. It's weird, but a HAM could have great antennas for every band, but he/she would still build/buy more. Your latest antenna is just a temporary fix until you get the next one. *lol*

Loved this video exactly what I was looking for and if you had not made it I'd still be looking for an answer to my long wire +balun project , all the best from m0omt stu in the uk

Fine business there Paul. Thanks. KC3BXZ Joe 73

ПРЕКРАСНО работает! US7ITC 73!

Well done - another very good video! By the way, what length counterpoise do you use for this End-Fed and your SPX100?

Great result from your antenna build. Your QTH must be an ideal location. Down the road a few KM and result might not be as good. QRP OP's that experiment with antennas know this so don't expect too much. We are happy when the antenna works better than expected. Great video and build. KB8AMZ

Nice video, thanks. 73 de M0OET - yes, M0OET!!! ;D

Thank you , you may want to explain the use of litz wire and why you scraped the ends for those who are trying to figure out the continuity testing . Nice work om

very nice!

Hi Paul, Interesting video nicely done. I'm curious about one thing, bearing in mind I'm a newbie. You gave signal reports of 59 on both calls but the S meter didn't show that. Do you have to make some adjustment to the reading? Is it just QRP convention?

Hi, out of interest Paul how long did you make your counterpoise wire? Bill G6ATO

Wow.. Awesome build wire Antenna..the swr test is so happy🥳 .. but Paul..the last qso .with only 5watt ..where was that station??.. was he far away from you in Kilometers?! Hi5 from P.K.NL😊

BTW -how are you satisfied with your X5105, can´t decide between this gadget and the FT-817ND for QRP :-(

Hello, thanks for sharing. Would a 9:1 UnUn improve my 150' long wire antenna (I have 4 different lengths attached to the same end fed antenna 150', 80',40', and 30')reception with my Tecsun 880?

If I were to put up a shortwave dipole, each leg being 12', without a balun /transformer/impedance matcher, which band(s) should I expect to receive? Thanks and 73! N4ANO

Thank you, once again for the video. I can imagine the joy you have derived at the result of the 'unUn" matching transformer, you made. The SWR reading was perfect. Your TX/RX set X5105 is quite remarkable. I will procure one, once my license is ready. What is your comment on X5105? By the way, I'm on the process of making your "Random Wire Antenna matching "unUn"9:1, transformer. You inspired me. Thanks. Stay safe and 73s

Super Job

You will find it better if you use three different colors of the wires as it will make it easier to get the right connection with the in and out connection .

Hello Paul, is the length right mot 20 m, I know for 1:9 and other lengths such as 6.5/13.5/16.5/26.5 m. What is the best length for the antenna wire? Thanks & greetings from LX Serge

What spay did you use to clean the soldered wire?

Hi Paul I am just starting out on ham radio. can you answer me one question please. can i use any ferrite core or does it have to be L15?

Hi, OM0ET, nice descriptive video. Thank you for your time and effort. In the article published by VK6YSF, he has used toroid T 15, whereas you made use of toroid T 130-26. I would like to know if it might be okay to use either of these toroids, namely, T50-6 or a T30-6 or T80-2 or T50-2 to build this 9:1 UnUn.

Is there any reason why you need the heat shrink tubing - or is it just to keep the wires together? Why not just use up the wire (divide in 3 parts) - your turns ration will always be 3:1? Do you have any idea what the core losses are like? (if they are high enough it could give an erroneously good swr).

I think you would get better results with the long wire higher off the ground plus add a counterpoise, but surprisingly you got good results even with 5 watts.

Is there a parts list or where I can purchase the box? Thank You

Great video. How long did you make the counterpoise? Have you used your counterpoise?

What material is the toroid you're using here made of? 🤔 Is it a solid yellow (usually type 6 ) or yellow / white (usually type 26?) The type 6 should be very similar to the type 2 (usually red) but with a frequency span 1 - 50 MHz while the red should be 1 - 30 MHz if I'm not mistaken. I recently made a 9:1 of a really small yellow / white toroid I had laying around after scrapping a SMPS since I couldn't find anything else in it but a solid green toroid which I can't figure out the material composition of, but I think it too is a powdered iron toroid. I made my 9:1 with 9 trifilar windings to compensate for the very small mass - outer diameter is only 18mm while the green one is only 15mm. Original recipe was 8 trifilar windings on a 240 size toroid. The transformer gives a low (1.1:1 - 1.3:1) SWR reading with a 45m long wire but it seems like it won't do much good under 7MHz and that's a bummer. Since I'm a pure digital (and morse) person I'm somewhat satisfied anyway since I get good NVIS coverage on the 40m band with the antenna about 5 m AGL, but my hope was that it would give better results. Well, it was free... I will of course re-make the transformer when I get hold of some usable ferrite mix toroid but it was worth the effort anyway... 😏

Thank you for this great video! But if I build an UnUn 9:1 just to receive using SDR - should the ferrite core be that big? Is it enough to use small one, like the one in Nooelec 9:1 UnUn?

Congrats and thanks for sharing. This toroid is a T130-26 or the original L15 ??

Will the SWR change when the antenna is higher?

Thanks for doing the video in english. Very good information, Ive just made one as well. :-) (M0MPI)

Electric heat is better than the flame. The flame is fine for emergency repair. I use my heat gun and get beautiful results.

Hi Paul, great tutorial my friend, one question. Does the size of torroid make a difference! If so how do you find the right size/dementions for a given project. Thanks again my friend. Regards Kevin