Dude, this is a 9:1 UNUN. The number of wraps around the toroid AND the mix of toroid will determine the frequencies that it will work at. Less turns = higher frequency. A bit of RED Loctite on the threads should solve the mechanical issues. It will also rust quickly, so anyone using this in a damp environment should wipe it all down, inside and out with isopropyl before storage. PS. I would be sure to add a choke on the input of this UNUN to decouple the coax outer shield from it. Not too bad for $14 actually. Always good to have a 1:1, 4:1, 9:1 and a 49:1 in the go bag. 73 OM, see you on the air. 👍
Seems to me it would work great for QRP, which I believe was indicated in the item listing. 40 watts or 70 watts is not too likely for someone operating a portable rig doing SOTA or POTA, for example.
I agree... this is likely a 'true' 9:1 unun. If the number of turns on the low-impedance winding (SO-239 connection) is only two turns, and the high-impedance winding has a total of six turns, that still reflects a 6:2 = 3:1 winding ratio. Once you square the winding ratio of 3:1, the impedance ratio becomes 9:1. Great video nonetheless. Thanks Dude! Ken -- WBØOCV
@@kensejkora4424 Actually, this is a trifilar coil - 3 wires wound 6 times. One of the wires is radio side and all three connected in series are antenna side, hence ratio (1:3)^2 = 1:9
I bought a 49:1 unun from Amazon. I put it up with 80 meter wire. It was about 60 feet from a 49:1 Chameleon EFHW EMCOMM III. IT BEAT THE EMCOMM on all frequencies. Better SWR, better performance. Some of Amazon’s stuff is pretty good.
I have one. Ran it with 62’ of wire and 50watts. Worked well 40m and up with my little MFJ manual tuner. Made lots of nets and contacts. Still in a drawer here somewhere.
I use one with 58feet of wire plus a 30 foot counterpoise and 2 17ft secondary counter poised 45 dg apart verticle. My feed point up at 30ft. Worked the world. From uk
Thanks Dude. I bought a CHEAP 4:1 off of Ebay to test during the Big "C19" lockdown. I was actually surprised at the quality. I've used it on an 80m Doublet with 135' of 14awg THNN wire, 75' of ladder line, and it worked surprising well. I guess that in some cases, it's just luck of the draw. I surely got lucky on it. Thanks again for all of the great content, time and effort.
I've always have had HF beams or verticals. This summer I tried a Palomar 9:1 unun with a choke outside and a isolator inside. Total wire length is 188 feet. My swr is less than 1.5:1 from 160 to 10. NO tuner. Low noise and if I can hear them I can talk to them.
I bought one of these some months ago and took it apart to see how it was made. Mine has *exactly* the same issues as yours; loose nuts and so239. I decided not to use it until I can get round to rebuilding it. 73 from 2E0LNS
Amateur radio is a hobby that licenses us to design and build ALL our own stuff, even with just a Tech license. It's a license to do, a license to learn. A good FT-140-43 toroid on Amazon is $6.95, and it's $4.99 for 32' of 22 gauge magnet wire, with enough wire let over to mae a 49-1, too. RUclips is full of vids on how to wind a 9-1 toroid. Mount it on a piece of wood or plastic. Solder the antenna wire and the coax to it or just wrap the wire around screws. The whole thing takes about an hour. Then the ham knows how to do something. BTW, nothing beats reading up on a little antenna theory to make them behave properly. Lots of good stuff online. With some hams I'm put in mind of someone buying a motorcycle because it a looks like fun, but expecting it to drive for them so they don't have to learn how. That's just silly. The fun comes from learning and knowing how.
For 16$ or whatever rewind the torrid, tighten up some nuts, at a little solder and you are in good shape. I dont think you can get a qrp unun kit cheaper than...
Great video. Really liked that you were able to show the core heat to the point where SWR skyrocketed. I never knew what would happen when running one of thee devices close or above the limit. Very informative. As an aside, could you explain when you would want to use a 49:1 unun vs. a 9:1?
Apart from the build "quality", I think that unit is a good buy, 18 bucks in Canada. The size of the toroid would tell me that it is intended for no more than 25 watts, QRP hams. Nice to see an object tested close to its practical limits.
Had one of these and twisted that coax connector right off in the first hour, can’t remember if i binned it or sent it back, either way should have kept it for the parts bin.
@@HAMRADIODUDE Yes, I just started playing with the Random Wire antennas and I am amazed what you can do with them. And I don't always want to wind one up so this is perfect.
Fun video! That's outrageously inexpensive. How can they even build it for that amount and still make a profit? Well, I guess we know how, but still, pretty amazing.
For $15 I could build my own. Well, I’d spend more than that getting wire, cores, boxes &c but I’d be able to build three or four of ‘em & at the very least know the parts quality & construction were my own damn fault. Which, I gotta add, I have done. Seven or eight times. And, were I a beginner, I’d have learned something too. So, nah. I’ll pass. But thanks for the video, amigo. 73 de W8IJN
Wow the innards of that transformer are punny! The quality control is less than good for this product. I think I'll stick to better known manufacturers.
Crikey! Flick your hands around as much as you want, some people are too much. I use a 9:1 with 73' of wire i love it though its a substantial unun. This one looks like a toy.
EndFed antenna's are pretty good. The mistake you make is you think of the past. When Ham's ran a EndFed into the home to a tuner. That could cause all kind of RF problems. But this is a different antenna. It still needs a 1:1 though.
Dude, this is a 9:1 UNUN. The number of wraps around the toroid AND the mix of toroid will determine the frequencies that it will work at. Less turns = higher frequency.
A bit of RED Loctite on the threads should solve the mechanical issues. It will also rust quickly, so anyone using this in a damp environment should wipe it all down, inside and out with isopropyl before storage. PS. I would be sure to add a choke on the input of this UNUN to decouple the coax outer shield from it.
Not too bad for $14 actually. Always good to have a 1:1, 4:1, 9:1 and a 49:1 in the go bag. 73 OM, see you on the air. 👍
Thanks so much for the explanation. That makes complete sense. I'll see you on the air. I'm going to try to work mobile next week
Seems to me it would work great for QRP, which I believe was indicated in the item listing. 40 watts or 70 watts is not too likely for someone operating a portable rig doing SOTA or POTA, for example.
I agree... this is likely a 'true' 9:1 unun. If the number of turns on the low-impedance winding (SO-239 connection) is only two turns, and the high-impedance winding has a total of six turns, that still reflects a 6:2 = 3:1 winding ratio. Once you square the winding ratio of 3:1, the impedance ratio becomes 9:1. Great video nonetheless. Thanks Dude! Ken -- WBØOCV
@@kensejkora4424 thank you
@@kensejkora4424 Actually, this is a trifilar coil - 3 wires wound 6 times. One of the wires is radio side and all three connected in series are antenna side, hence ratio (1:3)^2 = 1:9
I bought a 49:1 unun from Amazon. I put it up with 80 meter wire. It was about 60 feet from a 49:1 Chameleon EFHW EMCOMM III. IT BEAT THE EMCOMM on all frequencies. Better SWR, better performance. Some of Amazon’s stuff is pretty good.
Love your videos use to live in Marengo but moved to Tenn keep up the good work 🦿🇺🇸👍
Ham Radio Dude Rocks!
I appreciate your kindness, thanks!
Yes, yes he does!!!! One of the best ham's I have encountered!!
Thank you also! I appreciate the support
@robcue4543 Can you email me with your callsign? Thanks, and sorry. sean.klechak@gmail ... I must not have got it on the stream on Sunday.
I have one. Ran it with 62’ of wire and 50watts. Worked well 40m and up with my little MFJ manual tuner. Made lots of nets and contacts. Still in a drawer here somewhere.
Nice to know they actually kinda work. I was looking at one of those for a specific QRPish scenario for 6m.
I use one with 58feet of wire plus a 30 foot counterpoise and 2 17ft secondary counter poised 45 dg apart verticle. My feed point up at 30ft. Worked the world. From uk
Thanks Dude. I bought a CHEAP 4:1 off of Ebay to test during the Big "C19" lockdown. I was actually surprised at the quality. I've used it on an 80m Doublet with 135' of 14awg THNN wire, 75' of ladder line, and it worked surprising well. I guess that in some cases, it's just luck of the draw. I surely got lucky on it. Thanks again for all of the great content, time and effort.
I've always have had HF beams or verticals. This summer I tried a Palomar 9:1 unun with a choke outside and a isolator inside. Total wire length is 188 feet. My swr is less than 1.5:1 from 160 to 10. NO tuner. Low noise and if I can hear them I can talk to them.
If the rain decides to let up this week, I am going to try that length (or even more :) ) . Thanks for the length!
I got the same thing but dismantled it and made a better 9:1 unun. Its working fine for the most part.
I bought one of these some months ago and took it apart to see how it was made. Mine has *exactly* the same issues as yours; loose nuts and so239. I decided not to use it until I can get round to rebuilding it. 73 from 2E0LNS
Amateur radio is a hobby that licenses us to design and build ALL our own stuff, even with just a Tech license. It's a license to do, a license to learn.
A good FT-140-43 toroid on Amazon is $6.95, and it's $4.99 for 32' of 22 gauge magnet wire, with enough wire let over to mae a 49-1, too. RUclips is full of vids on how to wind a 9-1 toroid. Mount it on a piece of wood or plastic. Solder the antenna wire and the coax to it or just wrap the wire around screws. The whole thing takes about an hour. Then the ham knows how to do something.
BTW, nothing beats reading up on a little antenna theory to make them behave properly. Lots of good stuff online.
With some hams I'm put in mind of someone buying a motorcycle because it a looks like fun, but expecting it to drive for them so they don't have to learn how. That's just silly. The fun comes from learning and knowing how.
any good online resources you can recommend?
For 16$ or whatever rewind the torrid, tighten up some nuts, at a little solder and you are in good shape. I dont think you can get a qrp unun kit cheaper than...
Video coming soon, with an added "Special" trick. But yeah, For the price, why not.
I made a small one like this... never did twst as thorough as you did, but should.
Great video. Really liked that you were able to show the core heat to the point where SWR skyrocketed. I never knew what would happen when running one of thee devices close or above the limit. Very informative. As an aside, could you explain when you would want to use a 49:1 unun vs. a 9:1?
A 9:1 is for a random wire and a tuner, a 49:1 is for a half wave/multiple half waves.
Apart from the build "quality", I think that unit is a good buy, 18 bucks in Canada. The size of the toroid would tell me that it is intended for no more than 25 watts, QRP hams. Nice to see an object tested close to its practical limits.
Nice thorough review sean!
Thanks for doing the testing. I enjoy the videos.
Had one of these and twisted that coax connector right off in the first hour, can’t remember if i binned it or sent it back, either way should have kept it for the parts bin.
Did ya ever make the part 2 of this vid. Would love to hear more abt it
Unfortunately, I don't remember what part two was supposed to be? I may have... If not , I will.
@@HAMRADIODUDE ah. You mentioned using it in the field. Was hoping to see how it performed on ssb.
I own one of this and I had to literally resolder half of it after one use. Anyway it works. Cheap but not fake.
Definitely not horrible. I don't believe I ever said it was fake?
Thanks Sean. Fun antenna
Thanks for watching. It was fun
@@HAMRADIODUDE Mine arrived today ;)
@@don_n5skt that's awesome. What are you planning for it?...I mean, probably use it for an antenna.... Lol, but anything in particular?
@@HAMRADIODUDE Yes, I just started playing with the Random Wire antennas and I am amazed what you can do with them. And I don't always want to wind one up so this is perfect.
Wonder how long it would last if you packed it with dry ice😂
@@imahamjim :D
Great work tnx bro!
thank you!
So nice watching twice. The guts Might explain why my experimental rybakov didnt work! Bahaha
Ahhhh, yes that's probably it. Did you use the 4:1 from the same Amazon page? I bet the soldering is just as excellent
QRP un-un heats up at 100 watts ? Who would have thought ?
Oh boy! The $15 Amazon antenna special. I'll pass. 73!
I'll pay you to take it! 🤣
Fun video! That's outrageously inexpensive. How can they even build it for that amount and still make a profit? Well, I guess we know how, but still, pretty amazing.
It is remarkable. $9.50 now.
49.1 or 9.1 im confused
İt works...
For $15 I could build my own. Well, I’d spend more than that getting wire, cores, boxes &c but I’d be able to build three or four of ‘em & at the very least know the parts quality & construction were my own damn fault. Which, I gotta add, I have done. Seven or eight times. And, were I a beginner, I’d have learned something too. So, nah. I’ll pass. But thanks for the video, amigo. 73 de W8IJN
Nice seeing you. Thanks for the input, great point. Extra toroids for extra testing and experimenting
Wow the innards of that transformer are punny! The quality control is less than good for this product. I think I'll stick to better known manufacturers.
You should try HRD Industries for your antenna needs :D
Crikey! Flick your hands around as much as you want, some people are too much.
I use a 9:1 with 73' of wire i love it though its a substantial unun. This one looks like a toy.
Why the hell would any radio amateur worth his salt BUY an end-fed antenna? Have you learned nothing?
EndFed antenna's are pretty good. The mistake you make is you think of the past. When Ham's ran a EndFed into the home to a tuner. That could cause all kind of RF problems. But this is a different antenna. It still needs a 1:1 though.