I Bought the CHEAPEST End Fed Antenna on Amazon for Ham Radio 

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. 👍

Nice to know they actually kinda work. I was looking at one of those for a specific QRPish scenario for 6m.

Ham Radio Dude Rocks!

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 🦿🇺🇸👍

Nice thorough review sean!

Thanks for doing the testing. I enjoy the videos.

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 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.

Great work tnx bro!

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 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?

Good video dude!

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

Thanks Sean. Fun antenna

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. RU-vid 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.

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.

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...

Oh boy! The $15 Amazon antenna special. I'll pass. 73!

So nice watching twice. The guts Might explain why my experimental rybakov didnt work! Bahaha

I own one of this and I had to literally resolder half of it after one use. Anyway it works. Cheap but not fake.

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.

QRP un-un heats up at 100 watts ? Who would have thought ?

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.

Why the hell would any radio amateur worth his salt BUY an end-fed antenna? Have you learned nothing?