How to make a 9 to 1 autotransformer (UnUn)
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- Опубликовано: 5 окт 2024
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How to make a 9 to 1 autotransformer (UnUn)
In this video we make a 9:1 autotransformer, also called an UnUn. this device matches a 450 ohm load to a 50 ohm source. It consists of a trifiliar wound toroid, an So239 connector and a couple of binding posts.
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Thank you for the concise video. No extraneous "chit-chat!" Straight forward, clear and to the point!
Ha. I bought one of the kits from Amazon and the instructions might have well been in Chinese...Your video was exactly what I needed. I followed you and paused on your diagram... I was able to make it and I just worked NY from Arkansas on 1 watt at a flat swr. ... thanks
Oh nice trick with the marker to figure out how long a wire you need - Kudos!
Very nicely done. You have a great ability to explain complex tasks so that I can understand. Thanks, and I wish you good health. W2UW
This is the clearest explanation in youtube I have ever seen well done ! 73s
Thanks. The secret of balancing EF antenna impedance to RT/TX set is unfurled. That was very educative. 73s
Great presentation. Clear, concise, great visuals and well done all around. Tnx!!
One of the clearest explanation s of the topic! Thx
Excellence as always brother! I like your style. My dad went fast in 2015 didn't get the time to say all the things I wanted to...take the time
+area46241 Thank you
Thank you very much to share this video. Make an 9/1 laste week with a toroide of an old TV. Works perfectly in 11 meters also in other bands with other lengths. TKS so much 7351. The best antenna I ever home build with very very good results. Using for 11 meters 4,50 meters long attached to the Balun.
Nice explanaton and diagram. Thankyou for the walkthrough. You used 22 gauge wire and said that it was good for approximately 20-30 watts of power. If I wanted to use 100 watts of power 14 gauge ought to be enough I would think.
.... you would probably be OK with #20 wire on the same core, unless you use 100% duty cycle.. CW key down or RTTY. He's using color coded poly insulated wire but enamel insulated motor armature wire would be better and easier to work with... just keep the 3 winding parallel to each other, meter em out if your not sure. He doesn't mention the core type and material... Amidon T200 red cores are the correct core material.... rated 2-30mhz .. unless your doing 6 meters.
T200 is terrible! 31 or 52 mix is better.@@richardfryer3695
Thanks for sharing. Great tutorial. A simple schematic woul help clarify (see comments and questions bellow)
Nice presentation. Also, so timely for me. Thank you!!
About the best video I have seen on the actual construction of a 9:1. i want to build one now. Thanks so much. KI7OOM
Never mind. I see it now. The turns ratio is 3:1. The impedance ratio is the square of that.
I like the way you teach. Thanks 👍🏽
Thanks for the clear description and best wishes for your health issues. One thing: should you not use silicone or Teflon coated wire, rather than PVC coated, in case it heats up, as these are prone to do under load?
Wow! Thanks for some great tips! I have 3 magnets from a microwave oven that aren’t very “magnetic”. Will they work as a Torrid? If not, where can I find the right Torrid? Really need to know about this so I can move forward. Thanks so very much!
Do not need capacitor?
are there 9 turns or 8 turns in an 9:1 unun. I'm kind of confused
Any specifics on the correct toroid to use?? Is there a particular size, material to use for this application? Also best place to get a high quality one.
Super clear! Excellent!
nice video wish you stay healthy and share your precious knowledge
Thank you for sharing, may we know the size of the toroid? Thanks 72
Excellent video. Please take time for yourself, as needed.
+Peter Ashley I will, thank you
It helps if you draw out that diagram, then put a colour 'dot' next to the A1, B1, C1 lines, top set ( I used red green and blue wires...sooo...used red green and blue dots ( duh !).
Do the same thing for the bottom set of wire ends, they should be in the same sequence of course, both top and bottom.
Then draw the rest of the diagram. I found it just makes it easier if you need to refer back to the diagram at any time, which since I was being VERY careful...I did often !
Hey your working on the same kind of things I am! just got my tech license last week and just made a 1:1 balun.
looks like a 8:1 UNUN why not 27 turns with a tap on the 9th turn?
I had the same question, but otherwise, the video was extremely clearly presented.
No, this design is a proper 9:1 impedance matching UnUn. The impedance ratio is set by the three wires being connected in series (A feeds B which feeds C). The number of turns around the core does not determine the ratio.
Your graphic only shows 8 winds in the center of the toroid. Shouldn't it be 9?
Should be.
@@twohandsandaradio It's still a 9:1 though.
Thanks Paul, built my first one today, went good. Maybe I’ll meet you sometime we only live about four miles apart hi hi. 73
Really? Where about are you?
learnelectronics Up on Lee Ridge off 213.
Awesome!
Just one question, Which torrid did you use for this project?
Hello sir.
Good job you've done.
I have several toroids Amidon FT50-43, and 3 pin flat stranded ribbon cable 22AWG. I want to experiment with a Un-Un 1:9 random wire antenna. These toroids (FT50-43) are very small, do you think the 22 caliber will work well or do I need less diameter, 20 or 18 maybe.
Thank you for answering
73 Jorge
I am interested in reception only, I guess the power requirements are a lot less then?
Very Good Video. Thank you
Nicely done.
Thanks man, great vid
Great work as usual. Look after yourself and your family my friend. I'm sure we'll survive without the odd video! ;-)
+gartmorn Thanks buddy
A great video. Thanks. N2NUT
Can Someone PLEASE Explain to Me WHY ITS NEEDED FOR ANTENNAS?
Im Brand NEW In HAM Stuff.
I Made an antenna today and my radio receives MUCH MUCH WORSE THEN With my antenna :D
I Didnt think that its possible;e, but god damn, i remove my antenna and signal is beter
As previously stated the making of the 9:1 UnUn quite clear even a half whit can understand; but, I don't.
A single wire antenna? What sort of antenna would that be? I don't believe I'm familiar with any.
Longwire, or beverage.
Paul, would a Toroid Core FT140-43 Ferrite work? Also, what size of box did you use? I am planning on using mine for a random wire antenna for shortwave listening. I have some 16 AWG wire, will that work okay? Also, how can I connect the coax cable to my radio that has two screw terminals? I wish you the best of health and would like to support you on Patreon if you can sent a link for it.
What size toroid did you use and where did you find it? Also, what if you wanted SO-239 connectors for both antennas?
Good build and for making the video.
73
wd4dda
hello, kool video. can you make one for a 6:1unun
If C1 is being fed by the coax center conductor as in your diagram, and it comes out of the winding as C2 and goes directly to ground, that's definitely a problem right there.
Splitting it into B2 means half your outputted signal is going to ground before it even reaches the antenna. No way!
Saying "to your tuner" is not a concise explanation. It needs to be; feedline center conductor, outer braid (which is feedline ground or negative),and station ground.
In referring to the antenna; antenna feedline/antenna negative or ground/and earth ground. That is how to refer to these various elements.
Simply saying to the antenna or to the tuner is confusing. Thanks.
You mentioned transformer=heat. Does that make it wise to use hot glue?
If it gets hot enough to soften the glue, you are probably going to overheat the wires.
No apologies needed 👍🇬🇧🕊
Which torrid did you use?
How do you make a unun for something with 2500 ohm’s
Does it cost more to buy it, or cost less to make it?
Depends on what in your junk box and where you buy from. If you buy from palomar engineers it's cheaper to build it. If you buy from AliExpress, cheaper to buy.
Does the size or composition of the torrid matter. I've watched a few "training" videos some mention the size and some don't. I typed the number on the torrid in your video and came up with a bearing seal? Great video It's much fun learning this stuff from yous guys. Please keep it up. Thanks. W2AAO
The composition of the core matters, size only needs to be big enough. But different cores will react differently at different frequencies.
We have something like that at work. Except they're stainless.(Well probably not because they are easy to drill through). We use them for hinges on one of our machine gates.
But I think they'll have iron ones at the hardware. I can't think of the name of it off hand but we use them to keep things from sliding down a rod. I see the set screw in the one you're working with. One of the guys said he uses a "Powdered core" torrid.?
Yes, mine are powered core. It's just iron and other chemicals ground up and pressed together.
Was that a metric craptonne of power loss or an imperial crapton? Y
imperial
Big question is how do you determine the impedance of the long wire antenna? The Radio is already marked if it is not to old of a radio.
+Carl Davis I believe it is assumed that most long wire antennas are about 450. If it's out of that range, an antenna tuner would be required. I could be wrong here, RF has never been my forté.
👍👍 Another useful video! Take care my friend.
Thank you, sir. I will do my best.
Where does the 9:1 come from? I'm seeing A1 to A2, 8 turns, A2/B1 to B2, 8 more turns, B2/C1 to C2 (and ground) 8 more turns for a total of 24 turns. The tap at C1 is 8 turns to ground. 24:8 is 3:1.
Steve O'Shaughnessy The “9:1” refers to the impedance match. 50 Ohm x 9 = 450 Ohm. The impedance ratio of a transformer is the square of the turns ratio. The square of (3:1) is (9:1).
Thanks.
Thanks for the information on how to build a 9:1 . Thanks again and I pray that you and your family get doing better.73 AE4OY WILLIAM EM-81UF
Always good to know there is someone praying for someone else's family. God bless
I hope you AND your father are OK!
I am fine, thank you. My father is not well. I appreciate your thoughts my friend.
Incorrect picture. wire rotation on the toroid falls in the same position.
You Tube It’s an Escher toroid. 😄
Wiring a torroid...they teach that in undergraduate class??
+Michael Padovani nah, that's just my interest. This semester is all about passive components, Kerchov, and superposition. Lots of calculus, closed loop integrals dv/dt etc
learnelectronics ah yes fun stuff. Sorry to hear about your dad. On a brighter note, my 3 month baby girl likes watching your videos too! Health and people first always.
+Michael Padovani Thanks buddy. 3 months old... About half way to baby food if I remember right? I remember trying to feed my son baby food the first time, it was so funny. You are building great memories my friend.
If you want to get fancy, get some Solarez, after you are done winding the coil, dunk or coat the coil/toroid with the Solarez, put it into the sun for about 3 minutes and you have an instantly sealed and hardened coil, completely waterproof and secure.
Nice one! I'd love to see how to make an SWR meter. I guess you need one too!
That is on my todo list. But actually my X108G QRP radio has a built in antenna analyzer.
learnelectronics I really like the idea of combining the electronics and radio ham hobbies. I only have a few VHF/UHF handhelds and a DMR handheld so far. Plenty of plans to build a load of things but time and money is always an issue. :) Did a classic Pixie radio last year, you might want to have a look that are only a couple bucks on eBay.
Good video and explanation, but take care of Dad and yourself before anything else. ........................................Berni
+berni ken thanks
good luck to your dad
My father passed away Feb. 18, 2018
Да ладно, бифиляром тоже можно мотать, не страшно если перекрутятся.
GB Packers fan?
+Steven Brown No, Steelers fan here.
3:40 "...toroid, like we talked about yesterday." I had to go looking for that: ruclips.net/video/K4zzIqstFtQ/видео.html
Forget centimeters, millimeters, and all that metric junk and use SAE standard.
Maybe you'd like to convert all the ham bands to feet or yards while you're at it.
@@leybald60 - My yard is likely different size than your yard, that would be a problem.
you should have stuck to the drawing my god have some respect for your work
Your an absolute troll. Stick to.porn videos and let us worry about science things. The video is excellent.