Ham Radio - Building a 4:1 balun
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- Опубликовано: 23 июл 2024
- I'm working on an antenna project and needed a 4:1 balun. Believe it or not, I've never built one before. Extremely easy to make.
This is a link to my video on winding the common mode choke.
• Ham Radio - The back y...
This is the site of M0PZT who's design I followed.
www.m0pzt.com/blog/4to1-curren...
This is a link where you can purchase the cores I used.
www.amazon.com/AEcreative-T13...
This is a link to type 43 cores mentioned in the video.
www.ebay.com/itm/Toroid-Core-...
If you like my videos, please subscribe here: ruclips.net/user/loughkb?s...
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Just last night my local club held its monthly meeting. One of the other members brought in his balun he was having trouble with. I'll have to send him this video to see if it helps him! Thanks for being timely! hihi
Well, I bought a DIY balun kit on Amazon.....the instructions literally said "google it". I found this video, which basically told me the kit has the wrong number and type of core, and the wrong wire. I ordered the proper parts, followed these instructions and was pleasantly surprised at the results. I was at least able to use the box and hardware from the kit to make a 4:1 balun I know I can count on. It looks great on the analyzer. I wonder how I went 30 years as a ham without knowing how to do this, but that's the point I guess....keep advancing your own personal version of the radio art. Thank you for the info and the presentation. N2SUB
Excellent video and after reviewing your intro video and vast selection of topics i subscribed! As an old electrical engineer i know quality when i see it !!
Great video and demonstration on how to build and see what is happening with this 4 to 1 thanks to the minivna. You have mave visual what is often so lacking with a written page full of equasions and theory! Even I could build this neat little balun. Many thanks!
Really liked this one. Looking forward to the next one.
Hey Kevin, nice video. I built the 1:1 from your video. On this video, I see that the you mentioned 12 turns but on the 1:1 it is 8. I went with this recommendation and man does it work great! Had results as you have shown. With a 260 ohm resistor I easily got down to 1.5 with all but 80 meters which topped out at about 2.0, which is well within my auto-turner's range. I have watched several videos on baluns but yours was definitely the easiest to follow, full of great practical info and excellent video work. Thank you so much!
Burt
K4SRQ
Thanks for this. It was very instructive, especially the verification you did with the VNA. I'll really need to get one.
You could manually sweep the range with just about any antenna analyzer and measure the impedance. There's also a way you could do it with an oscilloscope, frequency generator and ohms law. :-) But the VNA is proving to be one of the most useful tools I have.
Great video, Kevin. I've used type 2 material cores for HF for several baluns and ununs and they work great, as you mention. Can't wait to see the antenna project you mentioned. Talk about a tease! 73 W9DKB
Great video, Kevin. I’m not too surprised that the two cores don’t interact much since the magnetic fields of each are highly concentrated in their respective cores. That said, there’s nothing like real data to validate theory. Thanks for making/sharing this video and Happy Holidays. - Jim (KK7CSC)
Glad to see you speak English bal un, gonna have a go at this one.
Thanks for the videos.
Your videos are excellent. I have to laugh at the way others have said how to pronounce balun. You are absolutely correct in your pronunciation of the word balun.
Keep up the good work, very informative and enjoyable to watch.
Hope to see you sometime if you make it back to the Fort and visit the FWRC or maybe field day or a fox hunt.
Take care and enjoy. Clark 73 KG9FM
I've heard them all: balun, balum, balloon, baylum, baylon (US guys seem to like these last 2). But the most way out one that I remember, sounded more like baa-lamb :) Ununs have less vocal variation, mainly younuns, or younoons! But seriously, thanks for yet another highly instructive practical video, Kevin!
Our club in Central Oregon is preparing for a field day when weather permits for building off center fed dipoles. I have a Nano VNA and had planned on using it to confirm I have 50 ohm at the coax. I am still just a technician so I am trying to get my feet wet. Thanks for the video.
Excellent video and presentation. I have used a home brew off center fed dipole with 4 to 1 balun for several years (10 or more years) for 80 through 10 meters. The performance is superb as long as you keep the legs of the dipole at least a foot away from tree limbs and other conductors. My balun is able to handle 1200 watts PEP and 600 watts RMS with ease because the toroids I used are muich larger than the ones you used. Amidon makes a kit for this balun that works great. The radiation pattern from the OCF on the higher frequencies seems to have multiple lobes but on 40 and 80 it acts just like any other half-wave dipole. It is my go-to antenna for portable operation. Thanks for sharing it with us. Great job, keep up the good work. 73 DE K7RMJ Frank
The antenna I'm building is a mono band and ocf. Works amazingly well on the band it's cut for but not on others.
Great info!! Thanks for sharing!!
The idea of this config of 4:1 Balun is it provides 4:1 matching but also if you use 43 or 31 mix cores the two 1:1 baluns connected series one end parallel the other end also give you common mode current choking as well all in one balun
Good excellent tutorial and info. Thanks
Great job Kevin. JJK
Hi Kevin great video.
I missed the Patreon video because I was contesting. Seven wire thermostat wire works good also. Now I'm confused Kevin. I been told by some EE's that mix 43 and mix 61 are good depending on the power pushed through the torroid cores. I don't think I will have any problem since MAX on phone would be 10 watts; 5 watts using CW.
Hi, I just made the same thing and terminated the ends with 200 ohms and SWR was great or to say low. I use the same materials.
Thanks Kevin
Excellent. I want a miniVNA.
Great video !!!!!!!!
I have been wondering if the Litz wire has been forgotten or is there some reasoning why it is not needed in these kinds of wound components. Just recently I had a reason to check the numbers again. The result was that resistance of both solid wire and ordinary stranded wire is in steep increase already soon above 100 kHz. That applies to AWG 18 size.
I can speculate that the Q-factor does not collapse at the higher frequencies as the inductive part of the formula also increases by the frequency. Anyway, my situation was dictating Litz wire use at 100 kHz due to overheating of ordinary wires. Another difference is that the shown toroid coils are pretty open, allowing cooling, while my choke needed to be 3 or 4 layers thick.
I'm on the verge of this and I've watched your's and other folks videos on building an unun. Mine will be for end fed. While you make it seem easy, my fumble fingers will make an easy job difficult. Who knows I may wind up with an antigravity torus or a fire starter Bear Grylls would be proud to own. I'm sorry for jumping on you about kerchunking. I didn't intend it to sound angry or vicious. Sometimes my fingers type with out consulting my brain.
Lew, I don't think you will be happy with 4:1 on an end fed wire. 9:1 would be minimum. You may need higher than that, depending upon the wire length and bands used.
Nice work, Kevin! Would this be considered a voltage balun or a current balun? In researching OCFD antennas in the past, some people seemed particular that it must be a certain type of balun (I think current IIRC). Maybe you could explain the difference in a future video and why it is (or isn't?) important? I was never certain if it really mattered because I thought it was impedance that the balun was converting. Impedance is a ratio that involves both voltage and current, so saying a balun is just one or the other didn't really make sense to me. At any rate, this was really useful to me because I was about to build a new OCFD as well. Thanks for the video and links!
This is a current balun. From what I'e read, a voltage balun would't work well in this application due to the phase relationship between current and voltage along the dipole antenna. Most antenna projects I've seen that involve a balun warn against using the voltage type and recommend the current type.
Thanks for the video.
I was wondering if this balun can go in a metal enclosure or if plastic is recommended.
I'm making one on smaller 43 cores and it would fit in an Altoids tin which I already have, but don't want to use if it will adversely affect performance.
I've put them in both. It doesn't seem to matter.
Thanks for sharing!! Could you post a link to where you got the VNA?
It was donated to the channel. However, a quick search on amazon.com should turn up several places that sell it.
Great Video! What if the results had been different and there needed to be adjustments? How would you adjust the windings to get the SWR down if needed? Thanks! 73 de KD4NZR
If the translated impedance was high, I'd have added a winding to each, if it was low, I'd have removed a winding. I think I got that the right way around! :-)
I hope this antenna installed as an inverted vee doesn't shoot everything straight up, I would like a suburban backyard antenna that can work some DX on it. My mast can support a dipole at 23 feet, and have plans to make it 31 feet max, with ends 6 feet above ground with angles going from 115 to 105 degrees when I get it higher, in a 79.5 foot space. I will be taking notes on this one. Thanks Kevin.
Well, this is a unique design. First I've seen of this type. It is a monoband antenna though. I've built it for 40 meters and it's performing better than any 40 meter antenna I've ever had. It would fit in your space, but you'd have to choose a single band.
@@loughkb One of my friends has a 80 M version and made another for his son. I was considering a 40 M sized version to try out by modifying an existing dipole. Or just making it a 80-40 coil loaded dipole. My friend has already sold me on the design, I am sure your going to really like yours. And I'll still be taking notes from you on this.The 4:1 balun design was another element I needed to know about too. Yours is easier.
Since this 4:1 transformer is made utilizing two common mode chokes, does it still function as a common mode balun as well as a 4:1 transformer?
Kevin , I noted you used multiple strand wire and not solid drawn wire. It never occurred to me to use multiple strand wire. It obviously works!
It will, but it's hard to work with since it doesn't want to hold its shape when wound. I used solid core wire. The photo from M0PZT site shows he used stranded.
I am a returning to hobby ham (yes one of the many.) I have built this Balun, and truly enjoyed doing it too. Now please dont laugh me too much out of the room, being a comedian its normally a requirement of mine, so when I ask my stupid question, feel free to use the more 'pantomime' BOO! for added effect. Ok here goes, oh if you're reading this YET you have still give it the thumbs up it deserves, shame on you ...right here I go... I know the radio end and the ATU etc, I'm just asking for a short diagram showing, radio, to balun and how it would connect to the antenna...Ok disclaimer time, I think Im looking at a dipole set up here but I have come across people talking about end fed types... So I'm sort of in between the two as far as my sapped knowledge is - so if anyone knows of a suitable video, I'd like the link. My call is G0TUZ my name is Marty, although I'll answer to most things, even dumbass as long as I get the info lol All Radio Hams & your family's Please stay safe and I wish you all many QSO's down the log. I just bought me an FT818nd for some QRP DX so listen out for a clunky bit of Morse on a frequency near you soon....Its great to be back in this superb hobby!
dah di dah, dah dit...!
I'm not entirely sure I completely understand the question. However, Your coax connector back to the radio and tuner would connect to the bridged wires on the input of the baulun, where I connected the VNA. The output of the balun, where I connected the load resistor, would go to your antenna wires.
Nice video Kevin! Will one of those work on 2 meters?
Not with these core types or windings. At those higher frequencies, you would need different components. Also, with a half wave dipole being somewhere around 38 inches, finding the 200 ohm off center point would be difficult. Impedance could change quite bit over an inch at VHF.
If I use this on an off center fed dipole do I also need a 1:1 choke to suppress RF on the coax or will this balun suppress it? Thanks!
Due to the way this one is wound, I think it will supress a bit of RF going back up the feed line. You probably won't see much on the band the antenna is cut for. If you force the antenna on another band with a tuner, you'll always get some RF down the feedline due to the mismatch at the antenna.
Yes, this would be used on an OCF dipole like a windom. Also used on a folded dipole.
@@loughkb thank you sir.
On the 1:1 choke video you me tioned 4 turns on each side as a 1:1. But here you mention 6 turns on each side for rhe 1:1? Thanks for any help great video easy to follow and understand
When just winding a choke, you can use any number of turns, as long as it's identical for both wires. More turns mean more 'choking' action, but maybe greater losses in the choke.
When winding them for use in this balun, the number of turns matter for proper impedance transformation.
@@loughkb okidoki thanks a lot! 73 de NP3JD
Yo Kevin!:
Great video! I too would l would like to know if this is a current balun or a voltage one. Would be very interested in the antenna project as well. Have some questions I will outlay in an email to you as well..
73's!
de seeker / Jeff
It is a current balun.
For higher power capability, would larger wire size be required? Core size also?
Yes and yes.
Hi,
Can this 4:1 UNUN be used "in reverse" -1:4- ??
I'm wondering if it's possible to use it on a Cobwebb 40...6.
Yes. Transformers are bi-directional.
Kevin great video ,your tablet is it iPad or some sort of Android device ,thanks 73 good DX Dave
It's a Samsung android based.
core material 2 not so usable for wideband common mode choke OR un-un. best for resonant purposes ...
where did you you purchase the mini vna?
It was a donation to the channel, I'm not sure where the viewer bought it.
This the one for an end fed Zep?
It could be used in any antenna project requiring a 4:1.
Hey Kevin, i made i bigger version of this 4:1 balun.....but i have a question.......do you think that i can mount this balun attached to the antenna, or i need to keep it far from it??
The 4:1 balanced to unbalanced matching transformer is designed to match a higher impedance balanced system to a lower impedance unbalanced feed line. So in the case of a loop, an off center fed dipole, or ladder line to coax, the balun needs to be at the high impedance point. So at the antenna. And that's what balun means, balanced to unbalanced.
@@loughkb sorry i asked something different, i was wondering if the antenna metallic boom would make some problem if i attach balun close to it
@@bairamzubi280 you would not want it too close to the boom. A few inches away at least
@@loughkb argh i have already mounted it on the boom.....with nano vna idont have any chage....i hope that it willthe same with 500W. cheers, thanks for sharing 73 IU4PSD
@@bairamzubi280 at 500 watts, I hope you used appropriate wire and insulation from the cores so it doesn't arc
Wonder what affect would be if you reversed one of the baluns so that the two wires tied together (brn/wht) are both on the inside. If I made myself clear.
Oh, was the part where you made the balun only available on the Patreon side? “Building a 4:1 balun” seems inaccurate as a title.
Well it wasn't put into a box, but the transformer was built in this video. All you need to do is wire it to a couple of connectors mounted in a box.
so, it’s a transformer AND a common mode choke?
Functionally it's just a transformer.
Play it back, you sound Scottish when you pronounce it incorrectly ;-) Excellent video.
61 Material would not saturate as much as 43
The two cores in the M0PZT balun that you reference are NOT wound "SYMMETRICAL" - why doesn't anyone mention that, and/or the possible affects of that ???
If you look, the red/black colors are REVERSED on the windings between the left and right cores.
On the right core, the winding starts with the black wire on the RIGHT, and on the left core, the winding starts out with the black wire on the LEFT, but yet the red's are tied together, and the black's are tied together on input!
What affect is this going to have on the phase, etc. (interactions?)
Can someone please explain this ?
At minimal, you didn't duplicate what he did, nor recognize/mention this in your video. You should fix that !
Yes, they are physically wound symmetrically. Nothing to do with how they are electrically connected.
Good morning... from a conspiracy theorist. Have a good day!⚔️🇺🇸⚔️
Go to bed Kevin. LOL
Don't Use the cheap Chinese Made One's,