Intro to Baluns
ฝัง
- เผยแพร่เมื่อ 28 ก.ย. 2018
- #HamRadio #AmateurRadio #Balun #KensProSound
Fiori Films Presents Ham Radio TV: How to make homemade baluns.
In this video Kevin N6VLF and Bruce N6THN, talk about baluns.
Special Thanks to Ken's Pro Sound for setting up professional audio to enhance the room's audio as well as supplying a direct feed into the camera. Check them out at www.kensprosound.com
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@ 10:02 I'm not sure what sort of explanation that is, but a balun is basically an RF choke that eliminates, or chokes via the toroid element, stray signals and RF from traveling down the feedline back to the transceiver. This RF can be produced from an unbalanced antenna. Strangely enough, an inverted vee is a balanced antenna if properly cut, so no balun is actually needed. Also, their saying you get 500 to 2000 miles from a balun is kind of hyping it as a magic box. You get the distance from your antenna and transceiver and feed line, the balun simply allows you to use an unbalanced antenna and/or feed line.
Watch this series, its exactly what you need. th-cam.com/video/kMlKfHHR8FY/w-d-xo.html
Actually, the inverted V is a balanced antenna but you are feeding it with "unbalanced" coax. If you don't use a 1:1 current balun at the feedpoint, CMC (Common Mode Current) can flow on the outside of the coax back to the equipment and cause distorted audio on transmit. The 1:1 current balun blocks the CMC and forces the RF equally into both halves of the inverted V or dipole where it can be radiated. So adding the balun can improve the range because all of the radiation is up high in the antenna where it belongs instead of running back down the coax shield where it will only cause trouble.
bravo..good job..my friends
Thanks for posting an interesting and informative video on a choke balun. M6APJ 73's.
Thank you. We want to make more videos around baluns, so stay tuned.
Thanks.
Welcome!
W5ESH Darrell what size wire is used to make the Baluns
I used a FT240-31 ferrite toroidal as described with 12 AWG PTFE stranded wire and wound it according to the instructions on the video. The Balun didn’t work. I got what appeared to be infinite SWR on all bands and could not tune with my antenna tuner. First thinking that my coax was shorted, I used my DMM and eliminated that thought. Next, thinking I wound it incorrectly, I double checked and everything was wound correctly. Next, I shorted the winding on the Balun to bypass the toroid and my SWR dropped to under 1:3. I rewound the toroidal using the Guanella current 1:1 style and everything worked fine. I am wondering if the design is incorrect.
9:30 where might I find this Balun Chart (that Bruce references) on the internet ???
can you all do a video/class on using an icom ah4 on yaesu and kenwood radios, such as the yaesu ft.450d and the yaesu 857d..... making a unit to start the tuning process.
Great Video, I am just getting into Radio (not even a HAM yet, just planing around with some SDR's). Thinking of building one of these for a 15M Dipole using strands of solid copper Ethernet cable.
As a network tech it's something I have in ready supply. I'll let you know how it work.
Awesome and good luck!
This was an excellent presentation with good teaching material! Thanks!
The title of this didn't live up to the video name. Nothing about wire gauge, insulation, bifilar, core permeability, impedance matching the list goes on. This was the equivalent to I bought a toroid core used a chart to wrap wire around the core I bought and used Teflon wire but further explanation.. How often is your balun going to be on fire? Anyway, really enjoy the geek sphere around radio - good work guys!
Excellent all your video ,only one question.For 20 and 40 meter a can use ft240-43 or ft240-31 wish one work better thanks in advance Eddy
I got a 9:1 UNUN, then started with 124.5' but 160, 80, and 40, were too high for internal tuner. Cut to 121' and working great with external tuner. Now, with internal, as high as 2:7. but at 5 watts.
If power is increased, even to 15 watts or 10, it will go very high. Will the chart I used work better with a 47:1 UNUN instead? It is an end fed with a 30' counterpoise, but planning to use a ground rod to see differences.
Now, 20, 15, 12, 10 and 6 are working great with internal or external tuner. Thanks.
can it be for RIG Alinco DR135 MK II radios?
If I'm doing a field construction of a balun to operate a manpack HF radio, how crucial would the ferrite core be?
YOU ARE Awesome !
Thank You!! I will pass the message on to Bruce / N6THN!
Hi guys from the UK. Great video. Look forward to seeing more... many thanks 🙏 just out of curiosity could you substitute 16swg enamelled copper wire instead Of Teflon coated?
Yes! I use RG8X coax for mine to keep the SWR low but I have used twisted magnet copper wire US AWG 14 and 16 (approx 5 twists per inch) without any teflon or other plastic type insulation. Most good magnet wire has 2,400 volts breakdown voltage but check with the manufacturer. Also, don't worry about rubbing the varnish and other chemical coatings from the magnet wire because 99% of all such wires come with a paraffin wax or pure mineral oil coating. Adding insulation increases capacitance and that is why you use either very tightly twisted magnet wire or coax to wind your choke. Remember that at 100 Watts into 50 ohms you have 1.414 amps and 70.72 volts RMS and at 1,000 watts into 50 ohms you have 4.47 amps and 223.7 volts RMS or 316 volts peak to peak. Also, note that if the effective antenna impedance is much different than 50 ohms, e.g. high SWR, the voltage can be higher but not above 2,400 volts. Good Luck!
What's the wire gauge?
Can this be used for 2 meter if so how would I build it
Will baluns in general make RX improvements as well?
very good video from 9w2asf from west malaysia
T 845 Thank You! Wow, Malaysia, that is very cool!! 73 Jason / KM6FAK
Can you give me the size of the core I heard the type 31 part?
i really love HF over in america, after listening to a few online SDR setups.. Americans seem to stop and chat a lot more compared to here in Europe, we just seem to CQ wait for a response, take call sign and then move on :(. i really like the 40m band too, i've spent a few evenings listening to some really interesting conversations between people in america
don't let the HAM bands die out guys! :)
👍
HF is a lot of fun and I hope propagation gets only better! Rag chewing is great and sometimes that comes after I've called CQ.
@@HamRadioTV
Hi friend. I have a question with you.
Recently in my neighbourhood I had a problems with my electronics portable devices. I have 2 led Flashlight and saw how dying like if they was taking by electromagnetic perturbations...
Can I use that with mitigate the interference?
Where did you get the electrical box for building the balun. I can't seem to find them. Henry
The ferrite ring (toroid) catalog data gives the inductance foe each. BUT it is a little confusing, because they can vary their units. Some give it per 10 wire turns, or per 100 turns and so on. The important thing to learn is that the inductance increases by the SQUARE of the number of turns. And then you naturally want to use the frequency dependence to get the impedance at your desired frequency. Here is just one arbitrary example. Assume you see a listing of 4 nH/ turn squared. So, with two turns you get 4 * 4 nH = 16 nH. 3 turns makes 9 * 4 nH = 36 nH. 5 turns produces 25 * 4 nH = 100 nH. Ten turns then is 100 * 4 nH = 400 nH or 0.4 uH.. That last one at 14 MHz represents 35.2 ohms impedance (not resistance). That is the core of the required knowledge. Beyond that, you are going to pay attention to the frequency range that the selected ferrite is specified. And for the kilowatt implementations also thermal issues. Different ferrite materials have different maximum temperatures. But that is enough for the basics.
Thanks for sharing that!
Good one, the Ferrite Rings are magnetic ones ? Cable can we use 16 SWG Copper insulated ones ??
Teflon high temperature wire is silver coated copper. Silver is a better conductor than copper. $$$ K5LYT
Very informative. May i ask how long for the wire do i need to tune for 145mhz and 460mhz? im using dual band. thanks
The commonly used formula for a 1/2 wave dipole antenna is 468/MHz.
460MHz is not amateur radio frequency. Ferrite core baluns don't work well at UHF.
Another excellent video...👍
Show
Roger that, we will be doing more videos with Baluns in the future.
Great info
Everytime i hear someone say 3 to 1 swr is ok then use the atu. I have designed antennas professionally, and reject anything over 2:1. Even then i carry on to get 1:1 at the center of the required frequency and under 1.5:1 for at least 80% of the band in the case if ham hf bands. Teaching people that 3 to 1 is ok is not good. Everything has a ressonant frequency, so its down to the basics of making it resonate at the desired frequency, then design a feeder network to get the desired impedance. Do that and you have a happy antenna, with a 1:1 swr and some bandwidth. Even situations where there are physical restrictions to length, there are allways options available to get a smaller loaded antenna working at a low swr with a correctly designed feeder network... If you havent done that, then you havent finished designing the antenna... I have no room for an ATU in my shack. My radio runs straight through a swr meter, a low band pass filter, an antenna rorary sw, and to any one of my hf antennas, that comprise of a choice of 3 windoms, 3 verticals, and a 5el 6 meter beam with my own dual drive design. Please don't t teach people that 3:1 is ok.... Its a poor compromise at best...
It sounds like you have a lot to say. Please make a video teaching your approach.
Does it matter what side of the balun is going to coax and antenna?
It does. Kevin just did a talk on baluns here: th-cam.com/video/HlmEOfWvJc8/w-d-xo.html
I built the Balun and is good at reducing received noise, but it acted like a loading coil and reduced the resonant frequency by 2 MHZ. I would have to trim maybe 6 feet of antenna on both sides of the dipole to get back to 40 meters.
Did anyone else have this problem
i did the same😢
On a 1:1 current balun like the one you described, is the connections to the SO-239 critical ? Can they be wired either way as long as I have the right ends soldered to each other ? ( which I do )
Wiring is not critical on the 239 connectors, just get + to + and ground to ground. Use an ohmmeter and your good. I used teflon coated wire. Equal turns on each side of the toroid. As few as 8 turns to 12 turns will work. 73 Bruce
@@n6thn But I don't understand how in this case .. there is a + and - if the other side is balanced and its a 1 : 1 ?
You can make one from coax surgest look at DJ0 IP website.
@@ElecTechie 1:1 is 50 Ohm in end 50 Ohm oud thats 1:1 what this antenna is al about. The windings is like a transformer. Good luke en 73 from PD1Y
Thank you for watching. We are working on a part two, for this video.
I love your videos, but can you guys provide details in the description like suggest parts to buy? The presentation really didn't provide any detail at all. It was more along the lines of here is the magic device and kind of how it works, but you will have to guess on what materials you will need to buy it.
Thank You!! Yes, I agree. We need to do addition videos on the Balun and provide more details as you mentioned.
He said right in the video it was a 240-31 ferrite core, he held up the diagram clear enough to easily read, and you got more than one good view of the finished product. How much detail do you need??
I wish there wasn't so much inconsistency on the construction of 1:1 baluns.
Some have 5 wraps up to the top on one side, back down, and then 5 wraps the other way up the other side. Some say double wire, some say coax, some say 12 turns, some say 8...
Excellent presentation on baluns. Thx,
How does this channel not have more subs
Thanks Jerod, I agree with you. haha! I just started this channel about a year ago and really only started putting in the time to make better stuff the last 6 months or so. It can be hard to find time, but I'm having a blast putting out videos.
Ham Radio TV love them
What was the toroid the number went by so fast I didn't catch it? KI5ACA
240-31. Here are some links. Info: toroids.info/FT240-31.php Amazon:www.amazon.com/Fair-Rite-Toroid-Core-FT240-31-Ferrite/dp/B01959LAFA
Why not just put the toroid on the thin jumper wire between the tx and antenna tuner? Can easily get 10 turns in, and don't need a box assembly.
Awesome info thank you for the video
As far as power handling goes, you can figure about 500 watts per toroid, so if you want a balun that will handle 1KW, you need to stack 2 cores together. Also, you have your wires wrapped wrong ! They should be wrapped 2 wires side by side like: II Not wind one wire on one side of the core and one on the other. You are trying to created a transmission line balun and winding them separate like that is not the right way to do it ! In fact, for a 50 ohm 1:1 balun, it is best to twist the wires together and then wind them on the core !
4:57 again, how does he know the wire he did use to wind the core are of the right impedance ? How does he knows how much attenuation he gets on common mode current ? They say 8k ohm, how did they measure that ?
Hmm...I will forward this onto Bruce, the presenter.
@@HamRadioTV thank you, there should also be a video on how to measure common mode attenuation...
See my comments at the first of this article. Use a nanoVNA to measure impedance (R + jX) and dB return loss. Must be an S21 measurement. Won't be accurate using a single port antenna analyzer to measure a choke.
what was the wire size bruce used on the balun
I used 18ga stranded, Teflon insulation.
is this what you wound around the ferrite
where you buy it . thanks
You can buy all these materials from www.dxengineering.com/
Not sure on 1kW, but it will handle 500w no problem.
for some reason i would think a horizontal dipole would radiate straight up into the atmosphere.
I hear you, radio is almost like magic! But yeah, a horizontal dipole will transmit of the sides heading right at the horizon. An inverted V dipole will transmit around 45 degrees up and out (depends how its installed), which helps more local contacts.
@@HamRadioTV I would think the ground itself would act as a reflector, depending on distance to the antenna, so most would go straight up and some of it would go to either side, probably quite a bit might end up heating up the ground. I think if you're going to do a dipole it should be vertical so you get the full 360 and nothing going up and nothing going down. to me that seems to make the most sense.
The first minute and a half of this video is commical 😂😂😂
Its a work in progress. Most of these presentations are shot in-front of a live audience at our club meetings. I then edit it down to the presentation that hopefully makes sense but I'm dealing with cheap talent...lol
You've got a great pool of talent. This is classic comedy. You should work with it 👍
I tried using #14 Thhn solid wire to wind that balun... NOT a good result! SWR 25MHZ to 30MHZ was well over 18:1 as measured on a VNA. I have some PTFE #18 stranded silver clad wire on the way and I'll give that a shot.
Yeah, solid wire is not always the best to use for RF due to skin effect. Good Luck!
Cool share Bruce and Kevin on the dipole
Wait.... 47:1 - not 49:1?
9:1 a balun? A 9:1 is a unun, transformer. Unun is unbalanced to unbalanced, a balun is balanced to unbalanced! A 1:49 or 1:64 is a transformer, can be used for multiband Half wave end fed antennas, resonant wire. A 9:1 unun needs a non-resonant wire, any wire length. For 80 m a wire of ± 84 feet will do! Keep in mind that this antenna needs a counterpois, and a very good common mode choke! I really don't know why everyone calls it a balun, when there is such a big difference!
Would have been useful to mention a 20/40/60m fan dipole
I agree. Look for future videos on the fan dipole, both horizontal and vertical.
Nice presentation.
TXS KQ4CDPaul
You are welcome!
This looks to me like a great Ham club! KN4UXO
Thanks! We have a lot of fun and work hard to keep all the BS out.
Can ham radio communication be encrypted?.
Good question but no. It is illegal to to encrypt amateur radio signals. That said there is always morse code and digital modes available. Which would make it a lot harder for the average person with a scanner or short wave radio to listen in.
A licensed ham would already know this answer
@@stickycricket2 thanks I'm not a licensed ham radio tech. Still learning
What does your question have to do with baluns, or this video?
There is such a thing as a no antenna area ? that's just wrong . how do people watch tv or communicate with one another ? I am so glad I don't live in some screwed up area like that !
haha, yup. Some of these HOA (homeowner's association) are just nuts and I would never move into one.
2023 thank you relevant still
Nobody ever charges "a hundred bucks" for a 1:1 balun. And a 1:1 balun does not prevent "goofy interference from your rig", it is to stop common mode rf from your antenna. Sorry, I couldn't stand to watch any more of this.
Here is a balun for $99.95 and they have more expensive ones too. Thanks for taking a look at this video and I hope there are other videos on the channel you like more. palomar-engineers.com/antenna-products/baluns-and-ununs/1-8-30-mhz-balunsununs/11-toroid-baluns/CUBE-Feed-Line-Choke-Unun-5KW-1-8-61-MHz-20-38-dB-Common-Mode-Rejection-Static-Bleeder-Ground-Option-p74536617
Guy in the red shirt needs to learn some basic manners.
This "balun" is a complete bogus :-P
OMG. Have you guys ever heard of Powerpoint? Or even a simple flipchart? Sorry, great content, but the presentation style makes a lot of it useless.
Thanks! We leave it up to the presenter on how they would like to deliver the talk. Each video we capture can be a little different, but we are also working on making it better every time! Thanks for watching!!
Funk you
@@HamRadioTV This is not even close to being a balun. I feel sorry for those who watch this.