How to make a 4 to 1 balun cheap and easy
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- เผยแพร่เมื่อ 4 ก.ย. 2024
- I built this simple air cored balun in next to no time. No need to worry about toroids etc. It works from 3 to 30 mhz and handles 200 watts easy. If you use thicker wire it will handle a cool 1KW.
@arizonabobusa Hi Bob ,
and thanks for the nice comment. I'm glad you liked the video I did on this balun. It was easy to build and I'm sure you will have no problem building it yourself. You may want to scale it up a bit for qro use. i have testrd it at 200 watts and it worked great. A friend ran 400 watts thru it and reported some heating in the so239 connector but otherwise OK.
All the best and thanks
Sandy
I built mine 4 years ago, fed coax instead of ladder line to an off-center-fed dipole. It works extremely well. 1 inch diameter pvc is what i wound the wire around, and then I encased it in inch and a half pvc with end caps, and have had zero issues with it. Works amazingly well! Thank you good sir!
Great vid nice to see people experimenting as for those who "talk the talk" I think they should "walk the walk" and make a vid, again well done and we'll presented.
Thankyou David.
I used to be a manager at Tandy, and that was interesting to see something that may have been made by the folks that purchased stuff from their.
Used to get a lot of people buying bits and bobs for projects.
An oldie now Sandy, but a goodie. Very interesting, thanks.
Hi paul,
You may be better to use multi stranded wire as this increases the surface area of the wire. the electrons like to flow on the surface. That way you will decrease any losses.
Thanks for your nice comment.
73
Sandy
Electrons flow on the surface. Only Really critical on VHF and above and silver plated wire is used. On UHF the amount of solder used can effect the tuning freq. Also cannot use wood glue to seal coils as it will boil on transmit. Nail varnish is used instead. Just extra info. I am just getting back into radio. Cheers from old George 13th june 2021.
Thank you for making the video, however this is a voltage balun and will also not have much reactance due to the air core. My first efforts at balun construction were also voltage baluns, though wound on ferrite cores. Having spent a while experimenting with various types I now only use "Guanella baluns", using ferrite very high common mode impedances can be achieved.
Hi, in the drawing one end of the thick black wire is left unconnected, but on the realisation I see that it is connected to middle conductor of the coax cable. which is correct? and if correct is the variant in the realisation of the balun then - doesn't it make a short circuit? Thanks for your videos!
Yeah, this video is really frustrating - all I wanted is to see how this transformer is wound - how hard can it be? But without a properly drawn diagram (with a wire hanging in mid air) I'm not sure how its done. I think this guy just copied some other design and is not sure what he built.
Thanks for the video. Good to see you are still active on TH-cam.
@2E0VJO Yes Jonathan I think it would work OK. I may make a few changes to the balun to improve it's efficiency,but so far as it is I'm having a lot of success with it. You could also just make a coaxial choke where the coax meets the ladder line on the G5RV. All you need to do is wind 8 or 10 turns of coax into a diameter of 6 inches or so.
Also do a search on the web for the "Ugly balun". That will also work and stop common mode currents or RF on the coax braid and lessen TVI etc
73 Sandy
Hi, to let you know, GREAT HORNY TOADS,,,,,, I just built one within one hour of watching this clip.... had 98 % of the material on hand... now I just have to go to hardware store and get the caps.. I tested it on meantime , and finally got 80m tuned in AT 100% FROM A 0%.... Though I had to make modifications in shack... and splicing...
Thanks a lot..73
Thanks for taking the time out to make this video, and to explain what you'd used. Big help to a relatively new licensed amiture. David (M0XQZ) Salisbury.
Not too far from me David. I'm in Swindon. Glad the video was of use.
Amateur.............fuck sake.
fantastic explanation now could you explain to this dummy what gauge wire and how many turns for a digital TV antenna?
Love the video. Very informative. I'm not certAin how long it will hold up in the weather but for learning purposes it's brilliant.
@reddog694uk Mark,
Your not dense. You would be if you didn't ask questions. You can use this balun to feed a balanced antenna system from an unbalanved coaxial feed. Both sides of the ladder line should have in theory equal and opposite currents flowing in them. Most modern balanced feeder is 300 to 450 ohm so this balun not only converts from unbalanced to balanced but also chasnges impedance from 50ohms to 300ohms.
I will PM you later
Sandy
Please watch the video again. If you pay attention you will see there is an annotation correcting the error.
Best wishes for the new year
Sandy
Great video, As far as looks ,it gets the job done!! Nice work Mate!!👍
Thank you for that clear, detailed and informative process video.
Your efforts are appreciated.
73's
1 : 1 HAS NO IMPEDANCE CHANGE, EG. 50 IN 50 OUT. 4 : 1 HAS AN IMPEDANCE CHANGE OF ROUGHLY 4 X THE INPUT
Thank you so much for the information on how to construct a 4:1 balun this will be real handy when I build my Delta loop. 73 AE4OY WILLIAM A. Peacock,Sr. (EM-81UF)
@g6vaq1983 Very interesting Fred. Thanks for your feedback on this. The cardboard tube should be fine. Infact I may just scale mine up a bit now.
73
Sandy
I thank the Wiltshire man for Balun info, I would encourage most Ham operators to put there mind to this money saving venture, It is so simple and Works it is difficult to understand why these emporiums put such an extortionate price on these as this me nothing, Two pieces of wire an old herb canister , inner toilet roll wound glued for strength and weight, pvc sealing tape............. GREAT.......
Hello Geoffrey, the balun shown is not as effective as those based upon toroids the reasons get rather complicated but take it from me that the experts are right in using baluns based on windings around toroids. Don't need to be expensive I have made a 4 to 1 current balun with FT240-43 FERRITE TOROID and using enamelled copper wire of about 1.5mm diameter, lots of info on the Web, hope to work you soon 73 Tony G3ZRJ
this is a voltage balun with a lot of loss, it wont stop your feed line from radiating.
Thankyou for you comment Craig. So true.
Sandy
Very nice job OM . Simple , effective , and CHEAP :) you did a good job explaining how it all went together and how it works . I've been looking for plans to make an air core balun instead of toroids and this is it . Like the homebrew ladder line also . 73 and gud DX
N7BDY
Interesting video which told me what i wanted to know🐻🤗👍
DESDE URUGUAY MONTEVIDEO ,, CIUDAD ,, SIEMPRE ES MEJOR HACERLO NOSOTROS MISMOS ,GRACIAS A LA AYUDA DE COLEGAS DE BUENA VOLUNTAD ,TIENE MAS GUSTO DE CREALOS NOSOTROS MISMOS EXELENTE TRABAJO ..GRACIAS POR COMPARTIRLO 16 11 2022 ,CX1BAN 73 CORDIALES ATI Y DEMAS COLEGAS . QRA EDUARDO ..
could that be fitted inside an atu,ie would metalwork nearby like the atu case upset its function? or would a torroid type be best?,cheers de m3vuv 73.
Brilliant video Sandy. I like homebrew.
72, Terry
Hi,
First, thanks for the helpful video.
Not to nit-pick, but the way you drew the schematic was, I think, incomplete: You did not show where to connect the second lead of the bifilar second winding (the one made with the marking pen). But the video shows it as connecting with the center tap of the coax, along with one end of the first winding (the pencil-drawn one).
73
Les
KE7SLX
I have just made your Balun and connected it to an antenna that l have made and it works perfect.
You are a genius like Nikola Tesla.
👍😁🥂🍾
how is he a genius, it's an old design that he stole from an RSGB or ARRL handbook.
been around for years.
Sandy, the legal USA limit is 1.5 kW. Most amplifiers rated at that output cost in the range of $3000 or more, 3X cost of the transceiver. I have amateur radio operator friends that have an amplifier. Probably bought on credit. I have never used an amplifier. Unless one is connected to a rig I use for my contest group I will probably never use one, ever. I have been a QRP OP since receiving my Novice ticket. The only time I transmit at 100 watts or less is when I contest with my contest group.
I discovered your channel about 3 years ago. Although I have not watched your channel since 2011 I have watched all your videos. I am current up to last week. Question about air cored baluns. Can they be used for 1:1 and 1:9 as well? P.S. Glad to hear the operation was successful. Hope to work you some day on the bottom portions of the HF bands. I rarely do phone. Best 73 de KB8AMZ
Hi Terry I have no way of testing just how effective this balun is other than saying I ran 100 watts into it and made many qso's. It was taken from a circuit diagram from an American magazine. A few years ago now.
Hope it works for you.
I read the wiki on Baluns, and I still have no idea why you would need one of these. I would think you should build your antenna to match whatever your receiver or transmitter requires.
I use a balun about like this, only I used 12 bifilar turns of Romex house wiring, I think it's 10 gauge solid copper, to feed my 260 feet long dipole for 10-160 meters and it works well, but a few days ago I connected a MFJ-259B antenna SWR/Power analyzer to the antenna inside the shack that has a piece of about 20 feet of RG8 coax on it out to the balun on the corner of the eave of the roof of the house and running it through the entire system including this balun on 3895 Khz I get a 25 to 1 SWR! I'm still able to match it using a Palstar AT1500CV manual antenna tuner and get great signal reports of 30 dB over S9 into New York state from here in North Carolina when running 700 watts from my Ameritron AL-80B amplifier. I feed the dipole with around 50 feet of 450 ohm ladder line, but that's still a huge mismatch. There's no way I could use it without the Palstar antenna tuner. 73 de KU4GW
I'm still learning although I have been a radio officer on board a ship for many years.
One never stops learning Ade.
thanks would be handy to have written instructions wires length , winding turns ect. ?
Could you do a video on a 12:1 balun air winding compared to a torrid winding? I am needing to match a 600 ohm balanced line to a 50 ohm coax feeder. Would be nice if you could also identify all the items needed and length of wire, size of the form and so on. Trying to decide which one to use a what the advantages are one vs the other. Thanks 73's
Thanks for the video and a money saver ideal. Only thing i would do difference would be when you wrap the outside of it, is use electric vinyl tape on the outside because duct tape tends to rot in a 1 year or so. Vinyl tape that i use has been on there 12 to 15 years. May i
ask you a question on warping the outside of the bottle ? What about spraying a clear coat seal on it. Would that work just as well ? Thanks for the video.
Look at 2:16 I have corrected it with an annotation
There is a need to "worry" about toroids if you expect to get bandwidth. Unfortunately, most hams can only measure SWR and assume, if that is decent, then the balun is working.
The most important parameter of the balun is common mode choking. This design is a voltage balun and only offers decent balance if the load (antenna in this case) is perfectly balanced.
A properly performing balun has enough common mode impedance to guarantee that the outside of the coaxial shield is not part of the antenna and to guarantee that noise from the shack will not be transported back to the antenna via common mode and reenter the shack via transmission line mode.
Dale W4OP
@johnrob281 Hi John,
I can recommend this balun. I like the idea because I didn't have any toroid cores and anyhow those cores can saturate and heat up! Very simple to build.
OK on Antennas your end. Perhaps you could try a small delta loop too?
I did clearly copy your callsign on 15 meters the other day.
We will try again soon. My delta loop only cost a £20. Thats about $30.! If youv'e got some fibreglass rods there all you need is wire! Make sure the rods are fibreglass not carbon
Sandy
HI can i just ask you one question, a Diamond 4:1 balun, used with WD 330J HF folded dipole, have you any idea if you should get continuity across the SO 239 connector, or is it capacitivily coupled, or is it inductive coupled might be a BU 50 balun...from Fred in England g4vvq.
Hi, Call me dense but.....you're going in with an unbalanced feeder co-ax........And out to a ladder arrangement, no indication of which pole is which on the balun, and what is the ladder wire for? I would have thought that the output would be one pole to earthed counterpoise and the other to long wire of required length. Please clarify for me....!!
Thanks
Mark
M3STF
@sois97 Iwan,
Why don't you construct a simple ugly balun made up from a few turns of coax. Just do a quick search on youtube or google under the headiong ugly balun and I think you will find some useful info. I personally don't have any videos on them but have built them in the past. They are really simple to make.
All the best
Sandy
Why does it have to be cheap? They're a core and some wire. How much cheaper can they get?
@determinist48 That is correct Les. I made a mistake with the drawing.
Sandy
Thanks. Most helpful
I could not hear how long the 1 inch tubing supposed to be.
Nice video sandy. Thanks for the info
just wondering...no iron core ??? all/most other examples are done with coils on ferrite rings..??
hI.. Can you explain the differenc in a 4;1 balun and a 1:1 balun.. and when and why you would choose one to one .... over four to 1..
A balun, short for "balanced to unbalanced transformer," is used in RF (radio frequency) applications to connect balanced transmission lines (such as twin-lead or twisted pair cables) to unbalanced lines (such as coaxial cables) or to match different impedances. The numbers in a balun's description, such as 4:1 or 1:1, indicate the impedance transformation ratio.
I am looking at a loop antenna which calls for a 2.5 to 1 balun. On suggestion is to make the windings as you do on your 4 to 1 balun except make 10 windings on one wire and 6 on the other. Do you agree? Any suggestions? Thanks for your videos. I like them.
Thanks for the info. Your 4-1 Balun works a treat. Mike.
great vid,wondering if i could use twin speaker cable or twin red\black dc cable?
any chance 12:1 balun design next for terminated folded dipole been wondering how these are wound?
rob
I don't understand the cables around the tube Ann after by inside the tube. May you explained
good but your diagram is missing one connection to the 239 centre pin is connected to the coil actually built.
Odd, the start of the heavy black wire at the bottom is hooked to nothing.?
Question. Is it AWG or SWG or doesn't it matter. Cheers from old George.
Hi: Thanks for posting this. Would this design work on a TV antenna? I need to attach a 75 ohm, unbalanced coax cable to a 300 ohm balanced antenna. Any advice?
Thanks.
Yes it would work as 300:75 ohms is a 4:1 ratio or you could buy a 4:1 receive only TV balun from a TV/electronics store or online. Cost about $3.00 US and free shipping on eBay.
Or two 7turns coils around 3/8'' ferrite rod, Brian M6BAQ.
In 1978 I had a Yaesu FT101ZD, and bought a second hand 3element Yagi, The seller left it in the back yard, I couldn,t erect it at that time but thought sod it I,ll try it and got straight through to capetown SA. on 11mtrs ( cb channel)pushing 12 watts, Who says you need a mast?
The drawing is not complited. on paper!!!!
corect. Black wire not finish
The black that is not connected should have been connected to the center of the coax as well as one leg of the ladder line...other than that...nice vid! de KN4FTT
You know I respect your abilities in many fields Sandy however, this design is not really good, , you really really do need some sort of core to get decent performance across a number of bands, I have used Moxon's 4:1 design from "Antennas for All Locations" book since the 1980s with great success, this is much the same as the job you show here but wound on a normal round ferrite rod of the type Henry Westlake sells for a quid of so. You will get better high power performance ( kW etx)with stacked T-200 torroids and thick wire say 14 SWG enamaelled copper covered with PTFE with the same basic design. This is a basic voltage design which isn't in favour these days however, I haven't had any problems with them. but if you want good performance you DO need a ferrite or ferromagnetic core 161 Tony G3ZRJ
+Venus Probe Thanks Tony. This was one of the first baluns I ever built. No doubt you are correct. Maybe I will wind another on ferrite and give it to Rich as he now has a linear.
Hope you and Sally are keeping well.
161
Sandy
+Wiltshire Man - in a perfect world, and ferrite balun might be superior, but I too prefer the air core. It's larger, clunky, and not as pretty but doesn't suffer from non-linear characteristics when the core is saturated. (harmonic generation, heating, etc...) Easy to do when the antenna is being abused or operated off freq. I'd prefer to feed the antenna with a balanced line and run it into a remote tuner box at the base.
+Venus Probe You are right. This design is terrible. People thinking it is a good balun, or even a reasonable balun, are kidding themselves.
Make a video of a good balun please!
I don't do videos. :) An antenna can make a lot of contacts and seem to fine with a terrible balun. They often work fine with no balun at all. It does not surprise me a poorly constructed balun will "work", since there is no minimum standard and even without a balun most antennas "work". If we are going to make a balun and go through the bother of telling others how to build a balun, we should at least make some effort to be sure we characterize the balun and know it is actually working.Where someone gets into real problems is with high power. At high power levels, common mode really can show up.
@g6vaq1983 Fred,
It's not precise. I believe you can use a larger or smaller dia pipe. I have tested this balun to 200 watts but a friend who has a linear has put 400 watts through it and reports the pl259 gets warm so perhaps avoid qro with it.
All the best
Sandy
please check to notation at 2:15
Would you make a balun for TV antenna 75 ohm to 300 ohm ??? Thanks
Awesome 👏
Did you wind the wire the same or different directions?
Great presentation! You should be a teacher.
Hi there, I' m new in ham, could you please tell me what kind of antenna may i use for this balun?, a long wire may be?, vertical pole?, a 40 meter dipole?
Thanks a lot for an excelent video posted
Malcolm Moreno
CA3MDI
buen dia... aqui hay un error falta una coneccion a salidad de rf del conector pl259 de chasis ......si no se hace correcto no funciona y las reflejadas estrarian infinitas... YV6AB
What about the black wire hanging at base. You did not connect it. I like the idea but it is not correct. Or finished
I am aware the diagram has an error but if you look at time stamp 4:28 you will see me showing it connected and explaining where the connections go. Sorry for the misunderstanding
Thanks. I like it
What's the difference between a 4:1 balun and a 1:4 balun ? Or they just the same thing ?
A 4:1 Balun can just as easily be a 1:4 balun. The Impedance ration is the square of the turns ratio. A 2:1 Turns ratio presents a 4:1 Impedance ratio...
Cool. Thanks
18ga speaker wire is that ok..can use 1/2 or 3/4 PVC PIPE...
So the free end on the drawing is grounded, too?
Hi.you missed a connection in your schematic,easily done;but wouldn't two times 12 turns
produce a 1:1 balun?
Of course an aerial tuner can cover a multitude of sins.Hi.
The heavy black pen winding start isn't connect to anything in the drawing
Hi/ this balun is for antennas digital tv ?
Hellow fellow can i used straight tô a delta loop 2
I've built a couple delta loops (6m & 10m) lt needs a 1:1 or an unun.
Hi Dave,
I wonder what it is?
Sandy
Just off to make one. thanks
COULD THIS BE USED INSIDE MY UNBALANCED ATU FOR A LADDERLINE FEED,ALSO WILL THE METAL TUNER CASE MATTER?
sandy whats it for
???
Can this also be used to match a 75 ohm coax to a 300 ohm twin lead for TV antennas?
I would guess so as it's supposed to be a 4:1 ratio
Thanks a lot.
Your ladder line is home made do you have a video on that?
@BENNYHAWKINS1000 Thanks Andy,
Yes this is a really easy balun to build and as you say it wieghs next to nothing.
73
Sandy
nice video one question how to arrange for UNUN? thanks for this video. 73 de K8JCR
also what I want to over 3mhz like 160m bc it look like only good for 80m to 10m..
Thanks How to make 2 to 1 Thanks again
For what do you want to use this BALun ?
This is the Balun used in the Duel Beam Pro ...
Nice cheers 👍
what size pvc pipe do you use
Thanks for sharing ... 73's VE3NCV Ont, Canada
thanks 73's
lovle!
Hi, ive watched your videos on bushcraft for a while now but didnt know youre a ham. Whats your callsign? I am VK2MRN.
Hi Chris. I am g0vqw
it is not complete.
the second wire no conected at start windig.