Building a 2:1 BALUN For Delta Loop Antennas.

Delta loop antennas are awesome when you feed them well, either using a quarter-wave length of 75-Ohm coax or a 2:1 transformer, which I am building in this video. It works best from 80 to 15m, but will go up to 6m in a pinch as you will see being used with my Racal VRM-5080 on 6m FM. Update: Some people say this is a 4:1 and using the wrong core... Any experts here to comment? The antenna analyser shows 43 Ohms using a 100 Ohm resistor.
BALUN case: www.thingiverse.com/thing:486...
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[@g7rmg]

Yet another super video Gil . Looking forward to traversing La Manche apres Covid in the near future. For me , your videos bring back happy memories of operating TK/p from the K75 moto 73 de Geoff G7RMG

[@RadioPrepper]

Glad to hear Geoff :-)

[@ssbfmcw]

Thank you for demonstrating this 2:1 transformer. (12/6)^2= 4 so 50 ohms input yields a 4*50= 200 ohm output transformer. This is consistent with the measured SWR approaching 2:1 (200 ohms/100 ohms = 2) demonstrated in the video. My initial calculation for a 50 ohm to 100 ohm transformer suggests a turns ratio of 5 turn primary (50 ohms) and 7 turn secondary yields 98 ohms. Alternatively a 12 turn primary with a 17 turn secondary should transform 50 ohms to 100 ohms. You have encouraged me to build and test these alternative windings.

[@TheTemporalAnomaly]

Sorry I am a little late to the party. You are correct with your calculations. I use the same ratio in a hybrid combiner to parallel two linear amplifiers. Just in my case converting 25 ohms to 50 ohms. Still a 1:2 transformer.

[@RadioPrepper]

Thanks, the results do confirm it..

[@shortwavesurfer]

Or 10 turns primary with 14 turns secondary?…. I wonder if there is an optimum number of turns if the 1:1.4 ratio is correct?

[@RadioPrepper]

It's the square of the turns ratio... I never saw anything other than a 49:1 or 64:1 made that way though..

[@loonypontoony]

Made a massive difference compared to the 75ohm coax I was using on a full wave horizontal 40m loop, could not tune 20m allthough 10 and 15m were ok, now flat swr 40-10m and very low noise, thanks for the post. 73s M7MNM

[@Linas_LY2H]

Nice experiment! I have built a 40m Delta Loop few years ago and still use it from time to time when operating from my countryside position mostly in the contests. I made it fed with the 1/4 length of the matching 75oHm cable and it worked just great with flat SWR accross all the band. I mounted it on the 13m mast. One big argument for the cable-matching system is it stands easily the full legal power (1kW in my case) provided the proper cables are used. It also is weather proofed easily and looks neat. 73! Good DX with your Delta! 73! Linas LY2H

[@RadioPrepper]

Absolutely right!

[@Wonoketingal]

Building a 2:1 BALUN For Delta Loop Antennas. 👌 🙏🙏✅👍😊❤️ WOW... tidak diragukan lagi channel ini sangat bermanfaat

[@radiotec76]

Gil this came just in time. i was wondering what good a transformer like that is good for now that TV twinlead has gone the way of the cassette.

[@keithjas25]

Glad it works but the theory was wrong. The ratio should be sqrt (120/50) which is roughly 3:2

[@np3jd37]

Ca tombe a pique !!!! merci

[@markno5s161]

Gil have you ever given any thought of the Spiderbeam Quad kit to go with the 12m Spiderbeam mast ? I was looking at it to make a 20-17-15 quad.

[@RadioPrepper]

I haven't checked it out, thanks.

[@Steve-GM0HUU]

Thanks for video Gil. Just wondering if the turns ratio on the bal-un is 2:1, the impedance transformation shall be 4:1? You could test with with a 200 Ohm resistor and see if you get 1:1 SWR.

[@RadioPrepper]

Not sure about this type of winding, but I will check, thanks.

[@datamedic]

Yes, turns ratio is 12:6 or 2:1 so impedance is changed 4:1. Turns ratio should be 14:10 to get a 2:1 impedance ratio.

[@johnyoung1128]

@@datamedic Yes I wondered the same thing that a 2:1 turns ratio would give a 4:1 impedance transformation. That ratio would not be a total disaster as it would transform an impedance of 120 Ohms to 30 Ohms.

[@Anonopsmo]

This is the first Comment. Happy Weekend, Gil and thanks for that Video. =) 73, Jan

[@RadioPrepper]

Thanks, you too!

[@ronleblanc9832]

What do you think of wraping power supplie plus and minus wires around thoroids to your radios ???

[@RadioPrepper]

Yes, it does reduce RF currents getting into the radio through the cable acting as an antenna.

[@ardilla8651]

For T130-2 is 18 turns, not 12, isn't? I am reading the same info than yours from OE ham

[@johnwest7993]

A suggestion: If you check the loss in that transformer and find it unacceptable (it will be significant,) you might want to switch to a Mix 43 ferrite instead of the red/clear Mix 2 powdered iron. Generally speaking, powdered iron cores are best for tuned transformers, while ferrites are best (lowest loss,) for broadband transformer applications such as this one. Even for tuned circuitry the Mix 2 is quite lossy on the higher HF bands. (Above 40 meters I always use a yellow/clear Mix 6 for tuned applications.)

[@RadioPrepper]

You would think... kzbin.info/www/bejne/rYmofYWPd6eopLM that was for a 9:1 though..

[@johnwest7993]

@@RadioPrepper, over the air tests are used as a last resort, but they have far too many unknown variables. Bench testing comparisons with a power meter or spectrum analyzer where you have control of all the variables are the only way to tell how much power is being eaten up by the matching transformer. DL2MAN describes how to test them in his antenna building series and what the variables are just within the ferrite Mix 43: www.youtube.co/watch?v=nNzTf1F12BE&t=930s

[@py2bnd-sota411]

John West You said it. The material 2 is not suitable for this application. It's a wrong and misleading recommendation. I'm very sorry to see such a content spreading wrong advices to many. Wrong content is multiplied finding this stuff all over. Later he mentioned the 1:9 UNUN for random wirer. That's a totally outher application where intantionaly is introduces loss by using a material 2 iron poder core to drop the SWR by introducing additional loss. And hey, You can explain it 1000x and this spreader of wrong content don't want assume that they spread missloading tecnical bullshit.

[@RadioPrepper]

I recently made a contact from the South of France to French Giuana, SSB, using 20W and this "not suitable" powdered iron core UNUN... I's on video. How do you guys explain that? LOL.

[@RadioPrepper]

That's 7208km BTW..

[@MrRaybl]

a delta loop at 120 ohm a 2/1 balun is ideal close to 50 ohm I personally experimented with the 4/1 and that didn't bother me. I got too low an inpedence I have been making antennas for years.... a antenna has an inpedence and inductance to be respected

[@micahhaislett1863]

Would a 240-43 work for a 2:1 balun for an hf antenna? Making a 80m full wave sky loop. I’m getting 175 ohms at the analyzer with a 100 ohm resistor. Trying to figure out where I went wrong

[@RadioPrepper]

What is a 2:1 HF antenna? I have no idea what you are trying to do, sorry. A 43 material toroid is wrong for a 2:1 BALUN.

[@micahhaislett1863]

@@RadioPrepper corrected my comment. A 43 mix is good for a basically every other balun in hf. I just assumed it would suffice for a 2:1 nonetheless.

[@RadioPrepper]

Assumption is the mother of all... ;-)

[@R2AUK]

Thanks for the video. Although I'm not sure if 2nd mix is recommended to be used on such high frequencies, or even for transformer at all. Would be interesting to compare with mix 43 or 31.

[@RadioPrepper]

43 for a 2:1 on 50MHz?

[@R2AUK]

@@RadioPrepper yep

[@clarkturner9413]

@@R2AUK Or at 61 ought to really work better up there.

[@clarkturner9413]

Yes, I note that powdered iron is not recommended for broadband designs in the normal case. The powdered iron appears to be more suited for a tuned circuit, or a single band design? Is there a reason you use the powdered iron (red) core rather than the 31, 43, 52 or 61 material that is far preferable for broadband use on HF and above for 49:1 transformers?

[@RadioPrepper]

I usually use 43 for 49:1 or 64:1 transformers, but many designs seem to call for 2 material for lower ratios like 9:1, 4:1, 2:1. I do not know why.

[@jeanbernarddelbare]

Bonjour Gil content de te retrouver à la lecture de cette vidéo ( un Om d'Armentieres 😉. Dommage pour moi la vidéo est en anglais !

[@RadioPrepper]

Bonjour. Jen ferais d'autres en Français.. He suis allé à l'école à Armentières, St Jude!

[@jeanbernarddelbare]

@@RadioPrepper je sait Gil c'est pour cela que me me suis permis de te faire un petit coucou ,merci de m'avoir répondu et bonne continuation

[@RadioPrepper]

Merci!

[@chuckcarter7864]

Thanks for the video however I don’t understand your balun . You appear to have a 2 to 1 turns ratio so that is a 4 to 1 transformation as it is the square of the turns ratio . 73 de VK2SS

[@RadioPrepper]

Weird yes, and yet the impedance is divided by two...

[@jfv65]

Will this 2:1 balun work for my skyloop antenna? It's only for reception.

[@RadioPrepper]

Yes, better if the wire is a full wavelength.

[@robertvantichelt6448]

If you want to try the air core 2.5:1 balun it is cheap with local parts and instructions are on the internet. It's wire wound on a short PVC pipe. Works great for skywire loop. AG6IF sells them on eBay if you don't feel like building one. But they are really inexpensive to build.

[@johnyoung1128]

I am not at all bothered by the way you pronounce “Balun” I understood what you were saying perfectly.

[@hectorpascal]

Many years ago (when there were sunspots) I was amused by a US "southern gentleman" in QSO with someone else, who was insisting it was pronounced "baaaay-lon". The Germans and Dutch seem to prefer "balloon". Whatever - it works the same!

[@RadioPrepper]

Exactly!

[@YO2DA]

Trifilar one is the best

[@MrRaybl]

une delta loop a 120 ohm un balun 2/1 est ideal se raproche de 50 ohm j`ai personnellement expirimenter le 4/1 et cela me narch pas ont obtien une inpedence trop basse je fabrique des antenne depuis des année .... une antenne a une inpedence et inductence à respecter mercie vous etre dans le bon chenin

[@woodskid4ever]

12÷6=2. 2^2=4. So why is this not a 4:1 balun?

[@py2bnd-sota411]

It must be a 1:4 UNUN, and constructed with a material 43 ferrite. The content here is wrong and missleading.

[@zhaqirhussein]

Is what same balun 2:1 for 27 Mhz ?

[@RadioPrepper]

For any frequency on HF. You.must use a full wavelength wire.

[@zhaqirhussein]

@@RadioPrepper Thanks your information

[@stormshadow_6477]

So I'm a bit confused... This is supposed to be 2:1, and the sqare root of 2 is sth like 1,4 and so on. The windings on the balum are 1,5:1 though. Wouldn't this give you more like a 2,25:1 Ratio or is my maths backwards? Greetings from germany.

[@RadioPrepper]

Not sure, confused too, but the analyser shows 43.4 Ohms on 20m with a 100 Ohms resistors as the load..

[@MrRaybl]

a delta loop at 120 ohm a 2/1 balun is ideal close to 50 ohm I personally experimented with the 4/1 and that didn't bother me. I got too low an inpedence I have been making antennas for years.... a antenna has an inpedence and inductance to be respected

[@RadioPrepper]

I guess the number is rounded off..

[@jeanbernarddelbare]

Bonjour Gil c'est l'Armentierois (; Aurais tu le schéma balun 2/1 pour une quad 1 élements pour le 11 metres Merci Gil

[@RadioPrepper]

Bonjour :-) Le mème je pense..

[@RadioPrepper]

Ou 2.5m de coax 75 Ohms...

[@jeanbernarddelbare]

Bonjour Gil ,merci toujours aussi réactif , oui le quart d'onde , certains Om parle de 1,84 mètre de coxial TV

[@RadioPrepper]

Possible, ça dépend du coefficient du cable..

[@DAVIDGREGORYKERR]

A 4:1 BALUN would have been better.

[@RadioPrepper]

Theoretically you get closer to 50 Ohms with a 2:1 (120/2). In practice I suspect it doesn't make much of a difference..

[@py2bnd-sota411]

​@@RadioPrepper It makes diference, and a big one. Sorry that You does not do sufficiant research before spreading this missleading wrong content. Be a little bit more carfull before spreading wrong stuff on YT.

[@bobblacka918]

So you are saying the impedance of a Delta Loop antenna is 200 Ohms? Is that correct?

[@DAVIDGREGORYKERR]

@@bobblacka918 more likely to be 300 Ohms.

[@RadioPrepper]

I must have read that somewhere...

[@danielhorvat4340]

Why, powder iron core? it is not suitable for a 2:1 ratio 1-30MHz at all. Why don't you do your research before spreading nonsense?

[@RadioPrepper]

That's what I thought too, but check out my video about a 9:1 UNUN using an FT-140-43 VS a T130-2. In theory it doesn't work. In practice it does.

[@py2bnd-sota411]

Daniel, he's spreading nonsense as just many times before. Many times he does not know of what he's talking about. Very annoying - There are outhers too, not knowing of what they are talking about. And later, when they face critics its always the same, insisting in there wrong concept. There are many comments about his wrong concept answering with a 1:9 UNUN for a random wirer who use intentionally the iron core but for a compleatly different concept. My conclusion is, also looking on outher videos from him, that many times he's doesn't know of what he is talking about. He has no tecnical background - Never studied suficiant about Radio electronics.

[@RadioPrepper]

Did you try both in the same conditions? I did. The powdered iron core worked better, period. Build both, test both, then comment about your results...

[@py2bnd-sota411]

@@RadioPrepper Outher point is that You claim it as an BALUN as it is in reality a UNUN not even understanding that an additional 1:1 BALUN is necesary to transform the unsymetric coax feed into a symetric feed for the loop. It's tecnicly a whole missleading mess of what You show on the video. Forget this 1:9 UNUN as reference since the random wirer antena using a 1:9 UNUN with a iron poder core is using of a totally different concept of matching by introducing loss by intention.. The iron core is not only transforming but also intentionally introducing loss to lower the SWR. And that's why You just found out in outher video that the 1:9 random wire is a death antenna in comparison to the different and efficient working EFHW. Some videos from You are annoying due to a tecnical wrong and missleading content. Also Your Minion problemes that are mainly coming from Your wrong build antenas sucks a lot. If You have a correctly build antena sistem there is no RF coming back to the tranceiver over the coax feed. You put a Tranceiver on a wrong build antenna and claim the Minion Tranceiver as the culpit of Your problems, mentioning that outher tranceiver does not care so much about back coming RF, ignoring that the root cause of the problem are Your bad build antennas. And, later putting the Minion under saltwater culping the builder for bad support. Put a IC705 or a Elekraft KX3 under salt water and ask customer supportfor repair. They will not even take a look on the mess, claiming it as a total loss recommending You to buy a another one! That are all things that are very annoying to see.

[@py2bnd-sota411]

@@RadioPrepper I build enough antennas to know how to do it right, not mentioning so much more that I'm coming from the professional side of university electronic Engeneering. There had been enough claimes of different viewers about this loop UNUN - It's really enough that You think about to put your head on deeper research before posting.