I learned something new today: Type 43 cores are the way to go. Thanks! de W3DJS (Patreon supporter) in Atlanta, GA

Mix 2 cores are powdered iron and 43 are Ferrite. They have vastly different characteristics in terms of permeability, saturation, stability (power handling/temp), etc. Powdered iron cores are good for high power applications because of their temperature stability (coefficient) and higher core saturation resistance. Ferrite has higher permeability, and is generally more efficient at higher frequencies. The inductance value of Ferrite is also frequency dependent; it's not with iron. For a given size core, an iron powder (#2) will require more turns than ferrite (#43) to get the same inductance. I would expect a powdered iron core based BALUN to require more turns than an identical ferrite core version.

@avt3216

5 жыл бұрын

"The inductance value of Ferrite is also frequency dependent; it's not with iron." Another piece of the puzzle solved (for me) then. Knowledge, well worth the price of admission here ; )

Use type 61 ferrite and you will get 50 ohms on the VNA everywhere from 160 to 6 meters ! You can also reduce the number of turns on the 43's to even the seep out between the bottom of the HF and top of the spectrum. Lowering the number of turns will lower the swr on the higher frequencies and give it better balance.

A picture is worth a thousand word as they say, great demonstration. Thanks.

Nice video Kelvin!! Checking the Balun for right performance by measuring it, the way You did it is realy the best way before hooking it up to the antenna. And with this setup that You showed, very simple, you can make the measurment with almost every antenna Analyser. Grate stuff, rarely demonstrated in practicel!!!

I've seen a comparison of 43 and 31. 31 won that one using the coax wound through a balun (Smokin Ape Which Material) . 43 is much better than 2 for lower freqs and seems to work fine at 10 and perhaps 6. Interestingly, many commercially made tuners want to use type 2 ? I saw one channel do a test for 1 to 1 use and found type 2 didn't have enough attenuation. 31 though, that seemed even a tiny bit better when it was tested beside 43 on KZread.

Thanks for the video. I was just thinking of changing my doublet to a delta loop when your video arrived. I got 2 type 43 cores at hand but wasn't sure if they were sufficient. Your video helped to clear it up..

I spent about an hour looking online for info about which toroid for what application. Little that I know the answer was right under my nose. Thanks for all the great info you give to new hams like myself. 73 KY4DA

The 43 cores will also give you common mode current choking the type 2 cores only give the 4:1 transformation

@n8nkqrp595

5 жыл бұрын

And actually, the type 2 cores are meant for inductors - not broadband transformers. For 80/160, an even better choice might be type 77 mix (FT240-77 has an Al of 3155).. but you'd sacrifice 20 I'm sure. Regarding power core size /power level/core saturation - people are going crazy. I've been testing core size, mix and Z ratio.. the the results are surprising. Each unun has 7 taps. An example: end-fed 1/2 wave wire for 80, 130' long. I tested 3 core sizes and two mixes. I wanted to test at 3:1 SWR so I adjusted the freq to give me that. type 43: FT120-43: 3:1 SWR, 80m, 1 minute key-down at 10w: No core sat, no SWR change, core luke warm. Higher P than that, core sat at just under 20w. Type FT140-43: 50w key-down for 1 minute on 80m. Same results. No core sat. No SWR change. Luke warm. Folks - this is 50 watts, key--down, for one minute... > 120w PEP... using a single FT140-43 core. This core han handle intermittend (low duty cycle CW.. and especially SSB) at 100w for a few minutes at a time.. and still probably not reach the Curie temp. Core: FT240-43: again, 3:1 SWR. 80m. Same wire ant. Power = 100 watts, key-down, for one minute. Core temp luke warm. I've been testing all three cores on the various bands that my 7-tap ununs can get a match on using this 130' wire. I use 3 different taps on my unun for 80, and can cover 3.5 to 4.0 with under a 2.5:1 SWR. And I can match anything except 12 and 10 meters using this wire - and generally with an SWR of under 2.5:1. Using a 130' chunk of 14 ga THHN wire and my unun. Jsut wanted to add my 10 cents worth. 73 OM

@Tantalicdavid

5 жыл бұрын

@UCoV7Bekk4G0o84zu9HwT3RA Yes type 2 & type 6 cores main purpose is for inductors The data sheets on cores give a good indication to there suited usage

@avt3216

4 жыл бұрын

@@n8nkqrp595 Very helpful!

Great information Kevin. Thanks!

Outstanding video!! Just the type of video many of us want to see. Get that antenna up and show us some amazing results (I hope) of the improvement. Waiting with "bated breath" for the next installment.

@loughkb

5 жыл бұрын

I've had a day to play around with the antenna and I can say for sure that it's performing much much better. I'll have to wait to redo the comparison though. Big storms are rolling in here late this afternoon through tomorrow. I'll be taking the antennas down later today and unhooking things.

Toroid selection depends entirely on the application. At HF, for a broadband transformer, or for RF supression a #43 ferrite is a good choice. For tuned circuits at the lower end of HF a #2 mix (red and clear,) powdered iron core is a good choice. At the high end of HF, roughly 20 meters on up, a #6 mix powdered iron core (yellow and clear,) is more efficient.

Thanks for this video I have just bought two 240-43 cores for a 4:1 Balun for a folded dipole. As an aside, I used a type 31 for a 1:1 balun which gave spectacular results, less than 1.2 :1 and 50ohms impedance across HF into 300ohm resistor. (They are not suitable for impedance transformation however, but for 1:1 they are ideal)

Ferrite mixs and which is appropriate for a given use is a very involved subject. I'm currently researching and experimenting with which is best for a upcoming 40-6 meter antenna build. There is an immense amount of variables and it is proving to be a great learning opportunity for me. Thank you for posting your experiment, and all the other great work you do on your channel. I look forward to more! 73 de AD0TP

Thanks Kevin for the balun type 43 core over the type2 core difference ..... I just happen to have 10 of the FT-50 type 43's ordered over a year ago to make some QRP baluns with =)

Now that was some great stuff. Just got into Civilian radio, and antenna's are all Greek to me. This cleared up a lot of questions I had from before, like, why would I use a balun, and what would I want some cores for? Thanks for clearing all this up for me. I do real well with visual than I do with reading.

Got here late but I'm happy I showed. I used this theory/experiment to select my 43 type toroid. My 66' EFHW and 49:1 lets my tuner cover the HF bands.

Yes, I also have mix 43 toroid for my 80m skylooop antenna. It also works great for AM and SWL. I like to suggest to take SWR/Impedance for whole HF bands spectrum for your 20m folded dipole, directly, ie, not using any balun. Get the lowest SWR/Impedance and make balun based on the value. It should be much accurate to match the antenna and the 50 Ohm feedline. Thank you, and have a nice day.

very nice study and experience... nice topic to explore using other kind of cores, and also, other kind of balum/ununs. I would like to watch more episodes like this one! I also use ferrite material 61 when making 1:1 baluns... 73 de PY1ZB

Very instructive and useful video. Thanks and 73 from PY5WHO.

Suggestion: if you have not yet done so, could you make a video about the situations where you would use: (a) a 1:1 common mode choke, (b) a 4:1 balun, (c) a 9:1 balun (unun?), or (d) something else. I, for one, would appreciate it, and perhaps other beginners. Many thanks for your work.

Excellent Video Kevin, 73s

This method of using two type 43 cores for a 4:1 balun is that each core is wound as a 1:1 balun then connected in parallel at one end & series at the other end to give you a 4:1 current balun

Great project and great video. Thanks for posting ! This makes me want to learn a lot more about these different core materials. Anyone know a good reference or text for this ?

Most hams I have come across hate toroids. You are making me want to work with them. Thanks.

43 has much higher permeability which means it has a much higher inductance than type 2. All transformers are "shunted" by the coil impedance. Higher impedance = less shunting. You can also change (or even sometimes have to change) impedance by using more turns (that has it's own problems like increasing parasitic capasitance).

@avt3216

5 жыл бұрын

"All transformers are "shunted" by the coil impedance. Higher impedance = less shunting." Well explained!!!!

@hoggif

5 жыл бұрын

I think an interesting try would be like doubling (or tripling) the amount of turns and see where 4x or 9x inductance would lead us. ..assuming there is enough room in the coil. May need to ditch single layer design.

Thanks for the helpful video, Kevin. Would the type 43 also work well in an EFHW ??

Kevin. Excellent video (as ever imho). Is there a reason why you put the windings on each individual core rather than just around the two cores stacked together. ( sorry if it's a dumb question)

Interesting to see 43 perform so nicely for baluns and ununs. I need a core for a wideband CM choke, where its performance in the 50-300 MHz region would matter. I take it 43 will be mostly absorbing energy there?

Great video. I did some testing with type 2 and type 43 a few weeks back with a 49:1 unun. What I did was make an identical pair of ununs and wire them back to back and hook it up to my normal dummy load with a power meter before the dummy load. I measured on every band with 10 input power and measured the power at the dummy load. with type 43 cores i got about 5w at the dummy load so given that there are two transformers in line I make that 1.5db of loss or 25% of the total input power. With type 2 cores however the meter at the dummy load was barely deflected so almost total loss. I also tried type 52 cores but they were not much better than type 2. I'm hoping to get hold of some other mixes and try those because apparently some perform better than 43 but are significantly more expensive. Also I have a big bag of high voltage capacitors left over from my 49:1 builds. If you want some PM me your details and I'll pop some in the mail for you. I've made a couple with various sizes of type 43 cores now and all work very well. Regarding type 2 cores I figured their lossy characteristic was exactly what would be desired for a common mode choke so that's what I've made my chokes out of that I use with my end fed although I'm yet to find a decent way to measure and quantify how correct that assumption is.

@paulsengupta971

3 жыл бұрын

I don't suppose you can elaborate on what you tested? Some of the tables I've seen have 3xFT240-52 as being the most efficient design for a 49:1. I'm currently using a single FT240-43 which is the next best thing apparently!

Like to see tha VNA directly on the 200 ohm resistor, as a comparison ??

Great videos on baluns at TRX Bench. I think the problem is in the words. Baluns are not transformers. Two different things.

I'm wondering what the difference in return loss is between them. Maybe you could take the resister out and measure the return loss with that miniVNA?

TRX Bench did a 3 part on this and you proved the 43 mix to be great for HF. Peter also did a DB test for common mode and it was great for that too. Steve Ellington has gone to using the 52 mix because of the currie temp for running MORE POWER!!!!

@user-xj8oh6fo2f

3 жыл бұрын

Yep, swr is only the half of the story. Common mode current attenuation is also important and could be measured with vna.

@ianboard544

3 жыл бұрын

TRX bench also spaced the windings on the 9:1. I was wondering which was better: tight packing or spaced out.

@user-xj8oh6fo2f

3 жыл бұрын

@@ianboard544 owenduffy.net/blog/?p=11727 Also check his other transformer articles, there are a lot.

Cool stuff tnx ! I love your little VNA ! Is it very expensive? Take care! 73 de ve3hip in Welland Ontario Canada 🇨🇦

Dumb question time: You have the two cores sandwiched as close as they can get. As a wire goes near the "other" core, it's so close it's touching. Doesn't this cause some of the magnetic field generated by that wire to "leak" into the wrong core?

@JayN4GO

5 жыл бұрын

David Casler yes in an rf environment. Ideally you want both cores held together with a dab on super glue. And then wind the wire. 240s give much more room

@avt3216

4 жыл бұрын

"Leak": Not really. The cores concentrate the magnetic fileld very well. You may get capacitive coupling in an extreme case, though.

@loughkb

4 жыл бұрын

In my building a 4:1 video, I mentioned seeing them.built with the cores together and I scanned it both ways. It seemed to behave slightly better when they were together. I haven't examined it further yet.

@davecasler

4 жыл бұрын

@@loughkb Thanks

i like you used -2 cores but was advised to use the -26 on a vertical i built. it worked well but tried the same 43ft helical wound pole with a 4-1 with the -2 core would not tune 80m the vertical has now gone and use a long wire in a inverterd u shape its 49ft long had a 9-1 with a -2 core no 40m unless i used a external tuner. same wire with the 4-1 i had all but 80m then i used a 140-43 mad a 4-1 tunes on all bands with internal tuner. found the 43 cores so much better i did suffer with the swr going up using the -2 core as well when i did ft8.

I found that for SWL the #43 works far better than the #2. I did side by side comparison of a tiny UnUn for a high-z telescopic whip antenna. #43 worked far better than the #2 or using no unun at all.

This is interesting. One question though - was there any attempt to optimize the windings for each type of core (eg number turns, spacing, etc...)? Or did you use exactly the same winding configuration for the different core types?

If you can scan both R and jX (not just Z) for any antenna, you'll get some major insights into where R equal approx 50 (as you want it) and where the reactance jX needs to be cancelled out. OT: I'd look forward to you demystifying end-fed antennas some day! (IOW, why they don't work for many people, and how to make them work).... worthwhile because end-fed antennas don't require radials, only a very small counterpoise. Bonus: Vertical end-fed half-wave antennas are GREAT for DX!!!!!

If you do the same test with a short circuit on the output side and an open output measurement you can get a better idea of the amount of power which gets absorbed by the toriod. Running 10/50Watts into a 200Ohm dummyload and a propper VSWR bridge/SA will probably give you a different result. Thnx for the video nonetheless!

Powdered iron and ferrite are very different materials. From a Micrometals app note (elnamagnetics.com/wp-content/uploads/library/Micrometals/Iron_Powder_Core_Selection_for_RF_Power_Applications.pdf): "Iron powder cores are commonly used to produce high Q inductors and transformers for selective circuits. Iron powder cores used in RF applications are composed of extremely small particles of highly pure carbonyl iron. The distributed air-gap of iron powder cores contributes to their rather low permeability and very good stability." I use type 31 for the lower bands (80m & 40m) it does OK on 20m too but #43 is best above 10MHz.

Nice video Kevin! Thanks..de WT3F

Excellent all your video about magnetic loop antenna only one question.For 20 and 40 meter a can use ft240-43 or ft240-31 wish one work better thanks in advance Eddy

@loughkb

3 жыл бұрын

I don't know, I haven't tested with a type 31.

@eddy4011

3 жыл бұрын

Kevin Loughin Thanks so much Kevin for your time my good friend 73 from Florida 🇺🇸KN4QFD

This is a little off the topic/subject but what software program do you run your miniVNA PRO with? I also have a miniVNA PRO but I am not running the same software program you are. I like your much better. Could you possibly tell 'us' which one you use. Thanks Kenny KD4HQQ

The folded dipole has 300 Ohm impedance. I like to see the performance if we use ladder line as the feed line down to the 'ground', and use the balun for 50 Ohm coax feedline to the rig. . In other words, we can see the performance comparison betweeen coax and ladder line as feedline Thank you again. :).

@loughkb

5 жыл бұрын

When I scanned the window line directly, without a balun, I read just over 200 ohms at the resonant frequency. I think the spacing of the twinlead affects impedance. The wider the spacing, the higher the impedance is the rule, I think. Especially in a folded dipole configuration. I know it doesn't match the expected impedance of the twinlead when it's used only as a feedline.

@bahathir_

5 жыл бұрын

Thanks for the reply. Great. Measuring the 'raw' antenna's impedance/SWR is very useful to tune the antenna and custom made the balun, to match precisely to 50 Ohm coax feedline. Looking forward for the real world testing. :) Yours, Bahathir 9W2GNU, 73.

@pathopkins4500

5 жыл бұрын

@@loughkb You are correct on the feed line ( Ladderline ) spacing affecting the impedance =)

Perhaps a similar comparison video for the UnUn transformer? Great video, Kevin! 73 from a Patreon supporter in Texas. Your radiation pattern lands your signal right in Johnson County where I live. W5ZYM

@loughkb

5 жыл бұрын

Yeah, I'll be doing that soon.

I was told by my Elmer to always use type 43s for HF. I complied, without understanding why. You demonstrated that well. Thank you. I hadn’t seen a miniVNA before. What all does it do?

@loughkb

5 жыл бұрын

Most all of the functions of a benchtop vector network analyzer. Go check out their page for full specs. It measures many things and I've only scratched the surface.

@MrPerrey

5 жыл бұрын

@@loughkb Shure!! Core material selection and the building technik for and specially the different testing technics of antenna transformers with VNA is a deep and rich hole for digging!!!

Your VNA does not run enough power thru the transformers to see all of the differences. Try measuring the forward and reflected power from a radio into a dummy load of the appropriate impedance.

I am curious, Why did you wind the first balun individually and not the two toroids together in one wind? THanks

@loughkb

5 жыл бұрын

That's the way the transformer is wired electrically. Here's the page with the design I used. www.m0pzt.com/blog/4to1-current-balun/

43 cores are definitely better hi Kevin hope you are well can u help me what command is written to get information on usb to serial adaptor regarding port speed from the usb computer side i.e. 4800-9600 and so on I want to make sure all match comp - linux mint usb serial cp2102 ? Kenwood ts2000 thanks Steve

Great comparison between the two. Thx! de KM4ACK

if you look at the specs between type 31 and 43, the ranges are 1-300 MHz and 25-300 MHz respectively... so why wouldn’t a type 31 be better / best for the HF bands?

So, Type 2 for 15m and above?

Oh the fun :)

that's a very interesting vid Kevin, I'm just starting and wonder if You could tell Me if I could use a CS610125 magnetic powder core toroid?, Being a bit confused at the moment I am asking You, for Your input??, Regards & 73s

@loughkb

3 жыл бұрын

Not for HF radio. Looking at the specs and datasheet on that core, after a simple good search, I see it's designed for noise filters and operation around 100kHz.

@bennockley

3 жыл бұрын

Thanks for Your reply, Kevin, I'll probably use them for boat anchors for model boats, Thought I had a supply I could utilize, 73s

Hi Kevin! I know this video is over a year old, but I have a question regarding the mix or mixes that can be used. I was looking at toroid cores on-line and looked at the specs for the 43 mix and it was good, but then I looked at the specs for the 31 mix and it was even better for the lower bands. What do you think? for let's say 160m to 10m would this mix work as well? Here is a link to where I got my information, they only have two sizes, but look at the frequency response data. www.jpmsupply.com/category-s/1840.htm

Yo Kevin! GREAT video, as usual! Got a great idea for you. Have you experimented with using TRANSFORMERS as Baluns/Ununs? Think it might make an interesting experiment. : ). (An idea? : ). 73's! de seeker/Jeff WA7LFP

What about type 31 vs 43?

@paulsengupta971

3 жыл бұрын

And add in 52 for good luck...

Hi Kevin, That was some test with the Type 43 cores. Looking forward the on air tests. How's the temps out there now? 73 WB3BJU

@loughkb

5 жыл бұрын

Still hot. Looks like it won't really start changing until the middle of August.

@johndeacon2101

5 жыл бұрын

Kevin Loughin What can you tell me about 31 vs 43? I am working on a 49:1 for a long wire. KB4OI

@loughkb

5 жыл бұрын

@@johndeacon2101 Nope. I dont have any to test with.

@johndeacon2101

5 жыл бұрын

Kevin Loughin Thanks Kevin. I was told that 31 types were good for lower bands, which is where my dad wants to operate around 80 meters. Thanks again.

Another excellent project vid. Thanks. The next experiment.....is there an optimal number of windings to use with each type of core? Most experimental and recommended info available is geared toward full power using ft-240 sized cores. It would be worth knowing what the curves look like for baluns built on these smaller ft-140 cores, with 11, 9, or 7 turns. Time to start saving money for a miniVNA of my own. :o

@loughkb

5 жыл бұрын

Except that it's not just about the total number of turns in a transformer, it's about the ratio between the number of turns in the primary and secondary. You might reach a point where core saturation becomes a greater factor than power transfer I suppose.

@ElDiabloLocoPoco

5 жыл бұрын

@@loughkb For these 4:1 transformers each core has the same number of turns for each pair. In the vid it appears your transformer has 12 turns. Changing the number of turns varies the inductance just like changing the core material. So the curves plotted should change with 11, 9 or 7 turns(harder to put on more turns without changing to smaller wire). Reducing the number of turns may find a sweet spot where both the 50 ohm impedance and SWR curves are flat. Or maybe 12 turns IS the optimum(it is certainly "good enough"). Good to know it works down through 160m though.

@loughkb

5 жыл бұрын

That's a fair point.

Where did you buy the core?

@loughkb

4 жыл бұрын

A seller on Amazon. Just search for the core type and you'll find several

Where's a good place to order these?

@JayN4GO

5 жыл бұрын

Steve Goyette mouser electronics

SWR/insertion are only 0.5 the story. Ferrite-43 has far higher permeability, so higher common mode rejection. This information is definetly 'out there' but there is lots of wrong and outdated information on baluns, some of it in books still sold. There's one more advance over what you have. The hybrid Ruthroff/Guanella offers optimised SWR/insertion across 3-30MHz and slightly lower insertion loss. I have seen

It is not so easy. Magnetic flux inside ferrite can be 2 Tesla max, inside iron core 10 tesla is maximum moreover Currie temperature that must be not exceeded in trasmission is about 200 degre celsius in ferrite but about 400 celsius in iron core. Ferrite is definitely better for RX but situation is not so easy for TX

@avt3216

5 жыл бұрын

TX: Stack"em!

You have missed the entire point of the purpose of a balun. A balun's function is to reduce common mode currents on the feedline. The primary measurement you should be making is a measurement to evaluate the common mode attenuation of the device. BTW, it appears that what you are building is a voltage or Ruthroff balun. To reduce Icm you should be building a Guanella or current balun. I cannot be 100% sure as I did not see a schematic of what you built. BTW, if you had placed more turn on the 31 mix you would have seen lower SWR at the low frequencies. The # of turns you used were too few for #31. You might also measure the insertion loss. SWR is the least important parameter of the three: Icm reduction, insertion loss, SWR.

@loughkb

Ай бұрын

A balun's function is to match a balanced to an unbalanced system. Hence the compound word name, balun. Usually providing an impedance transformation as well. A common mode choke is used to eliminate common mode currents on the feed line and can often be used in conjunction with a balun. Some designs of the four to one balun are symmetrical and therefore do a dual duty, providing a common mode choke as well.

@W4OP

Ай бұрын

@@loughkb Yes, the matching of balance to unbalanced results when common mode current is reduced- this takes an effective current balun and has absolutely nothing to do with SWR.. Again, you never measured the effectiveness of your "balun" as you never measured the common mode attenuation or the common mode impedance. Measuring SWR tells you nothing about the effectiveness of your device as a BALUN. And again, the #31 cores can be very effective in reducing common mode and have a broadband low SWR- but you only tried one model and when the SWR was high at the low end, you never tried adding more turns to increase the winding inductance. So you drew the wrong conclusion regarding #31 and #43 mixes. If you had looked at the initial permeability of each core you would have realized the #31 would require more turns.

@loughkb

Ай бұрын

OK

✌️

@loughkb

5 жыл бұрын

Yo. What up zombie hunter?

@charlesschindler1971

5 жыл бұрын

Kevin Loughin - Correct I am a ZOMBIE hunter! As you can see permit has expired. But current administration has removed the need of a permit to hunt them. Huge piles of zombie horns are being stacked by Patriots worldwide. Let me know if you spot any in the high desert area.I could be there within 36hrs. As long as there is no heavy rainfall they should be easily tracked. ⚔️☠️⚔️ You have my emergency line# 260-xZOMBIEx ⚔️🇺🇸⚔️

HUGE difference!! 73 de OA4CKN