Great illustration on toroids. Been a ham for little over 2 years now and there is a lot to learn. I find your channel very helpful regarding many technical topics. Thank you!
@@TheSmokinApe I'm currently building a 49:1 EFHW, and your toroid/unun video, and 49:1 transformer kit are fabulous resources. I didn't buy a kit, so I've been cobbling together as much reference material as I can.
Excellent introduction to toroids, materials and use cases. As a QRP operator, the 1/2 inch size is about as big as I go -- and I can confirm that in my experience, 'size doesn't matter.' Its the 'mix' that's important. I've also stacked 1/2 inch toroids for 'QRO' (50 watts!) and that works well too -- Its just even more of a challenge to wind the little beasts! 73 Bruce G4ABX
I accidentally ordered some 140-61 cores for my 80m EFHW antenna. The 61 cores are no goers on the lower bands, they start to work good above 24MHz. The transformer was wound as any 49:1 unun. The 61 cores are also good for transformers in 50MHz push-pull PA-s. :) This is my experience. 73's de YO6PNQ
SO GOOD to find these videos. I just drop a comment on a guy who was more interested in letting you know just how smart he is but was not very helpful. If you have your EE degree, you'll be right there with him. the rest of us, not so much. Not sure who his target audience was exactly. If you were able to follow him... you didn't need him. Lol!
Are there examples of series coax chokes wound on different cores? Such as a coax choke wound on a 43 mix toroid followed by a coax choke wound on a 52 mix toroid to get better broad band choking.
@@TheSmokinApe now on to what may seem like a silly question, but despite my years in ham radio, I have no direct experience winding my own toroids and such. So no laughing, please ;-) I see chokes being wound on the toroid and then placed in a weather-proof box. How susceptible are toroids to being exposed to the elements? Any harm in leaving a coax wound choke out in the winter elements for a month or two? The coax connections would be weatherproofed, and for short term I don't expect much, if any, UV damage to the wire ties. I want to first test to see if a choke would solve, or provide a large part of the solution, to an issue I currently experience on 15-30 meters that I currently solve by having quarter-wave counterpoises attached to the ground bond on my equipment. (Unclean audio quality that is very noticeable on FT8.) This sounds like a classic case of common-mode currents returning to the shack and wreaking havoc. While it seems the counterpoise solution is creating an artificial RF ground for me, I'd rather wipe out most of that common-mode current at the source.
Question, your tests are of a single wire wrapped on half the toroid. At 3:06 of your video, you show a double wire wrapped full toroid. How would that be tested? Would you solder the yellow then white pair together and test them separately? Or test all four wires separately and and the results together?.
Hey Carl, thanks for watching. The single wire test was just testing each of the toroid mixes to see which would do a better job of attenuation, we want to "choke out" common mode current. If I was going to test the yellow and white wrap you could solder the two yellow or two white together and test that way.
I was thinking of using my oscilloscope clip probes (wt 10x switch) since they are made for carrying frequency (though I wanna get some with higher rating) & bnc to sma adapter
I got a little lost on this but that is because I’m just not there yet. In a few months this will make more sense. Still studying for the general test. Ape you are a good teacher, sometimes the students aren’t ready. One comment you made I would like to see a short video about. That is when you said you mostly stay on 40-10 meter HF. What are the reasons for that? Thanks. Keep them coming
Love the videos! I'm still unclear how to calibrate the test leads for testing a choke using the setup you've posted? I'm unclear how to do it. My understanding is that I would need to place the open, short, and load at the end of the leads? Thanks!!
There are THREE big questions when it comes to toroids: 1. How big should I get? (100W needs more than 10W QRP) 2. What material should I get? (Impacts frequency etc) 3. What I get this wrong? (broken core from heat, or just over priced under performing)
The best way would be to perform comparative tests against known cores, if that's not possible you could compare test results against factory specs. I'd suggest not worrying about the mix and test it for the use case you have planned.
Hi, I'm looking for some advice as regards to building a 9:1 un-un for a random wire antenna. This needs to be suitable for around 100 watts, also I intend to add a choke to the feed end and one for the TX. The T140-43 seems to suit my needs, what gauge wire would you recommend please, Also can I connect the choke directly to the 9:1 and would this still work if the choke was mounted on top of the un-un to save space. Thank you
Hey Alan, not sure what bands you want to cover but even at 40 and up I'd suggest a 240-43 for the 9:1, 18awg mag wire and 18awg stranded copper for the element.
Thanks for the reply. Yes, 40 and above are what I intend to use. I would like to incorporate a choke also in the project box as well. I'm assuming there shouldn't be a problem with the two cores being close together and simply carrying on with the wingding to complete the choke. How many turns would you suggest for the choke, please? Sorry, I forgot to mention this for an EFRW
Gday Ape, If you were using the same mix with your test setup but with differing sized toroids (eg 240-43 & 140-43) would you expect the same attenuation curve? Meaning toroid size only affects power handling capacity and the toroid mix determines freq verse attenuation performance? Thanks
I have the nanovna saa2 using nanovna-qt software but there is no (s21 gain) as your nanovna to test the chokes. Do you know if (mag 21) could be the same just different name? Thank you!
I’ve got some FT400-31 and FT240-31 toroids. Would the FT400’s give me better RF noise filtering when used on DC power line feeds to my mobile or HF rigs?
@@TheSmokinApe , you know your content is great when the other popular UA-cam HAM channels frequently mention your channel for reference on various HAM related topics!
Thanks for the helpful video. I want to make some common mode chokes to use in conjunction with an active mini-whip and SDRplay for listening to VLF and SW. How can I determine the best size/rating of toroid core to make the common mode choke?
Very cool!! I made a choke with a type 61 and it works very well on 11m. I have a nanovna but wanted to know once calibrated what trace do I use? At the moment I have only 2 (SWR and smith chart) Hope I am making sense . Thank you!!
Hey RP, most hams are concerned with SWR first and then the Smith Chart to see why the SWR reading is what it is... SWR Measures the power reflected back from your antenna system to your radio when there is an impedance mismatch between the two. The Smith Chart allows you to view the actual impedance characteristics of the match / mismatch. Check out my NanoVNA playlist for more info. ua-cam.com/video/ay58sp8VaNM/v-deo.html
@@TheSmokinApe Thanks for getting back! Ya both SWR and Smith chart look good. I failed to ask how measure the choke I made. Not sure if I measured correctly but it seems to choke around 87db. I have it plugged into the nano with the 50ohm load at the end.
Just got a new FT-991A and seems I need some Toroids for 2m and 70cm. It is feeding back in to smoke alarm system. 240-52 on Power connection? How many wraps?
Nice video. Question - I am wondering what effect stacking several toroids on your antenna feedline. In your table one toroid provides some amount of attenuation. By adding additional toroids do you expect to get additive attenuation? i.e. if one toroid attenuates 27 dB, does adding a second toroid give you 52 dB, no additional or some mathematical summation?
@@TheSmokinApeThanks for your response, still a little perplexed. On the bigger toroids that you presented there are 10 or so wraps, this would be similar to adding 10 snap on ferrites no? So the 10 wrap example you would get the same attenuation if you only had one wrap? The extra 9 provide extra heat dissapation? Just trying to understand.
This is something I’ve been curious about. Do you have a video that explains the difference between a choke, an unun and a balun? I have an OCF dipole for 80-10 meters and I’m trying to decide what I need in that respect and I’m trying to decide coax vs ladder line vs window line. Any thoughts??
Hey Todd. Part 2 in the video series may be helpful... A choke, sometimes called a Balun or a Choke-Balun is generally used to suppress Common Mode Current (CMC) that can be present on the feedline, CMC can cause havoc in the shack (I do have a video on CMC). An UnUn is a transmission line transformer that is used to match the impedance of the antenna feedpoint to the feedline, or get it close enough that a tuner can match the antenna system to the radio impedance. I'm reasonably confident that your OCF already has a 4:1 transformer and may have a 1:1 choke as part of the design. What OCFD are you using? I have a video one the MFJ OCF Dipole that might be helpful. Best of luck!
Excellent stuff. Thank you for making these very informative videos. Just one question. You mentioned that the T140-43 is good for 100W SSB. If I wanted to go for higher power, do I need to stack 2 or 3 cores of 43 mix (or 31 mix)? Or would you recommend going for another mix instead? 73 de 4G1FBL from the Philippines.
The mix is about how the toroid works, size would be what we use for more power. You can use a larger mix43, like a T240 for example or even stacked 240's. Thanks for watching Elmore.
NOTE: I’ve bought two different versions of this power supply. One just needed pin 33 & 36 jumped (no resistor). The second, w/o resistor would only produce the voltage for
If I add a Common-Mode Choke (CMC) to an UnUn, then does that make it (according to the presenter here) a "Choke BalUn Unun"???? ABSURD! Each device has it's own function and name, and in a few cases the functions can be combined into one device (eg-a 4:1 Choke Balun).
Rudi, surely you know that unfortunately ham radio lexicon is littered with multiple terms for the same device and the same term being used for multiple devices. That's why I take the approach of describing what the devices actually do... what is absurd is that you you have the time and the desire to scour my videos only to post the same rhetoric on every one.
Sorry to be a stickler, but 'TOE-ROID' sounds like some foot growth. 'TORE-ROID' is the common pronunciation. I know it's prob your regional accent, so shhhhhh...I won't tell anybody. As an old radio broadcaster we used to chide each other daily about pronouncing stuff. Just a latent habit...
Great illustration on toroids. Been a ham for little over 2 years now and there is a lot to learn. I find your channel very helpful regarding many technical topics. Thank you!
Thanks Rumsin, glad to hear you like the videos 👍
I clicked the like button... and I've already clicked the subscribe button. It did indeed make me happy. Nice work Ape
Glad you liked it Hayden, thank for the support brother!
Thanks for the breakdown!
Glad you liked it 👍
@@TheSmokinApe I'm currently building a 49:1 EFHW, and your toroid/unun video, and 49:1 transformer kit are fabulous resources. I didn't buy a kit, so I've been cobbling together as much reference material as I can.
@@d3jake best of luck with the build, they are great antennas 👍
Excellent introduction to toroids, materials and use cases.
As a QRP operator, the 1/2 inch size is about as big as I go -- and I can confirm that in my experience, 'size doesn't matter.' Its the 'mix' that's important. I've also stacked 1/2 inch toroids for 'QRO' (50 watts!) and that works well too -- Its just even more of a challenge to wind the little beasts! 73 Bruce G4ABX
Thanks Bruce! I've seen people crazy glue them together to make it easier to wrap.
Good stuff, man! I'll be payin' close attention to this!
Glad you liked it 👍
Excellent video
Thanks, glad you liked it 👍
Thank You. This is exactly what I needed to begin learning
Awesome, stay tuned there more coming 👍
@@TheSmokinApe WILCO
I feel so happy... I clicked a button... Good series man!
Awesome! Glad it's helpful.
thank you Ape- good info
Glad you liked it 👍
I accidentally ordered some 140-61 cores for my 80m EFHW antenna. The 61 cores are no goers on the lower bands, they start to work good above 24MHz. The transformer was wound as any 49:1 unun. The 61 cores are also good for transformers in 50MHz push-pull PA-s. :) This is my experience. 73's de YO6PNQ
Hey Pityu, thanks for watching!
SO GOOD to find these videos. I just drop a comment on a guy who was more interested in letting you know just how smart he is but was not very helpful. If you have your EE degree, you'll be right there with him. the rest of us, not so much. Not sure who his target audience was exactly. If you were able to follow him... you didn't need him. Lol!
Lol, thanks for watching Jack 👍
Are there examples of series coax chokes wound on different cores? Such as a coax choke wound on a 43 mix toroid followed by a coax choke wound on a 52 mix toroid to get better broad band choking.
Hey Viron the part 2 of this video does just that 👍
Thanks for the information.
Thanks for watching Charles 👍
Thanks, I'll probably use a 240-31 for the choke that I plan to build.
That’s what I would do 👍
@@TheSmokinApe now on to what may seem like a silly question, but despite my years in ham radio, I have no direct experience winding my own toroids and such. So no laughing, please ;-) I see chokes being wound on the toroid and then placed in a weather-proof box. How susceptible are toroids to being exposed to the elements? Any harm in leaving a coax wound choke out in the winter elements for a month or two? The coax connections would be weatherproofed, and for short term I don't expect much, if any, UV damage to the wire ties. I want to first test to see if a choke would solve, or provide a large part of the solution, to an issue I currently experience on 15-30 meters that I currently solve by having quarter-wave counterpoises attached to the ground bond on my equipment. (Unclean audio quality that is very noticeable on FT8.) This sounds like a classic case of common-mode currents returning to the shack and wreaking havoc. While it seems the counterpoise solution is creating an artificial RF ground for me, I'd rather wipe out most of that common-mode current at the source.
Question, your tests are of a single wire wrapped on half the toroid. At 3:06 of your video, you show a double wire wrapped full toroid. How would that be tested? Would you solder the yellow then white pair together and test them separately? Or test all four wires separately and and the results together?.
Hey Carl, thanks for watching. The single wire test was just testing each of the toroid mixes to see which would do a better job of attenuation, we want to "choke out" common mode current. If I was going to test the yellow and white wrap you could solder the two yellow or two white together and test that way.
Very timely. Thanks for the advice!
Glad you liked it, thanks for the comment Jim 👍
I was thinking of using my oscilloscope clip probes (wt 10x switch) since they are made for carrying frequency (though I wanna get some with higher rating) & bnc to sma adapter
I’d love to have a scope, oh and know how to use it 👍
Great info! Thanks.
KM4ACK glad you liked it 👍
I got a little lost on this but that is because I’m just not there yet. In a few months this will make more sense. Still studying for the general test. Ape you are a good teacher, sometimes the students aren’t ready. One comment you made I would like to see a short video about. That is when you said you mostly stay on 40-10 meter HF. What are the reasons for that? Thanks. Keep them coming
Glad you liked it Randy. I mainly do those bands because I don’t have the space for a larger antenna, lol 👍
Love the videos! I'm still unclear how to calibrate the test leads for testing a choke using the setup you've posted? I'm unclear how to do it. My understanding is that I would need to place the open, short, and load at the end of the leads? Thanks!!
You could do that but we are mostly concerned with the through calibration, you could just do that part with the leads.
There are THREE big questions when it comes to toroids:
1. How big should I get? (100W needs more than 10W QRP)
2. What material should I get? (Impacts frequency etc)
3. What I get this wrong? (broken core from heat, or just over priced under performing)
For 100w a t240 should be plenty. Chokes get 31 and ununs get 43 generally speaking. If you run them hot enough long enough they will crack.
A question for you - If one has a toroid with an unknown mix, from the junk box for example, how does one determine what it is?
The best way would be to perform comparative tests against known cores, if that's not possible you could compare test results against factory specs. I'd suggest not worrying about the mix and test it for the use case you have planned.
Excellent video comparing chokes. Is the FT240-31 better then the FT240-43 or they are similar in performance ? Thanks.
The 31 is a much better choke 👍
@@TheSmokinApe Thank you.
Why do you use ferrite toroids rather than ferrite rods?
I just never messed with the rods, I do remember reading something that the can have losses at the ends 👍
Hi, I'm looking for some advice as regards to building a 9:1 un-un for a random wire antenna. This needs to be suitable for around 100 watts, also I intend to add a choke to the feed end and one for the TX. The T140-43 seems to suit my needs, what gauge wire would you recommend please, Also can I connect the choke directly to the 9:1 and would this still work if the choke was mounted on top of the un-un to save space. Thank you
Hey Alan, not sure what bands you want to cover but even at 40 and up I'd suggest a 240-43 for the 9:1, 18awg mag wire and 18awg stranded copper for the element.
Thanks for the reply. Yes, 40 and above are what I intend to use. I would like to incorporate a choke also in the project box as well. I'm assuming there shouldn't be a problem with the two cores being close together and simply carrying on with the wingding to complete the choke. How many turns would you suggest for the choke, please? Sorry, I forgot to mention this for an EFRW
I typically do 11 turns on a mix 31 core for the choke.
Thank you for the info, I'll put it into practice shortly and let you know how I get on
Just grabbed an FT-240-43, hoping it will help with my antenna setup, 73 Ape! Good video as always
It should help, check out part 2 in the series where we cover chokes in more detail. Thanks man!
Gday Ape, If you were using the same mix with your test setup but with differing sized toroids (eg 240-43 & 140-43) would you expect the same attenuation curve? Meaning toroid size only affects power handling capacity and the toroid mix determines freq verse attenuation performance?
Thanks
The size will play a role but it’s not as impactful as the core mix 👍
Silly question, do toroids rust? What if I wanted to leave up an efhw permanently?
I haven’t seen one do that, but I guess it’s possible 🤔
Could you mix them? What I mean is put a 43 and 31 together (or at least on the same feedline) to keep your attenuation low across the bands?
you can, check out my CMC video. I typically put a choke at each end of the feedline.
I have the nanovna saa2 using nanovna-qt software but there is no (s21 gain)
as your nanovna to test the chokes. Do you know if (mag 21)
could be the same just different name? Thank you!
I’ve got some FT400-31 and FT240-31 toroids. Would the FT400’s give me better RF noise filtering when used on DC power line feeds to my mobile or HF rigs?
They might, but you should be able to get what you need from a 240 👍
@@TheSmokinApe , thanks, sounds good! And thanks for all the great HAM content on this channel!
@@rays9033 thanks Ray, glad you like the videos 👍
@@TheSmokinApe , you know your content is great when the other popular UA-cam HAM channels frequently mention your channel for reference on various HAM related topics!
@@rays9033 that does make me smile 😃
Clicking the button DID make me happy!! ;)
🤜🏻👍🤛🏻♡♡♡
Awesome!
Awesome video. Definitely gonna follow this series, KO4DNI
Glad you liked it, thanks for watching!
Thanks for the helpful video. I want to make some common mode chokes to use in conjunction with an active mini-whip and SDRplay for listening to VLF and SW. How can I determine the best size/rating of toroid core to make the common mode choke?
Thank you! Excellent info. 73, AA4EZ
Thanks Raymond, glad you liked it 👍
Very cool!! I made a choke with a type 61 and it works very well on 11m.
I have a nanovna but wanted to know once calibrated what trace do I use? At the moment I have only 2 (SWR and smith chart) Hope I am making sense . Thank you!!
Hey RP, most hams are concerned with SWR first and then the Smith Chart to see why the SWR reading is what it is... SWR Measures the power reflected back from your antenna system to your radio when there is an impedance mismatch between the two. The Smith Chart allows you to view the actual impedance characteristics of the match / mismatch. Check out my NanoVNA playlist for more info. ua-cam.com/video/ay58sp8VaNM/v-deo.html
@@TheSmokinApe Thanks for getting back! Ya both SWR and Smith chart look good. I failed to ask how measure the choke I made. Not sure if I measured correctly but it seems to choke around 87db. I have it plugged
into the nano with the 50ohm load at the end.
👍
a toe roid sounds painful. Great video Sir!
Haha, thanks man!
Just got a new FT-991A and seems I need some Toroids for 2m and 70cm. It is feeding back in to smoke alarm system. 240-52 on Power connection? How many wraps?
I have a 240-43 with 12 wraps on my radio pier connection. Are you talking about the 110v into the UPS? I haven’t had to work on a problem like this.
@@TheSmokinApe I would say the power wires from the radio to the power supply.
Nice video. Question - I am wondering what effect stacking several toroids on your antenna feedline. In your table one toroid provides some amount of attenuation. By adding additional toroids do you expect to get additive attenuation? i.e. if one toroid attenuates 27 dB, does adding a second toroid give you 52 dB, no additional or some mathematical summation?
The stacking is more about heat dissipation 👍
@@TheSmokinApeThanks for your response, still a little perplexed. On the bigger toroids that you presented there are 10 or so wraps, this would be similar to adding 10 snap on ferrites no? So the 10 wrap example you would get the same attenuation if you only had one wrap? The extra 9 provide extra heat dissapation? Just trying to understand.
Looking to build a 49-1
My current antenna is a 49:1
This is something I’ve been curious about. Do you have a video that explains the difference between a choke, an unun and a balun? I have an OCF dipole for 80-10 meters and I’m trying to decide what I need in that respect and I’m trying to decide coax vs ladder line vs window line. Any thoughts??
Hey Todd. Part 2 in the video series may be helpful... A choke, sometimes called a Balun or a Choke-Balun is generally used to suppress Common Mode Current (CMC) that can be present on the feedline, CMC can cause havoc in the shack (I do have a video on CMC). An UnUn is a transmission line transformer that is used to match the impedance of the antenna feedpoint to the feedline, or get it close enough that a tuner can match the antenna system to the radio impedance. I'm reasonably confident that your OCF already has a 4:1 transformer and may have a 1:1 choke as part of the design. What OCFD are you using? I have a video one the MFJ OCF Dipole that might be helpful. Best of luck!
Excellent stuff. Thank you for making these very informative videos.
Just one question. You mentioned that the T140-43 is good for 100W SSB. If I wanted to go for higher power, do I need to stack 2 or 3 cores of 43 mix (or 31 mix)? Or would you recommend going for another mix instead?
73 de 4G1FBL from the Philippines.
The mix is about how the toroid works, size would be what we use for more power. You can use a larger mix43, like a T240 for example or even stacked 240's. Thanks for watching Elmore.
Where does Ape get his rhoids at?
The youtube comment section 🤣
Right
looks like jpmultiserve is gone ?
You can order direct here: www.jpmsupply.com/category-s/1840.htm
NOTE: I’ve bought two different versions of this power supply. One just needed pin 33 & 36 jumped (no resistor). The second, w/o resistor would only produce the voltage for
Is it possible to have too many turns of coax when making a choke with 31 mix?
You prolly would run out of room first.
If I add a Common-Mode Choke (CMC) to an UnUn, then does that make it (according to the presenter here) a "Choke BalUn Unun"???? ABSURD! Each device has it's own function and name, and in a few cases the functions can be combined into one device (eg-a 4:1 Choke Balun).
Rudi, surely you know that unfortunately ham radio lexicon is littered with multiple terms for the same device and the same term being used for multiple devices. That's why I take the approach of describing what the devices actually do... what is absurd is that you you have the time and the desire to scour my videos only to post the same rhetoric on every one.
Sorry to be a stickler, but 'TOE-ROID' sounds like some foot growth. 'TORE-ROID' is the common pronunciation. I know it's prob your regional accent, so shhhhhh...I won't tell anybody.
As an old radio broadcaster we used to chide each other daily about pronouncing stuff. Just a latent habit...
Everyone I know says Toe-Roid, I'm not sure where your hanging around that they double down in the R.
@@TheSmokinApe I had never heard "toe-roid" until watching this video.
@@gettingpast4391 that’s the proper pronunciation 🤣