If you don’t have an oscilloscope, there’s an easy way to determine the inner / outer foil sides. All you do is get the capacitor’s legs and switch them back and forth between the tip and sleeve of a guitar cable that is plugged in to an amp. Whichever orientation you find to be less noisy is the outer foil. It will be pretty obvious. It also helps to run the guitar signal through a boost pedal to make this more audible.
so the leg test.. equates to the foil side of the cap is quieter on the sleeve of the jack plug which is earthed, centre being live!😇👍 just to confirm.
I used it for ages, although not terribly often. For those without a good scope, you can use an audio amplifier and you ears as well. Nowadays I can use the built in generator in my scope instead of the 50 or 60 Hz from my fingers. The higher frequency increases sensitivity in the cases, where the capacitor construction is more challenging.
I remember my first year of electronic courses when I asked why this would matter. Oh, the good ole' days of innocence! I miss those days every once in a while. lol
lol, I use that solder too, dunno why its so much more expensive but I like the tube dispensers, lazy I guess or short handed, I can place the tube any where, pull a length out to feed the tip one handed so I can hold something with the other, I'll tape it down so it stays still.. should prolly just get a solder station with the arm holders lol, stewmac makes one you can put 10 arms on of varying lengths.. so far it's one thing at a time for me, and I like a solder gun I can easily move anywhere depending on where I feel like using it at that time.. when I see a nice solder station I always think welp I am going to need a certain amount of free space to set the unit itself then space in front of it to set whatever I am working on, like bringing a solder gun to wherever the unit that needs soldering, breakfast table in the morning, lunch table around noon then dinner table at night, and there is logic to this make no mistake and this worked with my wife maybe it works with your but the sound logic is that when its breakfast time or dinner time whatever she doesn't have to call me to dinner and I am never late.. there was only the one time where she said "i wished you would do your work elsewhere so I can get the table ready" my answer was "oh yea right sorry OK sure, I'll move it into the living room and use the new oak coffee table so i'm out the way.. she was like well ya know now I think about it moving all that "stuff" would take a lot of time and you'll get more done if you can just focus on it right there at the kitchen table.. I then said "yea you're right, you're always right, hopefully this year santa brings me the ncie samsung QLED 98 inch TV for the shop, a TV that size can heat the entire shop so it won't be freezing out there, then I can work on everything using those nice benches santa got me last year, and you won't have to look at the back of my head while you're working in the kitchen"... 🙂 very soon imma hit her with the, "welp, if I had a real nice solder station like the Hakko FM206-STA it would have to run off a power conditioner and that's in the shop but all my work would have to be done out there cuz that's where I would have to "install" it"... hehe... "with that Hakko and a TV i'd only need to come into the house to eat, unless someone was to bring me a plate?... lololololo Santa gonna need a big bag this christmas I already know, I will supply the paper plates and cups cuz I'm good that way...
Hi Jason and thanks for all you do and please I have a question about replacing caps in my grand dad philips vintage radio in my country I cannot find proper replacement for the paper capacitor so should I replace them with ceramic caps especially those with low farads and I am concerned with the polarity which ones have a polarity or not , so forgive me for taking your time and appreciate any response
Hi Abdullah don't overthink it, generally polarity in non-polar caps is pretty much optional and won't seriously affect function, it's just slightly better to stay consistent with them. I personally would avoid using ceramic caps unless they were used in the first place (they are selected for specific properties in some cases). Otherwise ceramics are noisy and drift with temperature. Any film type cap is a good choice to replace paper, regardless of type. Check out Mr. Carlson's video on selecting types: ruclips.net/video/67M7fsbLUIU/видео.html
You won't normally see that on film caps but you will on radial bipolar electrolytics. The same rule as polar applies: long is "positive", short is "negative", with the negative being attached to the outside of the can. So short = outside.
Are you using a Function Generator also to put across the capacitor under test? so you're just ONLY using the Oscope probe leads and it will measure an AC waveform, why? I'm guessing the capacitor metal leads are antennas picking up stray AC
I am getting the exact same reading regardless of which way capacitor is connected. Ive tried three different types of non polar capacitor including one you showed in vodeo I am not getting any difference at all
ended up using the audio amplifier method where you connect it across mic jack then reverse and see what end is loudest when you touch the body of the capacitor. This tells you which side is the foil side. It was very noticeable with volume cranked up while touching capacitor. Maybe I just don't know how to set up the scope properly but it didn't work for me.
If using either Polyester or PP caps with outer foils as coupling caps in a tube amp, should the outer foil (lower potential) lead be closer to the grid of the proceeding tube stage or closer to the plate of the preceding tube stage?
Easiest way to think about it: in coupling stages have the foil facing the incoming signal. So it will be pointed to the preceding stage. Some people over complicate it by saying "foil facing the lower impedance side of the circuit", as in the previous stage (output = low imp, input = high imp)
@@OddAudioCanada I guess in my head that would be backwards of what I’d expect because I thought since the cap blocks DC, lower potential direction would be after it (going to the grid of the next stage) but it seems that is not the case. What about if there are resistors on either side, and the resistor between it and the plate of the last stage is larger than the one between itself and the grid of the next stage? I have a unique case in my red knob amp between the phase inverter and power tube where this is the case.
@@on1ytheb3st It might be academic in your case, but I always think about it in terms of "shielding towards incoming signal" regardless of the circuit (or shielding to ground for bypass/filter caps). Oops used my other account, yes OddAudio is related to OddBike!
I reckon : one end of the tone capacitor is connected to ground, usually the back/casing of the potentiometer. You find the "shielding leg" of the capacitor.....THIS is connected to GROUND. 😊
Bonus fact: in bipolar electrolytic caps, the outer casing is connected to one side same as in a polar cap (where negative is connected to the case)... You can check continuity to the case to find this lead, but if you buy them new the leads are asymmetrical just like a polar cap... and the outer case is connected to the shorter leg.
This is exactly what I was looking for. I have some Nichicon Muse for an amplifier that i'm refurbishing and there is no continuity between the casing and the legs, and the oscilloscope thing also doesn't work. I hope that you are right about the legs though. Thanks!
Some film caps don't have a "foil" that you can measure (they measure the same both ways). Make sure your scope is set to highest sensitivity and extend the time base until you see the wave.
Same for me. I've tried this test with numerous capacitors many many times with both an oscilloscope and an audio amplifier and can tell absolutely no difference either way. The results are inconsistent at best.
That's because your scope is working properly... He must have an open ground if he's getting that much vertical deflection with just an inductive hum from his fingers...
If a capacitor is of rolled up construction, there is 100% an "outside foil". Many capacitors (not just electrolytic) are still made this way. Correct that there are certain constructions of capacitors that would have no "outside foil" though. It also probably matters less these days because even a rolled up capacitor has a much smaller cross-sectional area than an equivalent older one... thus limiting the potential coupling from the rest of the circuit into the outer foil. Long story short... if you can see the effect on the scope, it's there.
New caps are not made with old technology of the outside foil. Why would you be using old caps? Electronics components were not made to last forever. Even in the 1939’s planned obsolescence was part of the bigger picture, thus FM, Stereo, Transistor radios, and cell phones.
If you don’t have an oscilloscope, there’s an easy way to determine the inner / outer foil sides. All you do is get the capacitor’s legs and switch them back and forth between the tip and sleeve of a guitar cable that is plugged in to an amp. Whichever orientation you find to be less noisy is the outer foil. It will be pretty obvious. It also helps to run the guitar signal through a boost pedal to make this more audible.
Legend man....thanks so much
Yeah, that also requires a guitar amp.
thanks 👍,must try that, 😎just can`t find my oscilloscope no place
lmao... i know i put it down just here 😂🤣😁😉
so the leg test.. equates to the foil side of the cap is quieter on the sleeve
of the jack plug which is earthed, centre being live!😇👍 just to confirm.
I used it for ages, although not terribly often. For those without a good scope, you can use an audio amplifier and you ears as well. Nowadays I can use the built in generator in my scope instead of the 50 or 60 Hz from my fingers. The higher frequency increases sensitivity in the cases, where the capacitor construction is more challenging.
Good tip! Thanks for posting this.
I remember my first year of electronic courses when I asked why this would matter.
Oh, the good ole' days of innocence! I miss those days every once in a while. lol
thankyou!,good concise and valuable info, made easy enough to grasp
the essential application..😇👍
Thank you very much! I had forgotten this valuable trick
Very helpful and I never knew this.
lol, I use that solder too, dunno why its so much more expensive but I like the tube dispensers, lazy I guess or short handed, I can place the tube any where, pull a length out to feed the tip one handed so I can hold something with the other, I'll tape it down so it stays still.. should prolly just get a solder station with the arm holders lol, stewmac makes one you can put 10 arms on of varying lengths.. so far it's one thing at a time for me, and I like a solder gun I can easily move anywhere depending on where I feel like using it at that time..
when I see a nice solder station I always think welp I am going to need a certain amount of free space to set the unit itself then space in front of it to set whatever I am working on, like bringing a solder gun to wherever the unit that needs soldering, breakfast table in the morning, lunch table around noon then dinner table at night, and there is logic to this make no mistake and this worked with my wife maybe it works with your but the sound logic is that when its breakfast time or dinner time whatever she doesn't have to call me to dinner and I am never late..
there was only the one time where she said "i wished you would do your work elsewhere so I can get the table ready" my answer was "oh yea right sorry OK sure, I'll move it into the living room and use the new oak coffee table so i'm out the way..
she was like well ya know now I think about it moving all that "stuff" would take a lot of time and you'll get more done if you can just focus on it right there at the kitchen table..
I then said "yea you're right, you're always right, hopefully this year santa brings me the ncie samsung QLED 98 inch TV for the shop, a TV that size can heat the entire shop so it won't be freezing out there, then I can work on everything using those nice benches santa got me last year, and you won't have to look at the back of my head while you're working in the kitchen"... 🙂
very soon imma hit her with the, "welp, if I had a real nice solder station like the Hakko FM206-STA it would have to run off a power conditioner and that's in the shop but all my work would have to be done out there cuz that's where I would have to "install" it"... hehe... "with that Hakko and a TV i'd only need to come into the house to eat, unless someone was to bring me a plate?... lololololo
Santa gonna need a big bag this christmas I already know, I will supply the paper plates and cups cuz I'm good that way...
Hi Jason and thanks for all you do and please I have a question about replacing caps in my grand dad philips vintage radio in my country I cannot find proper replacement for the paper capacitor so should I replace them with ceramic caps especially those with low farads and I am concerned with the polarity which ones have a polarity or not , so forgive me for taking your time and appreciate any response
Hi Abdullah don't overthink it, generally polarity in non-polar caps is pretty much optional and won't seriously affect function, it's just slightly better to stay consistent with them. I personally would avoid using ceramic caps unless they were used in the first place (they are selected for specific properties in some cases). Otherwise ceramics are noisy and drift with temperature. Any film type cap is a good choice to replace paper, regardless of type. Check out Mr. Carlson's video on selecting types: ruclips.net/video/67M7fsbLUIU/видео.html
Good stuff.
I notes one of the leads was longer coult it be like on other components that the lead length is an indicator?
You won't normally see that on film caps but you will on radial bipolar electrolytics. The same rule as polar applies: long is "positive", short is "negative", with the negative being attached to the outside of the can. So short = outside.
thanks
Are you using a Function Generator also to put across the capacitor under test? so you're just ONLY using the Oscope probe leads and it will measure an AC waveform, why? I'm guessing the capacitor metal leads are antennas picking up stray AC
His body is the antenna I think
You must have an open ground on your scope probe to get that kind of deflection.
Sir, You Are great.
I am getting the exact same reading regardless of which way capacitor is connected. Ive tried three different types of non polar capacitor including one you showed in vodeo I am not getting any difference at all
ended up using the audio amplifier method where you connect it across mic jack then reverse and see what end is loudest when you touch the body of the capacitor. This tells you which side is the foil side. It was very noticeable with volume cranked up while touching capacitor. Maybe I just don't know how to set up the scope properly but it didn't work for me.
If using either Polyester or PP caps with outer foils as coupling caps in a tube amp, should the outer foil (lower potential) lead be closer to the grid of the proceeding tube stage or closer to the plate of the preceding tube stage?
Easiest way to think about it: in coupling stages have the foil facing the incoming signal. So it will be pointed to the preceding stage. Some people over complicate it by saying "foil facing the lower impedance side of the circuit", as in the previous stage (output = low imp, input = high imp)
@@OddAudioCanada I guess in my head that would be backwards of what I’d expect because I thought since the cap blocks DC, lower potential direction would be after it (going to the grid of the next stage) but it seems that is not the case.
What about if there are resistors on either side, and the resistor between it and the plate of the last stage is larger than the one between itself and the grid of the next stage? I have a unique case in my red knob amp between the phase inverter and power tube where this is the case.
@@on1ytheb3st It might be academic in your case, but I always think about it in terms of "shielding towards incoming signal" regardless of the circuit (or shielding to ground for bypass/filter caps).
Oops used my other account, yes OddAudio is related to OddBike!
So how would I solder a tone cap on a guitar once I have this information?
I reckon : one end of the tone capacitor is connected to ground, usually the back/casing of the potentiometer. You find the "shielding leg" of the capacitor.....THIS is connected to GROUND. 😊
@@vacuumelite2065 Thanks!
Bonus fact: in bipolar electrolytic caps, the outer casing is connected to one side same as in a polar cap (where negative is connected to the case)... You can check continuity to the case to find this lead, but if you buy them new the leads are asymmetrical just like a polar cap... and the outer case is connected to the shorter leg.
This is exactly what I was looking for. I have some Nichicon Muse for an amplifier that i'm refurbishing and there is no continuity between the casing and the legs, and the oscilloscope thing also doesn't work. I hope that you are right about the legs though. Thanks!
That technique has been used for decades....
Hi!
This method doesn't work with my scope at all.
Some film caps don't have a "foil" that you can measure (they measure the same both ways). Make sure your scope is set to highest sensitivity and extend the time base until you see the wave.
Don't worry about it. its all bollocks.
Same for me. I've tried this test with numerous capacitors many many times with both an oscilloscope and an audio amplifier and can tell absolutely no difference either way. The results are inconsistent at best.
If this mattered, it would be on spec sheets
If that would be true itd be wonderful😓
I've never been able to reproduce these results... probably my own fault for not knowing how to use my o-scope.
That's because your scope is working properly... He must have an open ground if he's getting that much vertical deflection with just an inductive hum from his fingers...
Nerds😂
Edit: I’m kidding
Tip is valuable but should have been filmed to a higher standard
New components aren’t marked because there is no outside foil. Only electrolytic caps are marked, good reasons.
En los Orange Drop que yo compro si ocurre este tipo de cosas. Yo veo muy adecuado hacer esta prueba. Saludos.
If a capacitor is of rolled up construction, there is 100% an "outside foil". Many capacitors (not just electrolytic) are still made this way. Correct that there are certain constructions of capacitors that would have no "outside foil" though. It also probably matters less these days because even a rolled up capacitor has a much smaller cross-sectional area than an equivalent older one... thus limiting the potential coupling from the rest of the circuit into the outer foil. Long story short... if you can see the effect on the scope, it's there.
New caps are not made with old technology of the outside foil. Why would you be using old caps? Electronics components were not made to last forever. Even in the 1939’s planned obsolescence was part of the bigger picture, thus FM, Stereo, Transistor radios, and cell phones.
I think you answered your own question.
just asking as complete noob,,, osc. probe is x1 or x10 set ?! Thanks
1x! You want the highest sensitivity, 10x is ... 10x less sensitive (used for high voltage measurements usually).