In order to determine the resonant frequency of a tank circuit you can also use white noise as signal source and look for the peek of the FFT at you digital oscilloscope. :)
I've been to Kokomo many times!!! I'm about 2 hours to the left from there but my dad would take me with in his semi to there! Great video john! Always good to absorb your knowledge, especially on inductors!!!
I forget who posted this idea for scraping off enamel but it works well. Buy or sacrifice a nail clipper, remove the lever and its pivot so it is like a little pair of tongs. Slightly bend them in a bit and they work very well for this.
Hi John regarding the new radio shack we have one here in the San Diego area. It’s nothing like the old seems like mostly Hobby stuff does have some components like before. Doesn’t really have much for sales as far as typical consumer products. There’s also an online radio shack as well
Y'know John, here in Summerville SC on 25Feb2022 there is a "Radio Shack" still open, it's actually a "Hurricane Electronics - Radio Shack." IDK where they get their parts, but they still have a lot of RS parts on hand. They seem to specialize in Auto Audio systems & installations. I get some things from them, but they don't have most stuff I'm looking for. They have many of the "popular kits" like Arduino Uno experimenting kits, etc, and they have many of the familiar tools and such. When we moved nearby in 2010, RS was still going, and there was a store closer to our home in Goose Creek. Oh, well. What I really miss is Delta Electronics in Atlanta! (Where I'm from) There you could get mil grade op amps & other chips really cheap, including some high integrated ICs like TI Electro-Optical things (from the 1970s). Plus all kinds of "subassemblies" that ranged from "one-offs" to "cancelled production runs." They usually worked but were not guaranteed, of course, but you could use them (or more often parts from them) for whatever project you were working on. Man, those were the days! I still have some of that stuff in my parts bins. Oh, I wish I could've moved my shop when we moved! Now I have no place to work, and no space to build anything! I have an approx 19" x 17" "workbench" in my crowded "office" that's supposed to function as a shop, it's just barely enough room to do some soldering, lol. Aaaargh! By the time we move to a large enough place, I'll likely be too old to build anything! I still have memories of the many hours I spent in the shop that I built in a 12' x 16' shed (that I had built from a Lowe's kit) by a grade school shop class, which I finished out in true custom fashion. Every cubic mm was planned out & functional. I had plenty of workbench space & all my power tools in there, plus a loft for storage. But when we moved (due to wife's job) it was too far to take, even if we did have room for it in the yard, so I had to leave it for whomever bought the house, and who didn't appreciate what it was! (That part really sucks!) It was heated & cooled and well insulated, you could be working through a storm & not even know. Good place to get lost in your work!
The radio Shack outlets that are still open are independently owned shops that have a little spot in the store for some RS stuff. I found one ISO of closing stores. I asked when they were closing and he said they weren't! Didn't look much like a Radio Shack, just a little area for a few panels in an independent repair place focused on CB and HAM.
We have a radio shack nearby, it’s privately owned. They still have some of the electronic parts. I don’t go very often because they rarely have what I need. 3M scotch bright pad works good to clean off enamel.
@@mrb.5610 too much hassle. any sharp stuff, from minus point screwdriver to utility knifes work very good if you don't have a piece of sand paper around.
Hey John, First of all, Thank You, for all your hard work. We appreciate you! And could i bother you to post a photo of that chart you used in the video with the ruler?
@@waynec369 Dont swear at me you idiot it was simply a technical question, can you answer it ?, clearly you no nothing about this subject or you would know that coil shape CAN be important in some circuits and not others this was a simple enquiry and nothing to do with you, John has already explained a preference for the orientation of the coil and I was taking a step further.
The coils sold at, say Digikey don't match what I need and cost too much. It needs to be air core and of the right gauge for current handling. Makes more sense to wind your own.
Who knew mickey would be so sensitive (narcissistic) as to believe someone was swearing at him/her ffs? Perhaps coil winding is, indeed, beyond your capabilities and you should "just buy" afterall.
Best way to remove the enamel is heating the wire end on an Aspirin tablet with your soldering iron. Do not inhale the fumes (they are not toxic but very irritant).
how about a method of feeding tank circuit square wave and just looking for ringing at the edges and taking the frequency of the ringing as a resonance?
What did you do in Kokomo? I was born in Logansport and graduated from high school there, but lived other places in between. Used to go to "stoplight city" for shopping and doctors. Useful video especially the coil winding part. Be glad you aren't winding toroids for RF applications.
@JohnAudioTech Yeah, everybody is from some place, especially when that some place is an old blue collar town in northern Indiana. I moved to Indianapolis in 1977. I think you're somewhere in northwestern Ohio, now, aren't you?
A variable that seems to not be considered is the measurement of the coil diameter or radius from the coil form diameter or from the centers of the conductors. In other words, 10mm coil form diameter or the coil form diameter plus one wire diameter, which is the same as half the wire diameter on one side plus half the wire diameter on the other side. If the wire diameter is 1mm then the calculations can be done with 10mm, or 11mm. But in any case, a small bend in the heavier wire could cause a small amount of space between turns, and this could cause a variation of a few percent in the measured inductance. It's to be expected that some amount of tolerance is going to affect every coil.
How you know what diameter cable you need? is it for amperage? recent i bought some inductor for a test and they where SMD and pretty small, like 5mm, I was watching some "classic" E.Q. guitar pedals that used inductors.
BTW, my first time watching you. Nice tight coil you wound there, you put in all the tips I would've! I like your workspace, maybe you could mount some of those drawer assemblies on the wall? Might free up some workbench. I like your idea of having your files freely available, man after my own heart! Maybe if you rent your own website you could do that. You'd have a place to post pages, and store files for download. And have your own domain name. I used to do that. I've also been the "host" /website manager for a couple of ham radio clubs, that worked for them as well. Anyway, good luck! I'll follow along.... >>Jeffro, ai4rv
The usual problem with capacitive loads is lack of decoupling from your feedback path. A resistive decoupling is what you want. An inductive output prevents an amp from responding to both load and input transients. Does that matter so much for an audio amp? Probably not where ordinary speakers with a low primarily inductive impedance are the main concern. As a general principle though output inductance is a thing to minimize! Since you've damped it with just 10 ohms it will be largely bypassed as a side-effect so this probably won't matter much, though you could equally lower the resistance a bit and get rid of the inductor altogether I think. As the ratio of the damping resistor to inductance becomes extreme you're eventually no longer approximating a low-Q inductor with that parallel arrangement at lower frequencies.
well one thing i really said all his vid is real and truth i redo again lm386 amp for my headphone i thought 386 has distortion issue but.. well....and i kind a tweak little bit more and sure enough 100% volume not even a littlebit distortion even on crossover i thank a lot of you ur the master of discrete design amp but fell fluttered to say i do design class ab amp power amp but litteral i much salute you more this things
John, what if amp uses larger value of the coil say 2-5uH. Will it have any adverse effects on the performance. I noticed a lot of amplifiers, especially ones with multiple output pairs, use higher value than 1uH and it seems to keep them more stable with highly capacitive loads like electrostatic loudspeakers or fancy spkrs cables (Audioquest or flat ribbon cables).
A higher value, such as 5uh has significant impedance at higher audio frequencies (.63 ohms at 20KHz) and will affect the frequency response and damping. That's probably not noticeable to most people but would look bad on the spec sheet.
The problems with the ultra-wide cameras: keeping your fingers away from the lens, no image stabilization, poorer lens design (less light). The normal lens is actually pretty wide on a phone. For miniature work, a phone might beat a cheap magnifying glass, assuming you can get the right stand for it.
Being a Tracfone member there were options for free phones but they were all sold out, so I got this one with the $75 discount making it only $70. It shoots nice 4k video direct to HEVC (H.265).
Great video John. I want to mention another method to measure Inductance, capacitance resistance(with better accuracy) with a PC sound card and REW. This circuit is mainly used for the impedance measurement of speakers. Since the speaker is identical to an LCR circuit, we could easily measure inductance/capacitance/resistance with the same. This circuit is available for purchase from Dayton Audio. But we DIY guys could do a similar setup with a lot less money. will leave a link to that video here:ruclips.net/video/Ag8hTO4QhsE/видео.html
REW, is rather designed for audio frequencies, I think 48kHz is max sampling possible, so I'm not 100% that with REW's accuracy, it will measure in uH range. I use it for the caps and coils used in crossovers, but the values are usually above 0.1mH for coils and 0.1uF for capacitors. It is a very capable software for loudspeaker measurements, I use it along with old Clio, which also has L-C meter. Also ARTA is a very capable software, but requires jig for proper functionality, and it supports 96k sampling freq. DATS from Dayton Audio will measure R-L-C, but don't know what are min values, together with Thiele-Small parameters. This one is close to where I live, but I haven't tried it yet www.sonicbeacon.com/Sonic_Beacon_Products_Loudspeaker_Test_Software.htm
In order to determine the resonant frequency of a tank circuit you can also use white noise as signal source and look for the peek of the FFT at you digital oscilloscope. :)
Close to hitting 50K subscribers. Can't wait to see that happen!
Oh my gosh that ruler + diagram thing in the databook is genius.
"Metric smetric, my car gets 40 rods to the hogshead and that's the way I like it!" - Abe Simpson
Yes, would love to see psu (and softstart) collaboration with eddieyahu.
17:19 Happy to see the RA pen, I have worked for RA as an engineer for the past 35 years! Oh, and sadly that Radio Shack store is NOT open.
The store must have closed recently. I don't know how it could survive in that small town.
I’m an EE in school right now and I’m very interested in these types of videos. Thank you John!
I've been to Kokomo many times!!! I'm about 2 hours to the left from there but my dad would take me with in his semi to there! Great video john! Always good to absorb your knowledge, especially on inductors!!!
wow, didn't expect to get a lesson about diy inductors.
Oh my gosh!! I have that same Radio Shack book too!
A solder pot might work well for removing the enamel.
I forget who posted this idea for scraping off enamel but it works well. Buy or sacrifice a nail clipper, remove the lever and its pivot so it is like a little pair of tongs. Slightly bend them in a bit and they work very well for this.
Very cool bud. Thank you for sharing this with me, and all of us cause this is important.
Thank you so much, totally made my day :)
I have that same Radio Shack Data book as well as the Forrest Mims Transistor handbooks! Great video by the way.
Hi John regarding the new radio shack we have one here in the San Diego area. It’s nothing like the old seems like mostly Hobby stuff does have some components like before. Doesn’t really have much for sales as far as typical consumer products. There’s also an online radio shack as well
Y'know John, here in Summerville SC on 25Feb2022 there is a "Radio Shack" still open, it's actually a "Hurricane Electronics - Radio Shack." IDK where they get their parts, but they still have a lot of RS parts on hand. They seem to specialize in Auto Audio systems & installations. I get some things from them, but they don't have most stuff I'm looking for. They have many of the "popular kits" like Arduino Uno experimenting kits, etc, and they have many of the familiar tools and such. When we moved nearby in 2010, RS was still going, and there was a store closer to our home in Goose Creek. Oh, well. What I really miss is Delta Electronics in Atlanta! (Where I'm from) There you could get mil grade op amps & other chips really cheap, including some high integrated ICs like TI Electro-Optical things (from the 1970s). Plus all kinds of "subassemblies" that ranged from "one-offs" to "cancelled production runs." They usually worked but were not guaranteed, of course, but you could use them (or more often parts from them) for whatever project you were working on. Man, those were the days! I still have some of that stuff in my parts bins.
Oh, I wish I could've moved my shop when we moved! Now I have no place to work, and no space to build anything! I have an approx 19" x 17" "workbench" in my crowded "office" that's supposed to function as a shop, it's just barely enough room to do some soldering, lol. Aaaargh! By the time we move to a large enough place, I'll likely be too old to build anything! I still have memories of the many hours I spent in the shop that I built in a 12' x 16' shed (that I had built from a Lowe's kit) by a grade school shop class, which I finished out in true custom fashion. Every cubic mm was planned out & functional. I had plenty of workbench space & all my power tools in there, plus a loft for storage. But when we moved (due to wife's job) it was too far to take, even if we did have room for it in the yard, so I had to leave it for whomever bought the house, and who didn't appreciate what it was! (That part really sucks!) It was heated & cooled and well insulated, you could be working through a storm & not even know. Good place to get lost in your work!
oh man I can literally feeeeeel the tech
The radio Shack outlets that are still open are independently owned shops that have a little spot in the store for some RS stuff. I found one ISO of closing stores. I asked when they were closing and he said they weren't! Didn't look much like a Radio Shack, just a little area for a few panels in an independent repair place focused on CB and HAM.
I setup and ran the sound for the Gus Macker basketball tournament in Kokomo Ind a few years back
Exactly ! I have used this online calculators to make this coil and it's works pretty well. 👍👍
We have a radio shack nearby, it’s privately owned. They still have some of the electronic parts. I don’t go very often because they rarely have what I need. 3M scotch bright pad works good to clean off enamel.
I use really fine grit sandpaper to get the enamel off the copper
....dipping in paint stripper works well on very fine wire .... less risk of breaking it !
@@mrb.5610 too much hassle. any sharp stuff, from minus point screwdriver to utility knifes work very good if you don't have a piece of sand paper around.
Excellent video John. Thanks. Always informative!
16:50 Hahahah I just mubled to myself "Murrica !!" when you said that, and then I looked at the screen 😂👍
Hey John,
First of all, Thank You, for all your hard work.
We appreciate you!
And could i bother you to post a photo of that chart you used in the video with the ruler?
Awesome video. Thank you for sharing
Fascinating stuff, could you just buy a 1uH inductor or is the shape important please ? big fan of Eddies too...cheers.
Anyone can "just buy" ffs...
Winding a coil is NOT rocket science...
@@waynec369 Dont swear at me you idiot it was simply a technical question, can you answer it ?, clearly you no nothing about this subject or you would know that coil shape CAN be important in some circuits and not others this was a simple enquiry and nothing to do with you, John has already explained a preference for the orientation of the coil and I was taking a step further.
The coils sold at, say Digikey don't match what I need and cost too much. It needs to be air core and of the right gauge for current handling. Makes more sense to wind your own.
@@JohnAudioTech oh yes that makes sense, thanks for the answer !....cheers.
Who knew mickey would be so sensitive (narcissistic) as to believe someone was swearing at him/her ffs? Perhaps coil winding is, indeed, beyond your capabilities and you should "just buy" afterall.
You can use nitric acid to remove the enamelation from copper wire. Another way is to use a little pot of solder bath at 400 to 500 °C.
Thanks for the video John, very interesting subject
There's a Radio Shack in Sylvania, Ohio which is near Toledo. I haven't been there yet.
It would be interesting to subject the tank to a step response and measure the resulting frequency and compare the results.
Best way to remove the enamel is heating the wire end on an Aspirin tablet with your soldering iron. Do not inhale the fumes (they are not toxic but very irritant).
22:45 maybe try Google Drive? Tag your stuff "for anyone"
You only have two scrape high temperature enameled wire, standard enameled wire will bear with the heat of the soldering iron and molten solder
how about a method of feeding tank circuit square wave and just looking for ringing at the edges and taking the frequency of the ringing as a resonance?
Do people south of the equator have to wind their inductors the other way? 🤔
Many years left until a mobile phone can handle what a dedicated camera can ... back to your Canon!
What did you do in Kokomo? I was born in Logansport and graduated from high school there, but lived other places in between. Used to go to "stoplight city" for shopping and doctors. Useful video especially the coil winding part. Be glad you aren't winding toroids for RF applications.
Kindergarten is about all I did there before the family moved down to Indianapolis in 1973.
@JohnAudioTech Yeah, everybody is from some place, especially when that some place is an old blue collar town in northern Indiana. I moved to Indianapolis in 1977. I think you're somewhere in northwestern Ohio, now, aren't you?
I only have used sand paper for removing enamel on the wire, just because that was how I learned in Junior High school in Japan.
A variable that seems to not be considered is the measurement of the coil diameter or radius from the coil form diameter or from the centers of the conductors. In other words, 10mm coil form diameter or the coil form diameter plus one wire diameter, which is the same as half the wire diameter on one side plus half the wire diameter on the other side. If the wire diameter is 1mm then the calculations can be done with 10mm, or 11mm.
But in any case, a small bend in the heavier wire could cause a small amount of space between turns, and this could cause a variation of a few percent in the measured inductance. It's to be expected that some amount of tolerance is going to affect every coil.
How you know what diameter cable you need? is it for amperage?
recent i bought some inductor for a test and they where SMD and pretty small, like 5mm, I was watching some "classic" E.Q. guitar pedals that used inductors.
THANKS FOR TIPS.
And I thought i was the only old guy that used my Radio Shack Books :)
You have a round tuit on your bench!
BTW, my first time watching you. Nice tight coil you wound there, you put in all the tips I would've! I like your workspace, maybe you could mount some of those drawer assemblies on the wall? Might free up some workbench. I like your idea of having your files freely available, man after my own heart! Maybe if you rent your own website you could do that. You'd have a place to post pages, and store files for download. And have your own domain name. I used to do that. I've also been the "host" /website manager for a couple of ham radio clubs, that worked for them as well.
Anyway, good luck! I'll follow along....
>>Jeffro, ai4rv
The usual problem with capacitive loads is lack of decoupling from your feedback path. A resistive decoupling is what you want. An inductive output prevents an amp from responding to both load and input transients. Does that matter so much for an audio amp? Probably not where ordinary speakers with a low primarily inductive impedance are the main concern. As a general principle though output inductance is a thing to minimize!
Since you've damped it with just 10 ohms it will be largely bypassed as a side-effect so this probably won't matter much, though you could equally lower the resistance a bit and get rid of the inductor altogether I think. As the ratio of the damping resistor to inductance becomes extreme you're eventually no longer approximating a low-Q inductor with that parallel arrangement at lower frequencies.
Nice video, thanks for sharing :)
Is the Feeeeeeeeeeltech not a 50ohm output?
well one thing i really said all his vid is real and truth i redo again lm386 amp for my headphone i thought 386 has distortion issue but.. well....and i kind a tweak little bit more and sure enough 100% volume not even a littlebit distortion even on crossover i thank a lot of you ur the master of discrete design amp but fell fluttered to say i do design class ab amp power amp but litteral i much salute you more this things
John, what if amp uses larger value of the coil say 2-5uH. Will it have any adverse effects on the performance. I noticed a lot of amplifiers, especially ones with multiple output pairs, use higher value than 1uH and it seems to keep them more stable with highly capacitive loads like electrostatic loudspeakers or fancy spkrs cables (Audioquest or flat ribbon cables).
A higher value, such as 5uh has significant impedance at higher audio frequencies (.63 ohms at 20KHz) and will affect the frequency response and damping. That's probably not noticeable to most people but would look bad on the spec sheet.
Interesting
The problems with the ultra-wide cameras: keeping your fingers away from the lens, no image stabilization, poorer lens design (less light). The normal lens is actually pretty wide on a phone. For miniature work, a phone might beat a cheap magnifying glass, assuming you can get the right stand for it.
Got your new phone?
Being a Tracfone member there were options for free phones but they were all sold out, so I got this one with the $75 discount making it only $70. It shoots nice 4k video direct to HEVC (H.265).
Those calculators seem to state figures that neglect frequency, which is never go to be terribly useful.
Great video John. I want to mention another method to measure Inductance, capacitance resistance(with better accuracy) with a PC sound card and REW. This circuit is mainly used for the impedance measurement of speakers. Since the speaker is identical to an LCR circuit, we could easily measure inductance/capacitance/resistance with the same. This circuit is available for purchase from Dayton Audio. But we DIY guys could do a similar setup with a lot less money. will leave a link to that video here:ruclips.net/video/Ag8hTO4QhsE/видео.html
REW, is rather designed for audio frequencies, I think 48kHz is max sampling possible, so I'm not 100% that with REW's accuracy, it will measure in uH range. I use it for the caps and coils used in crossovers, but the values are usually above 0.1mH for coils and 0.1uF for capacitors. It is a very capable software for loudspeaker measurements, I use it along with old Clio, which also has L-C meter. Also ARTA is a very capable software, but requires jig for proper functionality, and it supports 96k sampling freq. DATS from Dayton Audio will measure R-L-C, but don't know what are min values, together with Thiele-Small parameters.
This one is close to where I live, but I haven't tried it yet
www.sonicbeacon.com/Sonic_Beacon_Products_Loudspeaker_Test_Software.htm
In your equation for L you can still solve (sqrt(C))² = C, so L = (1/(2*pi*f*C))².
L=1/(ω²C)
and done.
Please never stop saying feeeeeeltech
ultra wide mode on these phones are poop , i have a similar samsung and if i ever make a video with it i use the normal camera.
Track phone sucks now that Verizon owns them the signal is terrible