@@Havilah_Springs I think it's called the LC-100 in most places. There are sold online. I don't have any preferred places. They do have 1 weakness. I am on my third. You must COMPLETELY discharge caps before connecting them.
That's a good question. I'm struggling with that right now. There are tradeoffs. First, you have to ensure you keep the inductance that you need. Then you want a bigger diameter coil for better efficiency, but that changes the number of turns needed. Then, the wire size makes a difference, smaller wire has higher resistance which is bad, but bigger wire may not fit on the core. And changing the wire size changes the impedance. All these things are interconnected. I'm working on a 1 foot diameter coil right now. I think I've got the values down, but how to wind it has me stymied.
making a HIGH Q resonant coil, say 2.5m in diameter, tuned with a high Q variable capacitor makes a great AM bcb antenna. then couple that to a tuned secondary cokl (equally high Q or possibly even higher Q) with a detector and a impedance matching network between detector and phones, that should be a good crystal radio with a directional antenna (both coils would have to be rotated). you want highest unloaddd Q (lowest possibld loss) in every piece of the set. that way you can load the resonant parts with the detector (diode and phones) without the bandwidth becoming so wide you can hear several stations on different frequencies at the same time, impedances must be matched A dual coil set with antenna coil being say 180-200micro Henry and slightly larger value for the detector coil is usually a good idea. the ideal ratio if coil length to diameter is around length 1 and diameter 1.6. an old rule of thumb was same length and diameter +-50% is best. cylinder coils with well ordered even windings are best, even minor irregularities degrade performance. spacing windings 10-30% increase Q. bifilar winding increase Q magnet wire coils will not benefit from wire larger than 1.6mm diam Litz wire #46-#50 for AM BCB is best. high vount, say 400-1100 strands, below 330 us questionable benefit coi former material should be as little mass as possible and low loss. polypropylene, PEMD, teflon, Polystyrene are good materials for coil formers. capacitors should be ceramic insulated and insulation should have little mass. capacitors should be silver, silverplated copper, copper or aluminium (in that order) (some may be gold flashed to prevent oxidation), brass or iron work but not the best. also the looser you couple the detector to the coils the sharper the tuning BUT sadly the lower the volume, the higher the Q the louder. TLDR the higher the Q coils/capacitor the more signal you can bleed from them without getting tuning too wide (i can easily cut sidebands enough to change the pitch to the voices with my best set) and high Q thus means louder.
It has 30 turns and is about 3x the 10 turns. There are several good coil calculators that will allow you to experiment on different combinations of wire and core sizes. Here are a couple: coil32.net/online-calculators/one-layer-coil-calculator.html www.66pacific.com/calculators/coil-inductance-calculator.aspx
Hey that was a very cool demenstration on coil variations . i have a question for u and any of your viewers wich is that I plan to try to make very sensitive high impeadance speakers for crystal radios and was wondering if and when i get around to setting it up to make a prototype i could send u one to see how it works if it works well enough . I'm building a CNC wire winder that I plan to wind my own coils and voice coils and electromagnets and I also want to design a low loss 3d printed crystal radio former with the wire groove cut into the former such that when i wind tha coil i can use non shielded tinned copper large gauge wire such that it won't short out and it would be easy to tap the coile anywhere and make a wiper for it , . ive been planning on trying to make my newer version of my crystal radio but have been pretty busy . but hope to get back on with things . but i want to make a light weight speaker motor assembly with 40 awg wire for a voice coil and a kevlar fishing string spider assembly and use a flat piece of paper for a speaker cone but make it like a dml distributed mode loud speaker like i and others use when using a speaker excitor . and have it in a 3d printed enclosure . back in the day they had high impedance speakers but with new amplifiers they can handle higher current so thats how we ended up with low impedance speakers . what im wondering is what would make the highest sensitivity coil. i know the more turns of the wire on the voice coil the better and all that . but like in the old head sets there like around 2000 ohms or somthing like that . but i wonder if going higher would be better . and if u have a way of showing what would be better for impeadance load on the crystal radio that would be cool . it gets tricky for me to calculate impeadence as i dont have a easy method of testing it but can wip out the o-scope and try to figure it out that way . but if u think people may be intrested in buying one and if u want to kinda partner up we could make some if they turn out , but im not sure what the cost would be and labor and if anyone would be intrested in bying them but that can be woried about later , also i should note that i'm compleatly blind from an injury a few years back so doing some of the more tecnical measuremens is more difficult for me as i have to try to explane to someone else about electronics so they can help me . anything more then reading a fluke can take a while in figuring other equipment out. i want to look for a nice lcr meter that is simple to use so i can more easly measure inductors and caps . for several years ive been wanting to make my first crystal radio and last year or so i made a fairly nice rough prototype but now i want to make a 3d printed one that will have a loosly coupled primary and have sliders that u can tune and tap the diode anywhere . and thats why i want to make a former with a groove in in it so that i can use non shielded wire cause its easier for me to make . but thats my plan for this winter if i have time . but i want to play around on making tha loudest speaker for crystal radios . let me know ur thoughts and if u have any tips or ideas , im all ears . lol
That will be a fantastic investigation. However, from the few projects that I have seen regarding this subject, success has not been achieved. I am no expert (at all!,) but a crystal radio just won't have the power to drive the paper cone speaker to audible levels, without a power amplifier. You may want to do a good bit of research to see what has been attempted, so that you are not wasting time and energy. That way, you can try methods that have not been previously considered. Do not misunderstand me, I am not trying to discourage you. No, I am trying to encourage you to work in those areas that have not been explored. I do believe that you can find a way, just as all the other great inventors! Cheers!
@@t1d100 understood but as many peaple i've seen on yt they use a high impeadance matching transpormer to step down the power to make it drive a low impeadance speaker and peeople have gotten it to work well but the only issue is finding a high impeadance transformer that won't load down the radio coil . and hard core crystal radio guys know of a transformer that works well but its over 100 bucks and there rare i guess . but if u have ever seen the old high impedans head sets from the early 1900 till i think the 60's they have a high impedance speaker but i think they claim its a moving magnet not moving coil . and i have ideas to make both . the reason why its hard to make is cuz u have to use very small enameled wire half the size of ur hair and u halve to rap a few thousand feet on the cormer and in industtry its to delicate for modern speakers . so i believe it will work well . and i am only using a thin sheat of paper with no foam bezel so that it has no impeadance in its movement .and ill use a strong rare earth magnet and what not . the only place u can find high impeadance speakers were in old 2000s cell phones but not sure if modern cell phones have them or not . hopefully i can get my set up going and make a prototype i know its possible but i wonder how well it will turn out .
Does a potentiometer in series allow any adjustment to the Lx value? Probably not is my guess otherwise we would seem them in circuits to fine tune coils. On the other hand a potentiometer is just a coil of wire like an inductor but with a variable center tap.
I think your guess is correct. I mean, a wound type resistor has inductance, but it's "accidental." If you want variable inductance, watch my videos on variometers. This is the last one: th-cam.com/video/z-4MAjnB4mw/w-d-xo.html
@@tsbrownie I just watched your suggested video and realized I have seen it before. I've owned several radios with those style tuners in them. I've got an old Crosley ACE radio that uses a simple looking spider web coil tuner. It's amazing how many different designs were manufactured during the golden age of radio experimentation. My current favorite modern take on the spider web tuner is a crystal radio made out of a credit card and it uses the credit card chip as the detector diode. Have you seen it? I've got old out dated credit cards but they predate the chipped cards we use today. The next time they send out replacement cards I know what I'll be building out of my old card!
@@tenlittleindians I am also amazed by the different approaches to the crystal radio. The guy who did that is Billy Cheung (sp?). He changed the name of his channel. I think it's now billyDIY or something like that.
Wouldn't it be better to use low capacitance pancake coils? For this application? In German those low capacitance pancake coils are called flache Korb spulen.
I have placed some comments here. Then they disappear. Have I deen banded. Puzzeleing to me is I don't know why. Or is a just a glitch. I'ne not noticed gritchse anywhere elso on youtube on by comments.
![ร้อยพ่อพันแม่ - WanMai [Official MV]](http://i.ytimg.com/vi/XY2pNYASEbg/mqdefault.jpg)
This is a follow on to this video on coil sizing:
Crystal Radio Coil Sizing (4K) th-cam.com/video/ejHk5tFeKHk/w-d-xo.html
Nice presentation especially because of the measuring device.
Thank you very much! The device is very inexpensive, but very useful.
@@tsbrownie What do you call said device, and where can I get one?
@@Havilah_Springs I think it's called the LC-100 in most places. There are sold online. I don't have any preferred places. They do have 1 weakness. I am on my third. You must COMPLETELY discharge caps before connecting them.
Sir, I have a question. If I had a very large coil, like the size of a Tesla coil secondary. Would I get a better reception ?
That's a good question. I'm struggling with that right now. There are tradeoffs. First, you have to ensure you keep the inductance that you need. Then you want a bigger diameter coil for better efficiency, but that changes the number of turns needed. Then, the wire size makes a difference, smaller wire has higher resistance which is bad, but bigger wire may not fit on the core. And changing the wire size changes the impedance. All these things are interconnected. I'm working on a 1 foot diameter coil right now. I think I've got the values down, but how to wind it has me stymied.
making a HIGH Q resonant coil, say 2.5m in diameter, tuned with a high Q variable capacitor makes a great AM bcb antenna.
then couple that to a tuned secondary cokl (equally high Q or possibly even higher Q) with a detector and a impedance matching network between detector and phones, that should be a good crystal radio with a directional antenna (both coils would have to be rotated).
you want highest unloaddd Q (lowest possibld loss) in every piece of the set.
that way you can load the resonant parts with the detector (diode and phones) without the bandwidth becoming so wide you can hear several stations on different frequencies at the same time,
impedances must be matched
A dual coil set with antenna coil being say 180-200micro Henry and slightly larger value for the detector coil is usually a good idea.
the ideal ratio if coil length to diameter is around length 1 and diameter 1.6. an old rule of thumb was same length and diameter +-50% is best.
cylinder coils with well ordered even windings are best, even minor irregularities degrade performance.
spacing windings 10-30% increase Q.
bifilar winding increase Q
magnet wire coils will not benefit from wire larger than 1.6mm diam
Litz wire #46-#50 for AM BCB is best. high vount, say 400-1100 strands, below 330 us questionable benefit
coi former material should be as little mass as possible and low loss.
polypropylene, PEMD, teflon, Polystyrene are good materials for coil formers.
capacitors should be ceramic insulated and insulation should have little mass.
capacitors should be silver, silverplated copper, copper or aluminium (in that order) (some may be gold flashed to prevent oxidation), brass or iron work but not the best.
also the looser you couple the detector to the coils the sharper the tuning BUT sadly the lower the volume, the higher the Q the louder.
TLDR the higher the Q coils/capacitor the more signal you can bleed from them without getting tuning too wide (i can easily cut sidebands enough to change the pitch to the voices with my best set) and high Q thus means louder.
using a crysral radio I have heard African stations so... high Q for the win
The 2 inch coil with many turns was not tested. Would it be like 31 uH if 30 turns?
It has 30 turns and is about 3x the 10 turns. There are several good coil calculators that will allow you to experiment on different combinations of wire and core sizes. Here are a couple:
coil32.net/online-calculators/one-layer-coil-calculator.html
www.66pacific.com/calculators/coil-inductance-calculator.aspx
Hey that was a very cool demenstration on coil variations .
i have a question for u and any of your viewers wich is that I plan to try to make very sensitive high impeadance speakers for crystal radios and was wondering if and when i get around to setting it up to make a prototype i could send u one to see how it works if it works well enough .
I'm building a CNC wire winder that I plan to wind my own coils and voice coils and electromagnets and I also want to design a low loss 3d printed crystal radio former with the wire groove cut into the former such that when i wind tha coil i can use non shielded tinned copper large gauge wire such that it won't short out and it would be easy to tap the coile anywhere and make a wiper for it , .
ive been planning on trying to make my newer version of my crystal radio but have been pretty busy . but hope to get back on with things .
but i want to make a light weight speaker motor assembly with 40 awg wire for a voice coil and a kevlar fishing string spider assembly and use a flat piece of paper for a speaker cone but make it like a dml distributed mode loud speaker like i and others use when using a speaker excitor .
and have it in a 3d printed enclosure .
back in the day they had high impedance speakers but with new amplifiers they can handle higher current so thats how we ended up with low impedance speakers .
what im wondering is what would make the highest sensitivity coil.
i know the more turns of the wire on the voice coil the better and all that .
but like in the old head sets there like around 2000 ohms or somthing like that . but i wonder if going higher would be better . and if u have a way of showing what would be better for impeadance load on the crystal radio that would be cool .
it gets tricky for me to calculate impeadence as i dont have a easy method of testing it but can wip out the o-scope and try to figure it out that way .
but if u think people may be intrested in buying one and if u want to kinda partner up we could make some if they turn out , but im not sure what the cost would be and labor and if anyone would be intrested in bying them but that can be woried about later , also i should note that i'm compleatly blind from an injury a few years back so doing some of the more tecnical measuremens is more difficult for me as i have to try to explane to someone else about electronics so they can help me . anything more then reading a fluke can take a while in figuring other equipment out.
i want to look for a nice lcr meter that is simple to use so i can more easly measure inductors and caps .
for several years ive been wanting to make my first crystal radio and last year or so i made a fairly nice rough prototype but now i want to make a 3d printed one that will have a loosly coupled primary and have sliders that u can tune and tap the diode anywhere . and thats why i want to make a former with a groove in in it so that i can use non shielded wire cause its easier for me to make . but thats my plan for this winter if i have time . but i want to play around on making tha loudest speaker for crystal radios .
let me know ur thoughts and if u have any tips or ideas , im all ears . lol
I just have no training or experience in that kind of thing, but maybe someone else will.
That will be a fantastic investigation. However, from the few projects that I have seen regarding this subject, success has not been achieved. I am no expert (at all!,) but a crystal radio just won't have the power to drive the paper cone speaker to audible levels, without a power amplifier. You may want to do a good bit of research to see what has been attempted, so that you are not wasting time and energy. That way, you can try methods that have not been previously considered. Do not misunderstand me, I am not trying to discourage you. No, I am trying to encourage you to work in those areas that have not been explored. I do believe that you can find a way, just as all the other great inventors! Cheers!
@@t1d100
understood but as many peaple i've seen on yt they use a high impeadance matching transpormer to step down the power to make it drive a low impeadance speaker and peeople have gotten it to work well but the only issue is finding a high impeadance transformer that won't load down the radio coil .
and hard core crystal radio guys know of a transformer that works well but its over 100 bucks and there rare i guess .
but if u have ever seen the old high impedans head sets from the early 1900 till i think the 60's they have a high impedance speaker but i think they claim its a moving magnet not moving coil .
and i have ideas to make both .
the reason why its hard to make is cuz u have to use very small enameled wire half the size of ur hair and u halve to rap a few thousand feet on the cormer and in industtry its to delicate for modern speakers .
so i believe it will work well .
and i am only using a thin sheat of paper with no foam bezel so that it has no impeadance in its movement .and ill use a strong rare earth magnet and what not .
the only place u can find high impeadance speakers were in old 2000s cell phones but not sure if modern cell phones have them or not . hopefully i can get my set up going and make a prototype i know its possible but i wonder how well it will turn out .
@@lmccleary411 Great! You have done the research and know what you are after. True best wishes for your success!
Does a potentiometer in series allow any adjustment to the Lx value? Probably not is my guess otherwise we would seem them in circuits to fine tune coils. On the other hand a potentiometer is just a coil of wire like an inductor but with a variable center tap.
I think your guess is correct. I mean, a wound type resistor has inductance, but it's "accidental." If you want variable inductance, watch my videos on variometers. This is the last one: th-cam.com/video/z-4MAjnB4mw/w-d-xo.html
@@tsbrownie I just watched your suggested video and realized I have seen it before. I've owned several radios with those style tuners in them.
I've got an old Crosley ACE radio that uses a simple looking spider web coil tuner. It's amazing how many different designs were manufactured during the golden age of radio experimentation.
My current favorite modern take on the spider web tuner is a crystal radio made out of a credit card and it uses the credit card chip as the detector diode. Have you seen it?
I've got old out dated credit cards but they predate the chipped cards we use today. The next time they send out replacement cards I know what I'll be building out of my old card!
@@tenlittleindians I am also amazed by the different approaches to the crystal radio. The guy who did that is Billy Cheung (sp?). He changed the name of his channel. I think it's now billyDIY or something like that.
Wouldn't it be better to use low capacitance pancake coils? For this application? In German those low capacitance pancake coils are called flache Korb spulen.
I have a video on those (I'm just starting on them) and some 3D printer designs online.
th-cam.com/video/jyIDbUwlTsU/w-d-xo.html
I have placed some comments here. Then they disappear. Have I deen banded. Puzzeleing to me is I don't know why. Or is a just a glitch. I'ne not noticed gritchse anywhere elso on youtube on by comments.
I see this. I think they may block comments with links or swearing. And maybe special non-English keyboard characters.
Yes, i did put links not to youtube, so that might be it. @@tsbrownie