On the end of the coils I used solder lugs I happened to have. You gave me an idea for my next set of coils. I'll use the double-sided tape length-wise with two strips. Before I covered the PVC pipe I used completely with tap. I'll show how to make the coil this time. As for you suggestion for not using the iN34 with the vacuum tube radio, I already did that and I'll ge ahead and make a video on it. It's called a grid-leak detector as you probably know.
It might work if you connect the end before the first tap to ground and leave the other end ungrounded and then connect the first tap to the antenna and use subsequent taps for tuning. There are many designs that work. The purpose of having two coils is to electrically separate them with a small gap for just a fluctuating magnetic field to cross. This helps with selectivity, tuning into only one frequency, though it reduces sensitivity or volume. See my "How a Crystal Radio Works" video.
My understanding is it's to help keep the antenna electrically separate from the tuning part of the circuit, the tuning part being the second coil and the capacitor. It's not a complete electrical separation obviously but it's supposed to help. Makes sense.
Thanks. I have an annotation at 6:13 mentioning that. I appreciate you bringing it up though. I really should try that the next time I need to strip enameled wire.
@murkava Great! I look forward to seeing your videos - especially the vacuum tube radio without the 1N43 which would just be really cool to see. I've subscribed so I won't miss them.
@murkava I doubt it would hold the wire down well enough to last. But then again, maybe there's some double-sided tape I'm not aware of that'd work - or if you use stiffer wire. There are other techniques though. For example, if your wire is stiff then you can simply give a twist where the taps are and the rest of the turn would stay in place. Another is to apply glue as you wind the wire, I guess 30 second krazy glue, provided the glue doesn't eat away at the enamel insulation.
@murkava But if I understand correctly, you used glass beads where the taps are so there was no break in the wire. Another way I could have done mine would have been to put a few twists at the base of each loop so that when I cut the loop to remove the insulation, the wire wouldn't unwind. At the ends, did you put the wire through holes in the cylinders to secure them or is the tape alone doing it? Nice vaccum tube radio you have! Very clean sound.
Hi, would this be the same concept in coil tapping a guitar pickup which is used to create variable impedance points with the use of a push pull pot, for example.?
That is what I used to make my coils and it works very. I am impressed with yours, so both should work. This thing won't let me post a link. Check out my video and go to vacuum tube radio. The video shows the coils I made. I'll give you a thumbs up.
If you use a ferrite rod inside the coil then the coil can be smaller (the size of the rod) and have fewer turns. In the formula for coil inductance there's a variable called the magnetic permeability for what's inside the coil. It's 1 for air like I'm doing in this video (the cardboard toilet paper tube doesn't count), and around 100 for ferrite. So it makes a big difference on what all the other variables should be.
What is the formula for how much inductance = what frequency?. To elaborate, for example 10 turns = 455 kHz frequency. If the copper wire and everything is standard, I can use this ratio to correlate between inductance and frequency you are tuned to. I am just trying to make a simple one without LC tank. Just a diode. Am radio receiver. But I just want to know the ratio...
The formula is a little more complicated then that, it includes number of turns, length, area and a few others. Since I get asked a lot, I made this video for the inductance formula ruclips.net/video/ARSQWTzWago/видео.html and another for the LC tank circuit formula ruclips.net/video/shZUI6B5bZw/видео.html . Or if you prefer, I have corresponding webpages with calculators rimstar.org/science_electronics_projects/coil_design_inductance.htm and rimstar.org/science_electronics_projects/lc_circuit_aka_tank_or_resonant_circuit.htm
The way I remove the enamel is to use a soldering iron with some melted solder on the tip and run it across the wire that I want to strip. That takes off the enamel and also tins the wire a bit which is always nice :) Keep up the good work m8 :)
Hi, very cool video and good technique, better than hotglue gun technique. Yes best thing for removing insulation is sharp knife (at least for me), jus wear safety glases. Thank you.
Why is it crazy? Does it eat away at the enamel? I was suggesting trying it because of its fast drying time but if it eats the enamel then it's no good.
Hello; A simple tip. If you go to a magnetic wire company web site; find there wire table. Look closely and find the column that tells you how many turns are in a specific unit of distance. Now all of you just need to measure out the number of turns you want. This reduces the tedium of remembering how many you have made. No more counting. : - }
Ill explain the wood glue more. You rob it over the whole coil to keep it from spinning off. Some people will use lacquer too but- hell with that. It is great for protecting the coil for long term use and storage too.
No, I don't think that the bottom of the glass won't have a significant effect. It's relative permeability is reasonably low so its affect on the magnetic field should be small.
Hi debbi, you really need to work out the values for a combination of the coil inductance and the capacitor capacitance since they work together to give the resonant frequency. I explain how in my LC resonance video here ruclips.net/video/tjD9I95RAbw/видео.html and on my webpage here rimstar.org/science_electronics_projects/lc_circuit_aka_tank_or_resonant_circuit.htm
@@RimstarOrg Thank you! I am trying to understand what would be the capacitance of L1 circuit (antenna ground), if we want to create a resonance with L2.
I guess that would explain why the radio coils in the 1920's /early 30's radios that were an inch 2 across shrunk down to less than half an inch by the 1950's .....
From here, www.rapidtables.com/calc/wire/wire-gauge-chart.html, it's a little over 0.4049. I say a little over because the enamel would add to the thickness but I don't know how much.
The 26 AWG wire is around 0.404mm or 0.0159 inches in diameter (from this random table here www.calmont.com/wp-content/uploads/calmont-eng-wire-gauge.pdf ).
Why is it that even when I plug my radio into a powered 5.1 system, I still need to hold my ear to the speaker to hear anything? Is there a workaround? And would a computer process the sound better ?
It could be that the signal that you're picking up is weak, the radio station is far away. A longer antenna should help with that, as long as possible in a straightish line. Also, make sure you have a good ground. It's also possible that your powered 5.1 system doesn't have an amplifier but since it's powered, it probably does.
If you can't get that same size tube use this: www.allaboutcircuits.com/tools/coil-inductance-calculator/ and a bit of trial and error to get the same inductance as 10 turns on the different diameter former. In the past I made a coil on a scrap bit of ABS "drain pipe" that was the nominal 4" diameter. It worked well
lol- no you gotta handle some people on here with gloves. Plus you make a mistake- your hit. With wood glue- you can peel it-rub it off. Also you can get it on your hands and fingers. It holds well but gives you time to correct the issue.
The antenna coil is optional. It's useful for tuning in just one radio station and filtering out any that are nearby in frequency. That's called selectivity, helping select just one channel without interference from others. I explain how it works in my How a Crystal Radio Works video at around ten minutes and forty-two seconds in ruclips.net/video/0-PParSmwtE/видео.html
On the end of the coils I used solder lugs I happened to have.
You gave me an idea for my next set of coils. I'll use the double-sided tape length-wise with two strips. Before I covered the PVC pipe I used completely with tap. I'll show how to make the coil this time.
As for you suggestion for not using the iN34 with the vacuum tube radio, I already did that and I'll ge ahead and make a video on it. It's called a grid-leak detector as you probably know.
It might work if you connect the end before the first tap to ground and leave the other end ungrounded and then connect the first tap to the antenna and use subsequent taps for tuning. There are many designs that work. The purpose of having two coils is to electrically separate them with a small gap for just a fluctuating magnetic field to cross. This helps with selectivity, tuning into only one frequency, though it reduces sensitivity or volume. See my "How a Crystal Radio Works" video.
Thanks for the tip! I'll keep that in mind for future videos and when people ask. I also just added it to that part of the video as an annotation.
You have amazing skills!! Unbelievably well crafted coil.👍👍
My understanding is it's to help keep the antenna electrically separate from the tuning part of the circuit, the tuning part being the second coil and the capacitor. It's not a complete electrical separation obviously but it's supposed to help. Makes sense.
Thanks. I have an annotation at 6:13 mentioning that. I appreciate you bringing it up though. I really should try that the next time I need to strip enameled wire.
@murkava Great! I look forward to seeing your videos - especially the vacuum tube radio without the 1N43 which would just be really cool to see. I've subscribed so I won't miss them.
@murkava I doubt it would hold the wire down well enough to last. But then again, maybe there's some double-sided tape I'm not aware of that'd work - or if you use stiffer wire. There are other techniques though. For example, if your wire is stiff then you can simply give a twist where the taps are and the rest of the turn would stay in place. Another is to apply glue as you wind the wire, I guess 30 second krazy glue, provided the glue doesn't eat away at the enamel insulation.
Do you mean the Texas Instrument Regency radios? I do want to do an amplified radio someday.
I searching for this type of channel really🤩
@murkava But if I understand correctly, you used glass beads where the taps are so there was no break in the wire. Another way I could have done mine would have been to put a few twists at the base of each loop so that when I cut the loop to remove the insulation, the wire wouldn't unwind. At the ends, did you put the wire through holes in the cylinders to secure them or is the tape alone doing it?
Nice vaccum tube radio you have! Very clean sound.
Hi, would this be the same concept in coil tapping a guitar pickup which is used to create variable impedance points with the use of a push pull pot, for example.?
That is what I used to make my coils and it works very. I am impressed with yours, so both should work.
This thing won't let me post a link. Check out my video and go to vacuum tube radio. The video shows the coils I made. I'll give you a thumbs up.
If you use a ferrite rod inside the coil then the coil can be smaller (the size of the rod) and have fewer turns. In the formula for coil inductance there's a variable called the magnetic permeability for what's inside the coil. It's 1 for air like I'm doing in this video (the cardboard toilet paper tube doesn't count), and around 100 for ferrite. So it makes a big difference on what all the other variables should be.
What is the formula for how much inductance = what frequency?. To elaborate, for example 10 turns = 455 kHz frequency. If the copper wire and everything is standard, I can use this ratio to correlate between inductance and frequency you are tuned to.
I am just trying to make a simple one without LC tank. Just a diode. Am radio receiver. But I just want to know the ratio...
The formula is a little more complicated then that, it includes number of turns, length, area and a few others. Since I get asked a lot, I made this video for the inductance formula ruclips.net/video/ARSQWTzWago/видео.html and another for the LC tank circuit formula ruclips.net/video/shZUI6B5bZw/видео.html . Or if you prefer, I have corresponding webpages with calculators rimstar.org/science_electronics_projects/coil_design_inductance.htm and rimstar.org/science_electronics_projects/lc_circuit_aka_tank_or_resonant_circuit.htm
@@RimstarOrg thanks buddy. I am pretty new to all this. This helped a lot.
verry cool video!
The way I remove the enamel is to use a soldering iron with some melted solder on the tip and run it across the wire that I want to strip. That takes off the enamel and also tins the wire a bit which is always nice :) Keep up the good work m8 :)
Nice idea, tinning it at the same time. Thanks!
Thanks. I tried but couldn't with my small antenna. But it's doable.
Hi, very cool video and good technique, better than hotglue gun technique. Yes best thing for removing insulation is sharp knife (at least for me), jus wear safety glases. Thank you.
26 gauge (AWG) copper wire with an enamel insulation coating. It's usually called magnet wire.
Very nice video sir from india
Thanks keep it up
Why is it crazy? Does it eat away at the enamel? I was suggesting trying it because of its fast drying time but if it eats the enamel then it's no good.
What wire did you use?
Heat, cig lighter, bunsen burner, gets rid of the copper wire insulation, bit of a wipe to remove the blackend residue.
Again whats the first coil for? So the antenna doesnt have to be that much longer?
Your Welcome!
Hello; A simple tip. If you go to a magnetic wire company web site; find there wire table. Look closely and find the column that tells you how many turns are in a specific unit of distance. Now all of you just need to measure out the number of turns you want. This reduces the tedium of remembering how many you have made. No more counting. : - }
I'm a newbie at 68but I enjoy interesting things.
Ill explain the wood glue more. You rob it over the whole coil to keep it from spinning off. Some people will use lacquer too but- hell with that. It is great for protecting the coil for long term use and storage too.
What would happen if you put a ferrite rod inside the coil ?
-Thank you-
I don't remember whether or not I tried with a joule thief. :) I may have to try again.
I’m interested in using something glass for my tube. If I used a uniformed drinking glass would the bottom of the glass affect reception ?
No, I don't think that the bottom of the glass won't have a significant effect. It's relative permeability is reasonably low so its affect on the magnetic field should be small.
Why not use double-sided tape?
Sir I want to hear down to about 1o to maybe 25 kHz. How many feet of wire would you suggest, if you have time perhaps thank you. I'm 68"
Hi debbi, you really need to work out the values for a combination of the coil inductance and the capacitor capacitance since they work together to give the resonant frequency. I explain how in my LC resonance video here ruclips.net/video/tjD9I95RAbw/видео.html and on my webpage here rimstar.org/science_electronics_projects/lc_circuit_aka_tank_or_resonant_circuit.htm
Thank you I don't see well appreciate tip.
Hi. I would like to know how do you do to calculate the primary winding (25 turns)?
I didn't. That part I got from a diagram in the book I refer to in the video description.
@@RimstarOrg Thank you! I am trying to understand what would be the capacitance of L1 circuit (antenna ground), if we want to create a resonance with L2.
Off-hand, I have no information on that.
@@RimstarOrg Ok! thank you. if I find something I let you know.
I guess that would explain why the radio coils in the 1920's /early 30's radios that were an inch 2 across shrunk down to less than half an inch by the 1950's .....
What's the diameter of coil wire in terms of AWG/ OR THICKNESS OF ENAMEL WIRE IN mm. Thanks
From here, www.rapidtables.com/calc/wire/wire-gauge-chart.html, it's a little over 0.4049. I say a little over because the enamel would add to the thickness but I don't know how much.
I just measured my coil and it's around 40mm long. 40mm / 90 turns = 0.4444 mm per turn.
Furniture/Wood Glue is safest and works best. Using crazy/krazy glue is just that-CRAZY. :-)
i remove the coating of the wires by using fire.but when doing it you should be careful, not to burn the wire, and yourself.
what is the diameter of the wire?
The 26 AWG wire is around 0.404mm or 0.0159 inches in diameter (from this random table here www.calmont.com/wp-content/uploads/calmont-eng-wire-gauge.pdf ).
Why is it that even when I plug my radio into a powered 5.1 system, I still need to hold my ear to the speaker to hear anything? Is there a workaround? And would a computer process the sound better ?
It could be that the signal that you're picking up is weak, the radio station is far away. A longer antenna should help with that, as long as possible in a straightish line. Also, make sure you have a good ground. It's also possible that your powered 5.1 system doesn't have an amplifier but since it's powered, it probably does.
@@RimstarOrg I put it through my turntable mixer and it was booming loud
That's good news. Thanks for letting me know.
Value of Diameter of the coil former ???
Cardboard tube that the coil is formed around is around 45mm in diameter.
If you can't get that same size tube use this:
www.allaboutcircuits.com/tools/coil-inductance-calculator/
and a bit of trial and error to get the same inductance as 10 turns on the different diameter former.
In the past I made a coil on a scrap bit of ABS "drain pipe" that was the nominal 4" diameter.
It worked well
Sir please make a fox hole radio new type home made free bettery new degine
lol- no you gotta handle some people on here with gloves. Plus you make a mistake- your hit. With wood glue- you can peel it-rub it off. Also you can get it on your hands and fingers. It holds well but gives you time to correct the issue.
Make it easy on yourself. Get a cheap Lighter from $ Store.
The coating on the wire will burn right off.
Do you even need the antenna coil or no need to
The antenna coil is optional. It's useful for tuning in just one radio station and filtering out any that are nearby in frequency. That's called selectivity, helping select just one channel without interference from others. I explain how it works in my How a Crystal Radio Works video at around ten minutes and forty-two seconds in ruclips.net/video/0-PParSmwtE/видео.html