Nice Video Peter! I really enjoy these tutorials where you dont need to wind a coil, or do any type of soldering. If you could do more of these videos, I would Appreciate! Thanks!
Thanks for doing these kind of videos Peter about the crystal radios as well as the other ones too. But this makes me want to break open the new breadboard and make a project similar to this.
Hi Peter, I made a crystal set many years ago. I used a pair of crystal headphones from world war one. And the coil was formed on a toilet roll. I used to listen to my local commercial station which was only 2 mile away. Couldn't hear much else. But I did learn a lot from building it. I have read one of your books. Most interesting and enjoyable read. Happy Christmas from David M0DUU
Built one like it, but 470uf inductors (had on hand) with capacitors, and MK484-1 AM Radio Integrated Circuit instead of germanium diode... worked like a charm!
Your parts list seems to be missing the most important components; the choke coils. I ordered some 100uf inductors and some germanium diodes and will give it a try. I did notice the 100uf coils come in many forms and sizes. Would any of them work? A person could design a circuit board and even use surface mount versions of most of the components to try and make it very small.
If you have a goodly number of capacitors, you can do series/parallel combinations to get many other values. I would do this on the solderless bread board. I will make up an example: Lets say you have a gap in your selection at 50pF but you have a bunch of 100pF capacitors. Two 100pF in series will give you 50pF The rule for series capacitors is CSeries = 1/(1/C1 + 1/C2) This is fairly easy to do on a calculator with a 1/X key. Try it with 100pF and then notice that you now have a 50pF Now use that 50pF and another 100pF in a string and you will discover you can also make 33pF You can now make your self table. To be extra clever if you have a collection of toggle switches and/or some sort of rotary switch, you can switch in and out capacitors. Also: I did a video showing how to make a home made variable capacitor. It isn't very good long term but it does work and will give you a wide range. It goes from something under 50pF up to about 1500pF
Always a lot of fun, also the smart approach! (thinking about beginners, very good!) BUT can you now also do this, but on SW? Healthy and Friendly greetings from The Netherlands! Rob
My experience is that unless you have a multi-kilowatt shortwave station within a single hop of you then shortwave crystal sets are no good and require AF and possibly RF amplification. Defeating the idea of a crystal set.
@@vk3ye I understand the idea, but it's not absolutely necessary for the circuit to follow the principles of an authentic crystal radio; it can also include amplification. The interesting part comes when you can experiment on HF or even VHF using various non-sophisticated things like transistors,ICs or diode detection with a adequate LC Tank circuit
@@vk3ye I just had an interesting idea. Stuff a good sized capacitor in place of the headphones and measure what voltage you get. Lower the parallel resistance until that drops by about 30% In my case, I get only about 0.1V so my idea won't work for me but if you have a really strong AM station, you now have a power supply to try to run an amplifier from for the SW set.
@@user-ue1nn3zk7r If you're going to have amplification on a crystal radio you might has well have regeneration for even improved performance. I've done many videos on amplified crystal sets for shortwave & small regenerative receivers.
What is the reason for the 220k load resistor --due to high Z if crystal earphones --? what value resistor would you use if coupling to an audio transformer to external amp? Thanks for your well presented tutorials, I always learn something. ps. I just ordered your more antenna book, there was enough readable on Amazon I could tell it was going to be a good manual. Take care De KF5HCR
@@vk3ye With a real 1N34, I found that no resistor is needed with a crystal earphone. The reverse leakage of the diode is enough to make it work. With what you often get if you try to buy a 1N34 you need more like a 2K resistor to make it work well. I found that 1N5711 works well like that and appears to be what is being sold as 1N34.
Nice Video Peter! I really enjoy these tutorials where you dont need to wind a coil, or do any type of soldering. If you could do more of these videos, I would Appreciate! Thanks!
Thanks for doing these kind of videos Peter about the crystal radios as well as the other ones too. But this makes me want to break open the new breadboard and make a project similar to this.
Hi Peter,
I made a crystal set many years ago. I used a pair of crystal headphones from world war one. And the coil was formed on a toilet roll. I used to listen to my local commercial station which was only 2 mile away. Couldn't hear much else. But I did learn a lot from building it.
I have read one of your books. Most interesting and enjoyable read.
Happy Christmas from David M0DUU
Built one like it, but 470uf inductors (had on hand) with capacitors, and MK484-1 AM Radio Integrated Circuit instead of germanium diode... worked like a charm!
What are 470uf inductors😂😂😂
@@TechniCraftYT 🤦♂ 470 uH Inductors ... oops!
Wind up variometer coil. Use plastic bottles and cat5 internet wire.
That's neat Peter !
Thank you. Fun.
You can use a DIL switch for the caps and a 30pF trimmer
Your parts list seems to be missing the most important components; the choke coils.
I ordered some 100uf inductors and some germanium diodes and will give it a try.
I did notice the 100uf coils come in many forms and sizes. Would any of them work? A person could design a circuit board and even use surface mount versions of most of the components to try and make it very small.
If you have a goodly number of capacitors, you can do series/parallel combinations to get many other values.
I would do this on the solderless bread board. I will make up an example:
Lets say you have a gap in your selection at 50pF but you have a bunch of 100pF capacitors.
Two 100pF in series will give you 50pF
The rule for series capacitors is CSeries = 1/(1/C1 + 1/C2)
This is fairly easy to do on a calculator with a 1/X key. Try it with 100pF and then notice that you now have a 50pF
Now use that 50pF and another 100pF in a string and you will discover you can also make 33pF
You can now make your self table.
To be extra clever if you have a collection of toggle switches and/or some sort of rotary switch, you can switch in and out capacitors.
Also:
I did a video showing how to make a home made variable capacitor. It isn't very good long term but it does work and will give you a wide range.
It goes from something under 50pF up to about 1500pF
You can do it on a solderless breadboard but you need a larger one than I had for a good range of values or use jumper leads to other holes.
Always a lot of fun, also the smart approach! (thinking about beginners, very good!) BUT can you now also do this, but on SW? Healthy and
Friendly greetings from The Netherlands!
Rob
On SW the coils are smaller and the antennas are far more effective
Groeten uit Groot-Brittannië
Very nice ❤👍
Try a Shortwave version of this circuit please :) more things to listen
My experience is that unless you have a multi-kilowatt shortwave station within a single hop of you then shortwave crystal sets are no good and require AF and possibly RF amplification. Defeating the idea of a crystal set.
@@vk3ye I understand the idea, but it's not absolutely necessary for the circuit to follow the principles of an authentic crystal radio; it can also include amplification. The interesting part comes when you can experiment on HF or even VHF using various non-sophisticated things like transistors,ICs or diode detection with a adequate LC Tank circuit
@@vk3ye I just had an interesting idea. Stuff a good sized capacitor in place of the headphones and measure what voltage you get.
Lower the parallel resistance until that drops by about 30%
In my case, I get only about 0.1V so my idea won't work for me but if you have a really strong AM station, you now have a power supply to try to run an amplifier from for the SW set.
@@user-ue1nn3zk7r If you're going to have amplification on a crystal radio you might has well have regeneration for even improved performance. I've done many videos on amplified crystal sets for shortwave & small regenerative receivers.
What is the reason for the 220k load resistor --due to high Z if crystal earphones --? what value resistor would you use if coupling to an audio transformer to external amp?
Thanks for your well presented tutorials, I always learn something.
ps. I just ordered your more antenna book, there was enough readable on Amazon I could tell it was going to be a good manual.
Take care
De KF5HCR
The resistor provides a DC path. Not needed if using an audio coupling transformer. Otherwise leave it at 220k but not critical.
@@vk3ye With a real 1N34, I found that no resistor is needed with a crystal earphone. The reverse leakage of the diode is enough to make it work. With what you often get if you try to buy a 1N34 you need more like a 2K resistor to make it work well. I found that 1N5711 works well like that and appears to be what is being sold as 1N34.
Why not connecting the capacitors direct in the breadboard?
you would need a larger breadboard with more holes that I didn't have
This is the question and answer I was looking for! Excellent video! I think this will be my first electronics project.
It can possible to explain mathematically calculation.every point of connection.
Yes it is possible, but why bother, it's a lot of work.
Use an existing circuit.
@@FarleyHillBilly sorry to say brother.it is my curiosity to how an electron moves in a circuit and how to explain mathematical equations.
Good! Where hides the crystal?
1N34 diode is the "crystal"