Crystal Radio Troubleshooting and Tips
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- Опубликовано: 2 авг 2024
- A bunch of tips and troubleshooting stuff for people making crystal radios. Includes:
- Antennas
- Crystal earpieces
- Speakers from piezoelectric crystal buzzers and crystals from gift cards
- Diodes
- Making good electrical connections
- Capacitors, measuring capacitance and making capacitors
- What is Earth ground and grounding and where do I get a good ground
(wall socket, radiator, metal drain pipe, metal fence post)
See also,
Step-by-Step How to Make a Crystal Radio video:
• How to Make/Build a Cr...
Make a Crystal Radio Coil with Taps video:
• Make a Crystal Radio C...
How a Crystal Radio Works video:
• How a Crystal Radio Works
For more about crystal earphones, visit:
rimstar.org/equip/crystal_earp...
For more about crystal radios, visit:
rimstar.org/equip/crystal_radi...
To follow me on Twitter:
#!/RimStarz
- rimstar.org 
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I'm glad you like them! Thanks for the feedback and for watching!
You're welcome! And thanks for letting me know; I'm always happy to hear when it helps.
Can we connect the wires from the piezoelectric buzzer to the diode and the ground connection directly?
Funny story about the 2 parallel wires for a better antenna. In the late 1990s I worked for Radio Shack, and noticed the stereo FM antenna was 2 parallel wires of just a few feet. Some guy came in and wanted a better antenna than that, but not amplified. I made an educated guess and sold him a roll of speaker wire to put in the FM antenna ports in back of his stereo receiver, telling him to wind it around the walls, or down out the window but advised of the risks of improper grounding of a wire outside his house etc. He came back to the store and told me it works so great, he got many stations from far away.
You can use a regular earbud, like for an iPod for example, but you need to add a transformer. See my video "Use Earbuds/Earphones with Crystal Radio " for that. Or you can make your own crystal earpiece from a piezoelectric buzzer from an electronics store or a microwave oven speaker. See my video "Make Crystal Earphone/Earpiece for Crystal Radio - Homemade" for that. You can find the videos on my channel page.
My pleasure. I'm glad you liked it.
Thanks, this was totally helpful. We pulled out the meter and checked for continuity. Ran a second antenna then waited for night time. We didn’t get anything during the day but were able to pick up a couple of stations and small amount of feedback later at night. Who would have thought getting feedback would be fun?!
It's hard to do without the germanium diode. You could try 5 silicon diodes wired in parallel. Parallel means all the ends with the stripes connected together and all the ends without the strips connected together and use where the diode normally goes. No guarantee that it'll work though. Another option is to make a razor blade diode as in my video "Make Razor Blade Diode for Crystal Radio/Foxhole Radio" but that's hard to get working too.
I built one of these from scratch for a 5th grade science fair in the 1950s with a single coil/cap, tank or resonant circuit. Worked great...I built this one with 25t/90t & sliding cap...nothing but weak static but static is an indication of "close". Put a 47K resistor across the high impedance Philmore earpiece and got a station...Skipped the 25T attaching antenna to the 90T...more volume...not criticism...just info for you to add to your projects...thank you.
Regarding the coupling, this originally came from a book and I don't know how to calculate it. The purpose of the two coils is so that unwanted radio waves will influence the path to ground from the first coil and the wanted radio waves will influence the tuning coil. The larger the gap the less interference but lower volume. The smaller the gap the more interference but higher volume. See my "How a Crystal Radio Works" video at 10:45 for more (see the link in this video's description.)
Thanks so much for the work you have done making these videos. They are very instructive and simply put. I love simply put high tech. Good points about the ground. You mention the Teflon tape on drain pipes. Interestingly, the Teflon tape while making an insulator will probably not have much of a negative effect because what you now have is a series of capacitors. Since the radio RF is AC, it ought to still kind of work OK connecting anywhere along the metal. I found interestingly that even tossing ten to fifteen feet of wire along the floor makes for a sufficient ground for most close-by stations so long as you have a good antenna above that point. It's part of what some crystal radio enthusiasts call magic or mystery ground. There is no real mystery to it since close proximity of the wire to ground or coils to each other (antenna on one coil, ground on a separate but magnetically coupled coil) make for a capacitor. I actually found this by accident in my lab when making one tube radio. I thought that the wire I laid down for ground was connected to the ground rod. It wasn't but stations came in very well. I figured it was capacitively coupled to the ground.
Fun stuff this radio, eh? ;-)
gabevee3 Good point about the Teflon tape on drain pipes making a capacitor being okay since this is AC. Makes sense. I'm glad you enjoyed the videos. And yup, this radio stuff is fun! :)
Cool video. I'm liking how you made a variable capacitor. Very creative.
Yes. I'm working on a new 555 time music player now so that will be one or two videos. Veritasium just put out a video with some interesting science I might play with and make a video for. Those will probably be next. I've been wanting to do magnetic boots for a long time. More Stirling engine stuff, lasers, FM radio, tesla coil making and how it works, plastic to fuel, ... The list is endless.
Hi Rimstar! Very good presentation. You are a PRO. Way back in the late paleolithic period, I built a voice powered speaker out of the carbon core of a D cell battery and a cottage cheese carton. Can you show us how to build such a voice powered speaker? You are the best!!! jp
I have a suggestion for an experiment you might want to try. Instead of using one diode use a Graetz rectifier circuit, in theory this would give a doubling of the power output onto the piezo earphone, i wonder if this would be noticeable. What might be a problem, and give a distortion in the audio, when using a diode bridge circuit you have two diodes per direction so the forward voltage drop is doubled. Certain silicon Schottky diodes like the 1N5711 with low barrier potential might solve the problem.
Would be interesting if you try and make a small video about it, i enjoy your videos.
Thanks. I just looked at it and still can't say without trying it myself, which I won't try since it'd cost a bit. It says it can take input from a 1/8" microphone. So either the output of the crystal radio would go directly into the microphone socket or you'd need some other parts in between to make them a better match. If you don't want to take a chance then you could look up how to make your own amplifier for the crystal radio. I have parts for that but haven't had a chance to try yet.
Do you mean where in the circuit? That was explained in my How a Crystal Radio Works video. The antenna is connected to one end of the antenna coil. In the comments to that video I just mentioned that a loop antenna is another possible type of antenna that takes less room. The circuit is a little different for a loop antenna so I'll leave you to look it up. I don't have any video about that one.
I don't know if you mean for the antenna or the coil but the answer is yes for either one. Just make sure the wire for the coil has insulation on it.
Another awesome video lesson, that was all I needed, thanks a lot again!!! :) Why should you use Germanium and not Silicon diodes?
That vari cap of foil on tubes is brilliant. Relying on pvc to give a thicker dielectric gap, and scaled up with thick turkey pan aluminum sheet, gonna make a lil random wire tuner for 27.385. I hope it does not jump the gap after 5 watt tune-up, then slingin' 12 watts p.e.p. LSB.
I honestly don't know. You may have to do some fiddling with the circuit to get it to work. I am curious about the mini amplifier though. Do you have a part number or name?
One end of the antenna is connect as I show in the video, to one end of the shorter coil. The other end of the antenna isnt connected to anything. Silicon diodes wont work with this circuit, only germanium. You could look for videos that use a pencil and a razor blade for the diode but I havent gotten it to work so I cant help you there.
Is the one in my "How to Make Crystal Radio Amplifier for Speaker" video okay? You can find it in my channel's video section, it's fairly recent, August 1st.
I've never worked with cats whiskers and crysta. But a quick look at the wikipedia crystal radio page lists galena, "iron pyrite (Fool's gold, FeS2), silicon, molybdenite (MoS2), silicon carbide (carborundum, SiC), and a zincite-bornite (ZnO-Cu5FeS4) crystal-to-crystal junction trade-named Perikon". You can certainly use a modern diode that uses germanium. I don't know what you might be referring to by the "other diode looking thingie". You didn't list a capacitor though.
Thanks! Great videos.
Great Video. Could you possibly provide some information on Ferrite Rod antennas/radios. I am trying to reproduce your setup with a smaller configuration, however I am unable to get any sort of sound response. Another question about your crystal radio was the number of coupling turns from the antenna to the radio circuit. Is it necessary and how did you decide how many you needed. Thanks.
Thanks for the video. I guess I'm doing something wrong as I can't get it to work except for hearing mild static like noises. Guess I'll try again when I can get some more parts.
Thanks! What a great project. I've been looking for a while for a tutorial to make a simple radio such as this one. Much appreciated.
+Victor Lazarian Yes, it's called a loop antenna crystal radio and it doesn't pick things up as well as a straight wire antenna. Here's mine ruclips.net/video/iunAvz9PbN0/видео.html
PS There's no Reply button under your comment because of your Google+ settings.
- go to your Google+ page,
- in the top, right corner click on your thumbnail icon,
- in the popup that appears, click on "Settings".
- for the 2nd question down "Who can comment on your public posts?" set it to "Anyone".
Thanx!!
It should be laid horizontally and preferably pointing in the direction of the radio station. The higher up off the ground you mount it the better. I just lay it on the floor and get okay results. The other end doesn't have to be hooked up to anything. But if you are using a metal tower at that end to hold it up, then don't connect it to the tower directly but run a foot or two of rope, something nonconducting, between the antenna and the tower.
Are you sure the rod is lead? Or is it ferrite? If you hold just the rod in your hand, lead would be noticeably heavy and ferrite would be lighter. How many turns are on the coil, what's the diameter, how long is the coil?
I have a question.
Is it possible to roll the antenna up into a coil?
It theoretically makes sense to me, but I want professional support on this idea.
You can even use a Schottky diodes if you can't get Germanium 1N34 diodes. Diference between these diodes is 0,1V. And you can use a guitar amp if you want more sound, works very good for me.
For the antenna I just use any insulated wire, the longer the better. Mine are around 15 feet long. The wire thickness doesn't really matter. For the coil on the toiler paper roll I used 26 gauge wire with enamel insulation, often called magnet wire, but it's really just copper wire with insulation on it. I would have preferred to use 22 gauge so I could have a longer coil. In both cases it doesn't have to be copper.
This Lloyd's crystal radio doesn't use a cats whisker but uses a coil with a lead rod in the center to tune, can be seen on some EBay crystal sets. I see on another site where they used a 470 picofarad capacitor but they used a slider across the coil to do the tuning So was wondering since mine tunes with a rod instead of the slider will the 470 capicitor be the one I need ? or something different with my rod tuning ?
I've bought them online in the past. You could try a Schottky diode but it may not work. A silicon diode won't work. This circuit needs a leaky diode and most germanium diodes are leaky. You MAY be able to get around the fact that a Schottky diode isn't leaky by putting a resistor in parallel with the earpiece. The resistor should be somewhere between 10 to 100 kilohms. You could try a razor blade and a pencil but I don't have further information on that; search youtube for "razor pencil diode".
no i was talking about after you hook it up to the circuit where do you put the other end
This is great ! Thank you i can use this expt. For my project !
One question, wat all can we use instead of a germanium diode?
a fox hole radio diode.
I'm trying to restore a '50 - 60's Lloyd's crystal radio. All I have is the radio box, dial which is still connected to the tuner tube which has both wires of the wire coil tube still attached. What I need to know is what type of crystal diode and what ever the other diode looking thingie is. Can I use any crystal diode (Germanium) ?
just to be sure the buzzer works do u have its number at radio-shack??? and thx you have been a great help
Good Stuff
I haven't made a ferrite rod one yet. According to my calculations with a 1 centimeter diameter rod you'd need only 30 turns on the tuning coil and no change for the capacitor. This is just calculations, not experience. It's on my todo list. Other possible problems: how long is your antenna, longer is better, is your diode a germanium diode, do you have a good ground connection, any radio stations nearby? Point your antenna at the radio station for best results.
Should I be hearing static or some sort of noise through my crystal earpiece while I'm trying to tune it, or is it just completely quiet until I have tuned into a station? And does my antenna have to be generally in a uniform direction or can I have it half vertical (coming down from the roof) and half horizontal (going into my apartment)? Also, is it bad if my antenna is too long? Mine is about 60-70 feet long right now. Sorry for so many questions!
SniperFox You should be hearing static or something while tuning. The ideal antenna is one that is very long, straight, horizontal and pointed at the radio station. 60-70 feet is great and even longer would be better. I can fit only 3 12 foot parallel wires connected together at the crystal radio, but it works because I have radio stations nearby.
thanks and what about the antenna? and i have searched for germanium diodes bt thy are nt available here..can i use silicon diodes.. i want to make this for my science fair..
thanks but where would u connect the antenna too?
i am using aluminium wire instead of copper will it work??
Can I use a germanium OA91 diode?
i have just one question can i use a mini amplifier of 5000ohms impedance for a speacker this can be found in radio shack if u want to see it plz reply and thx again for the radio crystal its my science fair project
hello.. can any other ear piece be used instead of crystal ear piece as they are not available here... and where is output of the antenna ? in the main video it shows where to connect bt then whr is it left out?
thanks but will a 24 gauge stranded 2-conductor speaker wire work for the coil, the insulation is transparent and it has copper on it
The part number's 273-0060. It's 86dB, 4-28VDC, 5mA (max.).
Dear sir, can you please couple a joule ringer and a high gain antenna to power it! try ittt!!!
can you use a normal am fm
radio that you buy and use by pluging in to the wall as a tranmitter to use for a christel radio
+Andrew Kimble No, not in any way that I know.
I got you're message so you said I can use my metal bed frame cooll got it ok I might try that is there other ground connections I can use like a watter pip that I use to watter with
+Andrew Kimble A metal bed frame might work. I've never tried it, mine's wood, so I can't say for sure. You can use your water pipe but only if you're sure that it's metal all the way to the ground.
hi.I watched your clip and making this for my skool project..... have some questions
1.is it necessary to make 25 and 90 turn?can I make about 20and60 to make coil
2.I Dint get thin magnet wire so I bought somewhat thick copper wire....my doubt is the will work or not after using it...?
3.what would be the problems if the radio doesn't works?
thank you....big fan of yours...and love your videos..:)
1. I'm not sure how well using 20 instead of 25 will work. I don't have any way for calculating that. 60 instead of 90 will work, but it means it will be harder to tune since the radio stations will be crammed into a smaller coil or tuning area. Overall, it's probably worth a try.
2. With the thicker wire you may not be able to tune in the lower frequencies, below 900kHz for example (radio stations below 900kHz). It's hard to say exactly since I don't know how thick your wires are. I'm basing all my calculations on the calculators I talk about in this video ruclips.net/video/tjD9I95RAbw/видео.html.
3. The problems are all the things I talk about in this video and in the tip and tricks section on my webpage here rimstar.org/science_electronics_projects/crystal_radio_tips_and_tricks.htm. It's probably a good idea to have an understanding of how it works as explained in my how-it-works video ruclips.net/video/0-PParSmwtE/видео.html.
It depends on the coil radius and the size of your wire (and your capacitor) that will determine what frequency you are going to get. I have 30 awg wire or so and 21 turns for me is supposed to tune in from around 5-11.8 MHz but I have no idea though I did get one 'ham' operator speaking. You might just be tuning an empty part of the band at the time.
Привет дружище класный приёмник спасибо тебе огромное за видео здоровья вам удачи и всего хорошего пока 🙏👋👍👍👍
3:47 Is that why when I adjusted the TV antenna (back in the day) the picture would come in clear but then scramble again once I sat down?
I can't say for sure but I suspect it's something like that. I still have a TV that has that problem.
I've bought them online in the past. You could try a Schottky diode but it may not work. A silicon diode won't work. This circuit needs a leaky diode and most germanium diodes are leaky. You MAY be able to get around the fact that a Schottky diode isn't leaky by putting a resistor in parallel with the earpiece. The resistor should be somewhere between 10 to 100 kilohms.
is there any way to make a mobile radio ? i have made a smaller version of this and kept 2 wires out to conect to varois metal around me as a ground, but is there anyway to acheive the effect that ground has on the curcuit with something more mobile ?
sylvr In my video "How to Make Crystal Radio Amplifier for Speaker" (I have a lot of crystal radio how-to videos :)) you can see that I have my left hand on one plate of the tuning capacitor. In that case my body acts as a ground. That particular one works without any ground but I get louder volume if I do. The instructions for making the particular crystal radio in the video are here "Portable Crystal Radio using Loop Antenna and Pizza Box".
can you make a video about make a simple amp thanks :)
If you mean where the wires connect together, it certainly does! :)
Is it possible to add a joule thief before the ear piece? Would this make the sound better?
No, it wouldn't improve the sound. It would ruin it in fact. However, if you have a long enough antenna (i.e. you're getting a very strong signal) the you could do that and have the joule thief light an LED instead. My antenna isn't long enough.
can i use tunning yellow capacitor insted cylinder capacitor. cuz im not have a capacitance meter
That depends on the capacitance of your capacitor. Is there anything written on it? As I say at around 5:15, it needs to be in the range of 40 to 355 picofarads.
Hi, RimstarOrg, your videos really help me out making explanation about radios receiver. I'm gonna do a shout out in my video as a form of a thank you. If, I may?
Absolutely, you may. No permission is needed shout out. Thanks.
@@RimstarOrg thank you, Rim🌟
The video should be watchable by now. I'm not as good and detailed as you at explaining, it's gonna be dope if I got your correction/suggestion on it🌻
Nice job!
Where would you get a antenna??? and what type of wire do you have on the toilet paper roll??
to connect to the ground, any conductor that comes under the cement is good?
If you're making your own ground by connected to the actual Earth then it must be a bare wire, no insulation, and make as much contact with the earth ground as possible to make good electrical contact with the ground. Some ground is better than others. Wet ground is best. Dry ground is worst.
Can u make a Geiger counter?
that's cool
Hi RimstarOrg! Does this radio work in any countries, like saudi arabia?
also, can i use any wires for my coil, or only enamel copper wire will do?
lookin forward for your reply.Thank u in advance sir :)
I don't know. It depends on if you have any AM radio stations nearby. If you have a normal AM radio then you can see what you can tune into. The longer your antenna is (in a straightish line), the better you can pick up far away signals.
Any wire will do but it has to be insulated. And you'll either have to remove insulation from the top as I did in my how-to-make video ruclips.net/video/VqdcU9ULAlA/видео.html or use taps like I did with this coil ruclips.net/video/Gi9EmhrcfIg/видео.html
@@RimstarOrg thank you so much sir, i'mm so honored for reply, greatly appreciated :)
Can you tell me what is the diffenrence in the audio when we use the buzzer instead of the earpiece ..
The biggest difference with the buzzer seems to be that it isn't as loud as the specially made crystal earpiece.
+RimstarOrg perhaps you can help me out. I followed your instructional. I used 26 guage wire to do my windings and connect my wiper blade to ground. For my capacitor i used 20 guage hookup wire to connect my capacitor to the diode and ground. The pizo earbud i connected to the side of the diode closest to the line, and i hooked up two 15 ft antennas one 26 guage and the other 20 guage. I triple checked the connections and everything follows the diagram properly however i cannot hear anything. For ground i am doing the same as you connecting to the bottom sprocket of the wall. The funny thing is if i touch the diode and ear piece connection i get static. not touching it no static.Moving the windshield washers around while i do this i can hear the scrapping, but the capacitor does nothing when i move it. Any idea what might be the issue?
Since you get results when you touch it, then most likely the ground in your wall socket is no good. I live in an old building and have tested the grounds in all my wall sockets and only one is good.
Make sure your antennas are straight for a long as possible. Since you hear static when you touch it where the ground should be but you don't tune into any radio stations, it's possible you don't have any radio stations nearby that are strong enough to pick up. You may need a longer antenna. You could also try more antenna wires in parallel, but I found that is of limited value as you add more. Make sure they are spaced apart by a few inches/cm to be worth it.
Also, make sure you're getting good electrical contact where the wiper touches the sanded part of the coil, but don't sand the coil so much that too many adjacent turns are electrically connected.
And of course, work on getting a better ground.
It sounds like you're on the right track. Keep trying, and let us know how it goes.
I have a doubt . Pls reply to it if u see , as i need to make a crystal radio for my school project . Is it ok if i use normal copper wire ( non insulated ) , roll it over a toilet paper roll and later paint it with a layer of clear nail polish for the inductance . Will it be effective?
No, that won't work. The wire must have insulation on it before you roll it on the toilet paper. That prevents the turns which are all beside each other from touching each other. It's okay if insulation touches insulation but it's not okay if metal touches metal. If all the metal touches then it is as if the whole coil is a single, very wide turn of wire only.
Keep in mind that a lot of thing wire has a transparent enamel coating on it which is the insulation. Because it's transparent, it may look like it's bare wire. Wire that's called 'magnet wire' has an enamel coating (it's called magnet wire because it's often used for making electromagnets).
@@RimstarOrg thank u so much :)
Till now I make a few crystal radio and I have to use mini amplifier to hear the station..without amp I cant hear the sound. Any suggestion sir?
The longer the antenna is, the better the signal. Making sure you have a good ground also helps.
i am facing a problem can i use a rod anntena
I used to make these up when I was maybe 10 I think. I once used tin foil and sellotape and made one insIde a matchbox. It wasn’t that good, but I loved it and used to go to sleep listening to the radio. That was over 30 years ago. Which seems very strange indeed!
What kind of wire did you use for ground and antenna?
I used 16 AWG wire but really any wire will do. The only restriction is if your antenna is a few hundred feet long then you'd need to use something relatively large diameter (i.e. not 30 AWG).
RimstarOrg thank you!!!!
If I wear rubber gloves will it stop all interference with the tuning of the radio?
Wearing rubber gloves when touching the capacitor doesn't help much because there's still a capacitive effect between your hand and the aluminum foil with the rubber acting as the dielectric.
RimstarOrg, how can I contact you to show you the differance between the american plug and easten-european plug?
You can send me an email. My email address is at the bottom of every page of my website rimstar.org
A rod is fine but it depends on how long it is. The longer the better. A 5 foot antenna won't work, even 10 foot is borderline. I use around 14 feet.
in your portable crystal radio, you didn' t put any ground connection. Can this crystal radio be used without ground connection?
No, the circuit is designed for the the 25 turn coil "dumps" energy from undesired frequencies to ground. You can remove the ground connection, but it won't work nearly as well. Even the portable crystal radio doesn't work as well as this grounded radio because it has no ground. But if you put your hand on one of the capacitor plates of the portable crystal radio in order to provide a ground, then it works much better. So basically you can try this one without a ground but you likely won't get anything unless you're near a powerful radio station and/or have a very long antenna.
Hey guys, i was an amateur in a simple electronic, but i was an absolute beginner in something like radio.
I have some question, So I (we) can each design our own crystal radio according to our needs and creativity and it was :
- How to determine the AM frequency range based on the coil (wire diameter and wire length or coil diameter)
- How to determine when and how to use variable capacitors
- How to determine the parallel resistor value on the audio output
- How to determine the inductance value using information on the highest planned AM frequency range
- How to determine the inductance value based on the length and diameter of the wire used in the coil
- How to make a variable inductor
That's a lot of questions. This video ruclips.net/video/EsZQS2GOMQE/видео.html shows how I made it and has all the dimensions for the capacitor and coils. This one has another way of making the variable inductor (coil) ruclips.net/video/d4ymSGH0-Jo/видео.html using taps. There are many ways to make a crystal radio, but the basic idea is to have capacitance and inductance to tune into a specific frequency (preferably) and that capacitance and inductance can be in the antenna, coil and/or capacitor. In my radio I use an inductor (coil) and capacitor in parallel (there are also series circuits). This video one goes into how the crystal radio works ruclips.net/video/HupFY_24o-4/видео.html and I have specifc videos for how the parallel circuit works but they're best viewed from my webpage which also has calculators rimstar.org/science_electronics_projects/coil_design_inductance.htm and rimstar.org/science_electronics_projects/lc_circuit_aka_tank_or_resonant_circuit.htm .
I guess you mean for a speaker. Good suggestion. Another approach is to cut up and tape the lid from a plastic margarine container, or even the plastic from a plastic coke bottle.
and also i am useing coils from radios that I ben given to me take apart and have to keep can you use the am fm radio coils out of a household am fm radios
+Andrew Kimble You can use other coils as long as you're removing the wire from those coils and winding your own coils in the way I show in this video. How long is your antenna? Is it a roughly straight line? Are there any radio stations nearby? What are you using for ground? Are you sure the tuning bar is making good electrical contact with the top part of the tuning coil where you removed the enamel?
+Andrew Kimble I'll reply here instead of in the other unrelated video and so its all in one place. You have to take the wires off the old coils since they are the wrong dimensions if you want to make one like mine. If you're making on with a different design then I don't have the time to figure out what you're doing and help you.
Um, 24 gauge stranded wire will work. 2-conductor will be a problem. I guess you're going to split the wire so you use only one conductor?
I built a radio and I thought it was just junk. A bunch of parts cobbled together that did nothing starting with the earpiece that sounds like shit like when you go take a hearing test where you hardly hear like this guys buzzer when hooked up to a transistor radio at full volume. I was going to throw it away in disappointment. My radio has a 4 inch 'antenna' and nothing was hooked up including ground. so I am sitting at the bench and it scared me. All of a sudden, I heard a voice while the earpiece was sitting on the table about 3 ft away coming from the earpiece I thought was no good. damn that's loud! Again, a 4 inch antenna here. I have no idea what frequency it receives but the coil is calculated for around 5-11.8 Mhz. Of course, my phone battery died while trying to capture the radio operator over the earpiece. ill put it up soon! :)
Hello i am 8 years late but 😂 i cannot find any piezeo eletctric earpiece so is there any solutions?? Or alternative
You can buy them here www.midnightscience.com/catalog5.html#part9 and I show how to make one using a piezoelectric speaker from a microwave oven in this video ruclips.net/video/OVapqz4yBCY/видео.html But have someone help you when opening up the microwave oven because there is a big capacitor in there which can shock you.
could you wrap the second coild more to get higher or lower frequencies ?
sylvr Less turns gives higher frequency and more turns gives lower frequency. You can see this illustrated in my video "How a Crystal Radio Works" at around 5:51 with the fuller explanation starting at around 4:50. But that's not necessary if you make the coil adjustable as I have. You can see how in my video "How to Make/Build a Crystal Radio" or using the method in "Make a Crystal Radio Coil with Taps".
RimstarOrg with the very small voltage that is coming from the crystal radio will my multimeter pick it up?
Owen Chase
The voltage is in the 20 to 30 millivolt range so if your meter supports that range then yes. But it isn't steady DC or sinusoidal AC so all you'd see is fluctuating voltages.
RimstarOrg ok cool
Is this possible in New Delhi, India where there is only one AM channel i.e. National Channel
Subhash Chandra Ghosh As long as you have the AM channel it should be possible. A quick search shows that All India Radio in Delhi might be 1017kHz, which is in the range that's tunable for the crystal radios I show how to make (540kHz to 1600kHz.)
RimstarOrg, i made the radio but the problem is i can't find a germanium diode
Isnt there a unpowered FM or AM or TV booster we could use... i am experimenting with just a germanium diode and antenna and ground (check my last vid) :) Also i found that CB radios give off huge power :) try that as a power source for testing.. I REALLY like your vids man im from Canada too :)
Does it work with a normal speaker?
If yes, and my speaker have battery, do i still have to connect to the ground?
It won't work with just a normal speaker but it sounds like your speaker has an amplifier in it since it has a battery. In that case, you'd be doing something more like I do here ruclips.net/video/JtPwxbOgBHw/видео.html with my homemade speaker and amplifier. The ground still helps in that case, but it's optional.
RimstarOrg hmm i tried following your other video but didn’t get anywhere. I’m using a peaq ppa20bt-sl speaker. Any tips? Do i need another speaker?
I looked at a manual online for that speaker but didn't see any place for an audio input.
would cooper be a good wire to work with?
Yes. Copper wire is all I used.
RimstarOrg Using enameled wire is a pain man
ok I made my christel am radio the right way I went back to go over my connections and all of them are posted to be. in the right places it still does not work I don't know why, what do u thing.
I still hear nothing out of my radio. I have everything hooked up exactly as in your diagram. I live about half a mile from the AM tower and I am using 50 feet of wire strung about 20 feet up as an antenna. I have tried replacing the capacitor with the variable type bought online but that didn't change anything. I was able to pick up one station very faintly with the same earpiece and diode using a simpler coil setup without a capacitor so I know that both of those are working. Now I have a store bought capacitor so I know that is working. Maybe this will help someone tell me whats wrong. I hear nothing unless I hold the wire at any open spot between the earpiece and the diode. Then I hear the hum of static. Any help would be appreciated. Thanks.
dpla5762 Since your simpler one worked I'm suspecting your tuning coil. When you sand the enamel off the top, make sure to not sand in between since you don't want each turn to be electrically connected to the next one. Also, make sure your wiper blade is making good electrical contact with the sanded off wire of the coil. Another possibility is that your wiper blade has an insulating coating on it or you're not making good electrical contact with it.
Since you mention holding the wire helping, that makes me wonder how good your ground is.
Can I use my hand to be the ground? If yes pls explain how to do it.
samuel virgil pe Rewire your crystal radio the way I talk about in 9:28 in this video. But don't connect a wire to ground. Instead use the radio by holding your hand on the outer cylinder of the capacitor, putting as much of your hand on it as possible so that you get a lot of good contact.
me to can you use you're hand as a ground or what andrew kimble here
+Andrew Kimble Yes. See my reply above for details.
I tried making the crystal radio you described, but despite your superior explanation, I'm not even getting noise. Now I'm a bit disappointed in my own abilities.
Don't give up. It's rare that something works the first, or even the second time. It does help to have AM radio stations nearby, like I do, but I've sometimes picked up some farther away. Try making a longer antenna, the longer the better for stations far away and it should be more-or-less straight for a lot of its length. Check all your connections. Make sure the top of your wiper blade is making contact with the copper at the top of the coils where you sanded away some of the enamel. A good ground is also important. Rather than repeat everything here, I've put more tips on my webpage here in mote detail rimstar.org/science_electronics_projects/crystal_radio_tips_and_tricks.htm Keep at it!
antenna be mounted in the air without touching anything else , ESPECIALLY the floor !
Radio waves propagate through air / space ; poorly through the wooden floor.
The coil is 1/4'' in diameter and 1'' long. The rod inside the coil seems to be a lead material or similar as its heavy. I tried installing the german diode and the 470 capacitor but it didn't work. Any ideas ? The circuit from looking at some similar youtube radio's is one end of coil is attached to an earphone lead which is attached to the diode which goes to the antenna terminal. The other coil lead is attached to the attenna lead also and the remaining earphone lead is attached to the capacitor which also goes to the antenna lead. I think my problem is that I don't have the correct capacitor.
You didn't say how many turns are on the coil so I can't do the calculation for the capacitor. I don't quite understand your circuit from what you describe. The position of the diode and earphone with respect to the coil and capacitor sound wrong but I'm not sure where the diode is from your description. You also didn't mention any connection to Earth ground, which is more likely the reason it isn't working than the capacitor being the reason. 470 picofarads is pretty typical for crystal radios.
Sorry about the delays but having problems responding here, tried many times saying that the coil wire is not much larger than a human hair so very difficult to count the windings but looks to be about 120. The circuitry all ends up at the antenna terminal, like I said one end of the coil goes to the crystal ph terminal, diode connects to that terminal, than to the ant. terminal. The other ph terminal connectes to the capacitor which connects to the ant. terminal and the remaining coil wire goes to that ant. terminal also. I got this wiring from looking at Lloyds's radios on Ebay and I also remember this from back in the '60's. Maybe I have the diode and the capacitor turned around ? This was an awesome radio as on a good day I could pick up Philadelphia and Mexico City but rarely from S Dakota where I grew up at. This radio did not use a ground as you can see from the Ebay radios there. I just built a crystal radio using the 470 cap. and diode which used a ground but when I added another 75' of ant. wire I couldn't pick up anything but buzzing so I unhooked the ground and it worked great but I did have to have the gr. connected with just 75' of ant. I'm 25 miles from a transmitter now. In town ('60's) the Lloyd's set just had to have the ant. wire from the radio threw across my shoulder to pick up stations, an awesome radio! Check out the Ebay radios and you should find the Lloyds radios there to check the circuits, some other brands use the same radio box and circuitry also & are the same rectangle shape with the round dial towards the top. I can't wire up the Lloyd's radio the same as the one I just built because it didn't use the one end of the coil wire. Another radio on Ebay uses a 500 K ohm than a wavy line (symbol) meg ohm, for the other capacitor or what ever it is Yes check out the radio's on Ebay.
Gene Schmidt
Okay, so in answer to your original question, might the 470 picofarad cap be the problem, I did some simple resonant frequency calculations that suggest that that would tune in from 77kHz with the rod pushed all the way into the coil and 772kHz with the rod pulled all the way out. But changing it to a 100 picofarad cap I get a range of 167kHz to 1673kHz.
Assumptions made: This is a simple parallel LC resonance calculation. I assumed a ur (permeability) of the rod of 100, and used 1 when the rod is pulled all the way out. A ur of 100 is for an iron rod.
I don't see how your earphone will get rectified radio waves given the wiring you've described. It looks like the earphone is in the circuit with the resonance going on between the coil and the capacitor. There are many circuit designs so I hesitate giving you yet another one if you already have one in mind, but check out my how to make a crystal radio video ruclips.net/video/VqdcU9ULAlA/видео.html and there's also my how a crystal radio works video ruclips.net/video/0-PParSmwtE/видео.html It might be good to try that one as a troubleshooting step.
I searched for "Lloyd's radios" on ebay.com but get only battery powered radios, no crystal radios. Maybe I missed it.
RimstarOrg I just checked Ebay and found one, I typed crystal radio and found a flesh colored one intitled "Vintage Germanium Diode Crystal Pocket Radio Boxed set " for $69.50 on page 2. They are showing the innards of the radio there. I'll check your site but all the ones I've checked on RUclips so far don't use both ends of the coil or they use the twisted coil every few turns, I have not found one that's wired like the Lloyds or the one in the above Ebay radio. I'm trying to make it as orginal as possible using the hollow coil tube and tuner like the one on Ebay. There are two on that page, its the first one.
Gene Schmidt
Oh, that's a very nice one! The circuit they show there makes sense to me. The cap and coil are paralleled with each other and there's a separate path for the diode and earpiece. There's the minor difference in how I tune my coil and that my cap is also variable and that I connect up a ground, but basically it's the same simple circuit I use. If that's what you were trying to describe in words, then I misunderstood what you were saying.
second hand stores have baskets full of discarded wrist watches. Very good source for piezos.
Stripping the wires gives you a much better signal.