How to Make/Build a Crystal Radio

Step-by-step instructions for making a tunable crystal radio. This is a radio that gets its power from the radio waves. I made it almost entirely from junk except for the diode (1N34 germanium diode) and the earpiece (though you can use a speaker from a phone instead.) The capacitor is made from aluminum foil and a paper towel roll. The coil is rolled on a toilet paper roll. The wire is enameled magnet wire. For the antenna I use a 15 foot wire laid out on the floor. For the earth ground I connect a wire to the ground in the household wiring.
I originally got this circuit from the book "Radio Receiver Projects You Can Build" by Homer L. Davidson.
For this circuit, the diode must be germanium. The following is a partial list of germanium diodes that should work:
1N34A, 1N60, 1N91, 1N119, 1N270, 1N277, 1N283
The following are not germanium diodes and may need a long antenna or a powerful radio station nearby to work:
1N4148 (silicon, found on a lot of circuit boards), B16 (zener diode), 1N5060 (avalanche diode)
The crystal earpiece (piezoelectric earphone) and/or 1N34 germanium diode and/or air core variable capacitors can be ordered from most of these sources:
www.midnightscience.com
store.scitoys.com/radio-kits-... (their variable capacitor is for if your coil has a ferrite core and is smaller than the one in this video)
You can find the circuit diagram shown in this video on this page:
rimstar.org/equip/crystal_radi...
See also:
How a Crystal Radio Works
• How a Crystal Radio Works
Crystal Radio Troubleshooting and Tips
• Crystal Radio Troubles...
Make Crystal Earphone/Earpiece for Crystal Radio
• Make Crystal Earphone/...
Use Earbuds/Earphones with Crystal Radio
• Use Earbuds/Earphones ...
Make a Crystal Radio Coil with Taps
• Make a Crystal Radio C...
Make Razor Blade Diode for Crystal Radio/Foxhole Radio
• Make Razor Blade Diode...
How to Make Crystal Radio Amplifier for Speaker
• How to Make Crystal Ra...
How to Make Amplifier for Crystal Radio Earphone
• How to Make Amplifier ...
Steps for How to Make Amplifier for Crystal Earpiece
• Steps for How to Make ...
How to Make an AM Radio Transmitter (so you can transmit to your crystal radio)
• How to Make AM Radio T...
Amplitude Modulation with Simple AM Radio Transmitter
• Amplitude Modulation w...
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- rimstar.org

[@joedavis4150]

... Beautiful and clear. Thank you.... In the late forties, I was sitting on the ground, leaning against a galvanized Iron Gate. It started receiving a clear radio signal. I think it must have been the zinc crystals in the galvanizing. This event seemed almost like a miracle, to 9 year old me.

[@martinkennard1669]

I was cultivating with a tractor out in no where and started clearly hearing a station. Nobody else around for miles. I can only figure it was thru my tooth fillings.

[@genericascanbe3728]

Like in the 1940s? wow

[@miscellaneousdon3377]

​@@martinkennard1669same thing happened to me in school after I got a new tooth filling.

[@KingOfTheBeyond23]

If I had a son/daughter I would watch this with them and build a radio. Builds bonds and teaches them things. Amazing vid, thanks.

[@yellowawesomeness3857]

I'd do that

[@Vexcenot]

Can I be your son/daughter?

[@robertturner5289]

Build my first radio, very similar to this, with my dad when I was young, great memory.

[@Adrian_AdamViolonDiGerma-tm3nq]

honest reaction : Fascinated 😆😃😄✨✨

[@americanspirit8932]

I made my first crystal radio, when I was 9 years old, I had a comic book instructed you how to make one. And it worked great at the time.

[@Pygar2]

""Superboy's Workshop" How to Make a Razor-Blade Radio!" Last reprinted in Four Star Spectacular #4, Oct. 1976!

[@TomM-iw3te]

Reminds me of when I made my first crystal set radio receiver in 1956 in Ontario Canada. Your video brought back some wonderful memories. I went on to build Televisions, HAM radio stations, Signal Direction Finders and eventually Computers. Thank you for sharing.

[@AdamosDad]

I built one when I was 10, 62 years ago. I was a little more carful in construction but the same circuit. thanks for the memories.

[@RimstarOrg]

The power source is the incoming radio waves themselves. No battery, no plugging into the wall socket.

[@michaelmyers3114]

exactly, this video is not about a crystal radio.

[@lizzy-o-glicht8051]

𝙾𝚔, 𝙽𝚘 𝚘𝚗𝚎 𝚊𝚜𝚔𝚎𝚍 𝚎𝚒𝚗𝚜𝚝𝚎𝚒𝚗

[@KRAFTWERK2K6]

I swear, winding the coil is the most difficult and painstaking part. Especially if you never did that before. Took me a while to find the proper way of winding it and making each turn nicely and the wire ending up sitting close together. So satisfying when it's completely wound and ready to be prepared for the next steps.

[@auntroachkiller6086]

I had a small crystal radio shaped like a rocket, in the 60s when I was a kid. Watching this video has rekindled my spirît , some sixty-odd years later. Thanks for the instructions on how to build my own personal model.Definetly will be a jewel in my video library. Sadly , kids of this generation probably have no such interests.

[@maggiebrookes-buttwriter3230]

Thank you. This is brilliant. I am researching for a novel set in a WW2 prisoner of war camp, where I've been told they had a crystal radio, built with smuggled parts. I couldn't quite understand how they could have built it, but now I can see the simplicity of it. This has given me everything I need to know! I also really liked your snappy delivery and the way you had filmed the video. Thank you.

[@trs80model14]

Indeed they did and more: look up Roy Kilminster's site, he was a prisoner in Stalag Luft I and they had a radio built with smuggled tubes. He was the keeper of the radio and has pictures of it and how they hid it in a wall.

[@possummanrld]

Very well done, Rimstar! It looks very primitive, but then the idea is to encourage people to try, and I think this is one of the best videos I have seen in that regard. The capacitor for the volume control is a very nice touch! Thanks for the time an effort you took to make this excellent and instructive video!

[@Monotoba]

I've been looking for a simple crystal radio for my young grandson to build. This looks like the perfect project! Thanks!

[@RimstarOrg]

Cool! Be sure to check out the playlist. kzbin.info/aero/PLFsZmHTZL-zlSltC6ELZW9PK4ks7wgPRz I made a bunch of related videos on the topic, including troubleshooting and tips and how-it-works.

[@Monotoba]

I've watch several already. You do a great job!

[@MuraliMadupu]

The crystal radio project is great for the younger generation, just I gone to the 1960s period when I was 10 years old I made this project, It was a great Joy to listen, to local radio station broadcast. Now I am 64 years old. Thanks for up loading you and You Tube.Now our younger generation should know how the radio works and be good at fundamentals of electronics.

[@jerrybomcool]

cant believe how simple this is, thank you for taking the time to make this video and showing us this cool experiment :D

[@joeorton1218]

R.i.p radio shack

[@survivalchef8684]

Lol

[@robert_redd1528]

i remember those days.

[@ronalddaub7965]

Absolutely I've got hundreds of old radios for parts

[@mikebucket1658]

Long live radio shacks.

[@billducas]

They are still online, but it's not the same. In the 70's they had most of what you needed and knowledgeable employees. Towards the end of their retail stores, they had nothing, and their employees didn't know the first thing about electronics.

[@cliff987]

Found these basic radio videos, 7 or 8 years on, and they are awesome. Thanks for demonstrating some of the very basics.

[@bruceroberts2269]

I have always enjoyed making crystal radio's ... we used to use a germanium crystal. This is an awesome tutorial ... the best I have seen !!!

[@RimstarOrg]

A foxhole radio is also a crystal radio. There are many, many variations. A foxhole radio usually uses a razor blade and a pencil for the diode, instead of the semiconductor one I've used here. I show how to do that in my "Make Razor Blade Diode for Crystal Radio/Foxhole Radio" video (see the link in the description below this video.) Basically a foxhole radio uses less off-the-shelf parts since there aren't any in a foxhole.

[@johnmckee7937]

I made a foxhole radio as a kid, much older now.

[@Adrian_AdamViolonDiGerma-tm3nq]

It is called Radio Trench if the ingredients are truly made by yourself and obtained from the local area (such as razors and pencils), usually called a crystal radio because the crystal radio circuit is obtained from a shop/commercial crystal radio. It's called a foxhole radio because... Was it made in a foxhole during the war, or because its structure resembles a tunnel (tube)?

[@annelieseocallaghan801]

This truly is great. The tunable capacitor from foil ! Amazing, high quality video.

[@trs80model14]

Especially as air-variable caps are getting more and more expensive.

[@mounachuang3989]

Really wish that I could have seen this when I was a child. So much curiosity was dead out without enough information or demonstration like this one.

[@HamletFasliu]

I just want to say thank you! It's amazing that all the knowledge one could want is on the internet for free. We all owe gratitude to you and to people like you who take the time to share your knowledge with the world.

[@subroto1961]

Wow ! Relived my childhood. Mine was a simpler one. I used to detach the earpiece of our chunky old telephone. Attach the two ends of a galena crystal to the two electrodes of the earpiece. connect the earth and aerial to each of those electrodes and enjoy the strongest available medium wave. The ground rule was, got to replace the ear piece before Dad gets home

[@RimstarOrg]

Cool! That's definitely about as simple as you can get.

[@sparkdetect]

What great memories...I did hours of listening on just a diode and earphone. And on tuned sets I DXed other states at night and even shortwave broadcasts.

[@drmrinalkantinath4336]

Jumpstart Jimbo: Have you uploaded the video about this method? I have a faint memory my elder brother did it in the way you mentioned. We used to listen to the local radio station so clearly. That was 70 years back when I was a small kid. I saw the crystal (so he said, there was no diode or any other thing except the telephone receiver which he bought from the Calcutta second hand market) and with a slider (that is the wiper) we can tune in the radio station. Will you please do a video about this method. I believe many like me will be interested about it and they will be benefitted . Please do it and upload the video if possible. I want tp make like this in memory of my elder brother who is no more in this world. He had curiosity things like this.

[@mikebledig7208]

Those were the days of learning about radios and how they work and how to build them. So many youngsters of todays generation could learn so much from videos like this, but many won't be interested because of computer rubbish. Thank you for this video.

[@freeze0895]

i like computers and learning how things work dont count me out on wanting to learn about this kind of stuff its very interesting

[@mikebledig7208]

@@freeze0895That's wonderful! Pity there aren't many like you 😊😊

[@freeze0895]

@@mikebledig7208 yeah I agree all of technology is so interesting pcs radios n64s game boys (game boy colors!) there’s so much yet not enough time

[@packingten]

My Dad made me on in 1958,We moved in 1962 then @ 11 years old I made a crystal radio,I remember antennae & ground,😇RIP DAD MISS YOU,Hope to see you other side!.

[@Pastshelfdate]

Back when I was around 8 years old, for Christmas, in the mid 1960s, I was given a "Lectron" set, which was encapsulated electronic components, in little blocks with square tops sowing standard circuit diagram symbols, with magnets for the internal contacts to link with other blocks, on a metal sheet (for a ground, I imagine). I enjoyed some success with most of the projects in the accompanying booklet. However, I could never get the crystal radio project to work at all. That made me sad, and with no support, I gave up. Today, listening to someone go on about crystals in a way that suggested someone hurt her, in the name of actual science, in her formative years. That's what reminded me about "crystal radios." I still don't understand the "crystal" part (Maybe that's the diode?), but your video was a lot of fun, and some healing. Thank you.

[@RimstarOrg]

Yes, the "crystal" part is the diode, or was the diode. Back in the early 1900s and galena crystal with the sharp tip of a wire touching it was used where today we use the diode. Today, a crystal radio is defined as any radio that is powered by the incoming radio waves.

[@pay9011]

As a kid I remember having little radios that you would alligator clip to something metallic (like a window) and it would receive AM via a standard earphone. We called them crystal radios. I remember them as being quite small and working well.

[@RimstarOrg]

A number of ways. Use a longer antenna. Make sure you have a good ground. Decrease the space between the two coils, though that may cause more interference between radio stations. You could also add an amplifier (e.g. one powered by a battery) but then it would no longer be considered a crystal radio since a crystal radio is one which is powered solely by the incoming radio waves.

[@adrianmiller3204]

Is it the answer to wireless and free electricity

[@RimstarOrg]

There isn't much power here. With a long enough antenna or a strong radio station nearby, you can power a single LED. And you still need a radio station somewhere to use electricity to transmit the radio signal in the first place.

[@wilwad]

Everybody please pay attention, we will be using these again after WW3

[@jonmorris6446]

wilwad if a war came along I'd be on the front line im a decent bloke fairly and I get well Larry wen Apple look at me funny down at the pub. I bounce em round like bunnies I've never broke a law in mi life and if a war came along I'd be on the front.line wig the best of em

[@Natalie-ez1zc]

*british* 100

[@BillAnt]

Probably...and since the internet might get destroyed too, those who posses this knowledge will be the new radio stars. :D

[@videolabguy]

That is a very very bad idea. Anyone who activates a transmitter after WWIII, will immediately receive a back up nuclear missile on their head. Radio silence will keep you alive.

[@alexbortnyk1981]

@@videolabguy after it ends tho

[@bub_lite_6361]

Neat design. I've never made a crystal radio with a tuning capacitor 'and' a slider before. Didn't even know you could still get crystal earphones. 5 years too late, but thanks for the video. 👍

[@VibrationsfromMirror]

Hardest part would have been the assembly of the outlet cord probably. Which, you skipped over. Thank You for making this video! Free energy was a gift we has been robbed. I'd like to see more science like this in our early school systems.

[@RimstarOrg]

I skipped over that part because it's dangerous if you don't know what you're doing. I show alternatives in my follow-up video kzbin.info/www/bejne/fou9nn6Qf9d8jZI

[@autogolazzojr7950]

It ain't free energy. The energy is put into the air by the radio transmitter.

[@richardturner5861]

I made a crystal radio from a kit when i was in the cub scouts at about age 10. It worked!

[@gametrue2229]

Richard Turner know how to make a potato radio that actually works?

[@survivalchef8684]

It more fun to build stuff out of crap

[@kwokng2771]

This video is a big motivation and knowledge source. Thank you so much for that. I am teaching a lab course and including this as the final project. So I had tried to make it as simple as possible and actually providing kits for every student. In the process, I have gathered the following thoughts: 1) Coil: I find the sliding option a bit challenging and intimidating, although I did get it to work. My modified design is a total of 65 turns, with a small loop at 40th turn. So there are 2 settings, 65 turns with the loop not touched, and 40 turns with the loop grounded. Between these 2 settings, the frequency range is quite good. After all, you just want to get some channels to show off, but not necessarily all the channels. 2) Capacitor: I tried to “improve” your design, but finally realized how good yours is. Thought of parallel plates that some people use, but bowing near enter is unavoidable, while your tube design has no such problem. I also tried other materials to make it more rigid than aluminum foil. I tried flashing materials (aluminum and galvanized steel) but they are too stiff and leave too much gap between the inner and outer tubes, so probably loosing some capacitance for the same size. I wound up using thicker aluminum foil available. I was also concerned about the contact by taping, but convinced myself that contact to capacitors is not that critical, since there is no DC current. 3) Speaker: This is more critical and difficult than I expected. Piezo earphone did not work for me, and it was a bit expensive ($7) and I returned it. Piezo buzzer (much cheaper) I could hear something but is quite faint, so hard to tune channels. I also tried piezo transducer, and it did not work. The best I used was a guitar amp, but not everybody has one. Next I will try are PC speaker and headphone (both suggested by your viewers). 4) Wish I could show a photo of my final project, but I did not see that option. Again thanks a million. It’s nice to see old school is kept and being pursued. I am retired and always wanted to do it. Well I finally did!

[@RimstarOrg]

Thanks for sharing all that. I've had the same problem when teaching a class, having to find the cheapest and simplest way that works. So I can relate. I'm glad to hear it worked out.

[@happyhome41]

This is fascinating in one respect -- no battery. Impressive

[@McProGriefing1st]

my great grandfather used to make radios, He died before i was born but the fascination with radios and electronics.

[@RimstarOrg]

Yes, you can use a variable capacitor. To match the coil in this video the capacitor should be in the range 40 picofarads to 355 picofarads if you want to tune in the whole AM radio frequency range.

[@alifr4088]

Can this pick up Shortwave?

[@RimstarOrg]

A diode is something that allows electrons to flow through it in one direction only. So if your power source is one that make electrons move back and forth in the wire but you have a section of your circuit where you want electrons to go in one direction only, then you'd insert a diode in that section. It's called a "crystal" radio because people used to make the diode by touching a Galena rock crystal with the tip of a wire. Nowadays, a modern semiconductor diode is used instead.

[@Mamabear21318]

You stoopid

[@lizzy-o-glicht8051]

𝙱𝚛𝚞𝚑

[@lizzy-o-glicht8051]

𝚈𝚎𝚊, 𝚍𝚞𝚑

[@bhavanabenrathod2706]

I have no ground connection in my home what I will do?????please five me answer

[@FishFind3000]

@@bhavanabenrathod2706 pretty much all homes have a ground. You can also use exposed copper or gas plumbing for a ground.

[@DonPastor1]

I was looking for my original crystal radio set I got way back in 1957. It actually had a little crystal item with crystal it it and a filler item you taped on the crystal until you found a radio station. A very simple unit.

[@dawsonkoren4529]

Im doing this for a school project and you are single handedly saving my grade. Appretiacte it

[@RimstarOrg]

My pleasure, that's what it's here for. In case it helps, I have an entire playlist about crystal radios kzbin.info/www/bejne/jKLHlIhvirF0oqM and tips and tricks to getting them to work on my website rimstar.org/science_electronics_projects/crystal_radio_tips_and_tricks.htm

[@RimstarOrg]

Ah, I see what you mean now. I'll be doing a variometer when I use my ferrite core, I just was familiar with the term. Thanks.

[@leialoha70]

Thank you! I am going to build this with my 12 year old son.

[@fflynnful]

This is a radio made from things you might find in your house! I like the idea.

[@dashfatbastard]

Huh! I've never seen the capacitor build before....nice! I built my first in 1972, when I was 11....worked like a charm. I built a few tiny ones for friends, too. That's the same 1N34 diode I used:) I never found that I needed an aerial to get a signal. I LOVE the audacity of using a standard 110v plug with only the ground connected...using an alligator clip to connect it to the screw-jead that held on the faceplate of the electrical outlet usually worked for me...I'd back it out, sand off the paint, and screw it in with enough play to give it something to grab onto.

[@RimstarOrg]

The purpose of the short one is to be an inductor. It's inducing current in the longer one. The purpose of the longer one is to resonate with the capacitor at the tuned radio frequency. You might be interested in watching my "How a Crystal Radio Works" video, which goes into all that in great detail and with animations. There's a link to it in the description below this video.

[@EMandMORE]

I can't believe what I see. Just genious. I love how you build all this beautiful things starting from scratch. Well...I should say way less than scratch! I've never seen anybody making a capacitor that way. Could you please answer my question? Please I'm very inquiring: How the hell is the circuit removing the carrier wave from the audio signal wave? I suppose it's impossible to do that on an FM signal using such a simple circuit so I think the input signal you're receiving must be AM. But still, I can't see any LP filter or anything else to remove the carrier wave. How is the circuit doing that? Thank you again for all the knowledge, entertainment and ispiration you give to me.

[@RimstarOrg]

That's a neat question, because the answer is so sneaky. :) The first obvious thing is that the diode chops off one polarity of the wave. Next, the piezoelectric crystal in the earpiece can't respond fast enough to each peak and zeroing of the carrier wave, so it responds slowly to the peaks only. The result is that the earpiece keeps up only with the audio wave. You can see this illustrated in my "How a Crystal Radio Works" video kzbin.info/www/bejne/Zl6zgZSoiNKqqqc at around 9:27.

[@EMandMORE]

I'm sorry, I found the explanation video just after I posted the question, now it's all perfectly clear. Thanks a lot, really. I was looking for a simple RF receiver but I just couldn't find a very basic one to understand, now I did, thank you again :)

[@E5Bobby]

Built one of these from a kit when I was a kid. Great fun for youngsters. Well done! Thank you for making this video. I might make one of these for my grandson. I know he'll enjoy it.

[@tonyv8925]

my first crystal radio was from junk parts when I was 8yrs old...I changed the diameter and turns of the inductor and used a variable ganged capacitor from an old Crosley AM radio...hooked up to guy wire on house antenna and ground to pipe in kitchen sink...had to buy the earpiece, from Allied Radio store...at late nite I could pick up international shortwave radio signals...have been in electronics ever since...still have my General Class Ham license too! 73, good video!

[@Disillusioned_one]

Enjoyed the video, and not one soldered joint.

[@RimstarOrg]

roy douce Glad you enjoyed it. Yeah, I avoided soldered joints so that anyone could make it.

[@RimstarOrg]

I never thought to look in an old smoke alarm. Thanks! They definitely sound like peizo buzzers. And yes, this coil and capacitor are for tuning in 540kHz to 1.6MHz. I'm away from my own computer this week otherwise I could easily calculate what's needed for 198kHz but I'm pretty sure you need more turns.

[@rva1945]

Great video, nicely explained and good to know that the radio can be built using junk materials.

[@ccchowie]

Love your videos, simple and easy to follow. Your voice goes very well with your presentations, loud and clear, Congrats and keep up the good work.

[@RimstarOrg]

Thanks for the recommendation. I find Crystal Radio: History, Fundamentals, and Design by P.A. Kinzie to be very good too.

[@lvxmagick9560]

Damn I knew this was a old video the second he said Radio Shack

[@alexpowers3697]

Ahh the Archer magnet wire set. Brings back such good memories. And Science Fair kits... O Radio Shack you will be missed. What they charge for those crystal earphones these days is highway robbery. They were commodity items when I was a wee scientist.

[@sargetech]

Brings me back to my Alfred P. Morgan, Radio Electronics days!! My mom would not let me mess around with the tubes, but I could make anything that did not require batteries! This was allowed. Also I just couldn't wait for winter so I could do static electric projects such as Leyden jars and electroporuses etc!! I was a real little mad scientist! :)

[@george330ful]

I am 73 and have two crystal radios one I made with a razor blade as the tuner in stead of the wiper . I can get three station one is 35 miles away wwva large powered station

[@RimstarOrg]

That's pretty good for a razor blade one. I know I had trouble getting anything with mine. How long is your antenna?

[@george330ful]

Over 250 ft I am also on the highest point in my county

[@RimstarOrg]

george330ful Wow. 250ft is great, I'm envious. Sounds like a great location.

[@subroto1961]

Yeah, remember that trick. Glue a razor blade flat on a wooden board, fix the head of a safety pin near it with a nail, touch the sharp point of the pin vertically on the flat surface of the blade. That'll work as a crude diode

[@Landotter1]

Jumpstart Jimbo I believe they used to call that a cats whisker

[@HBC101TVStudios]

Can you make a crystal SW radio?

[@chrisakarazor9612]

Yes, just make a shorter coil

[@travellingunderpants]

Greetings from the UK. I found my way quite by chance looking for something completely unrelated lol. Absolutely fascinated and enjoyed very much watching 😄. I'm gonna try and make one now! Not many AM MW radio stations around now but hopefully I'll be able to hear something! Lol. Thank you for posting 😃

[@jitendratayde7988]

I am 53 :)).... Always wanted to do this. thanks for posting.

[@chrisakarazor9612]

It's a great hobby!

[@RimstarOrg]

+Gabriels Raitis Kuma No, an LED won't work. The voltage required to start the LED conducting is too high for the radio. And it has to be a germanium diode, not a silicon diode. PS. Your comment doesn't have a Reply button because your Google+ settings are set to not allow "Anyone" to comment on your public posts.

[@Loundre3]

Will an Schottky diode work also?

[@RimstarOrg]

Some mentioned in the comments here that a low-barrier Schottky barrier might work. I haven't tried it myself.

[@power-max]

I bought the lowest voltage drop Schottky diode (0.29v @ 5mA) with very small leakage (within nanoamps) but I have not had luck so far. I suspect my crystal earpiece may have been damaged though.

[@RimstarOrg]

Thanks. Let me know if you do get it working. It would be nice to have confirmation.

[@power-max]

RimstarOrg I can pick up noise around 700KHz, and it sounds exactly the same on a surround sound system on the AM tuner selection. I think it is my PS3 or TV tuner. Even the tuner cannot pick up any strong AM stations, so if this does work, it is not very sensitive. I have had a germanium diode many years ago and that worked, but a HV transient popped it.

[@sarveshverma3577]

can we use silicon diode and less no of turns plz cmnt

[@RimstarOrg]

Typically, no, a silicon diode won't work. For that you either need a very long, straight antenna (over 100 feet) or to be next to a powerful radio station. And yes, you can use less turns. You just may have more overlapping stations since you're compressing them into a smaller length of coil for tuning purposes.

[@sarveshverma3577]

Thank you for valuable reply

[@sarveshverma3577]

RimstarOrg could you tell me any other alternatives of capacitor (trimmer capacitor)

[@RimstarOrg]

I show another DIY design in my crystal radio tips and tricks video kzbin.info/www/bejne/fou9nn6Qf9d8jZI. I have some links to where you can buy on in the video description.

[@sarveshverma3577]

Sir I'm working on this project and I have two questions 1. can we have any other option for grounding because it may be dangerous and I want to make it portable. 2. Can we use one earphones piece for sound will it be much sensitive to sound. Sir plz help its my project

[@travisnelson9104]

Really cool. I'm going to try this soon. Have been bored and craving an interesting project. Radio has always interested me.

[@iainmarais6965]

Very nice design. Built one myself along similar lines, but with a 0A41 germanium diode. I get some decent volume by using a tunable loading coil in series with the antenna before it goes into the radio. Output goes either directly into my PC or into an amp scrounged from an old PC speaker main unit

[@GlawberOliveira]

1:15 = money shot 🐲

[@MrHwilRRR]

:'D :'D :'D Oh god. :3

[@rbp365]

SB please tell me, what is this? How do you use this? What is it for? Where is the crystal in it because I missed that. Thank you.

[@RimstarOrg]

There is no crystal. In the original crystal radios from the early 1900s they did use a crystal instead of the modern diode and that's where they got the name crystal radio. But these days a crystal radio is any radio that gets its power from the incoming radio waves.

[@evilpaulosa]

8:57 25 turn coil and 90 turn coil ?

[@RimstarOrg]

I'm actually working on a video explaining how many turns now, but it won't be out for a week or so. The capacitor and coil form an LC resonant circuit. It doesn't have to do with wavelength the way you seem to be thinking about it though. In the meantime, I have some calculators here rimstar.org/science_electronics_projects/lc_circuit_aka_tank_or_resonant_circuit.htm for working out the right coil. I also talk explain it in my How a Crystal Radio Works video kzbin.info/www/bejne/Zl6zgZSoiNKqqqc.

[@mr007onfire7]

You can burn the insulation off with a lighter

[@KRAFTWERK2K6]

Yeah i too did that on the ends of each wire. However i would not recommend doing that instead of sanding off the coating layer for the wiper. You only wanna wear off the upper layer, not the whole coating all around the coil on that spot.

[@gualtergutierrez1166]

u can burn the whole radio with a lighter

[@lhacker39]

this video was very informative. I remember putting a kit similar to this together when I was 12 or so. (I'm 60 now). Mine didn't work as well as yours, but I like the concept of making it from things around the house.

[@lukacszoli5736]

had one when i was a kid, my older brother made it, the antenna run up the 4 level building all the way to the top, and we had some old telephone headset( the kind used by telephone operators back in the day when u had to ask one to redirect your call to ...whoewer you wanted) i loved being a kid...

[@matttrusty6100]

I want to make one but I don't think I have the patience. 😂

[@theduderski2848]

weirdest meth lab ever

[@BillAnt]

Different strokes for different folks at 1:15 ;D

[@OcotilloTom]

Built one just like the one shown in the build when I was 12, about 1958 or 59. I had to purchase the crystal from a radio wholesale supply company for about $5.00 which was a princely sum in those days for a 12 year old. I used the inside of our home phone earpiece. I almost got a butt whipping when my mom answered the phone and couldn't hear the caller. I crawled on the roof to run the copper wire antenna from one end of the roof to the other. The ground was a piece of pipe driven into the ground outside my bed room window. I later collected soft drink bottles and used car batteries to earn enough to by a single earpiece like the one in the video. Return on soda bottles was 2 cents, a car battery was good for a dollar depending on the size of the battery. Bigger batteries, more lead equal more money. I used the crystal radio for a couple of years until transistor radios came out. Again I saved my money and bought a cheap one with the single earpiece and without the internal speaker. They were too expensive but just as magic as the crystal radio.

[@andymate2006]

Very interesting, I use to make heaps of Crystal radios when I was a kid. Haven't made one in ages.

[@LevinoControle]

Great tutorial. I've searched a step-by-step for a long time, trying to find out what's wrong with my set and why it's not working. Then i've found in this video: I've used a common diode without a long antenna for it and i've connected the capacitor in the wrong way. Also, i've used a normal speaker in the wrong way, since i've used the small antenna and it woudn't give enough power to turn it on. Now i'm gonna fix it using a crystal earpiece and a german diode. Thanks for the video!! =D

[@RimstarOrg]

I agree. Crystal radio's are very simple, yet very rewarding and teach some useful basics.

[@amarok5048]

Great! Recapping my father explaining and making me one of these in the early 60s. Germanium diode used but a tuning from an old scrap radio. My aerial was the length of the garden and I could get Radio Luxemborg

[@Boules99]

Where was your radio located?

[@RimstarOrg]

That's actually why I made my first crystal radio, to see how much power I could get. It wasn't enough to pursue it further though. So I guess that's the problem with it. Of course after that I was hooked on the radio part of it anyway. And I'm glad you liked my instructions! Thanks for the feedback!

[@simonruszczak5563]

Build it and then understand it, the best way. Practical learning then theoretical learning.

[@paolocarasso5414]

Thank you.It's one of the best explanation I have seen on this matter.

[@tonymuto7294]

I used to make crystal radios when I was a kid. If you don't have a diode or a quartz crystal, you can use a rusty razor blade and a safety pin. It actually works!

[@RimstarOrg]

Hey Evan, That's excellent news! Congrats. There's nothing like hearing it working the first time. Glad I could help. -Steve

[@RimstarOrg]

Thanks for letting me know. I'm glad to hear it worked. I've wanted to try using a ferrite core for a while now but just haven't had the time to yet. I had to look up what a variometer is. I doubt that I'll make one but thanks for suggesting anyway.

[@KarlWitsman]

Thanks for the idea for a capacitor. I saw someone do a similar thing on another video, but they didn't explain it as well as you did.

[@CheekyMonkey1776]

Best video I’ve seen on building a crystal radio. Well done. Thanks! I’m your newest subscriber.

[@Xerdar36]

I remember doing this back in the 70s it's cool to see it now...

[@NatashaNDavies]

thanks for making this video. it will help a LOT on my science project.

[@ronalddaub7965]

I want to start building all kinds of them because there are all kinds this is amazing free energy and nobody talks about it much anymore this is my new favorite hobby

[@jeffster1070]

Freaking brilliant, man! Gotta try this project. Sad that RS isn't around, built my first crystal radio on one of their kits. Good times.

[@bowlineobama]

Thanks for showing how a radio works. Awesome!!

[@RimstarOrg]

Excellent! Glad to hear you found one. I hope you have a lot of fun with it.

[@CamdenBloke]

I remember as a kid (80s/90s) hearing about kids in the 50s building crystal radios out of quaker oats cylinders. I got a crystal radio kid that had basically radio shack components and a mounting board and building instructions. I assembled it following the steps and it worked but I never had a good enough idea of how it worked to build one completely on my own, especially from a quaker oats cylinder. Later as an adult, I got the Klutz crystal radio kit to show someone how they worked. The Klutz version had a really good explanation of how they worked. I could hear the sound, but the person I was showing it to couldn't.

[@steveperry1344]

when i was a kid back in the 50's and 60's i had these little red pocket type crystal radios that we bought at the store and inside it was kinda like you made there. i had so much fun with that thing, i could listen to baseball games and music at night in bed after lights out with the little earpiece. i used to hook the alligator clip to the radiator pipe. i still listen to a lot of radio today but i'm worried about the future of radio today especially AM with all the other media now.

[@pay9011]

As a kid I remember having little radios that you would alligator clip to something metallic (like a window) and it would receive AM via a standard earphone. We called them crystal radios. I remember them as being quite small and working well. I don't recall building them which makes me think we ordered them already made from some sort of catalog (of which we had many).

[@RimstarOrg]

Thanks. I've already got that one in the description below this video but your confirmation helps since I haven't tried that one myself.

[@paulschmolke188]

Terrific presentation!

[@RimstarOrg]

The obvious is adjusting the capacitor and tuning bar on the coil, but I'm sure you've tried that. A longer antenna improves this. Also, you can improve it by moving the two coils closer together, but if you have radio stations that overlap then doing so will make that worse. Also make sure you have a good ground. And you're welcome for the video. I'm glad to see so many people get finding it useful.

[@leostgeorge2080]

I could tell this was old when you said you purchased supply's at Radio Shack. Thank for sharing the knowledge.

[@xxrednovaxx3097]

I have a science fair coming up and I guess this vid is a life saver thanks!

[@RimstarOrg]

+G Reaper22 It can be tricky using these inside some buildings. I took it to a small Maker faire once and the sound was so low I have to use an amplifier to make it loud enough to hear (any amplifier will do but I used my homemade one kzbin.info/www/bejne/gKWzqKuYhMx1ftk.) You have to stretch the antenna out in a straight line so make sure you'll be able to do that. Also, you'll need a good ground connection. Luckily there was a big empty hall behind my table so I stretched the antenna out into it, and I used the wall socket trick that I show in this video for the ground connection. Good luck and have have fun at the science fair!

[@TrippinBowen]

This is great, I never thought that you could make decent D.I.Y components. I will definitely invest in some enamel wire and aluminum foil (;

[@paulcohen1505]

Excellent video thank you I haven't built one since being a child, great to see Thank You.

[@nathanw851]

I've been toying with electronics on and off for decades, I'm the equivalent of a tech level HAM in my country, and am currently building a Stockton Bridge SWR with a (esp8266) MCU to do the calculations, so this video should have been BOOOORING! But it wasn't! I've never actually built a crystal radio. I'm fascinated by how simply they can be made. That paper tube varicap is inspirational! Too easy to get lost in the complicated stuff and forget the basics of applied science. Thanks for a great video!

[@nathanw851]

... having just said that. I'm not going to be using an ESP8266. I thought it had two ADCs. It doesn't. Oops.

[@thinkingjohn2099]

I made this crystal radio as described it works great especially the home made capacitor ! sound quality and station selectivity is good to, It had been 50 years since I made a Crystal Set as a kid ! Last week I built a kit crystal radio it was rubbish good for spare parts though btw RimstarOrg the step by step video you posted is excellent thanks for posting !

[@RimstarOrg]

You're welcome! It's my pleasure! I'm glad to hear your's works so well.

[@GaryMcKinnonUFO]

Thanks, nice to see all the steps. To clean enamel off the wire you can also use steel wool and just give it a few tight rubs.

[@samuelscott7646]

Gary McKinnon that's what I do to strip the enamel off. I find 0000 steel wool works the best what about you?

[@GaryMcKinnonUFO]

Samuel Scott I give it a quick burn with a lighter first so any grade will work.

[@samuelscott7646]

Gary McKinnon oh that makes sense, thanks for the good tip. I will have to try it some time

[@Willam_J]

That is a very novel way of making a variable capacitor. I've spent 38 years as an EE and I'm having one of those "Why the heck haven't I thought of that?" moments. I've been working on some high voltage projects (Tesla coils, Jacob's ladders, plasma arc speakers, etc.) in my spare time and I need some high voltage variable capacitors to tune the circuits. I'm going to try this with adhesive-backed aluminum tape and ABS pipe. I've been struggling with how to do it and you may have just solved my problem. BTW, it's nice to see that people are still building crystal radio sets. Here in Illinois, we have a town named Galena because of all the lead ore they used to mine. It's kind of touristy now, but you can buy all the galena crystals you ever wanted. Poking around on a galena crystal with a 'cat's whisker' to find a sensitive spot is magic! Many crystal radios, even modern ones, are truly works of art. Great video! Thanks for making it.

[@RimstarOrg]

I'm glad to hear you got some value from the video and enjoyed it so much! Thanks! Regarding the variable capacitor made this way, there is something non-obvious to watch out for if you're using it for high voltage. Using aluminum tape on the ABS pipe is good since it won't move. But if you use a loose foil, as is done here for the other plate then the high voltage will make that plate be attracted to the ABS pipe plate. Since it's just a relatively loose foil, some of it will actually attract and then relax again in time to the frequency, or as close to it as it can. Since one parameter to capacitance is the distance between the plates, that means the capacitance will be varying, even when you think you have it just where you want it. So for the outer plate/cylinder, come up with something rigid.

[@James1Wayman]

Thanks for posting, I built one of these while helping my granddaughter build another one for a school science project. I only have one good AM station in the area and it I could barley hear it and it was a little garbled... I connected a 47k resistor across the crystal radio ear bud connections and it improved the sound from barley hear it to loud and clear! Thanks again and hope someone finds this comment helpful.

[@RimstarOrg]

Yup. My understanding is that the resistor helps when the diode doesn't have enough reverse leakage. I explain it in my How a Crystal Radio Works video kzbin.info/www/bejne/Zl6zgZSoiNKqqqc starting at around two minutes and four seconds in.

[@James1Wayman]

Thanks, great video!

[@dietermoreno]

Oh wow this is really good. best tutorial on KZbin for crystal radios for absolute beginners.