I've built a few razorradios and a lot of crytal radios.
15 stations is amazing even with a diode, especially on such a simple circuit! I wouldn't expect more than 3 or 4 stations with a slider coil and a razor.
Even if you're in a staion-rich area, that is really a high staion count.
Kudos to your son! If the judges were crystal set builders he would've gotten first place.
You're a good parent!! You are a role model! The world needs more parents like you. Your children should thank you one day for teaching them to think.
BLUE BLADES ARE EASY TO MAKE. get a single razor blade, the type that has a rigid piece of steel down one edge. heat it up with a blow torch and turn it all blue. Job done.. the "cats whisker" is about one and half inch of the write end of a pencil. make a contact by sticking a safety pin in the flat end of the pencil so the "lead" touches both the blade and the safety pin. Voila a cats whisker.
Doesn't use batteries, or electricity unless you want to amplify the sound by running the output into a stereo or computer input. The radio was designed to run on magnetic headphones... your 8-ohm stereo headphones won't work. Or, use a crystal earphone, or use a piezo-electric speaker with a 10k-ohm resistor wired across the contacts.
You can also use an old tarnished penny in place of the razor blade. Make sure it is one of the old 100% copper pennies, not the steel, copper-flashed ones made since 1994(?) (I forget the year)
If you're going to tune the radio by tapping into different turns of the coil (as here), it doesn't matter how many turns you make, AS LONG as you have the minimum number of coils for the lowest end of the AM band (650 khz on the dial). The lower stations are found with the most turns, while the higher stations (1700 khz and up) use the fewest turns on the coil.
I used to build these when I was a kid,I scrounged the tuner thing from and old valve radio,that was how I could tune mine,,and used a germanium diode in place of the razor blade...then if i hooked it up to an amp,I had a perfect AM radio that picked up all the local stations,my coils were 3inches in diameter and only used 80 turns of wire and worked perfectly.
@davidrodgersNJ Actually, the pencil and razor is a type of crude diode called the cat whisker, the diode or cat whisker in this case is the detector, the antenna coil tuner is one method, I used a tuning capacitor from an old transistor tube radio. the cats whisker diode, is not actually the tuner, by moving the pencil around you are fine tuning the diode for max detection, sort of like finding the sweet spot on the razor, if you want a tuneable fox hole, you need to-
@davidrodgersNJ If you want to tune a fox hole radio, you need to add either a tuning capacitor, or do what this guy did and make the coil tuner. for a more technical explanation, google Crystal set radios, and Cats whisker radios, and don't forget to click the images tab, you'll find lots of schematics for all kinds of designs,
where does the ground connect to? What does the yellow wire connect to? How does ground work? what would act as a good ground for that yellow wire that goes out? what do you have it plugged into? thanks...
@YoungMillionaire the term "ground" in electronics is pretty literal. The term originating from running it into the ground literally. If you can find a dedicated ground (such as the third pin on US wall outlets) that's the ideal way, but any grounded piece of metal will work as well in general.
Been looking at comments and have yet to see a correct answer to how the razor blade diode works. It is called rectifying. The signal comes in the form of a sinusoidal wave, the upper half is positive and the lower half is negative with a zero in the middle. The diode chops the wave in half (because it acts like a "valve" only half of the wave can come through it (which half depends on diode direction) on which it can carry data and modulate a high imp. crystal headset or earphone. (2000+ ohms)
@855h0le You are correct abou t the bridge and halfwave trectifiers but rectifier, but here you aren't 'rectifying ac like for a power supply, just detecting thee amplitude modulated"envelope" as the carrier rises and falls. one "side of the modulation signal positive or negative "modulation is all you need. so one diode works.
Cool. You were lucky to have access to an old blue blade. Any idea what you can do with blades that are available today. I've seen where others say to use a rusty blade. Most I"ve seen are stainless and won't rust with the coating that's put on them. You think sanding off the coating might work?
clamp the blade in a pair of vice grips and put it over a gas stove or torch. Get the blade GLOWING hot and let it cool....this is called "blueing the blade" and will accomplish what you need. Also, you will notice that you will tune in when putting the catwhisker on either the blade edge, or where the blade is marred. Good luck and let me know how it goes.
Every one of these things I have made have worked. Some have required some tweeking, however they all work. The act of god is what frequency you receive. That is why the tunable is so great.
The coil i did not measure, i just used enough for my turns.
The antenna was insulated telephone wire (i tore opart an old 50 foot phone cord). The ground was insulated 18g coper power wire. I do not think thickness of wire makes as much difference as the type of wire. I used copper, as it has the best conductivity for the price....FREE!!!
The razor was an authentic WWII blued blade out of my grandpa's army locker. Pretty cool.
These radios have NO amplification. They simply tune. Some older headsets work fine. If you want them on speakers, you will have to connect an amplified set to the radio.
BTW, the new Chinese-made crystal earphones that I've tried out have been VERY poor performers. Try to get authentic old Japanese crystal earphones on eBay.
Excellent foxhole radio, I'm surprised at its selectivity, it separates stations well. Also I didn't realize a razor blade diode could perform well in a tuned receiver. BTW, what the diode does is to remove the radio frequency portion of the signal, and allow the audio frequency portion to pass into the earphone or speaker amp.
AM radio transmitters use antennas that throw thousand of watts of electricity, thus creating the "radio wave" Radio waves are electricity all around us. Only at a much higher frequency than you use on your kitchen blender and at much...much...much lower amperages.
The radio waves produce small electric currents in an antenna, which the radio selects for a particular frequency, amplifies and uses to produce sound.
yeah i already bought my magnet wire and i'm just scared i might not get signal and where the wires connect. LOL i'm so bad at physics =( thank you so much!
start to finish.....less than an hour. It goes a lot faster if you have an extra set of hands to help you wind the coil. The first radio built took over 3 hours, but there was a lot of trial and error.
Just make sure you use magnet wire. I have had several people say they could not get it working...and it was due to not using coated wire. Magnet wire has just a tad bit of a coating for insulation.
nice one. lol now any other wise as better think befor they speak. thnx for sharing utahike. keep up the good work kid. and nice ww2 foxhole radio. they are fun. )
Go to RadioShack and buy a pack of magnet wire. It is simply wire coated with resin, which stops the wires from shorting when touching. Be sure to sand off the the colored resin where the tuning post will touch, or you will not get any connection. Let me know how it goes.
ive built one of of those accept used a ferrite centered coil,germanium diode,variable capacitor and built a high gain audio amp. I pulled out the entire AM band :D
give some more details...ie...what kind of wire did you use for your coil, what are you grounding to, what kind of razor blade are you using, what kind of speaker are you using?
I can help...it WILL work of done correctly...every time!!!
Im using magnetic wire! Does the ground have to go outside? (DOn't laugh but Im using speaker wire for a ground and Attenna.. I burnt the razor blade..its blue! Im using regular headphones for Speakers.. Come on 10yr old dude..whats wrong? (smile)
It sounds like you have a bad ground. Run it to a copper pipe under your sink (unless your house has plastic pipes.) Wedge the ground into the pipe really good. Also, try moving the cat whisker until you hear something. Once the cat whisker finds a station, it really doesn't need to be moved again. Everything from there is done with the tuning rod.
Your antenna really needs to hang out your window. If it does not, you probably will not get good reception.
Also, I have found that the cat whisker works best around highly oxidized areas...just around the edges of the oxidation...also along the edge of the blade. Post a video and maybe I can help more. Good luck.
Back in about the 1930's, an old friend of mine's brother made something just about like that. Down at the 'ol fishin hole, he winded up some wire on a hog-wire fence, & connected a speaker to it. They could listen to the farm report & music on the ONE station in that part of Idaho. Bill Hall was his name. I don't know his brother's name; but the brother later invented the phased-lock-loop circuit in his garage. Bell Labs stole it from him. It is the crystal timing part of the PC.
Yes....easily. You will get some interference during daytime, and less at night. Something to do with the sun. Also, electric equipment around you can effect the reception. This test was done during the day. The music station tuned into was over 50 miles away.
You should build one. I will admit that I didn't think that it would work. But when my sone fired it up, and it tuned in to a news channel...Well...I was baffled and shocked. I never would have figured it was so easy to make a radio.
We used an authentic WWII blued razor blade. If you do not have one...you simply need to oxydize the blade. Put it in some salty water for a couple of days....or easier, heat it with a torch or a gas stove until it glows and let it cool. Magnet wire is really easy to get...just go to radio shack and ask for it. Or..simply wind some solid core bare wire around the tube and spray it with varnish. This creates a thin barrier to stop it from shorting out.
No, no! Don't use bare wire for your coil. It will be completely shorted out and useless. Varnishing a coil of bare wire will not provide insulation to the entire surface of the wire.
I have tried using both magnet wire, as well as varnished bare wire. Both work perfectly....sooo....hate to call you to the table, but I will have to in this case.
Ask any radio expert. The only case in which bare wire would make a usable tuning coil would be one in which the turns do not touch each other. This is an important point. Now if you varnish the entire surface of the wire before winding the coil, yes that's fine.
you can't just spray it...you have to roll the wires....so yes, you are correct...to a point. we varnished one of our other radios after winding and rolled the wires slightly after spraying. This seemed to work just fine. Perhaps it was luck of the draw.
If the coil makes contact...then the coil ends at the contact point. good point....thanks
No power supply needed for radio itself. If you have earplugs you can hear without power. We did use amplified speakers for this demonstration. Thanks.
You have made a great radio!! I use to listen to one like that when I was younger, I could hear long distant stations at night from Canada, I live in Georgia, USA. but I used a diode 1N34A, instead of pencil lead and razor.
I've built a few razorradios and a lot of crytal radios.
15 stations is amazing even with a diode, especially on such a simple circuit! I wouldn't expect more than 3 or 4 stations with a slider coil and a razor.
Even if you're in a staion-rich area, that is really a high staion count.
Kudos to your son! If the judges were crystal set builders he would've gotten first place.
co2isgoodal 4 days ago
You're a good parent!! You are a role model! The world needs more parents like you. Your children should thank you one day for teaching them to think.
crackahcrackah 1 week ago
BLUE BLADES ARE EASY TO MAKE. get a single razor blade, the type that has a rigid piece of steel down one edge. heat it up with a blow torch and turn it all blue. Job done.. the "cats whisker" is about one and half inch of the write end of a pencil. make a contact by sticking a safety pin in the flat end of the pencil so the "lead" touches both the blade and the safety pin. Voila a cats whisker.
alexpmgr1970 1 month ago
I got a question. I built the coil but with the selector is the coils urathane sanded off so it makes contact so it can select the station
layedbackkustomz 5 months ago in playlist More videos from utahike
Made one but I cant find the God damn Cubs game!!!!!!
ManTheHarpoons9 6 months ago
Doesn't use batteries, or electricity unless you want to amplify the sound by running the output into a stereo or computer input. The radio was designed to run on magnetic headphones... your 8-ohm stereo headphones won't work. Or, use a crystal earphone, or use a piezo-electric speaker with a 10k-ohm resistor wired across the contacts.
mnpd007 7 months ago
You can also use an old tarnished penny in place of the razor blade. Make sure it is one of the old 100% copper pennies, not the steel, copper-flashed ones made since 1994(?) (I forget the year)
mnpd007 7 months ago
If you're going to tune the radio by tapping into different turns of the coil (as here), it doesn't matter how many turns you make, AS LONG as you have the minimum number of coils for the lowest end of the AM band (650 khz on the dial). The lower stations are found with the most turns, while the higher stations (1700 khz and up) use the fewest turns on the coil.
mnpd007 7 months ago
what will happen when broadcasts are digital?
AbuAvital 9 months ago
that's a great radio.. but it is difficult to explain how it works because there is so many things going on there
gilbertov4091 10 months ago
Would it work if you use a regular radio antenna instead of a wire?
jorgeswan 10 months ago
nice work. i'm gonna try and make one
carr869 10 months ago
this is the best radio i have seen on youtube, you explain it sooooo well!
thebteam300 1 year ago
how do you attach it to the speakers
fanoffail 1 year ago
@fanoffail Use an amp.
Dark0Lord7 1 year ago
wonder if pushing an iron bar into the toilet paper roll could find a station too. b/c the iron bar should change the resonance freq of the circuit
mdinka 1 year ago
An easier method is to add a variable capacitor to tune stations
renekenshin6573 1 year ago
I used to build these when I was a kid,I scrounged the tuner thing from and old valve radio,that was how I could tune mine,,and used a germanium diode in place of the razor blade...then if i hooked it up to an amp,I had a perfect AM radio that picked up all the local stations,my coils were 3inches in diameter and only used 80 turns of wire and worked perfectly.
catey62 1 year ago
what kind of razor blade did you use? platinum or stainless?
bngnaranjo 1 year ago
Can you explain the difference between the tuner that connects directly to the coil and the tuner that is the pencil connected to the razor blade?
BTW great job! thanks for posting.
davidrodgersNJ 1 year ago
@davidrodgersNJ Actually, the pencil and razor is a type of crude diode called the cat whisker, the diode or cat whisker in this case is the detector, the antenna coil tuner is one method, I used a tuning capacitor from an old transistor tube radio. the cats whisker diode, is not actually the tuner, by moving the pencil around you are fine tuning the diode for max detection, sort of like finding the sweet spot on the razor, if you want a tuneable fox hole, you need to-
RascalCoyote 1 year ago
@davidrodgersNJ If you want to tune a fox hole radio, you need to add either a tuning capacitor, or do what this guy did and make the coil tuner. for a more technical explanation, google Crystal set radios, and Cats whisker radios, and don't forget to click the images tab, you'll find lots of schematics for all kinds of designs,
RascalCoyote 1 year ago
I made a tunable foxhole radio with 120 turns and it works just fine.
TheLegoboy1997 1 year ago
where does the ground connect to? What does the yellow wire connect to? How does ground work? what would act as a good ground for that yellow wire that goes out? what do you have it plugged into? thanks...
YoungMillionaire 1 year ago
@YoungMillionaire the term "ground" in electronics is pretty literal. The term originating from running it into the ground literally. If you can find a dedicated ground (such as the third pin on US wall outlets) that's the ideal way, but any grounded piece of metal will work as well in general.
Rendaylor 1 year ago
shit
hitachi654 2 years ago
Awesome job son! I love foxhole radios.
roopr 2 years ago
ok now lets see you use a piece of galena rock and a safety pin
how bout a home made tuning cap?
mikewm9v 2 years ago
I wish I was as smart and curious as him when I was his age.
Great job.
ursushoribilisron 2 years ago
Will this work with a homade speaker?
theMISTERclean 2 years ago
@theMISTERclean Probably not. You will probably need a high impedence crystal earphone, aka a Piezoelectric headset.
TheLegoboy1997 1 year ago
can i use aluminium wire or any other wire instead of copper wire?
hyderpoker 2 years ago
Been looking at comments and have yet to see a correct answer to how the razor blade diode works. It is called rectifying. The signal comes in the form of a sinusoidal wave, the upper half is positive and the lower half is negative with a zero in the middle. The diode chops the wave in half (because it acts like a "valve" only half of the wave can come through it (which half depends on diode direction) on which it can carry data and modulate a high imp. crystal headset or earphone. (2000+ ohms)
Blissterd1 2 years ago
@Blissterd1 ARe you sure? Cause it takes 4 diodes to make a Full Wave Rectifier..
2 for a half wave when it comes to a/c to DC. I am curious now- Im having a Mental block and the answer should be ez..
855h0le 1 year ago
@855h0le You are correct abou t the bridge and halfwave trectifiers but rectifier, but here you aren't 'rectifying ac like for a power supply, just detecting thee amplitude modulated"envelope" as the carrier rises and falls. one "side of the modulation signal positive or negative "modulation is all you need. so one diode works.
46ace 1 year ago
**disclaimer** microwave oven have high voltage transformers and caps and can kill you!!
I found just about everything I needed to make one of these. mag. wire in the fan motor wires etc
rivethead469 2 years ago
how do i hook up headphones to the circuit?
wolfeman323232 2 years ago
I will build one. I just have some questions.
Where do you get antenna?
The "ground" paperclip must rely to a a radiator?
You need to just put wire from the paperclip to the radiator?
Thanks.
HalfLife2Beta 2 years ago
Your first question: just take a simple piece of wire...youll find it in an old computer or you may use yyour washing line.
2. : It neednt rely to a radiator, just choose a thing that is connected to the ground and has a good conductivity (so a radiator works best)
3.: Yes. Nothing more. Just connect the two things.
TNitroxT 2 years ago
Thanks very much.
HalfLife2Beta 2 years ago
no problem :)
TNitroxT 2 years ago
What happens if it is wound 122 or say 115 times?
AMBowers29 2 years ago
this has been answered before...please read past comments.
utahike 2 years ago
@AMBowers29 nothing...u will just get less stations
IvanSRBfilip 1 week ago
Cool. You were lucky to have access to an old blue blade. Any idea what you can do with blades that are available today. I've seen where others say to use a rusty blade. Most I"ve seen are stainless and won't rust with the coating that's put on them. You think sanding off the coating might work?
procrustes 2 years ago
clamp the blade in a pair of vice grips and put it over a gas stove or torch. Get the blade GLOWING hot and let it cool....this is called "blueing the blade" and will accomplish what you need. Also, you will notice that you will tune in when putting the catwhisker on either the blade edge, or where the blade is marred. Good luck and let me know how it goes.
utahike 2 years ago
@utahike How long do you let it GLOW for? We did this but were unsure how long to leave the flame on the blade while it glowed red. Thanks!
cuzuco09 1 year ago
@cuzuco09 until the metal is a bluish color.
RascalCoyote 1 year ago
bob dylan
smellpickle 2 years ago
It's so BIZZARE, it's like an act of god when one of those work, you know what I mean?
LawietStandard 2 years ago
Every one of these things I have made have worked. Some have required some tweeking, however they all work. The act of god is what frequency you receive. That is why the tunable is so great.
utahike 2 years ago
@utahike you need battery for speakers ? or what ? please answer with yes or no -.- tnx
robi4never 8 months ago
@LawietStandard I would prefer to call it, an act of physics.
RascalCoyote 1 year ago
what lenghth of wire do u use and what type?
also did you get the blued razor or make it yourself
mark3229 2 years ago
which wire are you asking about???
The coil i did not measure, i just used enough for my turns.
The antenna was insulated telephone wire (i tore opart an old 50 foot phone cord). The ground was insulated 18g coper power wire. I do not think thickness of wire makes as much difference as the type of wire. I used copper, as it has the best conductivity for the price....FREE!!!
The razor was an authentic WWII blued blade out of my grandpa's army locker. Pretty cool.
utahike 2 years ago
did you u just use bare copper wire foe the coil?
mark3229 2 years ago
no, you need to use coated wire. On this radio we used magnet wire purchased at Radio Shack. The wire is fairly cheap and molds easily.
Magnet wire has a thin varnish coating on it. If you use bare wire, the coil will end at the point of first contact.
utahike 2 years ago
how do you hook it upto speekers??
it wont work for me if i just hook them up
do they need to be powered??
mark3229 2 years ago
These radios have NO amplification. They simply tune. Some older headsets work fine. If you want them on speakers, you will have to connect an amplified set to the radio.
Let me know how it goes.
utahike 2 years ago
BTW, the new Chinese-made crystal earphones that I've tried out have been VERY poor performers. Try to get authentic old Japanese crystal earphones on eBay.
sparkdetect 2 years ago
Excellent foxhole radio, I'm surprised at its selectivity, it separates stations well. Also I didn't realize a razor blade diode could perform well in a tuned receiver. BTW, what the diode does is to remove the radio frequency portion of the signal, and allow the audio frequency portion to pass into the earphone or speaker amp.
sparkdetect 2 years ago
Thus....pulling the electricity of that frequency out of the coil....exactly as I said.
utahike 2 years ago
I had thought you'd said, the diode helps tune in the station...that would not be accurate.
sparkdetect 2 years ago
no...the tuning takes place on the coil.
utahike 2 years ago
correct, and correct.
Good luck, and let me know how it goes.
utahike 2 years ago
yup, 64 turns is about half of what you need. The turns determine the frequency. You need more wire.
utahike 2 years ago
is there a way to get the volume higher if you just use a headphone?
machuu32 3 years ago
Yes...and no. You can try using a longer antenna thus increasing the current to the speakers, and/or try a better ground.
We used amplified speakers for demonstration purposes.
utahike 3 years ago
Awesome! The tuning part is excellent: that's how it works inside the radio.
wilwad 3 years ago
WOW your so smart! that helps so much thank you! is it okay if i ask you any other questions later if i get stuck?
machuu32 3 years ago
no problem....and let me know how your radio works out.
utahike 3 years ago
woah woah woah....wwhere does this elecrical energy come from? this is so cool!!! i want to learn more please :)
machuu32 3 years ago
AM radio transmitters use antennas that throw thousand of watts of electricity, thus creating the "radio wave" Radio waves are electricity all around us. Only at a much higher frequency than you use on your kitchen blender and at much...much...much lower amperages.
The radio waves produce small electric currents in an antenna, which the radio selects for a particular frequency, amplifies and uses to produce sound.
Does that help?
utahike 3 years ago
ooooo thiss looks really interesting and fantastic!!! but one question sir, this project involve physics does it not?
machuu32 3 years ago
Yes, as it utilizes the electrical energy, and the motion of that energy in a radio wave to power the speaker.
utahike 3 years ago
yeah i already bought my magnet wire and i'm just scared i might not get signal and where the wires connect. LOL i'm so bad at physics =( thank you so much!
linaxnguyen 3 years ago
You won't know until you try. I will help you if you get stuck.
On the coil, be sure to use some fine grit sand paper to take the coating off where the tuning rod hits.
Ground adn the blued blade are the most imparitive parts of this task.
For your catwhisker (that's right...i said catwhisker) use a No. 2 pencil about an inch long.
It is really hard to get wrong...and remember...the longer your antenna the better. I just layed mine out on the front lawn.
Good luck.
utahike 3 years ago
hey! how long did it take you to finish it? it seems so.. easy yet complicating :(
linaxnguyen 3 years ago
start to finish.....less than an hour. It goes a lot faster if you have an extra set of hands to help you wind the coil. The first radio built took over 3 hours, but there was a lot of trial and error.
Just make sure you use magnet wire. I have had several people say they could not get it working...and it was due to not using coated wire. Magnet wire has just a tad bit of a coating for insulation.
Good luck, and let me know how yours goes.
utahike 3 years ago
Its pronounced cat's whisker. Try to build a one tube set.
diyprojects 3 years ago
Haha...I love it when a smart ass know it all screws up...."its" is pronounced "it's". Now shut up and sit down.
utahike 3 years ago
nice one. lol now any other wise as better think befor they speak. thnx for sharing utahike. keep up the good work kid. and nice ww2 foxhole radio. they are fun. )
WaffenSStiger131 3 years ago
Thanks....I am generally not like that...but do not put up with people like him.
Yes, these are fun. in the process of doing some othere tests on simular radios...will post when done.
utahike 3 years ago
Funny thing is.....I said it right....you, smart ass, are the one who is greatly mistaken.
catwhisker definition
cat·whisker (-hwis′kər)
noun
Electronics a sharply pointed, flexible wire used to make contact with a specific point on a semiconductor or a crystal detector
AGAIN....SHUT UP AND SIT DOWN. Stop opening your mouth and critisizing when you know nothing of what you speak.
utahike 3 years ago
F A N T A S T I C !
BrunoJoensen 3 years ago
Very cool radio! What is the tuning rod that is resting on the coil attached to? I built a foxhole radio too, but I have no tuning rod.
Daliwolf 3 years ago
It connects to ground, speaker and catwhisker.
Any other questions, let me know. And be sure to share how your radio goes.
utahike 3 years ago
Excacally what kind of wire did you yse mate?
Thanks! Great job btw
decade03 3 years ago
Go to RadioShack and buy a pack of magnet wire. It is simply wire coated with resin, which stops the wires from shorting when touching. Be sure to sand off the the colored resin where the tuning post will touch, or you will not get any connection. Let me know how it goes.
utahike 3 years ago
WOW! WOOOOOHOOOOO. THAT IS GREAT! I had heard it was simple! Thank you! Keep up the great work. You're my hero.
TonyTuthill 3 years ago
Do a google search for "retro-ww2-foxhole-radio" and you should find one on the gizmodo site that is like this one.
utahike 3 years ago
send it?
infiernus666 3 years ago
ok. i said. i want to make one, but i need a paper with intruccions, do you have one? can you send me?
infiernus666 3 years ago
quiero hacer uno mandame los planos en español, usa algun tipo de energía?
infiernus666 3 years ago
Sorry, I do not speak spanish.
utahike 3 years ago
ive built one of of those accept used a ferrite centered coil,germanium diode,variable capacitor and built a high gain audio amp. I pulled out the entire AM band :D
wow1022 3 years ago
my radio isn't working...
Bigtruck2007 3 years ago
give some more details...ie...what kind of wire did you use for your coil, what are you grounding to, what kind of razor blade are you using, what kind of speaker are you using?
I can help...it WILL work of done correctly...every time!!!
utahike 3 years ago
Im using magnetic wire! Does the ground have to go outside? (DOn't laugh but Im using speaker wire for a ground and Attenna.. I burnt the razor blade..its blue! Im using regular headphones for Speakers.. Come on 10yr old dude..whats wrong? (smile)
Bigtruck2007 3 years ago
It sounds like you have a bad ground. Run it to a copper pipe under your sink (unless your house has plastic pipes.) Wedge the ground into the pipe really good. Also, try moving the cat whisker until you hear something. Once the cat whisker finds a station, it really doesn't need to be moved again. Everything from there is done with the tuning rod.
Your antenna really needs to hang out your window. If it does not, you probably will not get good reception.
Let me know how it goes.
utahike 3 years ago
Also, I have found that the cat whisker works best around highly oxidized areas...just around the edges of the oxidation...also along the edge of the blade. Post a video and maybe I can help more. Good luck.
utahike 3 years ago
I forgot to tell you to sand off the coating on the coil where your tuning post hits. Otherwise you get nothing.
Let me know how it goes.
utahike 3 years ago
if u think thats hard... im 15 and built a 3 watt audio amplifier from transistors
wow1022 3 years ago
very cool. Good job. Post a vid.
utahike 3 years ago
Back in about the 1930's, an old friend of mine's brother made something just about like that. Down at the 'ol fishin hole, he winded up some wire on a hog-wire fence, & connected a speaker to it. They could listen to the farm report & music on the ONE station in that part of Idaho. Bill Hall was his name. I don't know his brother's name; but the brother later invented the phased-lock-loop circuit in his garage. Bell Labs stole it from him. It is the crystal timing part of the PC.
NotOfThisGalaxy 3 years ago
does it work in the day time? Can it catch a station 25 miles far from my house?
dinhnguyen0508 3 years ago
Yes....easily. You will get some interference during daytime, and less at night. Something to do with the sun. Also, electric equipment around you can effect the reception. This test was done during the day. The music station tuned into was over 50 miles away.
Let us know how it works out.
utahike 3 years ago
This is really neat. Good job! This would be a nice project to do. That song at the end is my favorite! Stuck in the middle with you.
drumbum0852 3 years ago
You should build one. I will admit that I didn't think that it would work. But when my sone fired it up, and it tuned in to a news channel...Well...I was baffled and shocked. I never would have figured it was so easy to make a radio.
utahike 3 years ago
I will make one. i just need some magnet wire. but did you need to "blue" your razor blade?
drumbum0852 3 years ago
We used an authentic WWII blued razor blade. If you do not have one...you simply need to oxydize the blade. Put it in some salty water for a couple of days....or easier, heat it with a torch or a gas stove until it glows and let it cool. Magnet wire is really easy to get...just go to radio shack and ask for it. Or..simply wind some solid core bare wire around the tube and spray it with varnish. This creates a thin barrier to stop it from shorting out.
Let me know how it goes.
utahike 3 years ago
Sure will! but it won't be for awhile i am pretty busy at the moment.
drumbum0852 3 years ago
No, no! Don't use bare wire for your coil. It will be completely shorted out and useless. Varnishing a coil of bare wire will not provide insulation to the entire surface of the wire.
sparkdetect 2 years ago
I have tried using both magnet wire, as well as varnished bare wire. Both work perfectly....sooo....hate to call you to the table, but I will have to in this case.
utahike 2 years ago
Ask any radio expert. The only case in which bare wire would make a usable tuning coil would be one in which the turns do not touch each other. This is an important point. Now if you varnish the entire surface of the wire before winding the coil, yes that's fine.
sparkdetect 2 years ago
you can't just spray it...you have to roll the wires....so yes, you are correct...to a point. we varnished one of our other radios after winding and rolled the wires slightly after spraying. This seemed to work just fine. Perhaps it was luck of the draw.
If the coil makes contact...then the coil ends at the contact point. good point....thanks
utahike 2 years ago
OMG what is this?????is that a bomb???
zoltan656 3 years ago
Haha...kinda looks like one. But...NO!
utahike 3 years ago
it is an detonator for bomb and you are an terrorist!!!!!
I Will call FBI!!!
zoltan656 3 years ago
And they will call you a moron and hang up on you. It is a radio...no more, no less.
utahike 3 years ago
that was cool can you make a diagram
i realy want to make one
rcswistak1 3 years ago
Do a google search for retro-ww2-foxhole-radio and you should find one on the gizmodo site that is very close to this one.
utahike 3 years ago
cool..
glaison777 3 years ago
do you have a diagram?
MockStoneLLC 3 years ago
Awesome!
Ubstudios 3 years ago
Very good! Nice going! don't quit! de kd4csz
JohnyAngel47 3 years ago
way to go kid. Anonymous congrats you!
anonymousburn 3 years ago
That is cool. I have always wanted to make on.
ticalcmaster 3 years ago
by the way,do you need a power seorce? im only asking because i dont see one
travisoffbjh 3 years ago
No power supply needed for radio itself. If you have earplugs you can hear without power. We did use amplified speakers for this demonstration. Thanks.
utahike 3 years ago
good job.
travisoffbjh 3 years ago
You have made a great radio!! I use to listen to one like that when I was younger, I could hear long distant stations at night from Canada, I live in Georgia, USA. but I used a diode 1N34A, instead of pencil lead and razor.
Tonyssongs 4 years ago
good job !!!
fabzzzxxx 4 years ago
Thanks!!! :-)
utahike 4 years ago