How to Make a Foxhole Radio

[bongcouver]

blued razorblade = tempered razorblade

[exter54321]

2:26 Is your t-shirt made inside out?

[XDhotpotatoXD]

where can i get a razor blade that is already "blue" cause i don't have a blow torch

i appreciate if you could help

[Kntryhart]

I like the siren just when you light the torch! LOL

[Dyluck387]

You have a magnificent chin...

Also great video, can't wait to test it out!

[uniqueandprosperous]

JUST LEARNIG ,,COULD U TELL ME WHAT THE PAPER CLIPS R 4? WHY DIDN'T U JUST HOOK UP STRAIGHT TO WIRE AND THEN TO CAT WHISKERS? THANKS

[scoobydoorocks10]

@uniqueandprosperous you could do that, but h used those just in case he wants to mod this later on

[GreatRino2000]

what do you mean by cat whisker? are you talking about the pencil or something?

[jeremiah0150]

would changing the number of winds affect the radio.........? i made 121 winds and i can clearly hear Chuck norris



[Eighteen87]

Could you just use uninsulated copper wire instead? And is the razor a must or is any peace of thin metal bit okay?

[Pygar2]

@Eighteen87 Sorry, the wire *must* be insulated- a coil of uninsulated wire is no coil at all, electrically. You can try other things, like minerals etc. but good old corroded razor blades were handy to the soldiers. The *best* homemade detectors used silver-bearing galena, a lead ore. Ordinary galena also worked. And people have tried corroded lead or copper, or "fool's gold". See if midnightscienceDOTcom is still out there- the best source of crystal radio info on the net.

[zerozedzed]

Cool project. Easy to make tunable. Just move the paper clip on the right to the center of the coil and stretch out the paper clip so that it rests on the coil with spring like tension. Make the coil almost twice as long. Use the edge of a metal file and remove about an 1/8" strip of enamel coating from the magnet wire. Tune by moving the paper clip across the coil to tap the coil in different places. :)

[mononqu]

great presentation

[v4mpirehunterd]

Toilet paper tesla coil

[Katalyzt]

Cool ★★★★★

[bccully]

Man I really miss when you youse to do weekend projects

[willferguson321]

really cool

[Shakespeare1612]

DAVE DAVE!  A tank is coming! Shhhhh! I can almost hear Duncka-shain.

[WorldMediaz]

is it me or has he got his top on inside out ?

[winnipegdiver]

Now that is cool

[Destroyingtoysrus]

Thats soo cool!

[WorldMediaz]

amazing



[sexking1994]

@hmed jamal

[fifthStitch]

Okay, really dumb question, but what is the ground wire for? Where should I attach it to? Will it matter if I omitted it altogether?

[timberwolves100]

@fifthStitch The ground wire is for preventing you from getting shocked from static electricity. You COULD run it without one but it you could get electrocuted or at the very least zapped when the electric components built up enough electricity.

You could just attach the ground wire to anything metal that will absorb the electricity.

[w1wcn]

Nicely done! By the way, the talk radio is Mike Francesa of WFAN in NYC. One of the smartest sports reporters ever. He's syndicated, so not sure what station it was.

[JNathanK2011]

wtf?

[MrSachingc]

for the first time in my life i have became a fan of smone! and its you!

[MrSachingc]

DUDE YOU ROCKKZZZZZZZZZZZZ

[ONLYUSEmeBITCH]

wow

[Ayrshore]

SOLDERING.... dumbass.

[onetongwa]

Loving this........

[inkey2]

so you don't need like a germanium diode like in a crystal radio???? This is amazing.....no, it's more than amazing....it's MYSTICAL

[mnpd007]

@inkey2

Original crystal radios didn't use a diode, because diodes hadn't been invented yet. Hence the name "crystal" radio. The name stuck even when the galena ore crystals become obsolete and germanium diodes took the place. A razor blade/old penny, etc simply substitutes as a detector for the old galena crystal, or the more modern diode. Nothing works as well as a diode, which is a connect-and-forget" device. The diode is loud, and doesn't require constant fiddling as older detectors.

[johnfarmingdale]

Fun, Great Project. Thanks

[amassi2010]

I didn't got it yet

[youngdrjung]

Maybe my question's been asked and answered, but what would result from 240 winds or 360 winds of wire, instead of 120 winds? Aside from a little added tedium, I mean.;)

[1ukjunglednbraver]

@youngdrjung i think it works to amplify the signal might be wrong a longer antennae will do that for sure

[mnpd007]

@youngdrjung ..... the more winds, the lower the frequency coverage of the radio. The fewer winds, the higher the frequency coverage of the radio. If the winding count is not correct, you will find that your radio either won't cover the low-end of the broadcast band, or the high end. Also, adding the antenna will change the resonant frequency of the coil to a great degree... if your radio won't tune the entire band; try a longer or shorter antenna wire.

[fjugui]

@mnpd007 Does it matter the size of the wire???

[mnpd007]

@fjugui

Only because the diameter of the wire will change the spacing of the turns... thicker wire will produce less inductance simply because there's less of it in a given length of coil. Google "Professor Coyle".... a free program which allows you to calculate coil values based on wire size, spacing, length, etc.

[mnpd007]

@youngdrjung

More turns will lower the frequency coverage of your radio. Too many turns will take it completely outside of the AM band. One of the best tricks is to wind a coil you know is WAY too many turns, but "tap" into the turns every 5th turn. Connect your antenna at different tap points until you find the one which gives the frequency coverage you wish. It's tough to get a crystal radio to cover the entire 550-1720khz AM broadcast band. You may only be able to tune part of it.

[Geroin09]

чё то Я не въехал, где бля там батарейка то???

[WerewolfSlayer91]

Why is the pencil with Graphite used?

[mnpd007]

@WerewolfSlayer91

Combined with the copper penny or razor blade, it "rectifies" the radio wave... removes the steady carrier and leaves the audio. Try your detector without the pencil lead and you will still hear something, even if just scratchiness. Experiment! The better the detector, the louder the radio.

[WerewolfSlayer91]

@mnpd007 Thanks, for enlightning. I though maybe the pencil it was used as a resistor to maybe counter act reflected waves so the wouldn't cancel out the signal. Because at end of cables signals can reflect causeing a "mirrored" signal which cancel the waves out.

[bosespeakersystem13]

Any ideas on how to blue a screw with a kitchen gas stove? Would it work?

[mnpd007]

@bosespeakersystem13

Try it! Use a propane torch and get it as hot as you can. Maybe you can even place the screw on a hot stove burner.

[bosespeakersystem13]

@mnpd007 I don't have a propane torch. I'm only twelve. But Ill try.

[petiekas]

@bosespeakersystem13 ask your mom to help you use the stove to heat that piece

[MrJonagikster]

Does the treated razor act as a capacitor?

[JATO457]

@MrJonagikster for the most part, yes.

[MrJonagikster]

@JATO457 Are you able to explain the mechanism? Thanks

[mnpd007]

@MrJonagikster ..... not at all, it acts solely as a "detector", which means it rectifies the incoming radio wave by removing the carrier and passing the audio.

[sciencechemistrygirl]

Instead of using a razor blade use a penny. Just scratch the surface of the penny a few times with a knife and then heat it over a flame for about three minutes. Until it gets a black spot. Then you can use a piece of wire instead of the pencil and rub it across the penny's black spot until you get a signal.

[mnpd007]

@sciencechemistrygirl

That's right. You can also take a #1 pencil (very dark carbon), and cover an old penny with a solid patter of scribbles. That will also eliminate having to use the pencil lead. Another thing is to use an old, all-copper penny dated before 1982(?). Pennies made during the last 30-years are not copper and will not work as well as a detector.

[sciencechemistrygirl]

@mnpd007 Good tips. PEOPLE LISTEN TO THIS!! lol :)

[WulfBand]

I heard of a guy making a toilet paper Tesla Coil & when he fired it up it shut down all communications around him for 1/2 mile :)

[melalitasan]

Thank u friend. It s very interesting. I ll try to make it. A question: What did you fire the blade?

[owlsrock150]

really cool.i just started out in the shortwave radio hobby after an injury has left me sidelined for the forseeable future.radios will become my ballfield,basketball court,punching bag,running track,oh well you get it.im an active guy but must curtail that due to a spinal fusion of 4 vertabrae.so thanks so keepin me in the game.

much respect!!!!!!

ps i subbed your channel and sent a friend request.

[srehturac2]

sirens as he starts a fire. kind of ironic

[bigbattles]

the blueing is to prevent rusting. You can get it by heating the blade up until it turns blue, not red hot. You can substitute it with a germanium diode if you are fancy enougf.

[geonylove]

eu nam reusit sa aud ceva cred ca antena na fost buna mentionez ca am avut antena d 10 m daca ati reusit informatima si pe mine cum

[dorriGa]

Muy bueno!!

[music2b4every1]

Aw, sweet!

[MrSethsiPodz]

WHERE THE FUCK IS THE SCHEMATIC DAMNIT!?!?

[mnpd007]

@MrSethsiPodz ...... If you could read a schematic in the first place, you wouldn't have to ask; you could simply draw one out based on the instructions here.

[MrSethsiPodz]

what can i use to replace the razor?

[mnpd007]

@MrSethsiPodz

Find any old solid-state electronics board and look for those cylindrical, transparent, twin-lead germanium diodes which have a painted ring on one end of the device. Look closely with a 10x magnifier and you'll see a round germanium pad which is being "tickled" by a tiny microscopic wire. Often find numbers on the diode, 1N34 or 1N60 work best.

[206kramer]

My son is making this for a science fair. You just made our project so simple! Thank you!!!!!!

[iFilmStuff4U]

where can i get the pdf?

[hamidfarooq1000]

Mr Bre pettis my foxwhole radio is not working properly plz help me in the creation of foxwhole radio my e addres is needfriend 75@yahoo.com

[nazaninkarchi24]

great



[nazaninkarchi24]

cool



[hackerdeehack]

cant believe this will work!

[MrDonneiDarko]

Hand wind. Cuban Style

[Aaryan83]

nice way to making ppl fool.

[mrmartinamartin]

how to switch channel and does the blue razor blade lose the effect? please respond~

[DATBOIPatGMAIL]

Amazing. Gonna try it.

[great2bcool]

The only problem i have found is finding HIGH IMPEDANCE ear/head phones.

They are rare and a must have.

[TFMediaVA]

Pipe from radiator goes into the ground so touching the radiator...

[yhevrah]

@crescentmoonpro im a noob? where exactly did he hook the ground? basically any metal with no charge?? neutral?

[TheBeatlesBaconator]

simalar to a crystal radio

[MrFlyinghellfish]

it no work

[DRAGUNOV1902]

Anyone tried this? is it really work?

[MrFlyinghellfish]

No offense, but you are VERY bad at explaining things.

[JugglingJona]

2:33 the firefighters were already on the way

[ledguy315]

The razor blade needs to be partially rusted. The iron oxide and graphite are what causes the circuit to pass a current. If anyone makes this, just leave the blade in a safe place out side to be rained on a few times. Rusting it with salt water or chemicals does not work as well. I hope this helps.

[TheBigBangC]

Why the razor

[utubeworms]

Not sure how you got the sound to the camera mic since there isn't enough power coming out of the radio to drive the mic. That's why you have to use that special ear-phone to hear the audio.

[elemineseslapolla]

Poor materials, now they have to let justin bieber through them

[pyromania321]

Can anyone tell me why you NEED to use pencil lead for the part where you make the diode from a rusty blade?

[CoolKillerClan]

@pyromania321 you know does turny weals that you put on the wall to make the light go down whit out closing it that what that does

[pyromania321]

Does this get am stations because I need something to work for a wireless telegraph reciever.

[Char1zard93]

Thumbs Up for siren at 2:22 - 2:44

[Enatbyte]

@Char1zard93 NO SOUP FOR YOU!

[maxim0815]

AWESOME!!!

[unisol98]

Why does it have to be 120 times?

If i do it just 100 times.. why would that be wrong?

[karatsu21]

@unisol98 maybe a black hole appears and whole mankind dissapears in it. don't wind it 100 times and don't divide by zero!

[IronNation0]

@unisol98 If you had been listening more carefully he said that the electricity is coming from the air, the more wire you have the more volts you get, plain and simple.

[unisol98]

@IronNation0 Thx.. :D my bad :D

[LauxHawk]

Lol Mike Francesa.

[terroristaloko1]

Vlado pedal si

[minex7xgod]

As soon as the sirens went off in the video they went off outside my hotel

[ChuddleBuggy]

You'd have to have a great deal of understanding of the theory to think up something like a basic radio. Makes you wonder what kind of people those GI were.

[TomsawyerNC]

what kind of earplug is that and where could i get one?

[villipoi]

does it work with a speaker instead of an earplug ?

[GratefulCraig]

Real cool! I watched it twice and that looks like a real cool weekend project.

[veronicachic]

this is frekin' amazing!!!!!

[Artyint123]

great

[MasterThief1324]

That's AWESOME!

[pike12345selmo]

do u have to use that razor or can u take a shavinh razer from a bick thingy and blue it

[XxLeurxX]

Whoa whoa whoa wait, if the power comes from the air (the radio transmitters) doesn't that mean there's an open door for us to pillage energy on from it?

[XxTheGreatBlakexX]

@XxLeurxX If we could it would be awesome, but the power is so low you couldnt do jack with it. notice how he wound the wire a couple hundred times? thats because you need all that just to have enough power for this.

[Webking271]

@XxTheGreatBlakexX Actually that has absolutely nothing to do with power. The coil (or inductor as it's called) is part of an electronic frequency-selective filter circuit. This filter is what "tunes" the radio to a specific station by only allowing a very small band of frequencies to pass through it. The frequency that the filter selects corresponds to the radio station you are listening to. You are falsely suggesting that there is some sort of amplification going on via the coil.

[XxTheGreatBlakexX]

@Webking271 I stand corrected. Now that I look back I should have done some research before i post. I was going from past knowledge(now incorrect) and just plain bad logic. That you for correcting that.

[Webking271]

@XxLeurxX No, the electromagnetic waves had to be first generated using a high-power radio transmitter. The law of conservation of energy is at work here... we are not getting it for free. Not only that, using the AM radio band at such a long distance is a terribly inefficient way of transmitting power.

[XxLeurxX]

@Webking271 We would be getting it for free. But other people would be the one paying to pump electricity out. I didn't say anything about "free energy" since there's no way to accomplish over unity at the moment (That I'm aware of). What I did say was "pillage energy" basically by stealing it from its intended use, but as another indicated, it would be so low, it would be technically useless.

[TelcoPhil]

I used to build these back in the late 50's or early 60's when I was a kid, but we used an old US Nickle, not a razor blade. For the last 3 years I've had all the stuff to make on stuffed inside an old round oatmeal box sitting on the top shelf just in case some day I may need it.

[robi4never]

YAY I WINDED IT !!!

[linopene]

were the radio get the power?

[robi4never]

@linopene ... watch whole video , he explained where he got power... AIR!!

[TelcoPhil]

@robi4never IF you can find an old Neon bulb and hook one end to a long wire (80-feet is good) and hook the other end of the bulb to ground, the bulb will glow. Did this back in the 50's.

Don't know if a LED will work or not, I kind of doubt it.

[robi4never]

@TelcoPhil maan how old are you ? im just curious...

[Gizmologist09]

@linopene Built this in '65 myself. The power is the radiated RF signal from the transmitter. That's all. BTW, use a # 2 pencil with a sharp point. The sharper the point, the easier it is to tune to a single station.

[Junctionuk]

DONT make this crap, Twin Circuit Set Google it There the best, Stupid American Thumb Taks, There F'ing Drawing Pins

[STREETRAT211]

where's the fucking skematic??

[hulago1234]

@STREETRAT211 the schematic is fucking simple. Scroll down to the last section of wikipedia:crystal radio.

[Jonskunk]

where is the pdf

[noahboysib]

Wow

You r so good At that relly

[ku4uv]

I have found that X-Acto blades work well for this project, much more so than the stainless steel variety. I use X-Acto #X292 blades. I heat the blade for several minutes using a blow torch until the blade is glowing red hot, then let it cool down. I then sand a small portion of the blade and solder a piece of enamled wire to the blade itself. I am currently trying to "rust" the blade in a bowl using aquarium salt to hopefully make it work better. Hope this helps someone!

[hulago1234]

are u using special earpiece ie crystal piezo earpiece? and are u located in the vicinity of AM transmitter?

[yeoj35368]

yes where plus minus

[yeoj35368]

yes in plus minus

[yeoj35368]

no battery

[bears7777777]

you should add a how-to on how to hook it up to a single transistor amplifier.

[Webking271]

@bears7777777 or even a tube amplifier would be cool with the whole retro theme going on here :)

[nathanallan1]

Very cool project!

[TheChinese01]

can i use cutter blade instead of using razor blade??????????

[mikeccuk2006]

If there's no need for batteries, this is some sort of free energy device?

[baco82]

@mikeccuk2006 hehe not really free energy or it would be a miracle :) it's very low energy coming directly from the radio waves. early receivers were built this way. check "crystal radio" on wikipedia.

[QuatreiZer0]

whats the pencil for?

[233EC052]

@QuatreiZer0 the pencil has carbon and it is use for detection of medium wave amplitude modulation. best results can be achieve using a germanium diode or transistor (if you can find one)

[QuatreiZer0]

@233EC052 Thanks for the info ^__^

[iyadaljam]

VERY GOOD

[iyadaljam]

VERY GOOOD

[4dojo]

awesome

[117boonmoo]

i like this weekend projects better than kipkay

[lucasmontec]

I miss this wekend projects...

[Manarmy777]

what is that earpiece called this radio will not work without that kind of earpiece because the radio has to be amplified

[GMSamuelRhine]

@Manarmy777 no it does not. AM radio can be powered of the electricity from the signal

[losthaze]

@Manarmy777 i think it's a piezo-earpiece or maby an electret earpiece (that's actually how it's spelled)

[terry455]

heh, I remember doing this.

Oh yeah, I got a cool station.

[terry455]

heh, I remember doing this.

[ronaldoskoza]

where i find magnet wire??

from speaker?

[k915]

@ronaldoskoza

no, try a small electromotor.

[chrismofer]

@k915 actually he can find magnet wire in a speaker. i think the most common places would be a speaker, a motor, or a power transformer.

[lofams]

That sounds like a radio station from gta 4

[gearman371]

Where did you get the magnet wire.I'm trying to also build a foxhole radio. And what kind if you know.

Thanks,

[MrSakajoao]

you have could cut your fingers of with the standmachine sir... not so good for children

[MonkeyWithAWrench]

i had to build a radio like this in ENG1000 in college. if you want to change the radio station, just stick a piece of steel through the coil to change the inductance. that will change the resonation frequency, thus a new station. ours had to be tuned to receive a certain station.

[vidfuse]

cool video,my uncle who passed away a few years ago like making this kind of stuff

[Eragon205]

Umm... To all those nicompoops who think it's not real because there's no battery, it runs of the energy from radio waves, received from an antenna (in his case, it was probably the radiator, other wise I have used a street lamp, or simply pipes running along a building)

[12quillemall5321]

Is this still possible? I thought we was in a digital age, not analogue.

[ventHARAS]

how is this even possible theres no battery...

[gigobait]

@ventHARAS Radio waves are electricity sent out in pulses, radios use batteries to amplify the signal...but you can listen to it with this device faintly. Also i think this is an AM radio

[SupremeRulahXenu]

@gigobait This is definitely old AM radio. Making an FM or SSB receiver is a lot harder.

[de0509]

cool intro

[bebeni89]

BUTT CHIN...

[MrUnidyne]

"Blue" razor blades had a silicon coating so they wouldn't rust. This was in the days before stainless steel was cheap enough for blades. You can still find a few in antique shops and on-line.

[outslider1]

Cool project, have to do this!

[Dazzystutorials]

thats awesome dude.



[americarox2007]

how do you make the earphones someone?? :/