Picture of Spooky Tesla Spirit Radio
News Flash!!!
The Spooky Tesla Spirit Radio and Mrfixitrick are now featured in a PC game called "Tesla".  Monsters and bats are battled, while helping Mrfixitrick find the seven parts of the Spooky Tesla Spirit Radio. Intriguing background music. From GODD Games at: www.goddgames.com/tesla.html

Have a look at the Crystal Quantum Radio devices of EJ Gold that helped inspire this instructable:  http://www.yoyodyneindustries.com/

"My first observations positively terrified me as there was present in them something mysterious, not to say supernatural, and I was alone in my laboratory at night"
- Nikola Tesla, 1901 article "Talking With The Planets

The Spooky Tesla Spirit Radio is more than just a crystal radio circuit in a jam-jar. It's a sound maker that plugs in to a computer, and makes awesome spooky sounds by responding to electromagnetic fields or light sources in real time.

Athough Tesla used different parts, this radio's basic L-C (Inductor-Capacitor) circuit uses a similar schematic to what Tesla experimented with in his early days. The versatile 1N34A crystal germanium diode used here, substitutes for the tricky rotating nickel detectors and sensitive relays, used by Tesla in the late 1800's. 

You can listen to AM broadcasts with this radio, but it was made to have fun with in other ways. (Besides, AM radio wasn't exactly what Nikola Tesla was interested in...in fact, he believed it was a waste of energy to transmit and receive Hertzian waves!) 

By using a program like Audio Hyjack Pro (Mac), the radio's output is tweaked at the computer to give some great real-time sound effects...and you can record them at the same time. 

In the following accompanying movies, I show how the Spooky Tesla Spirit Radio reacts to lightning, radio frequencies, the light spectrum, the computer screen, RF pulses, electromagnetic fields and more!

In the following video, the Spooky Tesla Spirit Radio is used to give voice to a Mac Hyperspace screensaver! The simple crystal circuit is apparently sensitive to the screen synchronization RF frequencies, and so it provides awesome background sounds...check it out:

The next movie shows "Spooky", the radio, beside a Dancing Ghost homopolar motor. The motor emits electromagnetic waves that are picked up by Spooky's antenna coils, and we hear the results translated through computer software in real time...spooky!!

Here's a movie of the action in the new PC game "Tesla", featuring the Spooky Tesla Spirit Radio;

onilx18 days ago
I'm absolutely lost on how you've got the cone antenna wired to the device... Can you draw a diagram or something? Thank you so much!
HannahW11 month ago
Hi again, so we have the radio made but can't get anything out of it except a very low static signal. And the variable capacitor does not seem to affect anything. We have the radio going into a sound card so we can connect to active monitors as the built in output on the computer was too low volume. So all we seem to be doing is getting cool effects off a very small amount of static, no am radio or variable with capacitor or light diode! I've read all the comments so not sure if there's much you can suggest but let me know if you have any more tips. Thanks, Hannah
mrfixitrick (author)  HannahW11 month ago
There may be a problem with a burnt diode or bad connection. The diode can burn from the heat of soldering it. (Note: Use a pliers as a heat sink when soldering. )

To see if things are working properly, you can try using a long antenna to get more gain on local radio signals. I use a 20 foot piece of copper wire strung across my living room ceiling! :) Otherwise without antenna, may be hard to hear local am radio.

You should be able to hear an electric motor for example as a test. A Dremel tool or electric drill close to the radio should be easily heard. Use multiple "Gain" modules if necessary to increase the volume. To hear laser, needs a delicate setup with lots of gain. The radio must be "on the edge" by being very sensitive.

You might be better off using the built-in output of the computer, and then amplifying that. (As the sound card may be cutting off and may use a different grounding system.)

What computer do you use?
mrfixitrick (author)  HannahW11 month ago

You must use Audio Hijack Pro or comparable Windows software to amplify the signal and give it texture. I use three levels of gain, and other modules to modify the sound. Then, static takes on a whole new dimension.

hi there - yes we are putting it through audio hijack and using your screenshots for reference - and yes the static does sound good! but i don't think the variable capacitor is working - should this change the sound of the static too? we get no change when turning the knob... also no change with electromagnetic interference or with shining the light on the diode...
thanks, hannah
CyrceD1 month ago
How can pay you to make me one of these radios?
JudyD22 months ago

You can call me dumb dora are anything you like but what is this spirit radio for.? I have seen the video's and post. Is it a listening device of some kind. Like a micro phone? That is what I am understanding. And if it is why go to all the trouble? Please email me because I will probably not remember how to get back to this site. I really would like to know what it is for. Also my great great great grandfather invented the radio receiver is this what this is.? Here is the link that explains his invention, his diagrams on how he built the receiver are there also.


Here is my email address if someone could explain to dumb dora please I am interested on what it is and what it is for. Judykdoolittle@gmail.com

Thank you !!

Powertripp6 months ago

Just built this.. I cant get anything but static. No sound reactions to light on the diode or anything. I can get am if I touch the antennas, thats about it.. I quaddrupil checked my connections and even dis-assembled and reassembled.. still absolutely nothing but am radio when touched and static when not touched... Help anyone??

mrfixitrick (author)  Powertripp6 months ago

If you get static and AM when touching, you have done everything correctly. I believe you need to plug into the sound port of a Mac computer running Audio Hijack software set with the Spooky settings... Also, Increase signal by using a 20 foot antenna and ground if you wish.

n71 mrfixitrick2 months ago

"Tesla's spirit radio"? :-) Are you for real? :-)

Been messing with it more.. Still nothing but static.. Diode is non-responsive to light, does pick up my soldering gun though. I used a variable capacitor along with a ferrite loop-stick from an old radio though.. Could that be the problem? What pf does any old radio usually pick up? I got a rad germanium diode by the way; i dont know if that makes a difference?

How can we trace down the original parts list that Nikola Tesla himself used?

You can't. Tesla simply didn't do this.

kaz.sommers3 months ago
Has anyone successfully built one?
Im willing to pay someone to build one for me.
n71 kaz.sommers2 months ago

People are naive, Tesla never did this nor it is any "spirit radio". This is disinformation and I think the creator of this joke is laughing at the ignorance.

n712 months ago

People really believe this is "Tesla's spirit radio"! Ridiculous! :-)

How can one use this with a PC instead of a MAC? Thanks :-)

KaceySama4 months ago

Hiya friends! I've got mine hooked p to a Macbook Pro, which means I had to use a USB external sound adapter since I don't have a sound input jack. Nothing is being picked up by the radio, and I haven't had any luck with light or touch altering the sound. I just get static. Any advice would be hella appreciated and returned with a good joke and a digital wink!

peter.jenko4 months ago

Hi, I've just received this loopstick antenna from ComtrolAuto - it has one black (knitted out of two) and two thin wires (on far left and far right end). Does it matter which thin (non-coloured) wire do I take to solder with non-ground C1 capacitor? Thank you so much for helping a newbie :) Kind regards!

InVIn4 months ago
can I plug in headphones ... directly into the jar...

i hear Nikola Tesla's research was shut down by the government because he posed a threat to their system, can any one tell me why?

lorddoomicus7 months ago

Why did you build it in a glass jar instead of on a wooden base like a more traditional crystal radio? Is there something special about the glass jar, that just building it on a wooden base would not provide?


mrfixitrick (author)  lorddoomicus7 months ago
The glass jar is mostly just a cool idea I thought of, but it does have some scientific basis. The clear glass allows the diode to receive unshielded environmental input such as ambient light, laser, and magnetic and electromagnetic waves without much interference, at the same time protecting the circuit from dust, dirt and young prying hands.

A wooden base is fine...but then it wouldn't be a Spooky Tesla Spirit Radio ! :) Cheers, Rick
julesjjv7 months ago

Hi, thanks so much for this great instructable! I'm just getting to work on mine now, and had a question about the ferrite loopstick antenna. I have a ferrite core (I bought this one, http://www.ebay.co.uk/itm/62mm-Rectangular-Ferrite-Antenna-Bar-AM-MW-LW-Radio-Loopstick-Core-/120852688164?ssPageName=ADME:L:OU:GB:3160), but wasn't sure about the wrapping. Is it just a case of wrapping a thin wire around the core 75 times? In the picture it looks like you have the ferrite core, then something (tape or cardboard?) around the core, then another small bar (what is this, iron?) and then the thin wire wrapped around that. If you could clear up what that is, that would be great. Thanks a lot!

Brockjay8 months ago
I created the spirit radio and It picks up higher frequency waves. Doesn't change a whole lot though.
I am unable to get light to affect it. Different types of lights even. I'm using a PC voxal software program.
Did I wire something wrong? Or is it my sound settings?
mrfixitrick (author)  Brockjay8 months ago
I had to use 3 pitch control modules added in the Audio Hijack software, double double gain, and a lot of fiddling and adjustments to get the light sensing to work. Try a laser first or even close to a 60 cycle lightbulb. The secret is that the laser will not read on the diode except when the light moves on and off of the diode. (i.e. With DC laser it is the CHANGE of light, not the light itself that gives the tone. An AC light will work as continuous tone )

I have played around with all of the settings that I know of. Tried AC and DC lights on the diode.
I have iPhones and iPad's but have been unable to find software that I know for sure works. Maybe one day Audio Hijack will release a PC version.

grenville.wood made it!8 months ago


Objective: build one Spooky Tesla Radio. (see Photo)

Outcome: Successful! Build time: about 4 hours once I had all the parts.

Turned out a little different than the instructions, different size jar (no idea what impact this has...I'm guessing purely aesthetic?)

Variable Capacitor: same as spec

Downloaded patch and using Hijack for Mac

Results: AM radio station test ok

Spooky noises test = Yes but hard to tune in (still working on it) Sounds like a lot of people all talking at once!

Lighting noises = Success!

Still need to make the cone antenna

Questions: Is there a specific set of filters in Hijack required to hear the spooky noises?

Is there a patch for this or do you only hear them once you've made connected the cone Antenna?

Cheers....great kit! :)

Spooky Tesla Radio.jpg
mrfixitrick (author)  grenville.wood8 months ago
I am always happy to see a new Spooky Radio come into the world!

Try these Spooky patches for Audio Hijack.

Spooky Radio Patch 1 https://drive.google.com/file/d/0B1ty3oeDN9qvVzlqdkxOSmxYdTQ/view?usp=sharing

Spooky Radio Patch 2

Cheers, Rick
Hi Rick,

Appreciate you sending the patches, let you know how they go.

bry529 months ago
Is it possible to buy one on eBay premade? I'm not so good with building things
HannahW19 months ago

hi there - do you know if there is an app that can be used on an ipad to filter out the noise from these radios, as an alternative to using hijack audio pro as you suggest above? many thanks!

mrfixitrick (author)  HannahW19 months ago
You can use Splashtop to access your desktop or laptop mac and Audio Hijack. The new Garageband for iPad may be able to handle the job as well...I need to experiment with it to see.
voningraham9 months ago
The Tesla antenna. Great fore RF hunting , It was a tricky thing to wind but had a lot of fun.
mrfixitrick (author)  voningraham9 months ago
Good one! Thanks for sharing it. Tesla said that shape had special levitation characteristics when activated properly! :)
AncleD9 months ago

Hello !
My Name is Oliver and i attend to HTX in Denmark and I want to as my final project, to build and explain how the Spirit Radio works.
I have looked through the references given in this article, aswell as the comments and the internet without luck I'm afraid.

But i was wondering if anyone had any sources, or at least pointers, as to where i can find formulas/equations to describe, primarily, the correlation between light and sound, aswell as the part where you use a magnet turn it into a microphone.

I need this information to prove that this is a do-able project.
If anyone can help me, please send an e-mail to Whirlz2300@hotmail.com
Thanks in advance!

voningraham9 months ago
cool little radio. sounds loud for a crystal set but very cool
Brockjay9 months ago
So I have all the parts except the plexi glass. I got all the recommended parts.
But I can't figure out how to cut the jokes properly on the glass and how many

Hi guys I took a small handheld am/fm radio to bits to remove the loopstick and antenna as this saves you money .

I am playing with different antenna shapes using solid copper wire .

I am going to attach an amplifier and speakers to it rather then the computer will this work ? email me any advice - marktlindsay@hotmail.co.uk Thanks guys .

mrfixitrick (author)  danceswithghosts9 months ago
You are taking apart a radio, and building a radio. It will likely
sound like a radio unless you have a computer to produce the special sounds.
theGNARTeam made it!9 months ago

thanks for sharing this. i have never followed through soldering together a circuit diagram before, but i did with this, and it works. its really weird how when my roommate turns on his florescent lights a few rooms away the spirit radio makes a loud pop sound. i also like listening to the sound of my computer surfing the internet. although, i dont understand how to use the "line in jack" or where that is on the circuit diagram.

max.wallin.1410 months ago

hello :) i am an 18 year old that really would like to build one of those. How ever i have a problem: some of the components i need can't be found in Sweden,( my homeland)and it seems that they can only be found in the us... Does anyone know about a good internet page whit components that ship abroad?

Im interested in making one also i would think copper wire from a old electric fan copper coil and ground wire from a drop cord the thick copper wire and small mason jam jar and a coil post from a 70s era car radio manual adjust type should provide the materials

mrfixitrick (author)  max.wallin.1410 months ago
ComtrolAuto is my favorite, but they no longer ship outside of US. Here is an Ebay crystal kitl that could work for you...

Thank you :) i think this will work fine for me

I only found a 60/141pf Variable Capacitor, it will work?


I think that cap will work for most purposes of the Spooky Radio.
vazquezl3111 months ago

Is it possible to replicate the design using laser cut acrylic box in place of a glass mason jar?

mrfixitrick (author)  vazquezl3111 months ago
That should work. The may be some electrostatic effect from the plastic, but that will likely add to the fun!
The Peddler made it!1 year ago

I made this device with great success. Here is a sound sample of my first audio test; http://llama-music.com/docs/TeslaTestTrack.mp3

The audio file was exported directly from the Audio Mulch program into WAV format and then converted to MP3 @320kpbs.

I was able to keep parts cost low thanks to taydaelectronics.com and comtrolauto.netfirms.com. The total for everything was $18.80. I made the copper antennas in a conical shape because to me, it looks better visually. Even when it's not plugged in, it looks great sitting next to synthesizers and other music gear. Lots of fun!

mrfixitrick (author)  The Peddler1 year ago

A great build with fun sounds! Thanks for sharing it.

mbernal991 year ago

I did make my own, but didn't come out as good as this one. Had problems making the antennas and can only pick up very week signs. I need a good program for the PC to give this more use.

Missy6661 year ago

Well be done Rick now for the one I am going to gain on to cause more hell for this is close to what I am looking for with what I am being given..... damn radios that I pick up and cant turn off...

Rickmick1 year ago

Nice job on this. The instructions are not complete because no one can see how you wired the football coil by your image. Could you please show how it is wired?

Sorry, I found your answer from a before that I over looked. Here it is for others that might also be looking.


mrfixitrick (author)

I'm not sure how to "properly" wire the football coil either!

There seems to be three basic styles...

Wind the coil starting from one end and right through to the other end,
all one piece of wire. that will give a connection point at each end of
the coil.

2.) Wire one end clockwise and the other anti-clockwise, join them in the middle.

3.) Same as 2 above, but don't join the wires in the middle.

original Tesla football coil used high voltage to activate it, so the
purpose here as a crystal radio antenna is different...therefor, there's
certainly room for improvisation.

Besides, by experimenting, you may come up with something interesting that has been overlooked!


lexlarson1 year ago

Alright, i got all the parts and got it all together, just bare connections, no solder yet, i have a few questions tho because it doesnt seem to register as an input and i know there's no shorting wires, so i guess first question would be how would i get it recognized on my pc? uhmm second question am i supposed to be grounding everything through the audio jack to the cpu? or is there a separate ground?

well i figured out one of those questions, if using a TRS audio jack with 3 connections, use tip for positive and ring for negative, still dont know about separate grounding, or the sleeve connection, but that solved the cpu not registering the radio, now i cant get any reception, i get a hum tho, and changing the cap seems to do nothing, however when taking a sample from recording on audacity, i THINK i can tell the diode is making signals,by comparing a blank run to shining a laser over it, and i can kinda hear a pattern if i mess with the audio a bit, any tuning suggestions? im using a 5 pf to 365 pf air gap capacitor from xtal, and using the induction method for coils, and im using the pancake antennas

mrfixitrick (author)  lexlarson1 year ago
Try using a mono cord instead of stereo one, that might help with the hum. Or, try soldering together the ring wire and the shield/ground wire mesh to ground it.

On my Mac, the computer acts as the ground. You might try a separate ground wire to a known good earth ground or the AC plug ground.

You can use a ac filter on the audio line. Some audio cords have that built in ( a bulge in the line where a transformer is)

You can also try a usb audio input device.

Once most of the hum is gone, you can use the software to tune out the pitch of 60 hz and harmonics of that. I used to alter the pitch control to higher or lower frequencies.

Make sure you use lots of gain. I used several gain modules in a row to increase amplitude to point of being able to hear well the small disturbances to the electronics.

Try hooking up a separate 20 foot long bare copper wire antenna for much greater sensitivity to begin with.

Well, there's a few things to go on!
Let me know how it goes...

Okay, i got the mono plug installed, and rewired the whole thing, soldering this time and with insulated wires..

Yes, changing to mono, and rewiring to solid connections really reduced the hum, almost silent now, and i know its still working because i get feedback when i touch an antenna, or any component on the circuit, including the ferrite rod

Still however i can't get any reception or any variance from what is basically static(44.1kHx) (been from 600 Hz to 60kHz) , regardless of how many times i amplify or change pitch and/or frequency, tested with presenting a laser to the diode as well as introducing an electromagnetic field around the antenna, and adjusting the capacitor.... still nothing, well i see very slight changes, but nothing more than what random changes happen from a blank run... Any other suggestions? i could send pics of wiring/set up in case i made a dumb mistake

On a side note I did already try a couple of those recommendations..

1. At least the way i had it wired, grounding the ring to the sleeve in a TRS audio cable makes it unreadable/unusable by the cpu and offered no output.

2. 20 foot antenna is really hard to support without it falling over and grounding itself making a VERY loud noise when speakers are turned up (might try again later with proper supports, idk like silk from the ceiling?)

Anyways, basically i THINK i have it all together and operating properly now, soo i guess... whats the best way i can test if its working properly? how do i tune into specific stations? and what am i looking for to amplify in these specific sound waves, like if i shine a laser through the diode, what sort of noise, or pattern should i expect in the waveform, and how soft/loud should it appear?

AllenMcG1 year ago

Working on getting all the parts together. I got 14 gauge wire and am trying to make the pancake antenna, but 14 gauge seems flimsy to me. Did you mean to say maybe 12 gauge or 10 gauge?

mrfixitrick (author)  AllenMcG1 year ago
You can use 10 or 12 gage. I used 14 gage.

wire gauge shouldn't matter, right? all I have in thick wire is 10 gauge. Was going to leave the insulation on it, though I could remove it.

mrfixitrick (author)  onewheeltom1 year ago
The wire gage doesn't matter very much for this application. It's best to remove the insulation.

I tired using 14 gauge wire and it is way to flimsy to make a pancake antenna like you are showing in the pictures. Am I doning something wrong or do I need thricker copper?

mrfixitrick (author)  AllenMcG1 year ago

My 14 gage antennas are quite springy and somewhat flimsy, but retain their shape. There may be different alloys of copper wire available. The closer to 100% copper, the softer and more flimsy it will be.

1.) Are you sure it is 14 gage (1.5 mm / .060 inch minimum) and not 16 gage (1.3 mm / .050 inch)?

2.) You can strain the wire first by pulling it over a couple of pipes. The idea is to work-harden the wire, so that it is more stiff to begin working with it.

3.)When making the antenna, pull the wire into a spiral circle on a flat surface, beginning in the centre. The tighter the circles, the better, as it will help harden the wire.

3.) Try using 12 gage wire instead. :)

I'm using a plastic lid from a jar of Trader Joe Mayo. They have other jars with lids that also fit a standard mason jar thread (Sunflower Seed Butter) perfectly. I'll probably mount the diode through the top of the lid between the banana jacks so it is exposed.

Which of the kits from comtrolauto is the one with the right parts? The only difference appears to be the taps on the coils...I ordered the CRK-1.

mrfixitrick (author)  onewheeltom1 year ago
The CRK-1 kit should work fine for you. good luck with your build!

@onewheeltom, I suspect you'll be fine, but please let us know so we can compare notes. I ordered the CRK-3 kit as it had didn't have the tap. I believe it's all the same as long as you don't need the taps, don't use them, but it would be nice to confirm. The PDF file that's associated with the CRK-1 kit makes mention something to the effect of "If you're not using the long antenna connection, don't cut the wires." so in this case you're not going to. I believe by using the taps you're just changing the inductance. I waffled on the decision quite a bit, since the loopstick without the taps is a different shape I worry it might not fit into a container as nicely, but I believe without using the taps they're all functionally equivalent. I'll definitely report back my findings once it all arrives. Please do likewise.

Question regarding the spiral pancake antennas...does the wire need to be insulated "magenet wire" with the enamel coating to provide insulation against itself, or will any plain stripped copper wire do? If the antenna wire touches itself, like where the vertical section heads up, is that a problem, or do we want to keep it insulated against itself? Thanks! Really looking forward to the parts arriving so I can get started on this project!

tree961 year ago

Brought 788 uh Ferrite Loopstick Antenna you said would work to me in a recent post, but the ferrite rod is a lot bigger and I have trouble fitting it into most jars! Is it possible to trim down the rod?

mrfixitrick (author)  tree961 year ago
Sorry, I didn't realize the ferrite rod was bigger.

I hate to give advice again, but ferrite rod will break fairly easily...perhaps you can break a piece off?
jsmock21 year ago
This looks like a fantastic project! I appreciate all of the time and effort you took to post this. Is it possible to post directions on how to make it work without using a computer? Or perhaps direct me to another site that has these instructions? (I tried to find it myself, but Google has thus far failed me) Thank you
mrfixitrick (author)  jsmock21 year ago
You can use a basic pre-amp and audio amplifier to get sounds out of the crystal radio circuit. It won't have the "augmentation" of using the computer audio software, so you might hear static at the times when there is much more richness with my technique.
Ah, now that I can see the hundreds of other comments I see that this question has already been answered. My apologies :-)
mstephenson6 made it!1 year ago

I finally completed it ^_^

My Radio.png
tree961 year ago

I can only find a 788 uh Ferrite Loopstick Antenna in the UK, other links only ship to US, will this work?

mrfixitrick (author)  tree961 year ago
I think the 788 uH will work fine for this purpose. Good luck with your project.

Thanks! :)

zwalker31 year ago

ive been having alot of trouble trying to get all of the parts here in canada. Is there a way i could pay you to ship them all too me? Also i remember reading somewhere that you would make one and ship it. how much would that cost? Ive got an experiment with some non-newtonian fluid and a tesla radio i would like to commence soon!

Canadian here. I was able to get most of the parts off ebay. The ferrite loopstick antenna, mono jacks and dials/knobs I got off a junk portable AM radio I got from goodwill. You can get a variable capacitor from the AM radio too but I just bought one from ebay with similar specs to what's in the instructable. I didn't find a reasonably priced crystal earpiece so I plan on making my own from piezo speakers I got from dx.com (you can find instructions from google). The copper wire for the antennas can be found at any hardware store. Hope this helps you and anyone not living in america.

msim935 years ago
 Pardon me, for it seems as if I'm asking a silly question.
I dont have the parts yet, but when it says "ground through the phone Plug" does that mean the negative of the computer phone jack?

Is that also where you would ground the C1 middle connection?

Like I said, it may be a silly/stupid question for me to ask. I'm still learning how to read schematics properly, and I just dont want to mess anything up.
mrfixitrick (author)  msim935 years ago
 You got it right on both accounts.

It seems that the negative of the computer phone jack works even better than a ground connection I made to a pipe in the ground.
Working on Aircraft My whole life. We always had to ground the airframe to the ground to remove static elecricity that can pop someone on the head and knock them out. That's when I started thinking about a Star Trek Stun Setting on their faser guns. I have seen guys knocked right out after walking under an area of an aircraft right after fight, A big PO on the head will knock you out cold. I think that would be better than teaser guns used by police. Maybe Someone could figure out how to use that kind of energy. Ya Think?? OH YEAH To ground air craft is to a copper rod about 12 feet long in the ground with just a couple inches high in a small hole on the ground. TAKES ALL THE SPARK AWAY. Ya Think??
Don't Feel ALONE, I'M AS CONFUSED AS ANYONE COULD BE. You are way in-front of my understanding. Some of the things you may call a silly question, are not silly at all because at least you know what the name of what you are asking about is, I Don't IF EVERYTHING WAS MECHANICAL I WOULD KNOW MOST ALL EVER NEEDED TO KNOW BUT THIS?? I'm not moving at all. I want to make it but I don't think I will be able to.
vger132 years ago
i am using a stereo cable i think that my be the problem,other than that i have tried hooking this thing up every way i can.right now it is connected like this one
mrfixitrick (author)  vger132 years ago
Try the mono cable and/or a longer antenna. You can also try hooking the two positive pins together on the stereo plug. To get stations, it pretty much requires a longer antenna. The short antenna is better for getting sounds from drills, motors, lights, etc.

vger132 years ago
ok ..i think something is grounded wrong,with patch cord plugged in i get nothing when i unplug and touch just the tip to the jack on the radio and touch tuning tip i get stations?
mrfixitrick (author)  vger132 years ago
Be sure the grounds are connected properly, and try my other suggestion of using a mono or stereo cable instead of the one you are using.

The antenna will likely have to be lengthened to 20 feet or so to get stations easily. Try the alternative antenna connections for long antenna, as seen in the schematic.
vger132 years ago
does it matter which side of the jack is ground?
mrfixitrick (author)  vger132 years ago
Try a mono plug and cord, or a stereo one if you already were using mono...that might make a difference. Also, try using a 20 foot or longer antenna to get a better signal, as it sounds like you are using your body successfully as one when you touch the tip!
vger132 years ago
no pc with audio mulch but your presets are no longer available ..goes to a cloud
mrfixitrick (author)  vger132 years ago
PC is more difficult, but here is an AudioMulch pre-set to try...

vger132 years ago
i have been trying this off and on since first posted,not sure what i am doing wrong but i get nothing other that static when hitting diode with laser ,used 100 mgains,.i dont see your unit grounded ..mabe it is..is that the problem?
mrfixitrick (author)  vger132 years ago
Hi vger13,

If you hear static when you hit the diode with laser, you are on the right track. Now, the static has to be converted to an audible sound. Are you using Audio Hijack on a Mac with the "spooky radio" settings?
nerd74732 years ago
Dorkinator2 years ago
Thanks for the fast response, Rick.

I'm having touble posting this as a reply, so I just made a new post.

I will try out your suggestions tomorrow.

As for now, I have another question. Assuming we have the right circuit, should we be able to hear some kind of noise if we shine a green laser onto the diode.? Would we have to change the pf until we find the range its in, or should it detect it almost right away?

I appreciate the help, Mikey.
mrfixitrick (author)  Dorkinator2 years ago
The laser will be detected no matter what range. The problem is the gain has to be turned way up to hear the response, and the pitch has to be tuned to give a good solid sound. As before, you should be able to hear the audio plug loudly when touching the tip of it with your finger, before plugging it into the radio.

Good luck, let me know!
Dorkinator2 years ago
Hi, we are making this for my school project,really enjoying but because we are in Canada I had to use a variable capacitor from midnight science (365pf with 8:1 planetary gear) but which has 4 lugs. My questions are;
1) how to wire the variable capacitor, I believe we can use any of the 4 lugs then use a ground connection for the other side?
2) we are using a ferrite antenna from a am radio but which has 4 wires3, on 1 side and 1 on the other.
we are using audacity and so far its not working, I know I didnt fry the diode, any ideas would really help, many thanks, Mikey Pratte

You can email me at fatal.404.error@hotmail.com if you need to.
mrfixitrick (author)  Dorkinator2 years ago
Hi Mike,

The variable cap will likely be ok wiring as you describe. The ferrite antenna you will have to try various orientations of the wiring.

Start first by knowing that you get a very loud hum/noise when touching the end of the audio wire plug (with other end plugged into computer)

I found Audio Mulch worked better than Audacity on the PC. http://www.audiomulch.com/download

I had to use 3 "Gain" modules to raise the volume enough.

Once you get a loud response, plug in the radio and put a source of EMF beside it, like a drill or motor or modem. You should begin to hear something.

For better reception, add a 20 foot antenna.

Let me know how that works for you!
Cheers, Rick
Thax2 years ago
I'm having real problems with my radio and I'm trying to understand the options you describe. I've built my radio as you've pictured yours, but I'm getting no signal or noise. I've checked all my parts and connections. "Run it direct with an antenna connection" doesn't help me understand. Can you clarify this? Thank you!
mrfixitrick (author)  Thax2 years ago
"Run it direct with an antenna connection" means when the induction coil does not have a 10-coil wire wrapped around it, and uses just the tiny wires of the induction coil in the circuit, as seen in inductor L1 and antenna Ant1 in the circuit diagram. The antenna Ant 2 and Ant 3 are auxiliary, and in some circumstances may work better.

For diagnosis, let's go back to basics first...
1.) Are you using a Mac with Audio Hijack, or what is your way of hearing the radio? Test: Do you get a very strong hum when you touch the end of the audio stereo plug on the wire that connects to the computer? If you don't, then the audio software or other adjustments must be made, as the radio needs tons of gain to be heard.
So, touching the end of the plug that goes into the radio, should sound very loud.

2.) If above test is ok, plug in the radio. Is there any sound at all? Turn up the volume if necessary. Touching the antenna should increase the sound.

Let me know, and we'll go from there!
I loaded Audio Hijack onto my Mac, but couldn't see how to make it open the windows you present. Then I loaded AudioMulch, which appeared much closer to 'right', but I still couldn't get anything out.
Better option, I thought, was to apply an Oscope to it and see if there was anything there. I found nothing but what I believe was that 60 cycle hum you mention. Phoey.
I hard wired the funny little 1970's earpiece that came with the crystal radio kit so I could more easily monitor if I made any change from further tweeks. In fact, your suggestion of removing the 10 coil seems to have some change. When I poke the variable cap a tiny burst of noise comes through the earpiece.
Still, this kit was supposed to be for kids, and it mocks me. I feel dumb.
mrfixitrick (author)  Thax2 years ago
Ok, what you likely need is lots more gain (assuming the radio is wired correctly and the diode was not overheated durting soldering ;)

Here's what to do: You need to set up Audio Hijack with my Spooky Tesla Spirit Radio Patch, which I just stored on Google Drive at this web address;

Go to the above address, and download the patch file there to your desktop. Then, open Audio Hijack, look at the top row and click on "Control" then select, "Import Effects Patch". In the window, find the patch on your desktop and open it. It should make Audio Hijack ready to go except for minor tweaking.

Note: You may need to set "Source Type" to "Audio Device". There should be 6 modules set up, AUBandpass, 10-Band EQ, 3 of AUPitch, and Reverb.  Be careful, as it could be very loud, turn down gain if necessary. 

The other thing that makes a huge difference in sound level is to attach a 20 or 22 foot long piece of wire to the antenna circuit and stretch it across the room. 
You should hear a sound increase by touching the antenna.

As a kid I spent hours messing with a chunk of germanium and a needle-like gizmo probe to finally get a station...and it would disappear the next day!  The crystal radio pros have big tuned coils and proper antennas. It becomes all about the tuning, selectivity and sensitivity at that level. 

Good luck, and let me know re: Audio Hijack. 
first, thank you for taking the time to work with me here. It is really a big help. I found a few mistakes I've made that have made a big help.
1: the output port I have has three leads. One ground, and two that appeared to be connected. I realized today that when the plug is in they disconnect and I had the circuit to the wrong lead. Fixed!
2: Audio Hijack is not the program I needed. Audio Hijack PRO provided what you've been describing that I couldn't find. Hallelujah! (on a side note, I used Pro for only a matter of minutes before it started piping in noise to get me to buy. grumble.)

So now I can hear a very deep low throbbing hum. Actually I get it even with just the patch cabe. Touching the antenna gets more static, better than nothing. I'm ready to attach a long antenna. Where in the circuit do i wire it to? Ground as the other seems to be? Or a separate floating 10 loop coil around the loopstick as it appears in the diagram? Or, as I find in another crystal radio circuit, on this unused third thread into the main antenna coil?
mrfixitrick (author)  Thax2 years ago
Glad to hear you are getting some results. That is the hum you are looking for, and the hum should be less with the patch cable connected to radio and computer. The free version of Audio Hijack PRO (hehe) will run for 10 minutes without static being added. Then just re-start the program. I liked Audio Hijack so much I gladly bought it.

As for antenna, I would wrap a 10-coil copper wire around the induction coil, and attach one end to "ground" or negative, and the other end to the long antenna. You may be wish to attach the antenna directly to that "third thread" wire instead of the 10-coil. Try each technique and see what sounds louder.

Especially with the antenna, if you are close to an AM radio station, you should be able to hear something when adjusting the variable cap. You might need to centre the "AUPitch" pitch controls to make sense of it.

Keep in mind, for the kind of fun I have with the radio, it's often best to tune outside of the main stations instead of on them. The AUPitch and other modules are used for "tuning". The idea is to crank it up with gain, so it becomes super-sensitive to whatever you are listening to, and adjust pitch and reverb, etc. for best sounds.

Have fun...it's a perfect Halloween activity!
frostybob2 years ago
So must this is almost like a mircophone then? As portable as the computer its plugged into. How easy would it be to record straight onto a tape without first going through a computer? I'm just generally wanting to take it outside and see what I can whilst out there
Any help would be much appreciated
mrfixitrick (author)  frostybob2 years ago
The radio does and can act as a microphone, among many other things. I have done a movie about that in fact. However, if you record straight onto tape, it will not have enough gain to hear much, or have any of the effects that create the ambiance. You might hear an AM station if you are lucky, along with plain static, for example.

An old MacBook would be the cheapest and best way to get the cool sounds while being mobile. Windows laptops may work with some software too.
Mvtnns2 years ago
Will the AA113 Ge diode work with this?
mrfixitrick (author)  Mvtnns2 years ago
The AA113 germanium diode is similar in function t the 1N34a, and may work in this application. I can't say for sure, as it is not a direct cross reference to the 1N34a. Try it...it can't harm anything.

Perhaps another reader has more info on this diode?
It had been a week or two but here is my finished product
mrfixitrick (author)  TheFabricationist2 years ago
Cool! It looks really nice.

Can you get it to talk, that is the question! hehe

The Dell PC is harder than the Mac to use, but there was a comment I posted here below that goes like this...

" ...and PC program called Audio Mulch and it will work fine for the purpose of the Spirit Radio with a PC. It's expensive to buy, but you can download a 60-day free trial that works great .

I set up three "MGain" patches in the Audio Mulch software and it increased the volume enough to hear radio stations and electromagnetic fields clearly. Then I added various controls such as pitch and reverb for strange "spirit" effects.  "

Good luck and happy hunting!
So far I haven't gotten the voices yet. I downloaded the free trial of audio mulch but I know very little about it, I have been plugging my radio into a guitar amp and I get all the volume I need to hear a few am stations and the electromagnetic fields. I will tinker with audio mulch and let you know If I hear the voices.
I know very little if anything about circuits and radios. So my question is (and please forgive me is it is unbelievably stupid) could i open up any old analog AM radio and get the majority of the parts i need?
mrfixitrick (author)  TheFabricationist2 years ago
Some of the parts from an analog AM radio may work, including the antenna coil, a variable capacitor, and possibly a resistor or capacitor. However, the main item missing will be the 1N34a diode, which is particular to crystal radios and hard to find elsewhere. I have a 1500 page electronics catalog that doesn't have them!

You won't be able to get the parts from an analog radio, but you can simulate the effects by plugging in the audio out from the radio into the audio in of your computer. Then run software to increase the gain (volume) and alter pitch such as the suggested program Audio Hijack Pro on a Mac is best. There may be PC alternatives for software.

The technique would be to tune off-station, in the places where you normally hear static, then crank up the gain so that the background noise becomes what you listen to. However, you would not be able to have as much of a variety of other uses for the analog radio, as "Spooky" does.

Without the 1N34a diode, some of the trickier experiments like shining a laser on the diode, or hearing a lightbulb, won't be possible. Diodes are cheap...if you can find them!

Question, all the ferrite loopstick inducters i have seen have 4, 6 or even 8 wires coming out of it, to have different sizes of coils. How do i know witch one i need?
mrfixitrick (author)  RocketPenguin3 years ago
The coil should have the micro-henrys indicated in the literature. Use the pair of wires closest to 680 uH. If you don't have that info, then experiment with each pair of wires to get the best signal.
Oppzuz3 years ago
Those signal pulses appear to be the WIFI "Beacon" set by default on my router to 100 milliseconds (10 Hz). Those are constant as long as the WIFI is enabled.
Have you tried to test if this receives radio waves or energy that can be converted into voltage through the use of a radiant energy device which through the use of a simple circuit converts radiant enrgy into voltage?
mrfixitrick (author)  WV_Kokamo_Joe3 years ago
This circuit already converts radio waves and/or light waves, laser light, and/or sound waves into voltage. The voltage is converted to sound wave frequencies that we can hear. The same diode circuit could be used to recover energy from, say, the sun, or a light bulb. But solar panels are much more efficient!

Where is your definition of "radiant energy", and what real and working radiant energy device do you refer to?

I just built a device with 4-ceramic 50V .1uFdisk caps, 2 radial 100uF 250V caps and 4 germanium diodes 75PRV .005A, which when hooked up to an antenna does in fact produce voltage from the thin air ;}, low amps of course but does create voltage.

I am studying how to step this up to get more amperage as well as volts so I can possibly build a device that provides voltage without the use of batteries or any other form of man-made voltage.

I already know that if I connect 2 of these circuits together that it will double the output.

I am trying to find plans on a suitable antenna that will harness energy waves such as your antenna, for input of the energy I need.
mrfixitrick (author)  WV_Kokamo_Joe3 years ago
Nikoila Tesla, in his Radiant Energy patent,( U.S. Patent 0685957 - Apparatus for the Utilization of Radiant Energy) claimed that a flat surface that was "as large a surface as practical" and "highly polished or amalgamated" was best to act as a receiver.

Tesla also notes that the best in insulation (mica in his time) must be used for the antenna because the slow accumulation of power from such a set-up might get bled off otherwise. A good ground is also very important.

There might be some kind of scalar antenna that will work for you, as new ideas are coming out regularly.
kmysterio4 years ago
hii dude..!!!!
this 1 s awesome...but can i know wat is the software u used..???
mrfixitrick (author)  kmysterio4 years ago
The software I used for Spooky is "Audio Hijack Pro" for Mac computers:

If you have a PC, you can try "Audio Mulch" at
If i modified this design a little do you think i could use it as a Microphone for my Ham Radio,or my Spark Gap transmitter? I'm trying to make a cool looking nice microphone and instead of using a Morse code key in my spark gap transmitter replace it with a microphone so i can transmit voice instead of Morse code.
mrfixitrick (author)  Stefhan Albayaty3 years ago
Although I have demonstrated the use of the Spooky Tesla Spirit Radio as a microphone,http://www.youtube.com/watch?v=-oCI9XvFU_M I can't say my configuration would be the best choice for your application. It may work with the addition of a sounding board with larger magnetic coil...then you would be starting to duplicate a microphone.

Is there a circuit you have seen for converting Tesla coil output to music/voice ?
redyellow3 years ago
Scott's electronics only sells 60/141pf variable capacitors now. What if any effect will this have on the radio? Thanks.
Ian Fowler3 years ago
what voltage are the caps?
Southclaw3 years ago
hmmm,now,how could you get this to work with a regular set of ear buds? It was kind of hard to tell if you are using a crystal or a vfo,which are you using,and I don't see why it could be that hard to get it to work with a regular set of ear buds,what exactly did the computer do? please explane.
mrfixitrick (author)  Southclaw3 years ago
The signal from the circuit is very weak and will not drive a set of regular earbuds. You must use crystal radio earphones, (which are high-impedance), or use an amplifier. Then you would be able to hear a scratchy local AM station...if you are lucky.

The Mac with Audio Hijack acts as both an amplifier, and as a pitch (frequency) changer in real time. This enables one to hear what would normally be static, for example, as enhanced sounds with deep texture and ambiance.

Signals we might not normally hear get amplified and "translated" by the software. This requires an extreme gain (volume) increase and a shift in frequency, otherwise the subtle sounds are lost.
I've built it per instructions. But, instead of "spooky" sounds I get strong broadcast of local radio channels.
I needed it for sound effects for a horror movie I'm working on.
Any suggestions what mods I can implement to achieve the "spooky" effects?
Thank you!
mrfixitrick (author)  artemmishin3 years ago
You are on the right track by being able to receive stations.There are two things that come to mind to get spookier sounds from your radio... 

First, are you using the Audio Hijack Pro software for Mac OSX, or Audio Mulch for PC?  Audio Hijack works really well to alter sounds. The AUPitch control is one easy way of doing that. Even a strong broadcast can be made alien-sounding.
-My custom patch for Audio Hijack is here: https://files.me.com/mrfixitrick/6axuh4
-My patch for Audio Mulch is here: https://files.me.com/mrfixitrick/0f04x2

Second, the radio you have made happens to be overwhelmed by strong local stations. You need to be able to tune BETWEEN stations if possible. When you turn the variable capacitor do you hear only strong stations? Is there any place on the dial where there is not a station?
-You can try adding or removing a few coils from the 10-coil winding that goes over the induction coil. 
-If necessary, you can "re-tune" the radio to to other frequencies by using an antenna induction coil that has taps for different frequencies.
-A variable capacitor with more range will help too.

Some effects are done by resonance with the induction coil, such as running a drill close to it will produce a sound. Some effects are done with light played on the diode. The antenna is less necessary in those cases, and so it could be shorted with a piece of wire to ground, which should stop the reception of local stations. Or, try removing the antenna altogether for those type of effects!

Thank you so much mrfixitrick!
I will try all the suggestions and report back!

PS Trying to use both Mac and PC.
PS 1 These links don't work anymore, by the way:
-My custom patch for Audio Hijack is here: https://files.me.com/mrfixitrick/6axuh4
-My patch for Audio Mulch is here: https://files.me.com/mrfixitrick/0f04x2

mrfixitrick (author)  artemmishin3 years ago
Ok, for some reason those patch files did not stick. Instead, you can select Go/iDisk/ Other User's Public Folder, user "mrfixitrick", and find the patch files, or this link: https://public.me.com/mrfixitrick
Now,are you using a crystal for the jam jar then on your computer changing the frequency? all I really want to do with it is hear lightning like in your vid,if the computer is doing what I think it is doing,that could be accomplished with a simple synthesizer,yes?
mrfixitrick (author)  Southclaw3 years ago
You can hear lightning in an AM radio, if that is what you want. Hook up the radio to your synth, and then amplify and modify the sounds.

Otherwise, to get the sounds that I got, you need to try what I suggest with the crystal circuit and a computer. A PC computer with the program AudioMulch can also be used, but it doesn't work so well as a Mac and Audio Hijack.
ok, sounds like if I could somehow make it work with earbuds I need volume and a vfo, ok
nerd74733 years ago
this is so cool i want one
Southclaw3 years ago
you say that you changed the sound with the computer,what dose it sound like without any of that?
mrfixitrick (author)  Southclaw3 years ago
Without the computer, if you are able to hear it at all, you will get static sounds and maybe a feeble local radio station.
alcurb3 years ago
I was going to look at your parts source: http://comtrolauto.com/ but the web site is no longer active. It's a dead link. Can you mention other sources for the var cap and ferrite antenna?
mrfixitrick (author)  alcurb3 years ago
Try the following and let me know if it works. If not, just search E-bay for "crystal radio" to find parts and kits.

For my browser, http://comtrolauto.com does an automatic referral to Scott's electronic page here:  http://www.angelfire.com/electronic2/index1/index.html

Thanks for the other source. From there I ordered the diodes and a substitute for the variable cap. I ordered the Dual 266/266pf Variable Capacitor. I figure that with the substitution I can explore lower frequencies. I also ordered their ferrite antenna coil which is 680 uH but it has a 470 uH tap. Can I use the tap instead of the 10-turn external hand-winding? In your project you wrapped it 10 times with a thicker gauge wire while the tap is 20 wraps of the fine-gauge.
doesdeer4 years ago
My living room subwoofer some times picks up the local am radio station despite there being no input, that is, from the receiver's output. I have yet to be able to predict lightning from it.
JuCo doesdeer3 years ago
i stepped on my guitar cable that was coiled up on the floor once (at the time, i was using a really cheap cable with no shielding) and all of a sudden i started hearing a korean woman's phone conversation coming out of my amp. she was probably using a cordless phone,

the weird part was that it didn't sound like the mother of the korean family that lives next door, so i don't know how far off the the signal came from.
A friend of mine had a chair attachment with speakers, and if you plugged the speakers into the adapter included halfway, it would bring in some radio station through the speakers... not sure which, though.
mrfixitrick (author)  doesdeer4 years ago
Apparently, some peoples teeth do the same thing!
mazoo4 years ago
Just not sure of how to wire up the "football' antenna start ,ends,loops etc
please advise?
mrfixitrick (author)  mazoo4 years ago
I'm not sure how to "properly" wire the football coil either!

There seems to be three basic styles...

1.) Wind the coil starting from one end and right through to the other end, all one piece of wire. that will give a connection point at each end of the coil.

2.) Wire one end clockwise and the other anti-clockwise, join them in the middle.

3.) Same as 2 above, but don't join the wires in the middle.

The original Tesla football coil used high voltage to activate it, so the purpose here as a crystal radio antenna is different...therefor, there's certainly room for improvisation.

Besides, by experimenting, you may come up with something interesting that has been overlooked!
Thanks very much. I will certainly give it my best shot!
all the best!
mazoo mazoo4 years ago
10 gauge wire is impossible to find in my area...<2.59mm>for pancake ant.
can I use 2,5mm or 2,65mm also the wire is coated...also unable to get uncoated!
14 guage I am able to get 1.6 mm only
much appreciated!
mrfixitrick (author)  mazoo4 years ago
The wire you have should work ok. I stripped my household wire of its plastic coating.
ninja_joey4 years ago
Any advice on how to process for the pancake antenna? My team and I have a bit of difficulty doing them!
mrfixitrick (author)  ninja_joey4 years ago
I hand-wound the first pancake antenna without a form...but it was not easy or perfect.

Then I made a form using 2 of 4 inch diameter round pieces of clear 1/4 inch polycarbonate plate. Drilled a 1/4 inch hole in the middle where I inserted a bolt, with nut and washers.

Bolt the two halves of the form together with the bolt after beginning to wind on TWO pieces of stripped 14 gage wire about 5 to 6 feet long.

Leave a gap between the two plates equal to the exact wire thickness, and then wind the two wires around the bolt simultaneously. When finished winding, you are left with two intertwining perfect coils that can be removed after separating the plastic plates.

Hope that helps!
Yes. It does.

Would you happen to have any images that show the plates you used to coll the pancake antennas?

mrfixitrick (author)  ninja_joey4 years ago
Here are some pics of the pancake antenna/coil winder form I made:

mrfixitrick (author)  mrfixitrick4 years ago
The two wires go through the two holes first, then the plates are bolted together.

Two wires are used, as one is the spacer for the other. Then two antennas can be removed from the form when finished winding and then separated.

Or they can be wound in a Bi-filar way, and then remain together.
The completed antenna or coil can either be left in the form, or set loose.
doesdeer4 years ago
Do you know if Tesla had run across what is known as a "whistler" in today's world?
mrfixitrick (author)  doesdeer4 years ago
"Whistlers" result from lightning travelling along the Earth's magnetic field lines. I'm sure Tesla was listening to whistlers in his Colorado Springs experimental receivers. Listening to lightning was one of his main activities there.
freyes44 years ago
have you a tutorial in spanish? i can't translate every word :C i need build this radio ps: sorry my english is very bad
Hey, si tienes paciencia yo lo puedo traducir, ya que tengo todas las ganas de hacerlo!!

Hey, i can translate it for i would eventually going to make this instructable!


Do you agree? The only thing i crave for is patience.
Gracias Thanks, tengo paciencia, te esperaré
mrfixitrick (author)  ndeclares war4 years ago
Thanks for the offer!
I would be happy and grateful if you would do a translation!
Then, i´ll do it =D
mrfixitrick (author)  freyes44 years ago
I don't yet have the tutorial in Spanish.

However, I would be happy to help you to understand. You can use "Google Translate" to get a rough translation. Perhaps I can help with explaining something difficult in a different way.

Tell me what you need to know to get started. Can you get a basic crystal radio kit ? Do you own a Mac computer?

if i dont have a mac computer ... aahmm cant use this radio?
only this radio work if i have a mac computer?
solo funciona si tengo un mac?
mrfixitrick (author)  freyes44 years ago
It will work as a normal crystal radio, but to get the "spooky" effects, you need a real-time audio program that can amplify, alter and record sounds in real-time. The Gain must be increased very much, and the Pitch needs to be altered as well.

There must be a PC program that will work as well as the Mac program Audio Hijack Pro, but I have not seen one yet.
mrfixitrick (author)  mrfixitrick4 years ago
I have just tried a Mac and PC program called Audio Mulch and it will work fine for the purpose of the Spirit Radio with a PC. It's expensive to buy, but you can download a 60-day free trial that works great here.

I set up three "MGain" patches in the Audio Mulch software and it increased the volume enough to hear radio stations and electromagnetic fields clearly. Then I added various controls such as pitch and reverb for strange "spirit" effects.
mrfixitrick (author)  mrfixitrick4 years ago
PC users can download a SpookyRadio preset for AudioMulch here:   https://public.me.com/mrfixitrick
pbebergal5 years ago
Hello, Must I use a PC for this project, or can I use a small amplifier? Thanks, Peter
mrfixitrick (author)  pbebergal5 years ago
Some small amplifiers will produce sound, but the sounds will be mostly static, humming or a radio station. Adding a pre-amp may help, because the gain must be turned up high to hear the background sounds we are looking for. The software alters the pitch in real time, which is critical for picking up interesting harmonics in the upper and lower than hearing ranges. That's why the software helps so much for fine-tuning. For example, lightning sounds like simple static when using a plain amp, but it can sound like real thunder with the real time audio software, through pitch alteration, reverb. and lots of gain. I use a Mac and Audio Hijack Pro software. I don't yet know of an equivalent real-time program for the PC, but there must be something that's close.
mrfixitrick (author)  mrfixitrick4 years ago
Folks can try a 60-day free trial of Audio Mulch at http://www.audiomulch.com/download.htm for real-time audio software that works with both PC and Mac.

This seems to be a solution for PC users, but it is expensive to purchase.
mrfixitrick (author)  mrfixitrick4 years ago
I have made a preset for AudioMulch called "SpookyRadio1". It's available at my iDisk here: https://public.me.com/mrfixitrick (after downloading, use File/Open in AudioMulch to use it.)
yarzuza4 years ago
Hi, I want to know how can i do Ferrite Loopstick Antenna because i see there is a little piece between the copper wire and i dont know what it is! can you tell me plz how can i do it?
mrfixitrick (author)  yarzuza4 years ago
Besides the ferrite, sometimes there is a tiny magnet wound into the coil.

If you don't have the ferrite rod type coil, then you will need to build the antenna coil differently.

The ferrite increases the coil inductance which moves the frequency lower. The capacitor is selected to resonate with this frequency.

So, if you hand-wind a coil, it will have to have more inductance than the ferrite one by winding more loops, or using a "tapped" coil. The form for the coil would be larger in diameter as well. A toilet-paper roll has been used traditionally.

Search google for "crystal radio coil" for examples.

It's usually worthwhile to purchase a pre-made ferrite coil for a couple of dollars from a crystal radio parts dealer.

Does that answer your question?
yeah, thanks. another question, why is it necessary using the audio software in real time? can`t I just using the PC sound recorder? We put it together and it doesn`t work and we dont know why.
We didn´t found the 1n34A, but we want it to respond to other electromagnetic fields. Can you help us?
mrfixitrick (author)  yarzuza4 years ago
If you listen to the radio in real-time with audio software, it will be easy to hear if it works or not. The signal MUST be amplified very much in order to hear it.

If you record with the PC sound recorder, you will need to increase the sound volume through several gain increasers. That means amplify the signal, amplify it again, and then amplify it again. You will be amplifying a lot of noise as well. Even then, you may just hear static.

The Audio Hijack software converts harsh static into a range of pleasant sounds with the live pitch control, reverb and gain.

 The 1N34A diode is necessary to convert the AC antenna signal to DC, in order to hear the AC radio signal as sound. (That is probably why you get no sound!).

The 1N34A diode is inexpensive, and may be ordered from a place like ComtrolAuto or other crystal radio suppliers. Shipping will be expensive, however. Perhaps check a local Ham Radio club to see if someone has a 1N34A diode they could give you.
mrfixitrick (author)  mrfixitrick4 years ago
Folks with a PC computer can use the sound program AudioMulch to amp the sound signal from the radio. It can be downloaded here:http://www.audiomulch.com/download.htm it's free for 60 days.

I have made a preset for AudioMulch called "SpookyRadio1". It's available at my iDisk here: https://public.me.com/mrfixitrick
(after downloading, use File/Open in AudioMulch to use it.)
geek101024 years ago
could this work with the cyclotron d electrode style antenna
mrfixitrick (author)  geek101024 years ago
Definitely. "Spooky" loves to work with quantum physics...Spooky action at a distance is it's speciality!
riverreaper4 years ago
you say picks up radio unless you turn freq way up , do u have a knob that you can turn the freq up an down on , is it picking up am or fm radio freq. ? an if you hooked up difernt tunners to it would it then work like my scanner an or c.b. radio could it also pick thoues freq. up ? if i had dipole antenas of like say ham or c.b. could thous be hooked to it , if so im thinking a swichbox for antennas might be in order . what grounds it or is that why its all in a jar ..also when you talked into the jar if your niebor had one an was on the same freq. would they have been able to pick u up ?
mrfixitrick (author)  riverreaper4 years ago
The tuning knob is an adjustable capacitor that usually changes the resonant frequency of the circuit to be in tune with a different range of the AM band.

Crystal radios tend to be tuned to the AM radio band because that is easiest part of the electromagnetic spectrum to pick up with the relatively crude technology.

This radio uses sources other than the AM band, such as direct magnetic waves, capacitance, light waves, etc. The tuning knob helps tune in a resonant or otherwise interesting waveform to listen to.

I sometimes attach a 22 foot indoor antenna for much better reception of AM and lightning. You should use a properly grounded antenna for lightning detection. ;)

The ground is through the computer internally by waay of an audio cord. I find the computer ground works better than a ground to earth wire or a wall-plug ground wire, because the computer sound input ground seems to filter out 60 cycle AC hum.

I don't know about the talking in the jar thing you mention. The radio may act as a transmitter, especially when hooked up to a separate antenna, but as an unpowered transmitter it would have a very short range if it worked at all.
you should ground that antena outside atleast 6ft deep if lissening to lightning an three grounds off same line would be best , try this too if you want harmonic
or other interferances gone ,...6 ft down from end of your anttena ciol the line that will feed into your radio 6 times at diamerter of a a coffee can {coffee can is easyest to use to coil it } use duct tape to hold the coil . try aplieing enough tape so its ridged an not saggy . seems thou if you have to mutiplie the sounds threw your applicator that much , you might have told about thoues steps a bit more in detail . it does look cool thou ,...but i can repucate all them noises with my synth an dont need to wait for lightning to come along an fry the computer or an me :O) saffty first isnt always pointed out in here thou it should be ....
While I agree with your safety concerns, you might however be missing the point entirely when it comes to sounds received by the device. I can make strange noises too, but to capture them from an otherwise unknown source is part of the mysterious nature of this device. The only mystery your synthesizer would present is why the operator is making such odd noises with it.
Absolutely awesome Instructable! Truly amazing effects and perfect for a Hallowe'en party. An attractive little thing to look at too.

Such a shame Tesla wasn't recognised as its inventor before he died.

Thanks so much for posting!
duboisvb4 years ago
Hello, I built this radio and it works!! Thanks for the instructable. When I was testing it with jumper cables ,I could get a station very clear and loud at 1390 on the dial. After soldering it all together, I get a station at 950 but not the 1390 one and it is not so loud or clear but still pretty good. Do you have any insight into what may have changed or what can I do to get the 1390 one back?.
mrfixitrick (author)  duboisvb4 years ago
Congrats on making this project!
Welcome to the sensitivities of the crystal radio set...

I too, find it difficult to reproduce these crystal circuits with any accuracy, due to the funkiness of the assembly, the "loose coupling" of the antenna, the difference in length of wires, the ground system used, etc.

It's all about resonance...

Perhaps the jumper cables you used were enough to lengthen a wiring connection, and so alter the resonant frequency of the circuit.

Perhaps the antenna connection is different, with a shorter or longer lead to the induction coil or antenna.

You could try less (or more) wraps of wire around the induction coil to alter the receiving frequency range. Or try changing the antenna length. Good luck!

Hi sir, Very nice project ! I would like to know why did you use that capacitance / inductance. I mean, 680 uh and a variable capacitor that is 60/160 pf. According to my calculator your circuit will resonate at 0.483 mhz to 0.788 mhz. Why do you choose that range on the band ? Is it for any special reason ? Very nice radio. Thanks in advance. Carlos
Hi Carlos,
Glad you like the project. It has much to offer an experimenter.

Generally, AM band radio waves transmit best, and are easiest to pick up with a crystal set. The AM radio band frequencies are 535-1605 khz. (or .535 to 1.605 mhz) so the radio is tuned to the low end of the AM spectrum. A variable or tapped induction coil can provide a greater range of tuning.

The spirit radios of EJ Gold inspired my Spooky Tesla Spirit Radio. His circuit is tuned to two AM stations that are close in frequency and by wave cancellation, the resultant resonating frequency is 7.8 Hz.

7.8 hz is the Schumann Resonant Frequency of the ionosphere, and it also happens to be our Theta brain-wave frequency. For more on that aspect, see http://www.brane-power.com
stehen5 years ago
Hi, i would like to build The Tesla Spirit Radio but i am terrible at electronics.Would you be willing to build it for me and sell it to me.I live in bristol in England in the UK.I enjoyed watching the videos on The Tesla Spirit Radio.My favourite video was The Tesla Spirit Radio wormhole voyage #1.Can The Tesla Spirit Radio open up a wormhole? I think that your Tesla Spirit Radio is very good.Kind regards. Dennis
mrfixitrick (author)  stehen5 years ago
Hi Dennis, Glad you enjoyed the Spooky Tesla Spirit Radio. I think in a sense it can really open up wormholes. Some say that wormholes open for us every day, but we do not normally see them or make use of them. I can build a Spirit Radio for you, but I have to charge $130. Canadian, plus shipping. That would include the two spiral antennas, but not the special "football" shaped antenna. Also, you will have to use a Mac computer to get the sound effects I do. Are you still interested? Cheers, Rick
why do you have to use mac? ive studio one an it works with both mac an pc
mrfixitrick (author)  riverreaper4 years ago
I use the Mac and Audio Hijack Pro because it works. There must be a PC alternative setup but I have not found one yet.

It must be a program that can both record and alter the sound in real time, using adjustable sound modules such as AUPitch and AUGain. The gain is raised several times over through each gain, pitch and reverb module.

The big secret is the pitch controls which can produce very interesting results. Reverb helps accent the fainter sounds as well.

Using three AUPitch modules in series enables fine tuning of high frequencies...and low ones, by transposing the pitch of the radio's sound through several tens of octaves up or down.

Dear Rick, thanks very much for your reply.I am still interested. I am delighted that you will build the spirit radio for me.You said that you will charge $130, canadian, plus shipping.That is alright.You also said that you have to use a Mac computer to get the sound effects you do.I do not have a mac computer.Just a normal personal computer.Will that be alright? If not where do i get a Mac computer and how much would it cost? Would you accept payment by Western Union.You go to a Western Union outlet with a reference number i give you and you collect the cash. My address is 7 Moorfields Close, Redfield, Bristol BS5 9BY, England, UK. If you give me your details i will make arrangements for payment to you with Western Union.Kind regards. Dennis
Or Stehen... You can use a FOSS program called Audacity (http://audacity.sourceforge.net/) theirs ports for linux, MAC's, and windows machines. if this doesnt have all the variables you need just keep looking into FOSS as theirs literally hundreds if not thousands of interesting Fee open source software projects with binaries available for many platforms. $130 is okay if you the type to really just buy things and not want to really get the parts etc and DIY fab your own setup, Currently i think i might like to incorporate a nifty little circuit bent CR setup with some sort of midi interface/ light curtain sytem for live performance of my band called "Fecal Fetus"
mrfixitrick (author)  stehen5 years ago
Ok, let's communicate by e-mail, as this is the Instructables comments section. My e-mail is mrfixits@telus.net Send me a message. You may wish to delete your last instructables comment with your address, etc in it. I have saved it to another app. You would be better off with a Mac, because I have not found suitable PC software. There may be PC software that will work in a limited way. It can be an older iMac like one I have that is 4 years old. (flat-screen type iMacs) Mine won't run the latest system software, but it can run the Audio Hijack Pro software fine. Macs are good for sound and music recording and playback. It will likely cost a couple of hundred $ (Can) Audio Hijack software is free for trial use up to 10 minutes at a time. $32 gets the full version with no time limits.
jimwi4 years ago
Has any body tried this as a BetaBlocker yet and if so how did you do it? Do you hold the coils or put your head between them? I would like to try and see if it works but not shaw how and I do not wont to pay 2 or 3 hundred dolars to find out. BTW That is a very nice radio I just love the coil look TOP JOB.
hello i love the invention and would like to incorperate it into my music, but dont know where i can get all the supplys (i live in canada and cannot get the parts shipped from the company you suggested, is there a canadaian based one?) and was also wondering if you knew any sugested programs for using the radio on windows computer.
mrfixitrick (author)  didgeridoodle5 years ago
The supplies can be bought from http://www.comtrolauto.com who do ship to Canada. They use Paypal as well. I have not found an adequate and cheap sound program for PC that will work in real time. Some programs will work as audio amplifiers, and some work to modify the sound file after it is recorded. I'm willing to try a PC program if you can suggest one.
i sent comtroolauto an e-mail and they say do to to much lost products in mail out of america he only ships in america now. so i would have to get him to mail it to a friend in america to mail it to me. Are there any canada based companys i can look for? or someone in america i can ship it to to ship it to me
there are companies dedicated to simply reshipping to different destinations.

i searched google for “reship to canada” and immediately found two options.  just figure out what is best for you.
Hey didgeridoodle. Sorry you can't get your parts but for recording check out Audacity. You need the lame mp3 encoder but it's all free. Works well.
mrfixitrick (author)  didgeridoodle5 years ago
I'm sorry to hear that, and I'm working on it.
if you make that 130.00 take that an go buy a AUDIOBOX-USB it will come with studio one artist program as well , nice little bounes . that will alowe you to use a pc an notr limit you to mac .
arhodes185 years ago
very, very, very cool!!! Tesla is my hero, in fact I plan on becoming an electrical engineer! 
How much total do you imagine this would cost? 
I once saw on a show that on normal AM radios, you can pick up the sound of Jupiter in the desert at night if you tune it to the very high frequencies, I just so happen to live in the desert and I was wondering if this would be able to tune high enough to pick up the sounds of Jupiter?
I will make of these very soon!!!
Fave'd and +5 btw...
mrfixitrick (author)  arhodes185 years ago
 Good to hear you wish to become an electrical engineer!
The basic crystal radio parts can be had for about $10, then there are the fittings for banana plugs and so on that can add up to another $20 or so. So with $30 to $40 in parts, this device can be built. 

The antenna will make a big difference in getting sensitivity out of this radio. Generally, the longer the better, but 22 feet is often chosen as a harmonic compromise.

There are reports of hearing the sounds of the cosmos through one of these little units, and of parallel worlds we will not speak! (hehe)

Very nice instructable. I've got parts on their way for mine. I do have the question regarding the 22' antenna.  Does this need to be linear, or is the 22' coiled up what you're talking about. Would longer produce different results? 

mrfixitrick (author)  odiekokee5 years ago
 I was referring to an external linear 22' antenna. I string mine across the living room ceiling. A longer antenna usually produces a louder sound (more gain). For sounds from a local source, the antenna on the radio works fine. Most local electromagnetic disturbances are picked up by the ferrite loop-stick antenna anyway. The longer antenna is for more sensitivity to AM broadcasts or listening to lightning.
So this antenna must be linear instead of the coiled/football?   This thing will spend most of it's time in my office, so it would be helpful if it is as compact as possible.
mrfixitrick (author)  odiekokee5 years ago
 I would try the radio as is, and see if it works ok for your purposes with just the coiled antennas. The football coil is tricky and less sensitive for AN use, so avoid that. And a longer linear antenna may pick up on office equipment noise anyway.
 Ok. 100% built according to instructions, but with a different container. Electrics are good.  Now, I don't have access to any apple based computer. What other windoze programs could server the same purpose?

anyone know of a windows or linux program that will give me the real time editing needed??
 thank you for the information. just out of curiosity, do you 'have' to use the audio jack to the mac? I do have a mac but I was just wondering if you could hook it up to some little speakers instead, or if I was understanding this part wrong...
mrfixitrick (author)  arhodes185 years ago
 In order to get the sounds that I did, you need to run software that can amplify and co-create the sound in real time. The Audio Hijack software pitch control, for example, allows certain resonance's to occur, and both ultra-low and ultra-high frequency sounds to be somewhat brought into the normal audio range. Also, normal audio can be raised or lowered in real time to a whole new level.

You can hook up this radio to amplified speakers, and you should get AM radio, and some other static sounds. An external antenna and a good ground may be needed to hear it well. However, without a way of increasing gain (volume), and adding the pitch control and reverb, the sounds will be relatively flat and empty. The audio software adds a whole other dimension to the sounds, and is actually part of the L-C (inductor-capacitor) tuning process.
 oh ok i understand... is the software free? and would it be effected to make an amplified speaker circuit using an op amp, because i have found how to make one that has adjustable gain and volume controls...
mrfixitrick (author)  arhodes185 years ago
If you have a Mac, the software to use is Audio Hijack Pro. It's available as a free download that is full-featured, except for static is overlaid after about 10 minutes of use each time it's used. It's $32 to buy it, which I think is a great deal.

If you have a PC, there's a chance that a program like ProTools can be used, or a similar real-time sound editing PC program. I hope to experiment with a PC soon with the Spooky Radio.

The op amp may work; I don't know. How about experiment with it and get back to me?
 sounds good, ill let you know how it works out!
wiiman8 go here to get the right perspective in Electrical Engineering. http://www.cheniere.org/ Traditional schools will fall far short of what you need if you actually have Tesla as your hero.
I will have a look! Thank you! I really appreciate the support!
 Haha, I remember watching a documentary about Tesla back in grade 11 physics, and he became my hero too, lol.

*high five*

 haha very nice!
meanbean4 years ago
I just want to know how to make the spinning ghost!!
mrfixitrick (author)  meanbean4 years ago
The Spinning Ghost is simply a homopolar motor with a tissue set on top.

A homopolar motor consists of a neodymium magnet, a AA battery, and a piece of solid copper wire (any gage from 8 to 16 gage will work).

The wire is bent into a heart shape and the lower legs contact the magnet while the top of the heart contacts the battery.

See my Youtube movies on the homopolar motor at http://www.youtube.com/user/MrfixitRick#grid/user/CE35CBBBFEF6E365
Articas5 years ago
Sorry probably stupid questions but do i have to make the jam jar enclosure of can i use a bread board to make it also where do i connect the ground of the variable capacitor and can i use head phones with it
mrfixitrick (author)  Articas5 years ago
You can use a bread board instead. The middle connection of the variable capacitor is ground. Regular headphones won't work if you are trying to use this as a normal crystal radio. High-impedence earphones work with crystal radios and some old-time phone handsets too. If you run the radio output through a computer or other form of amplifier, then you could use headphones.
so i could use a crystal earpiece
GGShuffle5 years ago
I absolutely don't understand what this thing does ... ??
mrfixitrick (author)  GGShuffle5 years ago
Your program will not have the same settings as Audio Hijack Pro, the program I used.

There is a new screenshot of the settings in step 8, third picture.   

Basically, there are three pitch modules in series as well as two other forms of gain, "Gain"  and "10-step EQ". The reverb also adds to the volume.

The radio's audio signal must be amplified severely in order to get the effects I do.
rsobchak5 years ago
Is there any links you have of pictures to where I can clearly see your pitch and reverb settings? I have a program to record, then edit sound and would like to know what settings you have it at.
mrfixitrick (author)  rsobchak5 years ago
Your program will not have the same settings as Audio Hijack Pro, the program I used.

There is a new screenshot of the settings in step 8, third picture.   

Basically, there are three pitch modules in series as well as two other forms of gain, "Gain"  and "10-step EQ". The reverb also adds to the volume.

The radio's audio signal must be amplified severely in order to get the effects I do.
You can't leave out that he didn't think it was worth receiving and sending Hertzian waves because he wanted to transmit electrical energy across/through the Earth.
mrfixitrick (author)  typenamehere_____5 years ago
That's absolutely correct. Tesla considered his transmitters to be only 10% Hertzian waves, and even that was a waste. Tesla was essentially working with standing waves, and waves that behave as "sound waves in the ether". Longitudinal waves as opposed to transverse. This way, Tesla wanted to transmit power as opposed to radio-wave information. He said that information (words, music, pictures) would be easily encoded into his power delivery system. Imagine you turn on your radio to listen to the news, and it charges your house battery system, or electric car, at the same time!
(following upon already posted reply) There was a nuclear powered car built, but it ended up exploding a few minutes after it was first started.
Oh my god, electric cars! I never thought about that! We could harness wind, geothermal, and nuclear power (safely) into transportation. Might get fined a couple billion if there's any *gasp* radio interference... Oh, wait; that does deserve a gasp: no cell phones until they are adapted.
Kasm2795 years ago
Nice iMac :D I see you are still on Tiger!
Hetoumon5 years ago
Hi, I dove to find all the components?
mrfixitrick (author)  Hetoumon5 years ago
I don't understand.  Can you ask your question in another way?
msim935 years ago
 In your version of "audio hijack pro" the reverb boxes are set up differently than the version I downloaded a few days ago.

What version are you using? you appear to have many more options than I do. It is just hard to copy settings when it doesnt look anything alike.
mrfixitrick (author)  msim935 years ago
The recent update to Audio Hijack completely changed the AU Pitch control.

You will just have to play with it, or get the previous version (version 2.92) of Audio Hijack.
msim93 msim935 years ago
 I meant Pitch, not reverb. My bad.
peeeeetr5 years ago
What's the wiring diagram from the primary to the secondary? It looks like you've wound the two halves of the primary (small wires) separately, then connected them. How are they connected, is it just connected in the middle? Then, it looks like you connect the secondary (large wires) in parallel. Is that correct? Also, are the primary and secondary wound in the same direction, that is, both clockwise?

Lecture5 years ago
 man, the lid needs to be made with that kind of material? or i can use a normal glass can lid?
mrfixitrick (author)  Lecture5 years ago
 A normal metal lid will conduct electricity. It could possibly be used as a common ground for the components. The wiring would be different accordingly.

You can use thin plexiglas or lexan, or a piece of stiff plastic cut to size. Maybe part of a plastic jar lid. A thin piece of wood could work too, as a non-conductive surface.
 Thanks! =D
What is the lowest and highest hertz produced by the radio?

I'm going to have the input hooked up to a Cmoy-type single amplifyer hooked up to speakers or headphones.
mrfixitrick (author)  brooklynlord5 years ago
 The hertz produced in the output of the radio ranges from a few cycles per second to above hearing range (20,000 hz plus)

The problem is the signal is very weak, and an amp may not be enough to bring up the sound. I use software and add several gain controls to keep upping the volume. Extreme pitch control is also useful to get results like I do.

Try it, maybe it will work!
What gain do you have aon your computer software? According to tangentsoft.net, you can change the gain with the value of the resistor.

However, if the gain is truly high, maybe i can build a gainclone....
Also, is there a simple adjustable pitch-tuner circuit that is easy to build?
mrfixitrick (author)  brooklynlord5 years ago
 There might be a pitch oscillator circuit available. I use software; it's easier and works far better for these purposes.
mrfixitrick (author)  brooklynlord5 years ago
I use Audio Hijack Pro for the Mac. There is a free evaluation copy available that runs for 10 minutes at a time before adding static. I liked it enough to buy it. Audio Hijack has easy-add modules to increase gain, plus AUPitch controls to really alter pitch and further increase gain.

If you have a PC, I'm not sure what to use yet. The software has to work in Real Time to alter sound and record it, preferably.
jetgoggles5 years ago

Is it possible to hear the conversations between an airplane and an airport?
& Is it true that we can hear ghosts ?

mrfixitrick (author)  jetgoggles5 years ago
Generally, airplanes use higher frequencies than AM radio, which this radio is primarily tuned to.

Regarding ghosts, it is true that many people believe they can hear ghosts. Perhaps some people can and some can't...or won't!

There are certainly ghost-like sounds that come from this radio and ones like it. 

Biotele5 years ago
At the time of tesla there was no diode and I am not even sure if they had electromagnetic speakers. What doe the original patent say? Can you post the patent?
mrfixitrick (author)  Biotele5 years ago
 The diode was available to Tesla in the later part of his life, but I doubt he would have cared. By that time, Tesla was way beyond AM radio.

In his original experiments, for example at Colorado Springs, Tesla used rotary coheres partly filled with ground nickel in circuit with sensitive solenoid-type detectors that gave an audible beeping sound. The diode makes a handy replacement for those in the basic LC circuit.

Here is a link to the radio patent in question, #645,576. There are other associated patents and circuits, however. 

where exactly does refer to his radio? From where do you quote Tesla? I am curious as to how heard speech on his device. Did he suffer from musical ear syndrome?

mrfixitrick (author)  Biotele5 years ago
Tesla usually refers to his radio as his Magnifying Transmitter or World Power system. Tesla did not believe in the utility of Hertzian waves, thinking of them mostly as a waste of energy, and an unfortunate side-effect of his system.

I quote Tesla from "Talking With The Planets", an article he wrote for Colliers Weekly.earlyradiohistory.us/1901talk.htm

Here's Tesla's Colorado Springs Notes that have much of his experiments with radio LC circuits.

Here's a detailed investigation into Tesla's Colorado Springs receiver experiments:

There are many articles on Tesla's radio, his interplanetary communications, and his philosophy at Pepe's Tesla Page...here is the link:
Your circuit is half built. You have to excite the circuit into resonance (this increases sensitivity) then you rectify the output. The Corums explain that the Tesla radio is an early type of regenerative radio. But keeping with Tesla's theory of scalar waves and magnifying coils, one coil should be bigger than the other but both should be resonantly coupled like a in a normal Tesla coil.

What you should do is build a solid state low power Tesla coil, then rectify the resonant signal in the circuit.
tesla radio.jpg
Scalar waves are a very recent idea (and probably more of a pseudoscience than an actual idea, at least as far as I know). Tesla's theory did not involve scalar waves at all, he didn't even mention such a thing. He did say that his transmitters used "non-Hertzian waves" (i.e. not radio waves), but this was because he wasn't using a "wave" at all. He was using the electrostatic capacitance from the Coil top to the ionosphere, and then from the ionosphere to a receiver coil. I recommend reading this:
There is a debate about what Tesla meant by "non Hertzian" waves. But it is clear that Tesla was talking about and electromagnetic wave that propagated in a different mode than Hertzian waves. The only other mode is longitudinal waves and Tesla many times described the wave transmitted from his Tesla coils as resembling sound waves, which means that the waves are longitudinal and therefore scalar in nature. There is an excellent explanation from K. Meyl. He describes in steps a though experiment that explains Tesla's waves:


Look under documents for the PDF.
But what exactly does "scalar" mean? I only know that it has something to do with mathematics, and that it is something that con men use to try and make their "magic pendants" seem scientifically credible.
If the waves are longitudal (which I do believe they are), could they be the same as electrostatic lines of force between capacitor plates? (which do, in a sense, travel in a strait line, as longitudinal waves do.)


very famous video on Longitudinal waves
Meyls best describes it here:


This website explains it more concretely:


mrfixitrick (author)  Biotele5 years ago
The  way I understand it, the crystal radio circuit is already a resonating LC circuit. That what LC means...Inductance and capacitance combine to produce resonance. The 1N34A diode acts as a rectifier to produce dc output from the ac input in order to drive a speaker.

the coil have to be tuned to couple resonantly. Meaning CpLp should have the same resonant frequency as LgC' (in the circuit diagram above).  Tesla used an electromagnetic oscillator represented by the gap to energize the circuit. The coherer "a" feedbacks energy into the oscillating tank CpLp. L is a High frequency choke preventing energy coming from the antenna to short to ground. Tesla used a telephone receiver to listen to the signal.
The coherent nonlinearlity slighty rectified the signal.
mrfixitrick (author)  Biotele5 years ago
Thanks for the clear description of a "proper" Tesla circuit. 
Perhaps it would be a good instructable to do! Interested?
I am interested but I have no time to build it. I can however explain to you how you can modify your circuit in order to best approach tesla's original idea.
vger13 Biotele5 years ago
can you post that or send to me in email i have built a few tesla coils from small to large but i do not know the math so if you could help i would greatly appropriate
Biotele vger135 years ago
Below is a rough circuit schematic of my approximation of Tesla's original radio. It uses a relay buzzer to energize the circuit just like Tesla's original radio. The diode replaces the cohere "a" in the original radio.

I placed the earphone exactly where Tesla placed it, behind the battery. But it can be placed after the battery.

The radio works at just at one frequency, that of the Tesla coil.

The variable resistor in the schematic is not necessary, but can be placed there to slow down the relay switching.
mrfixitrick (author)  brooklynlord5 years ago
 That is it exactly!

Keep in mind that the diode will only respond to the light from one direction (I'll let you figure out which way ;)
Also, the diode will only respond to A/C light (ordinary light-bulb for example) or DC light (laser, flashlight) that is moving.

Good luck with your experiments!
Uhhh..... when you said one direction you mean.........?
mrfixitrick (author)  brooklynlord5 years ago
The diode is directional. If you direct the light toward one end of the diode, you get a response. If you direct the light at the other end, there is no response.
Shadow13!5 years ago
I wonder how the spirit radio would respond to the Wii's motion sensor bar. All the bar really is is two infrared lights that the wiimote use to triangulate it's location. I also wonder how the radio would respond to the same visual on a screen on different types of screens such as plasma or led tv's or the old picture tube tv.
mrfixitrick (author)  Shadow13!5 years ago
The 1N34A diode would likely respond to the infrared, if it was directed at just the right angle, and there was a variation in the signal. (straight dc light does not activate the diode, but a change in light intensity does)

As far as the radio responding to different screens, that is a response from the radio and magnetic spectrums in both the ferrite coil and the antenna systems. 

It would be fun to try your suggestions to see what happens.
The radio response is different from my 5-year old iMac flat screen compared to a newer one, for example.

tenpcrisps5 years ago
if i were to buy a crystal radio or crystal radio kit, would i be able to make it do the same thing?
mrfixitrick (author)  tenpcrisps5 years ago
 That's what I did...it's a simple crystal kit, and any antenna can be used. The longer the better, ideally more than 20 feet helps greatly. You will need software to get the weird sounds I do, otherwise a regular amplifier will give normal radio sounds...but only with a good ground and antenna.
awesome, thanx :) thats great news
i dont want to pick up radio stations so much; i want to pick up disturbances from inside a room as people walk around it, perhaps from their shadows from certain lighting, or from their bodies, or both. it would be great if i could make a few of them, to place around the room, but somehow connect them all up to one laptop or something. also, i have windows so im not sure what software would allow realtime effects, if you have any advice id be really grateful
mrfixitrick (author)  tenpcrisps5 years ago
In order to pick up disturbances like you wish, it may require a special type of antenna set-up.  The antenna would need to be super sensitive by being very long, and perhaps in a spiral pancake shape. The gain on the radio circuit would have to be turned way up through the software.

You might consider metallic threads or thin wires hanging from the ceiling and attached to the main antenna. When people touched or got close to the wires, it would increase the volume, like touching a regular AM radio antenna. 

If a laser was played onto the 1N34A diode in the correct , exact direction, then when the beam was broken would produce a sound. A constant DC light like a laser won't make sound with the diode until the beam is broken or moved over it.  An AC light will make a hum sound when within a foot or two of the light-sensitive diode.The laser will work from a long distance.

What you really need is the Tesla Bulb. Tesla had a special bulb with a purple glow that would react to people in a room, and could respond to electrical phenomena that was many miles away!

The crystal radios could be connected with some audio splitter connectors (two inputs into one stereo 1/8 plug) into one cable that plugs into the computer.

I'm still trying to find correct real-time software for Windows and PC's.


tenpcrisps5 years ago
eventually id like to make one like this but for now id like to make a quick one to include in an art installation :)

mrfixitrick (author)  tenpcrisps5 years ago
If it has to function, then hook it up to a Mac and use Audio Hijack Pro to make sounds. The software is available as demo, and but only works for 10 minutes at a time then. That might work for your purpose  
tenpcrisps5 years ago
hi, id like to quickly make a radio, can i just buy a crystal radio and stick a large coiled antennae on it?
mrfixitrick (author)  tenpcrisps5 years ago
 Sure, you can do that. Go for it!

However, to get proper signal and be able to hear stations clearly will require either a long antenna (20 feet plus) and a good ground, or lots of amplification. That's where the software comes in. I use Audio Hijack Pro (Mac) to increase gain and alter pitch in real time. 

Cool project! I don't quite have the aptitude to interface the device with a computer (PC) but I want to try in the future.

I was wondering if this device could be adapted to function as a simple AM radio receiver until I get and learn the software. It appears that adjusting the capacitor would "tune" the device to different stations. Is this the case?

Also, when the device is tuned to a local AM broadcast, could a speaker powered by hosehold AC be used to increase the volume of the sound?

mrfixitrick (author)  mad_science_FTW5 years ago
Yes, the variable capacitor is used to tune in AM stations.

A powered speaker can be used as long as there is a good signal from the circuit. A good signal comes from a 20 foot plus long antenna and very good ground. Otherwise, a weaker signal can be used with the shorter spiral antenna that is seen with my unit, but it requires much amplification and filters through software like Audio Hijack Pro (Mac) to hear the AM radio sound.
Zettu5 years ago
would a 12pF~180pF variable capacitor work about the same for building this radio you think?  any comment to this question would be greatly appreciated,, :)
mrfixitrick (author)  Zettu5 years ago
 That variable capacitor should work fine. It is within the recommended range.
hleon5 years ago
herrdoktor5 years ago
Do you have to use the polycarbonate for the cover or can you use the actual metallic lid that comes with the jar? We have a ton of jars and I don't have access to any cutting machinery. Will it interfere with transmission in any way? Thanks!
mrfixitrick (author)  herrdoktor5 years ago
 The metal lid can be used as a common ground or perhaps as a common antenna +. Either way, some items will need to be electrically insulated from the metal lid, such as one of the banana plugs and the audio jacks. Having a metal lid should simplify the wiring. The metal lid will definitely affect the radio...but I'm not sure if it will be better or worse! 

I normally hook the metal lid ring to the + antenna connection, so that when you touch the ring, the body acts as an antenna booster, which increases the volume and clarity of the reception. If the whole lid was also that way it might improve reception even more.

Alerick5 years ago
I am interested in picking up lightning. I noticed on the video you had a red wire coming out from the radio. Is this your Long antenna? and what exactly is a spark gap arrester?
mrfixitrick (author)  Alerick5 years ago
 Yes, the red wire with alligator clip attached to the antenna of the radio, goes to a 22 foot linear antenna, stretched across my living room. It improves the volume and clarity of the radio significantly. An antenna spark arrestor uses a small gap between the antenna and a grounded wire, as a safety precaution in storms. The idea is that lightning would prefer to jump the gap and go to ground, rather than fry you and your equipment. This is more of a problem with outside antenna wires than inside.

If you make a serious antenna, spend the time to research a proper lightening protection device...or disconnect the antenna during lightning storms. (but that kind of defeats the purpose of listening to lightning...;)

Here's a link to listening to lightning and making more sensitive circuits.www.techlib.com/electronics/VLFwhistle.htm
bigdeee5 years ago
I built this contraption and so far, so good! I managed to get an AM station pretty clearly after boosting the gain WAY up, as you described.

HOWEVER...I have massive amounts of hum (grounding?) throughout most of the variable cap's range.  I've tried touching the lid, etc. and that helps a bit but I was wondering if you might have some tips on reducing the hum a bit more.

My concern really isn't receiving broadcasts. My intent is to receive the "voices" and detect lightning and possibly hear earthquakes/tremmors.
I haven't tried any of this yet because I'd like to hear any advice you might have, first.

Also, I may try running through Ableton Live instead of Hijack since I can probably increase the gain much more as well as tune the other adjustments with more control.

I eagerly await your response,
mrfixitrick (author)  bigdeee5 years ago
Congrats on your build!

I find a mono audio cable works way better than a stereo cable for hum reduction.

Make sure the audio jack is wired properly. Its ground connection goes to the centre connection of the variable cap. And, make sure the tip connector of the audio cable is the only "positive". 

Keep away from nearby lights to reduce hum. Even a 60 watt incandescent light within 2 feet can activate the diode and cause hum.

Keep the radio unit  more than a couple of feet away from the monitor screen.

An 22 foot long antenna will give a better signal-to-noise ratio. I have one across my living room ceiling that helps a lot. Outside would be even better.

A separate ground connection to a copper plumbing pipe or a metal stake in the ground "may" help, unless a ground-loop circuit forms between it and the computer ground, which can make the noise worse.

Also, you could use a separate 60-cycle hum filter to filter out the noise.

And finally, the software can be tweaked to reduce the hum as much as possible. Try Adjusting the AUBandpass, 10-band EQ, and AUPitch controls to phase out the hum.

Audio Hijack can add additional modules to increase gain. I just added a "Double Gain" module.

Good luck and "stay tuned"!

 All very good points that are too easily overlooked.  I live in a small room of an old residential hotel so I'm close to old wiring, lights, and even my computer.  Maybe that's why my hum is considerably loud. It sounds like a 60-cycle filter is the way to go for my situation, although a ceiling antenna made of wire strung into the shape of some occult symbol would really set the mood.
Thanks for posting this great project and congrats on your win!
Photo 37.jpg
DmanD5 years ago
I'm going  to make this Spirit Radio.  Will Total Recorder from High Criteria work for PC?
McGrep5 years ago
Absolutely fascinating... this may seem rather ignorant of me, but I did not know that Nikola Tesla conducted such experiments. This is an excellent, well-written Instructable. Now, I must try it out!
 I happen to already have a 1N60 diode. Could that work? If so, would I have to use new parts, like a different resistor?
mrfixitrick (author)  yellowexample5 years ago
 The 1N60 "black diode" can substitute and will be more sensitive to AM range stations, but will lack the light-sensitive aspects of the clear glass 1N34A. So it will only be half the fun in that respect, but would make a good radio circuit. 
mrfixitrick (author) 5 years ago
One of the results of this Instructable, was the making of a PC game called "Tesla".
Tesla was developed by EJ Gold and the good folks at GODD Games. It stars "Mrfixitrick" as the Canadian scientist and Hoover repairman, and involves finding the missing seven parts of the Spooky Tesla Spirit Radio!!

The Tesla Game is fantastic and great fun to play. I think everyone should try it! (of course, I'm a little biased in the matter ;) Here's the link to more info and the download:
Opcom5 years ago
Very interesting. Things that translate environmental parameters to audible stimuli are alot of fun.

Not to detract, but to show an alike thing of sorts that people whom like this project might like.
mrfixitrick (author)  Opcom5 years ago
Not a distraction at all; the link you provided was right on topic as far as I'm concerned! A cool little device, for sure.

Perhaps in the near future, augmented hearing will enable folks to hear frequencies they haven't been able to hear before. For example, to hear ultra-low frequencies (below 60 hz), and ultra-sonics, directly from the environment, would give one another perspective on life.
Berkin5 years ago
I designed my own spirit radio circuit and tested it out. Here is an audio file of my findings.
mrfixitrick (author)  Berkin5 years ago
Fun sounds to listen to...and thanks for posting. It's interesting to note the background sounds that seem to weave in and out separately from the predominate sounds of the AM station.

I did do a bit of cleaning-up on the track, to get rid of the annoying 60hz buzz from the wiring in my walls. Before editing, I didn't hear the AM station or anything, so I was pretty surprised by that.

I'll be sure to get a few pictures of my spirit radio as soon as I can.
I just finished making this instructable and it has been very successful. I've only managed to pick up AM stations as of yet as i've been testing it on an old guitar amp with the gain turned up. I presume you need the computer software for finer tuning so that to create the amazing 'soundscapes' you show in your videos?
Plus does anyone know of any free downloadable software that i can use for this as i have a pc not a mac?
Once again, Very nice instructable. Thanks for the walkthrough.
mrfixitrick (author)  Patterngenerator5 years ago
 You are correct that audio software is required for best effect. I have heard that ProTools for PC might work. I will be doing some experiments with PC audio apps later this week.
arhodes185 years ago
 another question, i just took apart a radio, and it had both a variable cap and a ferrite loop-stick antenna that had four wires coming off it, but neither one tells the ratings, how can i figure out the ratings of each one?
mrfixitrick (author)  arhodes185 years ago
 You can measure capacitance and inductance by a number of methods; the easiest is with a meter. Here's a site that tells of several methods to measure capacitance, if you would like to know...

And here's a site with 3 techniques to measure inductance...

I'd tend to say, just try it and see if it works. It's likely that the capacitor and the ferrite loop-stick are compatible for AM reception. The loop-stick with the four wires will have a tap part way down the coil. Again, experiment with different connections to see if your target station comes in louder and clearer.

 sweet! thanks for all your help!
vger135 years ago
will it matter if i am using 1 or 2 inches of hook up wire in between some components rather than direct wire
vger13 vger135 years ago
i am doing something wrong  even with the earbud  iam barely getting the crackle of a am station that is onlt 5 miles away and that is with connecting to a 80 ft piece of coax that runs across the top of the house. i get nothing out of the patch cord but i think i have stereo instead of mono does that matter  
mrfixitrick (author)  vger135 years ago
 The coax won't work as an antenna because it is designed to prevent radio signals from interfering with the central conductor wire by having the ground wire wrapped around it (as in the Faraday effect). You need a copper wire, about 20 gage, preferably stranded. 20 feet or more, preferably outside.

What happens when you touch the centre tip pin of the patch cord that goes to your computer ? There should be a very loud hum from your computer sound when you do that. If you don't get a loud hum when touching the pin, then you do not have enough Gain in the software...or there is a problem with the patch cable itself. 

Is the earbud you are using the high-impedance crystal radio type one? A regular modern earbud won't work because it takes too much power and isn't sensitive enough.

yes i do get the loud hum and it is the earpiece that came with the kit i uased the outer on the coax but i will try some other ant  ,tried ablton live ,i dont see any way of raising gain...didnt one person say they just used windows recorder and it worked
mrfixitrick (author)  vger135 years ago
 Ok, good at least you have hum. There should also be a faint audible hum when not touching the tip of the patch cord plug, which changes when plugging it into the radio. The hum should either go away, or become louder, when the cord is plugged in.

Double-check the connections to the patch cord jack at the radio.
You could be having trouble with mono vs stereo on the connections, or a bad connection at the jack itself.

I had trouble with that jack because of twisting it too much when installing it, and two of its connectors crossed. Took me half a day of replacing parts to figure out! 

Plug the cord into the radio and leave the other end loose to test.
You can then use a continuity test or meter to check for continuity between the tip of the cord plug and the variable capacitor/diode connection. There should also be continuity between the ground connections at the radio and the outer part of the patch cord plug.

You still need Gain on the software end. I hope to have a windows machine in the next couple of days, to experiment with audio software and provide a recommendation.

mrfixitrick (author)  vger135 years ago
 In some radios, longer hook-up wire will make a difference, but for practical purposes in this design it should be fine.
vger135 years ago
ok i have taken apart and put back together 3 times with nothing..have a strong am signal near,..do i need a actual earth ground or is the wire length i have pc and just using the sound blaster utility but if this thing would work with just a little ear bud this i should hear something here right?
mrfixitrick (author)  vger135 years ago
The ear bud only works if it is the high-impedence crystal radio type, and the radio has a good antenna and ground. 

You will not be able to hear the radio through the computer without increasing the gain substantially. One way the gain can be increased is by adding additional antenna length; generally the longer the better. Touching the antenna will tend to do the same as a test.

A good ground will help too for gain, but I needed no extra antenna, or ground, when doing most of my experiments.

The radio signal gain needs be radically increased by software. In the Audio Hijack software (for Mac), I use a Gain module and three more AuPitch modules in series to increase the gain enough to hear properly.

The software "ProTools" might work for you. I'm sure there are others that work in real time to increase input gain and shape the sound. I need to explore the real time audio software options for the PC, but first I need to get a PC! That will happen soon...

Alternatively, you could run the output of the radio through a pre-amp, and then hook the pre-amp into the computer sound-in.

You should at least get a hum or some sort of noise. The hum should be very loud when touching the centre tip of the patch cord with your finger, then should mostly go away when plugging in the radio.

Make sure the connections are good by a continuity check between the patch cord ground(outer) and the centre terminal of the variable capacitor. Then check continuity between the tip of the patch cord and the diode.

Good luck and let me know.

Stephen_A5 years ago
How much would you charge to assemble a completed Spirit Radio? I want one just for the "spirit chatter".
mrfixitrick (author)  Stephen_A5 years ago
Hi Stephen

I seem to be getting into the business of making these! (just got my first order...)

I am charging $110. for the Spooky Tesla Spirit Radio in a jam jar with 2 Flat Spiral Antennas. The "Football" Antenna is tricky and I would have to charge $100 extra for it. Shipping would be extra.

Do you have a Mac or PC? I use the Mac software called Audio Hijack Pro to make the "spirit chatter" sounds from the AM radio in real time and record them. It provides radical alteration of pitch mainly, with reverb thrown in and a band bypass, all in real time. I don't know if there is an equivalent PC program, so "results may vary" with use on the PC.

It may take up to two weeks to get parts and assemble one of the Spooky Radios. What do you think?
Is there a difference in the effects for Spooky Effect # 2 - Disembodied Spirit Voices and Spooky Effect # 4 - Create Freaky Music between the flat spiral and the football antenna?
mrfixitrick (author)  Drillbit5 years ago
 The antennas don't make that much difference for those effects. I found the Football coil looks cool but didn't work as well as a spiral antenna. The main antenna is actually the AM ferrite coil in the jam jar, and that is what picks up most of the EMF.
Aww, it's outside of my hobbyist budget right now. Thanks for the super fast response though - I'm sure there are other users interested :)
All it is is a crystal radio ! Build one! You can find a whole thing over at midnightscience.com

There are even SUPER sets you cab build for cheep!!!!
mrfixitrick (author)  Dr.Bill5 years ago
 Thanks for the link. Also, complete crystal radio kits from ComtrolAuto start at $7.45 
Light_Lab5 years ago
Hi, This is really cool - I would like to build one with my son if I can get him interested in something other than computer games.
I notice the circuit from Ant1 to the right is identical to the "crystal" radios I used to build as a kid.
The only thing that doesn't make a lot of sense is R1 the 47K resistor. I imagine this is to provide a load to the diode because of the original hi impedance earphone used in the kit. The input impedance of most computer circuits is lower. You should experiment with this resistor perhaps even leave it out.
The use of a germanium diode is important as it has a forward bias voltage of only 0.3 V (ie nothing happens until you get to 0.3V of signal) silicon diodes need 0.6 V.
I suspect the change in signal from the light is because the threshold voltage of the diode is effected.
Early crystal radios used a natural germanium crystal and a "cats whisker" of very fine wire that was moved around to find a good spot on the crystal.
Another early diode was based on copper oxide; if I remember correctly this only needs 0.2V bias. (I have seen a way of making one somewhere on the net).
Prisoners of war made radios using point contact diodes made out of all sorts of things, even rusty spots on razor blades.
It would be fun to experiment with the diode part of the circuit.

mrfixitrick (author)  Light_Lab5 years ago
Thanks for the great comments. I believe you are right about the resistor that it can be eliminated for computer use; One crystal site said it was optional...I'll have to try it.

As far as the light affecting the diode...a DC light needs to be moving across the diode to produce sounds, but stationary AC light will make a tone from it. Perhaps threshold voltage is involved there.

In early wartime, they sometimes used the barbwire fence around a compound for an antenna!
vger135 years ago
as i said..great build but even better that that is all the questions about Tesla.very few days go by that i do not think touch or talk about something tesla and i hope is is opening a few more peoples  eyes to Tesla.we would not be where we are today without him
tompaige5 years ago
masonrulz5 years ago
id just like to point out that all of jiffycoils comments have been removed
Bebop5 years ago

This instructable is very cool!.I'm curious to understand the theory behind this passive receiver, the part about the antennas.Seems strange the use of two antennas made with different wavelenghts and in opposite phase.
Mrfixits ,can you explin me what is going on?Thanks.. 
paulgo25 years ago
Now that's what I call fun!  You realise what you have here is the precursor for a "tricorder" as seen in Star Trek ??

If you were to etch those coils on a circuit board and incorporate the diode etc. along with a small amplifier and meters it could pretty well "detect" anything. How does it react to the proximity of a human body and if you amplified the signal input would it discriminate same?  Or am I way off beat here????

Asuraku paulgo25 years ago
 It's reactive to RF signals and electro-magnetism. Being that humans can't produce radio signals and are non-ferrous, I would have to say it would do a terrible job at sensing anything but electronic signals.
mrfixitrick (author)  Asuraku5 years ago
 Our brains work with low frequency waves that definitely can be sensed with electrodes. Electrodes are sensitive coils of wire similar to the induction coil in the radio. There might be a way to detect the brain's waves with the radio. For much more on the topic of radio waves affecting brain waves, check out EJ Gold's new book, "Parallel Worlds Explored".

Besides, humans will float in a strong magnetic field, and can't live long without an active magnetic field around them. (Nasa tests prove these)

As far as non-ferrous, haven't you heard that humans get tired from low iron? (hehe, joke...;)

the brain is a VLF machine. It is not however an efficient transmitter at these frequencies and therefore it is difficult to detect brain waves with a VLF radio. This is why you have to use electrodes that have very low resistance contact with the skin when recording brain waves.

However, you body is a big capacitor and it is a good receiver of 60 Hz electricity from the power socket which is not very good for your health:


mrfixitrick (author)  paulgo25 years ago
 You are not off-track at all with this idea! I feel like I'm on the deck of the Enterprise when the sound fires up on this baby. The radio circuit will start to detect the human body from a few inches away, or if I put my hands close to the antenna. The body works as a big antenna!

If the gain was increased even more with software, the results could be interesting, but the 60 cycle hum interferes with extreme amplification. A choke filter may fix that.
vger135 years ago
this is i think the coolest build i have seen i a long time,ordered parts this morning and already on the way,just a couple of questions...does one coil need to wound in the opposite direction than the other and  does number of turns matter on either coil. Again  great instructable
have not fired up my coil in a year now but here is a run  from a few years ago
mrfixitrick (author)  vger135 years ago
 In order to properly tune an AM station, the antenna size/length must be matched with the correct capacitance. However, "correct" is a rather loose term when one is using the radio in the way I have...;)

I did notice some subtle differences with flipping the coil antennas around, but for most purposes they should be fine any which way.

For decent AM reception and a clear signal, there should be an external antenna and good ground anyway. 

So I say, have fun with it, try different configurations to see what effect there is. Who knows, maybe you'll discover something...spooky!
Calorie5 years ago
WOW! Great Job. I really enjoyed that. I live in Florida and we seem to have constant electric storms. I've used an AM radio tuned to static to listen for them. I'll have to get some lexan cut to size.
bigdeee5 years ago
 Simply brilliant! Great to see Tesla's descriptions brought to life.
This is a definite must-build!
plopcow5 years ago
 hey great instruct able.  im pretty sure my house is haunted so i thought one of these would help me as it picks up electro-magnetic field changes. i have adobe audition pro and so i could set it up overnight and see the audio on my screen for quick scanning
tomasina5 years ago
one of the most clear& concise instructibles i have ever seen
and such a cool idea for sound effects
..........you win my vote
turnhandle5 years ago

Planning on giving this a try after Halloween is over, too much on before then. If I get stuck I'll call or drop by as I'm on the lower island too. I'm hoping to try it with a VLF antenna, >100 feet looped, and see what happens. Will be voting once it opens.

mrfixitrick (author)  turnhandle5 years ago
 Cool! Looking forward to your results. Thanks for the vote support, too!
rseymour5 years ago
Seems like something straight out of Pynchon's "Against the Day" something that the Chums of Chance would've had onboard their vessel. Maybe... maybe I'll build it someday.
What is the AM reciever for? I figured that the antennae would be sufficient, so is it necessary to produce this radio? I actually have one laying around somewhere, but I don't want to tear up my workshop looking for it.
mrfixitrick (author)  student.mckinney5 years ago
The AM circuit serves as a general LC (Inductor-Capacitor) resonating circuit that picks up on many frequencies. An antenna alone won't pull in radio waves in sufficient amplitude; the resonance of the circuit increases the sensitivity many times over.

The receiver circuit also includes the 1N34A diode, which serves the purpose of a rectifier of the radio AC wave into a usable DC audio wave which can drive a speaker through an amplifier.

Perhaps an old transistor radio plugged into the computer would work for the purposes here as well.

seedub5 years ago
That is impresive two thumbs up i have always been interested in crystal radios but this blows that out of the water! good job
johnfromnj5 years ago
Could your radio be used to generate enough white noise to block anyone trying to eavsdrop on your conversation or monitor your screen output or keystrokes ? Sounds like you could make a "virtual Faraday Cage"of sorts.
mrfixitrick (author)  johnfromnj5 years ago
It does seem at times like a "Cone Of Silence" (from TV series Get Smart;) fills the air, when I can barely hear myself talk from the extreme harmonics and beat frequencies. There seems to be a kind of wave-cancellation process that sometimes kicks in when that happens. It's only happened a couple of times, but it made a big impression when it did!
xsonic885 years ago
Is it important to use glass for the enclosure? Could a clear plastic bottle/container work just as well? And does the metal rim of the jar interfere or influence the signal in any detectable way? Thanks for the instructable, this is really awesome.
mrfixitrick (author)  xsonic885 years ago
 A plastic or wooden enclosure will work fine. The metal rim has little effect normally, but I ran a wire under it to the antenna circuit, such that when you grip the rim it will increase the volume and signal of the radio! (the human body makes a great antenna!)
colinhester5 years ago
Just got my parts from http://comtrolauto.com/ in one day.  Just waiting for my son to get home from school to breadboard this contraption!
mrfixitrick (author)  colinhester5 years ago
 Hehe, glad to hear you are going at it! Do you have a Mac or PC?
I have PC, but I have a 100w guitar amp, that would work, right?

mrfixitrick (author)  juanvi5 years ago
 The amp will likely work raise gain enough to hear radio stations, and be useful for some effects, but I don't think you will not get the cool sound effects without a real-time audio program such as Audio Hijack Pro. It has to be able to subtly alter the Pitch, Bandpass, and Reverb in real time so that what sounds like simple static or hum from the radio circuit becomes a rich soundscape.

I understand a program like "ProTools" can do this for you on Windows. There are likely a few free PC programs that will work in this way.

Well I also have Cubase and ProTools, so i could do it with that...

and conect it to the amp for an extra BOOOM!!
mrfixitrick (author)  juanvi5 years ago
 That should work! There are plug-ins like this VST "PitchWheel" one that can alter pitch. www.quikquak.com/downloads.html
oh thanks for the VST's page...i'm downloading all of 'em!!

oh thanks for the VST's page...i'm downloading all of 'em!!

Got it up and running!!!!  Only spent about 4 hours building and rebuilding it  - yeap, bad patch cord, damn.  WLW, that 50,000W AM blowtorch, is coming in great.  It helps that I live about 1/2 mile from the tower.

Couple of quick questions, if you don't mind.....

First, the fixed cap is listed as 0.001uF in the parts list and 0.001pF on the schematic.  I assume the uF value is correct.

Second, L2 is made of 10 turn 20ga. Cu wire.  I assume this wire needs to be coated.  Correct? 

I did not do the pre/amp combo, but went stright into the mic jack on my PC and used "Sound Recorder" on Vista to monitor progress.  Worked like a champ

Got a few kinks to work out (hummmmmmmmm) and making it pretty, but a real positive success for my first Instructable.  Many thanks, mrfixits......C
mrfixitrick (author)  colinhester5 years ago
Congrats on a sucessful build!

The .001uf cap is the correct value. Thanks for noticing. I made a note in the Schematic.
 And yes, the 20 ga. wire should be coated magnet wire.

The hummmmm is the good old 60 cycle variety and its harmonics, I'm sure. One way to deal with it is to raise or lower the real-time pitch to a more tolerable octave, or off the audio scale completely.  Otherwise, a choke coil can be made to reduce the hum.
I have a PC, but will ampilify  through a mono tube pre amp and tube amp in to an 8" full range driver.  It won't have the special effects (reverb?) going on that yours did, but I think Tesla would smile :) ......C
mrfixitrick (author)  colinhester5 years ago
 Hehe, I think Tesla smiles every time he hears his name these days...
and-reas5 years ago
Fun project, I think even the Mars Volta could use it for intro's and solo's.
eternaluxe5 years ago
Hey, I think that Audacity http://audacity.sourceforge.net/ would work as software, and it's available for Windows, Mac and Linux.
mrfixitrick (author)  eternaluxe5 years ago
 Sorry, Audacity won't work, as it has no real-time effects abilities.
You're right.  Audacity will not work this way on Windows without a bit of hacking: http://forum.audacityteam.org/viewtopic.php?f=26&t=5033
For Mac and Linux one might try Ardour:
And on Windows (or in spite of it) one could go for a live cd with Ardour included, such as dyne:bolic: http://www.dynebolic.org/
Great instructable, by the way.  I can't wait to try it out!

mossimo35 years ago
It is people like you who are absolutely inspirational; and when you build things like this it makes me love electronics that much more. Thanks for an excellent build!
bears05 years ago
 did you know that there is diffrent layers of time and if we could speed up we would go through the they are right in front of your nose but you cant touch them cause when you try it still keeps the lead no matter how fast you move
mrfixitrick (author)  bears05 years ago
 There is more in front of our faces than we are led to believe.

Check out EJ Gold's book "Parallel Worlds Explored", available at www.idhhb.com/parallelworldsexplored.html for ideas about space, time, wormholes and such.
NetReaper5 years ago
is it actually generating those sounds?
mrfixitrick (author)  NetReaper5 years ago
 Yes! All of the sounds in the videos are generated in real-time by the Spooky Tesla Spirit Radio, which plays through the computer with the Mac software Audio Hijack Pro.
Wow, this seem so cool; i gotta make one soon
ZxxxY5 years ago
This is a wery nice small thingy! Made it from scratch! For loopstick used ferrite stick from old computer power suply and spined thin wire from motor on it about 100 times.... Thanx for such a fun and easy and awesome thing!
Apologies if I'm missing the obvious, but exactly which loopstick antenna from comtrolauto is the correct one to use for this?
mrfixitrick (author)  ouroborosity5 years ago
Nope, it isn't obvious!

I've added the part number to the parts list for the ferrite loopstick antenna, which is ComtrolAuto # LSA680-1. Note that it is included in the "Simple Crystal Radio Kit", ComtrolAuto # SC-Kit-1, along with most other of the radio parts.
colinhester5 years ago
I wound the coils and ordered the parts today.  This will be my first Instructables adventure.  Thanks for sharing!
mrfixitrick (author)  colinhester5 years ago
 Congratulations and let us know how it goes!
Whales5 years ago
 And if you can't get it to work, it looks extremely amazing. Maybe i should make a giant one that sits on the floor, definitely be able to pickup AM signals with that.
mrfixitrick (author)  Whales5 years ago
 This coil antenna uses over 6 feet (2 metres) of copper wire. A good length for a crystal radio is about 22 feet, or about 4 times the area of this antenna. That means only a diameter of about 8 inches would work to achieve that 22 foot length.

Of course, longer is usually better in crystal radio antennas, so a floor model could use several kilometers of wire!
In the video, this sounded a lot like the "talking" over the baby monitor on Signs.  Do you think they used something like this to make that?
mrfixitrick (author)  skittlespider5 years ago
 They likely used something a lot more sophisticated, and with multiple recordings and tracks. The beauty of this unit is in its simplicity and real-time sounds.
idogis15 years ago
I've got  almost everything I need for this in my basement. I'll see if I can make one.
RetroTechno5 years ago
Interesting!  I'm thinking of building one of these.
During construction of the spiral antenna, would it be advisable to use some kind of small plastic spacers every now and then to keep the distance between conductors a constant?  If these are left in, do you think they would adversely effect the performance?  Also, just for reference, what is the diameter of your coil and the height of your vertical element?
mrfixitrick (author)  RetroTechno5 years ago
 I suspect the plastic washers would get in the way more than help, because of the wire springiness, and possibly kinking the wire. The plastic spacers would not likely affect the performance if left in.

The antenna is a learning-to-bend-wire thing...basically winding it up by hand on a flat surface after making the first turn with pliers.

I made two coil antennas of 3 inch and 4 inch diameters with 6 feet (2 metres) of 14 ga copper wire each. I added a vertical 4 inch antenna to each of them, but I wish I had incorporated the vertical extension into the bending process, instead of soldering it on.

Good luck in building, and have fun with it!
rimar20005 years ago
Good work, MrFixIt, thanks. This is very interesting. Nicola Tesla was an incredible scientific.

Could you do this with just and old am band radio only?
mrfixitrick (author)  spacepirate045 years ago
It might work, but most radios have chokes and bypass circuits so that higher and lower frequencies are excluded.

AM radios are normally designed to pull in strong AM signals only, not weak signals from all over the electromagnetic spectrum.

Also, the light effects I demonstrate will not work with an AM radio substitution. There must be a 1N34A diode for that to happen.
knife1415 years ago
Interesting, and a very well done instructable!  I think I'm going to have to make one of these.
Warlrosity5 years ago
Nice, very nice, Buuuut
Will it work on a iMac? And uhm looks nice, nice antenna
mrfixitrick (author)  Warlrosity5 years ago
I use an iMac as the interface for the Spooky Tesla Spirit Radio. I plug the radio right into the sound-in jack. I run software called Audio Hijack Pro, which is free and functional for limited use, but I liked it so much I bought it for $35.

In this case, the real question is "Will it work on a PC?" hehe. I don't know, but I suspect it would with appropriate software. I hope to experiment with that soon.