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:

Have a look at the Crystal Quantum Radio devices of EJ Gold that helped inspire this instructable:

"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 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;

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The Peddler made it!21 days ago

I made this device with great success. Here is a sound sample of my first audio test;

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 and 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 Peddler8 days ago

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

mbernal991 month 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 month 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 month 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!


lexlarson2 months 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)  lexlarson2 months 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?

AllenMcG2 months 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)  AllenMcG2 months ago
You can use 10 or 12 gage. I used 14 gage.
onewheeltom2 months ago

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)  onewheeltom2 months 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)  AllenMcG2 months 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. :)

onewheeltom2 months ago

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.

onewheeltom3 months ago

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)  onewheeltom3 months 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.

amikolajczyk3 months ago

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!

tree963 months 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)  tree963 months 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?
jsmock23 months 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)  jsmock23 months 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.
jsmock2 jsmock23 months ago
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!3 months ago

I finally completed it ^_^

My Radio.png
tree963 months 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)  tree963 months ago
I think the 788 uH will work fine for this purpose. Good luck with your project.

Thanks! :)

zwalker36 months 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 (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.

msim934 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)  msim934 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.
vger131 year 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)  vger131 year 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.

vger131 year 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)  vger131 year 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.
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