Giant induction coil picking up Audio 5 feet away!
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- เผยแพร่เมื่อ 25 เม.ย. 2024
- This is an expanded video of my Giant Inductive pick up coil experiment.
Have you ever wondered how far the electromagnetic fields from power lines can be picked up? In this experiment I brought a large coil of wire with me far up in the mountains, and attached it to my audio amplifier, and much to my surprise, I still had a pretty strong 60 cycle AC hum at a great distance from the power lines.
The other reason I wanted to get away from the 60 Cycle AM hum, was that I wanted to see how far a giant inductive coil would be able to hear small electromagnetic signals powering the speaker in my small digital tape player.
Regarding my question about what you might hear, if you constructed a giant induction coil, I think the video at this link pretty well explains it.. • Earth's magnetic field...
For anyone interested in knowing the coil size. I used two coils in this experiment. Each coil was wound on a spool that had 34 inch circumference, and each coil weighed about 6 pounds. The wire appears to be 30 gauge. You can use copper enamel magnet wire, or whatever you happen to have, but it seems that the larger the diameter of the spool it's wound on, the more sensitive it appears to be, and the more turns you have, the more sensitive it appears to be.
Have fun and please be safe.
Thanks to the suggestion of a viewer, I tried attaching two identical coils together in a parallel circuit, so their output polarities were in opposition to each other, and this eliminated much of the AC hum I was picking up when I placed the coils in the right position, but this also seems to have reduced the coils sensitivity, so my experimenting continues.
Could this pick up Bluetooth?
@@Damianmarleyfan No it can't get Bluetooth signals, but it can pick up inductive waves from any speaker if you're close enough.
You could try the "big hammer" approach of putting a highpass or notch filter on the signal to get rid of any 60z component.
Or perhaps, space your opposite-polarity coils apart and put your item of interest in between them.
@@antonliakhovitch8306 I tried placing the coils apart as you mentioned. and it greatly reduced the AC hum.
Use a high pass filter. 60 Hz is much lower than the high frequencies of radio signals so the right High pass filter should eliminate that low frequency signal.
In the 1970's, there was a project in Popular Electronics detailing passive, wireless headphones. The output of a hifi amplifier was connected to an 8-ohm load resistor, through a loop of wire that was run around the entire perimeter of a home. A pair of high-impedance headphones was then wired to a coil of wire wrapped around an iron core within a plastic box which one carried in a pocket. Playing music through the amp and into the dummy load would create a magnetic field within the home that varied with the audio. This field induced a current into the coil of wire connected to the headphones, and the music could be heard in the headphones, anywhere inside the home. It was mono only, to be sure, but it worked.
From what I've seen, a coil with a much larger diameter does a better job of picking up electromagnetic flux, so making a much larger coil sounds like another worthwhile experiment.
@@GrantsPassTVRepair Absolutely.
@@GrantsPassTVRepair The december 1970 issue of Popular Electronics is available from the world radio history website. The project is at page 49. This idea has been previously explored in the '30, the proposed use back then was as precursor of pager systems.
@@paolocanali3361 Thanks for the information.
Theoretical can create stereo version - two transmitting wire loops in 90 degree angle and two receiving coils in 90 degree angle.
1970 wireless headphones with wireless power :D
Better than bluetooth headphones :D
This universe is wild. The deeper I look the crazier it feels. Excellent video!
Yes! Try listening to Bashar, or “the Seth Material”!
It just gets weirder!
Back in the days when I was a wee lad, I hooked a ( _then common_ ) high-impedance headphone to a ferrite antenna. I don't know why or what I was expecting but I do remember, I could hear the 50hz hum. I could find where the wires were in the walls and floors. At one point I heard music. It turned out to be the place where my neighbour had a speaker. Then I found out that if I detached the speaker of my radio and ran a few loops of copper around my room, it became a wireless headset. And all this without any power source. No recharging, no flat battery.
Experiments do not always need a purpose. It's fun in the first place. And later on in life, you realise you did learn a thing or two by just playing.
That's how the first discoverers like Edison Tesla and Faraday made their discoveries.😁
Your videos are too cool!
You should be INDUCTED into the Electrical Hall of Fame!😅
😂
We used to make coils 6 foot by 2 foot, and connect it to an amp, and listen to all the EM in the area. By moving the coil around and changing the position, we could increase or decrease some of the noises we were picking up. Depending on where you were, you could find lots of noise from many objects, but walking around with a wood frame the size of a door, wrapped in wire and wearing headphones would get the attention of some people thinking you were snooping into their privacy...
That sounds impressive. Your drive to experiment sounds much like my own.
Outside of the privacy perception, what I cool idea.
@@jasonschlegel4027 The down side to EM radiation, is the government was able to make it possible to view what was on a CRT screen by processing the 'noise' into a duplicate of what was on another computer terminal. What else they were able to do with it is not being talked about, and it was surprising that they announced the ability to do what they had done! And makes me worry about what they can do after 40 years with the technology.
@@jeffreyyoung4104 Surely the tech has evolved and been honed. Thank you for sharing.
@@jasonschlegel4027 Does it make you wonder what they can do with the tech?
I did a similar thing using large, single turn loops of wire. I used a 100 watt amplifier and a tone generator. The frequency was 1.8 kilohertz, the range was 2.1 miles.
Sounds interesting.
100 watt amplifier for the transmitter or receiver?.
@@MarkyBhoy-fe1xfMuch better to amplify the signal at the transmitter (the power source) than amplify at the receiver because amplifying the received signal also amplifies unwanted noise.
Skyscraper size induction coil -- we would hear people crying because they're stuck in an office when in reality they want to be you in the mountains conducting experiments. ❤😂🎉 Thank you for sharing your wisdom and talents with us.
I always love these kinds of impractical experimentation just for the sake of it! Can't wait to see more :)
It's only impractical until you want to make pickups for an air guitar.
Your video caught my attention. I wound a bike wheel with a spool of #30 enameled wire. Connected to an audio amp. My favorite application was to hike up a small hill that overlooked a drive in movie theater and pick up the audio of the scene on the giant screen from all the speakers filling the parking lot. The other item we heard was frequent occurrences of high frequency tones that would drop in frequency over several seconds and then disappear. I was told by a scientist from TRW Inc that these were likely meteors entering the atmosphere, and he supplied a paper that described the phenomena. This was in Southern Calif, about 40 years ago.
I did not know that meteors entering our atmosphere could be detected in this manner, but considering the explosive nature of a meteor at such high speeds I'm not to surprised.
Beautiful view of the mountains, so serene and quiet, errr, wait, here comes the hum 😅😊😊
I didn’t know that I wanted to know until I found out what you knew, now I’m glad to know.
It's good to know you're glad to know what you didn't know.. ;-)
Make a mains frequency notch filter
ChatGPT should be helpful
I once made a mains frequency notch filter and placed it directly on the mains so that I could see what other electrical frequencies were there using an oscilloscope across a low value resistor that was in series with that filter. Kind of like viewing another dimension of signal power mitigated by distance and distributed loads.
I have a partial solution, but Good idea on trying ChatGPT.
Some genuine video finally poped up in my feed! No drama click bait with purple lights and stupid facial expressions! Thank you! Doing and sharing things just because you can and wonder. Keep up!
It's like a gigantic guitar pickup. For some ideas to draw inspiration for further experiments, I would look towards various guitar pickup designs. "Humbucker" types such as the PAF, Filtertron, & Fender CuNiFe wide range make use of common mode rejection, but are distinct from each other. Designs made by Lace Music, such as the Lace Sensor & the Alumitone are very unique. Electromagnetic sustainers such as the Fernades Sustainer & the Maniac Music Sustainiac are super cool as well. When you spun the motor, it was almost musical. It's actually not all that different from some of the earlier electric organ designs. Very interesting how it made a stronger tone when the motor leads were left open.
Thanks for the info. I've had a few people mention the Humbucker, so based on the Humbucker principle, I tried attach two identical coils to my amp that were out of phase with each other,. and it did reduce the hum.
@@GrantsPassTVRepair Pickups such as the PAF use a bar magnet attached to the underside & have ferrous pole pieces placed under each string. Hot-rail types are the same thing, but use a slug that runs the width of the transducer. Fender Wide Range types use cylindrical magnets instead of using ferrous pole pieces. P-90 types have their slugs sitting in between 2 magnets that have their "like" poles facing each other. Lace Alumitones are seemingly a solid block of metal, but are actually a coil with just a single turn. Guitar players (myself included) obsess over the subtleties of all these things. Laughingly, the audience probably never notices. Leo Fender, one of the most influential figures in the world of guitar, was not a musician. He was a radio repairman. His passion was innovation.
To answer one of your questions, there are magnetometers at various labs around the Earth recording changes in the geomagnetic field, as produced by disturbances arising in the Sun. They needn't be of the size you propose, though they are pretty big. The ones I know about are in Boulder, Colo., Fredericksburg, Md., and College, Alaska, since they're the ones NOAA uses to compute its data.
This comment is somewhat on the same level as the coils you are experimenting with fella.
I took a dozen garden hoses and connected them together to form a star configuration. The center point I connected one short hose. When I put the hose to my ear I could hear tremors which had to be earthquakes from a distant location. This would happen off and on from time to time. This happened regularly. This setup was in use for a few years. Never stopped working till I took it apart and sold the rubber hoses. Peace v
I love your style. Simple but super cool. Great demonstration, thank you!
You are so welcome! Thanks for the comment.
Finally a use for that 60 HZ notch filter.
Thanks for the tip.
@@GrantsPassTVRepair I always wanted to build one* but I never really had an application. *From Forrest M Mims, Engineers Note books.
@@GrantsPassTVRepair Get filters from old microwave ovens. It's that little board at the 115 volt AC input side.
@@gortnewton4765 That is not notch filter.
@@user255 I did not say it was a notch filter.
This channel is literally gold.
Thanks!
* figuratively
I love these experiments. So many questions.
You've invented an audio magn[et]ifying glass of sorts.
I don't know what it's good for, but it is pretty cool.
Passive headphones were already invented.
No, it's called a coil/spool antenna. It's already invented.
Just an idea.. run the coil or amplified output into an audio limiter or clipper so you don't blow out a recorders input from sudden loud sounds picked up and run it through a very low noise preamp to really increase the gain. This of course after you deal with the 60Hz hum which as other people have suggested a notch or high pass filter will help with up to a point. A pair of diodes in parallel and opposite of each other across the coil output can make a quick and dirty limiter for ear/recording protection at high gain.
Very cool experiment, your surly thinking outside the box ❤
Double thumbs up for being the person asking 'what if?'
Position the coils in opposition and in series to cancel out fields that cross both coils, but move the coils physically apart (mayube 1 to 3 meters) so that something between the coils can still be detected. This is sort of similar to how a figure-8 microphone works. Large fields far from the source have more uniform fields, but a small close object has very curvy fields. So the interference fields will cross both coils and cancel but the test fields will not. BTW, underground cables could still be emitting fields if there are any there.
I tried this theory with another set of smaller coils and had some degree of success, but when the AC field is so wide, it's challenging to find the perfect orientation for both coils to produce perfect cancellation of hte hum.
This is basically just a metal Detector, with the pulse! Awesome!
No, it's called a coil/spool antenna. It's already invented.
A giant pickup would receive ionospheric whistlers, thunderstorms, and perhaps electrical signals from ground movements as tectonic plates shifted. It probably isn’t necessary to use huge multi turn coils. The area inside a single coil is what counts and multiple coils just add to the amount of pickup. Far cheaper and more efficient to use electrical amplification to get the desired signal level.
I think it would sound like this. th-cam.com/video/iHY-GMrqK9A/w-d-xo.html
I made a large coil and it was great for picking up whistlers. You needed to be well away from any buildings or power cables.
@@StabilisingGlobalTemperature I would like to have seen how you built your coil. Did it have a much larger diameter than what I built?
@@GrantsPassTVRepair I had a polystyrene block about 3 ft x 3 ft x 4 inches. I cut two thin sheets squares of plywood a couple of inches larger than the polystyrene and glued them on. Then put tape around so the wire would not dig into the polystyrene. And wound about 800 turns. Winding evenly as possible, across the 4 inch width. Then used an op amp low noise amplifier module (from eBay) and a digital audio recorder. The amplifier mounted on the coil former, and powered from a battery. A few yards of cable between the amplifier and the recorder, to avoid the coil picking up any emissions from the recorder. Then transferred the recordings to Audacity, and applied filtering. I lent the coil to a student and did not get it back! But it was quite impressive. It is best to make the coil area as large as practical. That was about the largest I could transport in my car at the time.
@@GrantsPassTVRepair I wrote a reply but it has disappeared. Coil on a polystyrene block approx 800 turns 3ft x 3ft x 4 inches. Plywood side cheeks glued to the polystyrene. Used a low noise op amp module battery powered, and a digital recorder. op amp module and battery fixed to the coil former and several yards of cable to the recorder. I used a recorder rather than a laptop but you could use a laptop but keep it far enough away from the coil. Laptops are quite noisy electromagnetically.
Excellent video!
it is possible to hear a beating heart
It's possible, but not with this coil in its present design.
The first audio tube amp I built picked up radio stations when I touched the volume knob, and didn't have giant inductors like yours.
Very interesting 🤔 Thanks for sharing
Awesome love the experiment!!
WOW Mind blown Dave!
Using that same sort of method, I transmitted audio several 100 feet. My transmit was one large coil and the receiver was another. Both coils were about 5 feet in diameter. IIRC there was 1000 feet of wire on each. The receive amplifier had a notch filter for 60Hz and another for 180Hz.
This is super interesting!
Nice, thanks for sharing.
Cool. Thanks for sharing.
We had a similar system in The Royal Shakespear Company theater in The City of Londons Barbican Compex.
The whole auditorium was coiled to transmit the main mix of mics and music from the stage.
Any thing in the Auditorium would be induced with the main signal.. Hearing Aids - Walkmans.. I pods.. ear buds.. Boom boxes etc. ect.
It was quite a strange but practical effect for the hard off hearing.
I think the concert hall had the same giant induction loops.
Interesting findings. Seems to me that if you were to find the right size capacitor, you could turn this into an LC circuit. Then, you could put a secondary on it to ramp up your voltage and discharge it thru some kind of spark gap or its equivalent (or a grounded capacitor) to produce useable power.
I did something similar to this long ago. I put 20 or 30 turns of 32G wire around around a 12" plastic ice cream container lid. I transmitted sound through my wall...
Next video, " I got away from the AC hum up here at the polar cap" lol. Cool upload Thanks
Excellent!
Thank you for experimenting!!!😁💖✌!!
You are so welcome!
Very interesting. I made a coil about 3 ft square with 800 turns. The former was a block of polystyrene with plywood end cheeks. Took it outside as you did. And heard singing. Very strange. I worked out it was coming from a church about 300 yards away. It was from the induction loop for hearing aids.
That's such a cool experiment and great question at the end of the video. My imagination says it'd sound like the northern lights, maybe like a slow, soothing whoosh or whirl.. fun to think about
I'm guessing it might sound like this. th-cam.com/users/shortsn5fAF6B4Lw4
This is cool!
There's so many interesting things in this video. Including the question "Airconditioning hum, in the mountains? They're truly mental in the US. Oh, wait. Duh. This guy is a science geek; he means Alternating Current, of course!" :D
Very interesting. I did not know that.
Just add a passive high pass filter with a cutoff just above 60hz. Wind a 15.6 millihenry coil and use 4 ohms worth of resistors. Harmonics might be strong enough to merit a set of tuned notch filters.
Amazing experiment!! i will try myself 😁
Have fun!
Very cool.
That would be a good question
if you make a large (6 foot square) induction coil or larger, you can pick up things like the "dawn chorus" and other electromagnetic oddities. there was an article about it in one of the electronic magazines in the 90's and I really wanted to build one. I ended up building the circuit which was basically just an audio amplifier, and made a pickup coil but didn't hear too much. searching for 'dawn chorus' should bring up some good results.
I'd like to build one. I found a youtube video on what it sounds like. th-cam.com/video/Cmxlp6uYnDg/w-d-xo.html
Humm, humm ,humm-you are pushing through something-whats the tune?-way fun man
Fun! But the larger you make your coil in diameter, the less turns you need to keep inductance the same.
Otherwise it will not be able to pick up higher frequencies. The actual frequency response will depend on the coil and amp's capacitive properties as well as the total inductance of the coil.
Too big a coil (too many Henrys) and you can only pick up base.
You have to get really far away to get rid of the hum. It's possible to receive 60 Hz AC hum in Europe with a decent antenna ;) (we have 50 Hz)
Cool experiments!
Nice share
Very cool
An interesting expansion on this, hook the coils up to the output of your amp so it is like a speaker without a driver or cone and see if a mike can pick up the induced changes and if so how understandable is it.
Interesting. Thanks!
Thanks for watching. :-)
Skyscraper size induction coil - wouldn't want to be anywhere near that in a lightning storm or a coronal mass ejection coming our way.
Interesting demonstration, it clearly shows that magnetic field lines couples into electromagnetic fields - which in theory has an infinite range and propagates at the speed of light.
I think it's really cool. You've got yourself an extrasensory perception device to unviel the unseen world around us. If only there weren't so many friggin AC units lol
Idk if this is close enough to your last question, and you probably already know, but super low frequency or whatever it is called (just a few hertz) transmission wires that are like 20 miles long (underground) exist to communicate through the earth and saltly ocean with submarines.
Pretty cool stuff.
The US National Radio Quiet Zone [NRQZ] around the Green Bank observatory in West Virginia _might_ be far away from the 60Hz hum, except that there is regular electric power service to residents in the area... Otherwise, I guess it's like light pollution in the night sky. You need to go really far into an uninhabited area on land.
The middle of a large body of water might work well too. Besides distance from transmission lines, the water is electrically conductive and will shield from RF. Water is also diamagnetic, so, um, it might also shield magnetic flux by itself (maybe?)
I'd suspect the opposite. RF isn't an issue here, since 60Hz is not RF. However, the high electrical conductivity of water means that any AC return currents passing through the earth will preferentially favor the lake.
Someone mentioned it's near impossible to get away from, but at some point I'd like to try this much further away form any city of power lines.
@@GrantsPassTVRepair Underground in a cave, perhaps?
Great!
I have a bunch of amplified speakers that use induction technology. They are the boom touch speakers and there are two coils on top and you place your phone on top of the unit and when playing music through the phone's internal speaker the boom touch picks up the induction waves from the phone speaker. I did a video on the boom touch and I played a bunch of things on it.
You can remove the hum by feeding the output of your inductor into a balanced line audio stage, which offers 'common mode rejection'. Look it up.
I don't think that will help. Surely, most of the noise is picked up in the coil itself, rather than the wire going from the coil to the amplifier.
Flipping one of the coils around will offer common mode rejection, but then the item that you *want* to hear will have to be in between the two coils.
Interesting experiment. You could try to add a variable capacitor in parallel to the coil and try to tune it a bit.
amazing
The only AC hum free place I found is in the middle of big lake - no nearby power lines. Try this test on the boat!
This is absolutely amazing! But you don't need to worry about the 60 HZ coming from the power lines,you can filter that out using simple audio equipment.Have you ever thought about trying that ? I have always been curious about what all is out there on the spectrum! Again, I think the filter would open up all kinds of possibilities for you. BTW, the spinning magnet sounded just like a pulsar......... imagine that 😊
Exquisite
Very good experiment can you make a longer video for the experiment with testing with different things
60hz 1/2 wave dipole is like 8 million meters, so maybe you have like a 1/64 wave tuned antenna with all that magnet wire lol
I figured such an antenna would be to large to build, but it would sure be fun to see how much such a large antenna would pick up.
There is software available that can cancel the background disturbance.
Its a long shot but could you inject an apposing AC waveform to cancel the hum interference? The only problem is that you could still pick up hum from motors etc near by perhaps.
Try a cave if you can to see if the AC hum is down there too.
That's a great idea!
Can you do energy harvesting from the coil? I mean the reverse of your demonstration.
Wouldn't a capacitor across the coil leads help to filter out the hum? Three types of capacitors to try would be: 1. Polarized. 2. Non-Polarized. 3. Rotary Air-Gap Tunable. Would also be interesting to attach an oscilloscope to see how the output varies with each type of capacitor. One method would be to use a capacitor "decade box" for variations.
I have a question. A friend of mine for years made a 10" square of wood and wrapped thin wire around it hundreds of times. He turned a radio on with no reception on a random frequency and placed this square in front of it. The radio came alive and Crystal clear audio from somewhere nowhere near here. What could this contraption of antenna be? Some kind of beam?
sorcery! lol. i wonder if the skyscraper sized induction coil would pick up the electrical impulses of a people's heartbeats.
We need to construct this thing youre talking about to pick up the earths hum
For sure. Perhaps in a future project.
Where did you go for that video? Looks a lot like the Idaho Springs area.
I would be curious to know how far you have to go from any AC lines? For instance, a rural house still has an AC line going to it.
But, one might have empty state/federal land behind them, where they perhaps could get a few moles from any transmission lines…
What the…. Tv repair man. Now I get it 👍
Any ideas for an (ultrasonic?) detector for liquid in a pipe?
You should study the work of Faraday, Maxwell, and Heaviside. They were predicting this over 100 years ago.
Hell yeah!
You have to go out to the middle of the middle of nowhere 😂
😂 where is that ?
You made my day
@@petrichors probably like the middle of the ocean. Lol
That was fascinating! thanks for sharing!
I wonder if an electric guitar can be amplified through it?
Very impressive. Fun experiment, but it's picking up EM produced by your items (moving magnets and coils), not "audio" (changing air pressures). It might be fun to see if a moving coil (dynamic) microphone would be a suitable transducer (audio to EM) to see if your coild to pick up the tiny field generated, like the input transformer of an "audio" amplifier. "Wireless microphone" (as long as you are 100 miles from town).
See you at the southpole, say hi. to the pinguines
Have you thought of using a 50/60Hz notch filter to remove the hum?
That one experiment might pick up the Schumann resonance, but it's below audible frequencies. However, you could use some electronics to observe it's periodicity.
Very Very interesting experiment! Thank you. I too am interested to know what one could hear from the Earth's magnetic field and also I wonder if you may have to get way out into the desert somewhere or up at the highest altitude in your state in order to escape the AC hum?
Here is what the earths magnetic field sounds like from outer apace. th-cam.com/users/shortsn5fAF6B4Lw4
Amazing.
Could you please do a video about the superheterodyne?
What aspect of superheterodyne receiving are you interested in?
With sensitive audio amplifier can hear VLF natural radio ( sferics, tweeks, whiatlers, auroral chorus )
Bird and frog like chorus from space :)
I would not doubt it. Sometimes I tune my cars AM radio to a blank spot, just to see what I pick up while driving around. I should look into this.
The bass speaker in my living room hums at 44db with the surround sound off and I hear it and it's driving me nuts. I am going to disconnect it to see or hear if it stops.
How about using a high-pass filter in the inductor? The sounds below 100hz may be a worth loosing to gain more clarity above?
I'm not sure, but I've had some success reducing the hum by using two coils, and arranging their position, so their outputs are in opposition.
@@GrantsPassTVRepair Yes that removes "common mode" interference but will cost you signal amplitude of your desired signal as well (unless you can shield one coil from the desired signal). A high-pass filter would make a bigger difference I think :) Thanks for the reply!
Could you put a filter on it to block frequencies specifically in the 50-70 hz range?
The best I've come up with so far to eliminate the AC hum,, is to have two identical coils with outputs that oppose each other. I hope to make a video on this soon.