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.
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.
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 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.
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
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.
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.
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...
@@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.
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!
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.
You've got a great way of introducing topics and I've been really enjoying flicking through your archives as I learn more about electronics. Thanks for all you do! Im v happy I found this channel :)
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 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.
@@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.
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.
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.
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.
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!
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.
@@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.
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.
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?
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.
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.
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.
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 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
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.
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.
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 😊
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.
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.
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
What signal do you expect to see from the ground? You'd need an alternating field to produce a sound from this thing, and the earth's magnetic field is pretty static.
Such a signal from the ground would likely be related to the earths magnetic field if it was detectable. I don't believe it's entirely static, but it might be necessary to speed up the fluctuations on an audio recorder to hear the small changes in the earths magnetic field.
@@GrantsPassTVRepair very good. Thanks for taking the time to reply. Are you familiar with the Thunderbolts Project? Their Electric Universe, Plasma Cosmology makes the standard model look idiotic. My page has become a glossary for EU and dissident science, I invite you to take a look if you find time. Basically it is cosmology from an electrical engineers perspective.
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
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.
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
Can I Merry you? You have some very interesting afterthoughts toward the end. Please keep me posted! I can hear humming without any equipment. The last few years I’ve notice the Drum like sound that Refrigerators make. Why is this? And keep your experiment going. I absolutely love leaning what is possible. I’m currently doing a few experiments myself. The next one is copper. Nothing fancy. The measurements of different types of water is very interesting. Something I want to dive deep into seeing how I just moved and the place here is on tab water. I keep telling folks that tab water makes my hair, skin feel not so good compared to the well water from my last home. They think I’m crazy tho. So I’m in the process of making me a magnetic stir plate. Magnetic gears and springs Fascinate me Along with vortex, golden ratio, Hebrew alphabet, electrioculture, emotional intelligence learning, and the world around me. I figured everything I’ve learned in school was bullshit so I better become my own scientists of the physical and the unseen. Thank you so very much for doing these video.
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.
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.
Did you see from A scope what's frequency of the Hum is😏? Did you know that you could pick up the c.a. 8.7Hz Hum of the Schumann Resonance? Did you also ever played with Rogowski coils? Build a huge one from that. The Rogowski coil can pick up Alternateing magnetic Felds down to a few mHz till a few MHz.
02:23 What if it could pick up the piezo-electric signals from variations in atmospheric pressure on the local rocks? VLF though! Many years ago I wondered if we could extract power this way. No wonder I liked this vid.
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?
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.
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.
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.
he did, it's behind the little car , a little guitar amp and a car battery. i hope he tries an electric guitar on his coil on the next test, and extra little guitar amp and someone to play some van halen,, mean streats.. that could get some viral spread.. i bet it would be the coolest soundin' guitar on the planet.
@@GrantsPassTVRepair Sorry, I didn't notice because the camera wasn't picking up the long cable on the ground. That was easy for me to miss. I thought that was something else by the car.
@@GrantsPassTVRepair hey, did you see my reply about testing a guitar ? you might have something worth big bucks to reproduce and sell if it sounds like i think it will.
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…
Could you tune this and direct it with a phased array, and tune it with the sum total of the wire length? If both - that’s a hell of an eavesdropping device. Big, and likely a ton of power consumption - but hey - why use a highly sensitive capacitance array when you can use an induction coil? 🤷🏼♂️
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).
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.
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...
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
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.😁
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!
This is really interesting, I saw the short about the small solar panel hooked to a phone amp and had to check out more haha
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.
This is gold,
Thank you!!!
@@edwardmiller4048 yes sir
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?
Really appreciate your work
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!
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.
Your videos are too cool!
You should be INDUCTED into the Electrical Hall of Fame!😅
😂
Haaa... I get it. 😂
You've got a great way of introducing topics and I've been really enjoying flicking through your archives as I learn more about electronics. Thanks for all you do! Im v happy I found this channel :)
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.. ;-)
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 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.
Thank you so much for this video it just helped me understand so many things
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.
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.
Dang...
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.
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. ua-cam.com/video/Cmxlp6uYnDg/v-deo.html
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!
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. ua-cam.com/video/iHY-GMrqK9A/v-deo.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.
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.
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.
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. ua-cam.com/users/shortsn5fAF6B4Lw4
That was fascinating! thanks for sharing!
I wonder if an electric guitar can be amplified through it?
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.
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.
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.
I love your style. Simple but super cool. Great demonstration, thank you!
You are so welcome! Thanks for the comment.
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.
This is basically just a metal Detector, with the pulse! Awesome!
No, it's called a coil/spool antenna. It's already invented.
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.
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.
@gortnewton4765 That is not notch filter.
@gortnewton4765 Then I don't see the relevance of your comment.
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 these experiments. So many questions.
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.
An eccentrically English approach.
Beautiful view of the mountains, so serene and quiet, errr, wait, here comes the hum 😅😊😊
How did u learn these skills??
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!
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.
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 😊
Yea, that makes sense.
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.
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.
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
Neat, wonder if the background hum can be filtered out.
Yes with two identical coils in a parallel circuit it can be greatly reduced, if one of the coils has an output that is out of phase with the other.
You can try sticking a small magnet to a flexible membrane and talking next to it
I suppose that would make a giant microphone.
Try a cave if you can to see if the AC hum is down there too.
That's a great idea!
Very cool experiment, your surly thinking outside the box ❤
This is amazing. Thank you.
Im going to add you to my page under Experimenters.
I wonder if it would pick up a decent signal from the ground?
What signal do you expect to see from the ground?
You'd need an alternating field to produce a sound from this thing, and the earth's magnetic field is pretty static.
Such a signal from the ground would likely be related to the earths magnetic field if it was detectable. I don't believe it's entirely static, but it might be necessary to speed up the fluctuations on an audio recorder to hear the small changes in the earths magnetic field.
@@GrantsPassTVRepair very good.
Thanks for taking the time to reply.
Are you familiar with the Thunderbolts Project? Their Electric Universe, Plasma Cosmology makes the standard model look idiotic.
My page has become a glossary for EU and dissident science, I invite you to take a look if you find time.
Basically it is cosmology from an electrical engineers perspective.
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
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.
WOW Mind blown Dave!
You need a 60hz notch filter
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. ua-cam.com/users/shortsn5fAF6B4Lw4
Can I Merry you?
You have some very interesting afterthoughts toward the end. Please keep me posted!
I can hear humming without any equipment. The last few years I’ve notice the Drum like sound that Refrigerators make. Why is this? And keep your experiment going. I absolutely love leaning what is possible.
I’m currently doing a few experiments myself. The next one is copper. Nothing fancy.
The measurements of different types of water is very interesting. Something I want to dive deep into seeing how I just moved and the place here is on tab water.
I keep telling folks that tab water makes my hair, skin feel not so good compared to the well water from my last home. They think I’m crazy tho. So I’m in the process of making me a magnetic stir plate.
Magnetic gears and springs Fascinate me
Along with vortex, golden ratio, Hebrew alphabet, electrioculture, emotional intelligence learning, and the world around me. I figured everything I’ve learned in school was bullshit so I better become my own scientists of the physical and the unseen. Thank you so very much for doing these video.
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.
Interesting experiment. You could try to add a variable capacitor in parallel to the coil and try to tune it a bit.
Amazing.
Could you please do a video about the superheterodyne?
What aspect of superheterodyne receiving are you interested in?
Are you certain that it's not feed back humm in the amp?
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.
Very good experiment can you make a longer video for the experiment with testing with different things
Can you do energy harvesting from the coil? I mean the reverse of your demonstration.
Did you see from A scope what's frequency of the Hum is😏? Did you know that you could pick up the c.a. 8.7Hz Hum of the Schumann Resonance? Did you also ever played with Rogowski coils? Build a huge one from that. The Rogowski coil can pick up Alternateing magnetic Felds down to a few mHz till a few MHz.
02:23 What if it could pick up the piezo-electric signals from variations in atmospheric pressure on the local rocks? VLF though! Many years ago I wondered if we could extract power this way. No wonder I liked this vid.
Have the induction coils power a very sensitive Galvnometer !
That sounds like an interesting experiment. Thanks for the suggestion.
Next video, " I got away from the AC hum up here at the polar cap" lol. Cool upload Thanks
Double thumbs up for being the person asking 'what if?'
Humm, humm ,humm-you are pushing through something-whats the tune?-way fun man
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?
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?
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.
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.
Where did you go for that video? Looks a lot like the Idaho Springs area.
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.
It's like am radio picking up lightning.
There must be a coil length limit due to resistance. Nice experiment
Is there a speaker somewhere off camera that is connected to the coil. I think we'll be more appreciated if you show that as well.
he did, it's behind the little car , a little guitar amp and a car battery.
i hope he tries an electric guitar on his coil on the next test, and extra little guitar amp and someone to play some van halen,, mean streats.. that could get some viral spread.. i bet it would be the coolest soundin' guitar on the planet.
Yes, I pointed the camera at my amplifier and speaker near the car.
@@GrantsPassTVRepair Sorry, I didn't notice because the camera wasn't picking up the long cable on the ground.
That was easy for me to miss. I thought that was something else by the car.
@@GrantsPassTVRepair hey, did you see my reply about testing a guitar ? you might have something worth big bucks to reproduce and sell if it sounds like i think it will.
Are you picking up hum from your recording device?
Yes I am when it's in the recorder is in the play back mode.
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…
There is software available that can cancel the background disturbance.
Do you have a violin or other musical instrument you could try that with? Use the coil for direct recording a see what it sounds like.
We need to construct this thing youre talking about to pick up the earths hum
For sure. Perhaps in a future project.
Could you tune this and direct it with a phased array, and tune it with the sum total of the wire length? If both - that’s a hell of an eavesdropping device. Big, and likely a ton of power consumption - but hey - why use a highly sensitive capacitance array when you can use an induction coil? 🤷🏼♂️
Good video - Could you perhaps filter out the 60Hz ?
Excellent video!
it is possible to hear a beating heart
It's possible, but not with this coil in its present design.
Have you thought of using a 50/60Hz notch filter to remove the hum?
Did you use a diode or did you just connect the coil straight to the amp?
I attached the coil directly to the amplifier.
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).
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.
Can't you make a filter for the hum ?
Wonder if you are near any high voltage cross country power lines to get that hum?
Perhaps a mile away as the crow flies, but no wires were visible to be.
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...
has all the vibes something Doc Brown in the the back to the future films say and do? just sort and Marty cameo ?
The amp is feeding back on the coil
Face them away from each other will significantly reduce the hum
Was the hum coming from your car?
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.
Thank you for experimenting!!!😁💖✌!!
You are so welcome!
So the coil was connected directly to the audio amp ? Hard wired ? Just coil to the audio inputs?
Yes it was hard wired directly to the amp.
What gauge wire is that and how many feet of wire is that?