Using a PC sound card to receive VLF radio signals
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- Опубликовано: 11 сен 2024
- Just connect an antenna to your computer's microphone input, and you can receive VLF (Very Low Frequency) radio signals! A sound card (or built-in sound chip) with a recording sampling rate of at least 96 kHz is recommended.
Example of using this method to receive VLF signals from Russia and Europe:
• Excellent VLF receivin...
SDR Sharp software (for Windows) to receive and record VLF (and many other) radio signals:
sdrsharp.com/#d...
Similar SDR (Software Defined Radio) applications are available for Linux and Mac OS.
Lists of VLF stations:
sidstation.loud...
www.smeter.net/...
Common sources of radio interference and recommended solutions:
www.ccrane.com/...
About the accidental recording of VLF station GBR (16 kHz) contained on Mike Oldfield's "Tubular Bells" album:
alancordwell.co...
gkircher.storml...
en.wikipedia.or...
This was the most interesting video I have seen on RUclips for a long time.
***** I really have no clue what you want to say with that. ;-)
VectrexRoli MAGYAROK MINDENÜTT!!!!!!!!!!!! :D
Nice to see a video on low frequency radio that isn't conspiracy theory BS. Good upload!
The easiest way to make a really good ground is to take just a four foot long copper pipe from the hardware store and hammer, don't bury it, in to the ground with 4" sticking out. The ideal length is 8 feet as any longer adds no benefit but pounding 8 feet without hitting rocks isn't possible in some soils especially the east coast above Maryland. Take steel wool and get the end of the pipe shiny, then take a piece of stripped copper wire and wrap it around the top of the pipe 10 times and solder it to the pipe if you can use a soldering gun DO NOT use flame it won't conduct. Wrap this in electrical tape to stop oxidation. Then lay that wire above the ground directly to the back of your receiver or antenna balun Makes a night and day difference clears up most noise and reveals stations that you couldn't hear.
If the dirt is too hard to pound a 4 foot copper pipe like here in the Arizona desert, you can dig a trench that's a foot or 2 deep and 6-8 feet long, line it with a bit of salt, and lay the pipe in and bury it. If it's summer and the ground is dry, keep that area of dirt wet when you want to use the ground. You can definitely use a flame to solder the pipe; it makes sbdolutely no difference how you melt the solder. Use flux for a very good solder joint and clean the copper with Emery paper before soldering. Those without the ability to do this can use their water pipe that comes in from the water meter underground.
Thank you, I really enjoy seeing technology used in unintended ways. The Mike Oldfield connection was fascinating.
Why has nobody liked this comment?
Just looked through some other 70s albums to see if they should have something similar to the signal on "Tubular Bells", and I found out that Pink Floyd's "Atom Heart Mother" has the GBR signal as well! It's not as strong as on "Tubular Bells", but it is there about 2 minutes in on the track "Atom Heart Mother Suite".
I am pretty sure most of these were intentional, and were added as an easter egg.
Cool ill check that one out !!
Incredible! I just to discover this in an article of the magazine of Argentine Radio Club! I'm ham radio operator for more than 40 years and sound engineer and Mike Olfield's fan, this drives me crazy!! Thanks for sharing!!
That is beyond awesome. I need to try this sometime.
Thanks again for creating this video, VWestlife. :-)
I first saw it when it first came out 5 years ago, and have been having a blast experimenting with SDR-Sharp and similar programs ever since. :-)
Funny… This channel had me reading online about radio technology out of curiosity, and when I read about VLF I casually started wondering if you could stick a free wire or antenna of some sort into a sound card's input and pick signals up. Then I came across this video. :)
slinky springs make great vlf anntenas, just strech it out and connect wires to either end, if your receiver only needs one wire just connect one end.
i have a really small slinky sort of like a "toy" version(i know a toy of a toy, this when slid on a broom handle and held either end with tape and wires attached makes a great scanner antenna you just stretch it out for different wavelengths when the signal is strongest put the tape on the end to hold it.
Hello, I am very interested in your little toy. Can you share your little toy? My mailbox lk68091618@gmail.com, thank you
Thank you! I'm going to give this a try. I'm a total newbie so any advice on making this work would be super appreciated.
Thank you for sharing this experience...I d/l'ed SDR # and it works very nicely with my Dell D630 laptop and about 100 feet of wire laid right on the ground and link-coupled to a coil wire wrapped around a 5 gallon bucket, coupled to the mic input jack through a couple of transformers audio transformers....works beautifully. Minimal AC hum, and I see the sub broadcast signals at 21.4 and 19.8 and 23.2 and 24.0...21.4 is the strongest here in the central coast of California ...I've had this system going now for almost 1 week and am having a blast exploring the VLF world :)
Thanks for the heads-up on the Tubular Bells album, thats pretty cool!
Wow. This makes you wonder what other albums out there might have some VLF or other hidden interference embedded in it.
Just a tidbit of information, at 24Khz, a 1/4 wave element is 1000 feet. So, a half wave dipole is 2000 ft long. Better get a couple of high towers to install it on. And YES, a good ground is essential.
If, you can get the antenna at least 1/4 wavelength, you will receive any shortwave signal.
Dennis N7TZQ
Nice work and interesting fact about the already quirky Tubular Bells classic.
That is very interesting! I didn't know you could do that. It's cool that you could get a signal from the other end of the country... and even Europe if you had a bigger antenna.
Also, I find that with some TVs, simply having them turned off doesn't cut all the interference, you have to unplug it. My early 2000s RCA does that, a lot of newer electronics don't seem to be properly shielded.
Thank you for sharing this. :)
It would be interesting to check other CDs recorded in Europe to see if they too have radio transmissions piggy-backing along with the intended program.
For my setup I salvaged a pair of degaussing coils from an old 32" Sony TV, arranged them in a crossed-loop and connected them to the line input on my Dell D630 laptop. Works very good. Eventually I will build an impedance matching/amplifier and it will work even better. As-is it gets lots of FSK signals at times, according to propagation conditions. A whole new world to explore. :) :)
This was the coolest thing I have seen in many a day. Thanks for doing this! I loved it.
Very interesting video, thanks for sharing! I have a Yaesu FRG-100 that tunes down to 50 kHz, so about all I've heard on the LF band is WWVB on 60 kHz, and LORAN on 100 kHz when it was still in use.
interesting to see the range of the jim creek transmitter 50 miles north of me. it's a massive transmitter site with an insanely huge antenna array that zigzags back and forth between 2 mountain ridgetops and 12 steel towers. the array is pointed west, so if you can receive it 3k miles in the opposite direction with a skimpy antenna it must be able to broadcast all the way to southeast asia. 1.2 megawatts of power helps too.
That's great, I have a HF communications receiver that tunes from basically 1khz to 30mhz (AOR 7030) and with a metre diameter magnetic loop I can pick up 60khz and 77.5khz time stations and can sometimes hear the alpha signals but it's nowhere near as good as this method. Great vid. I'd love to try this method.
OMG ! I bought that record when it came out. Who would ever have guessed it had an embedded CW message. I didn't have a pc with spectrum analyzer and waterfall display back then LOL
Very well organized - nice video, description, and helpful links.
"Don't do this during a thunder storm"
But you'll miss the whistlers!
I never knew you could use a sound card as a radio!
This video earned you a subscription , one of the best and interesting on YT
My late father was in the Royal Navy, and one of his jobs was testing the now defunct submarine communications transmitter at Rugby.
That is SOOO cool! Also, I spy a powermac g4 quicksulver... XD
The anti-aliasing filter certainly does get in the way. My card (okay, chip, given it's on the motherboard) can do 192kHz sampling, but everything above 20kHz is really weak.
Fascinating. I wonder how many more albums recorded at 'The Manor' carry similar signals.
Thanks for pointing out that fact about Tubular Bells.
Coolest thing you ever showed.. never knew it was possible
First, I learn about Rush's YYZ and now this. This is cool.
what about YYZ?
Intro is YYZ in morse code
You know about Kraftwerk?
I listen to Kraftwerk at least once a week.
nice. I did this in 2011 and 2012 as a part of my diploma on the university. I used a low noise amplifier with a 1000x amplification, an external audio card, and a long antenna. I also tried with an underground microphone on a remote location. even tried with the underwater antenna. tried to get elf signal.
The Nevada Test Range @ Groom Lake has a VLF station but it does not transmit continuous. I discovered it while repairing a guitar amplifier for a friend in Las Vegas, it was being picked up by the instruments pickups and amplified.
We did manage to track it down to the test range area as far as we could legally go.
Sorry if you mentioned this in the past, but what camera do you use to record? I am looking to get a different one for my tech videos (my auto focus took a shit in mine).
Thank you for this very wonderful video, I think there are lots of wonderful applications that I might test on what you have shared... with range from 1hz to 48000hz, I may use a frequency generator to send signal to a particular object (resonance frequency), and using loop antenna I might be able to locate certain object vibrating through signal emitted by the frequency generator... maybe worth a try, what do you think boss?
I can only receive 50 hz intereference signal
Seus videos são ótimos! Sempre acompanho seu canal, sou ham radio operator e uso o SDR e acho que um passo para o futuro dos ham radio operators.
I had no idea about the hidden 16khz signal on 'Tubular Bells'. Amazing, thanks for that. If you got a miniwhip antenna outside, you'd be amazed how much the noise floor drops and the signals come up. They're easy to make. It actually works from DC up, not 10khz up. dl1dbc.net/SAQ/Mwhip/Article_pa0rdt-Mini-Whip_English.pdf
I saw the large antenna array at Rugby when I was passing by in a train there in 1970. Most of it was demolished a few years ago.
You're so awesome! Tell me, what camera do you use for your videos, and how do you get it to record screens so clearly?! :O Also, how would I find out the relevant specs of my sound card?
Evil Roda I use a Canon FS200 camcorder. If you Google the name of your sound card or the sound chip it uses, you should find the specs.
I'll try this with my XP laptop which has Realtek HD Audio, I don't know what the sampling rate of the MIC in is but I'll try that.
Perhaps this is also why "Line in" is muted by default in windows?
This video is so informative and interesting, that I couldn't help logging in to my gmail account just to say thank you very much for making such great video and explaining all the stuff. Also many thanks for those informative links.
J
My sound card has a 96KHz/24-bit DAC, I wonder what I could pick up!?
I know it. My microphone input just doesn't care :( Anyway. Really cool, dude! Had no idea it was that easy. Nice low-cost way to experiment with an SDR when you don't have a USB dongle that allows you to scan an even bigger range of frequencies.
For everyone interested in this there's a website to listen to some of these signals "websdr", without the need to use an antenna.
Yes, you're right but if someone does not have the equipment this would work to see how it sounds.
Interesting thanks a lot
Jean-François
This is amazing and interesting as hell, I might even try this soon...
I downloaded a mp4 version of this, but it didn't contain the morse code at 16.100
Seemed like a good idea... but the software doesn't work for me.
I downloaded the SDR software, then tried to run the EXE... but it told me I have to install ".NET Desktop Runtime"
I downloaded this... tried again... I still get the same message. SDR package refuses to initiate.
Might be some incompatibility issue with WIN-10?
wow, really interesting
Awesome video! Been playing with SDR# with a RTL-SDR stick. I should try this. I live right in Maine, few hours away from Cutler though. :P
Thanks for the video! I have built several ELF/VLF receivers but this appears to be much simpler and easy to use. Look forward to seeing more from you.
I cannot download the SDRsharp program. Do you know of another spectrum analyzer program that you could recommend?
I see that you have "IQ file (*.wav)" selected as your source, instead of a SDR radio, at the top left..which means you are playing an already recorded radio audio file..I believe I am right..
Yes.
I have a vinyl America - Perspective and I noticed that at the beginning when I drop the needle there is a 23+ KHz tone immediately after the needle drop and the music starts about 3 seconds after the needle drop and the tone is continuous from beginning to end even between songs on both sides until after the last song is over and the tone disappears before the groove spirals rapidly towards the record label. I think it's from the master tape where the vinyl was cut. No idea if pressings from other countries also have this tone. My copy is an original Filipino pressings from 1984. The frequency of the tone slightly fluctuates up and down that matches the rotational speed of vinyl because the hole of vinyl is slightly off center. I can't hear the tone but I'm using an audio editor to see it. CD can't respond above 22 KHz so if your copy is a CD you're out of luck.
This will be a nice extension to my RTLSDR setup.
Awesome work...
You got it working so good...nice video!
Hi first time here.
And I have a question, if I may?
I have a person using vlf or vhf to hear my thoughts or slight throat movements and I need to combat this.
These people are very bad people and I have to assure my family is safe
I believe there are pinhole cameras in my house also. And I can hear them complain when ever I think about going to the D.A.s office
Or contacting the Department of justice. These people have a thing for watching people 24 hours a day. It breaks every god given right I know of.
Any help or input would be greatly appreciated.
Thanks
It looks like you're having some transient noise. You can try the Noise Blanker to reduce it. The noise reduction may help also.
Very enjoyable demonstration. Thanks.
Oh my God! That's so awesome :D
Wonder how many other albums have been done at that studio that had the same issue
Many, many recordings have a 15.75 kHz tone in the audio due to someone using a CRT monitor or TV in the same room as the recording studio.
"Just connect an antenna to your computer's microphone input, and you can receive VLF (Very Low Frequency) radio signals! " Wich model of antenna?
No model. You have to make it yourself.
@@vwestlife Excellent! I will make. And the software ?
I can definitely see how an LCD monitor can interfere with VLF radio reception if it's a cold-cathode-backlit model, the cold cathode tubes & inverter (basically a miniaturized fluorescent lamp) can emanate all kinds of RF interference. But I'd imagine a LED-backlit LCD display would not, correct?
And that's quite fascinating about "Tubular Bells"' hidden VLF transmissions of station GBR, I did not know about that! I have that album on vinyl, I wonder if that would be able to carry GBR's signal for decoding--I'd guess it'd have to be a clean, little-played (or ideally unplayed) copy, with a phono cartridge & preamp that can respond well at 16 KHz.
Excellent video ! I will give that a go !
I use a shortwave radio receiver with the onboard whip antenna tuned down all the way to 150 kHz where it’s quietest in terms of interference.
The signal in the Tubular bells CD is Pazuzu, the minion of Satan, the King of the wind demons, the bringer of drought, famine, and the storm, destroyer of crops by bringing forth plagues of locusts. Being acknowledged in the motion picture, "The Exercist," delighted Pazuzu to no end. He then added an evil message to the recording of the soundtrack as well.
May your crops be bountiful and strengthen all who partake of them.
As Spock would say "Fascinating."
That is really cool.
Would it be possible to get a USB receiver (maybe a DVB-T dongle) and using it with SDR Sharp?
And could one possible even record all radio that is being transmitted in that time into one single WAV file?
That would be simply awesome.
That's really cool especially that there is no radio needed!
What irony, that song was the Exorcist sound track. Very cool
What if you buy the most expensive 2 mHz sampling rate sound card just to listen to am radio.
With this software I discovered that the realtek audio chip of my mothrerboard has a bandpass filter that filters the mic input to 20kHz no matter how high is the sampling frequency. Even with sampling rate of 192kHz, over 20 kHz or so, no signal passes through. So I'mm wondering what is supposed to be the purpose of having the capability to sample at 192kHz, if there's a fixed banpass filter at 20kHz in the input. Bah....
Tried the line-in?
use another soundcard, then. this principle should even work with external usb units, I would imagine...
This is because the human ear doesn’t process or hear audio above about 18 khz, so anything above 20 khz is basically un-wanted noise in most cases. Buy an external sound card used for recording/processing music, and you should be able to sample above the 20 khz cut off
interesting video, wouldn't a high speed data acquisition device such as an oscilloscope provide a better signal? they have them in card and USB now, connecting to the soft ware you mentioned to it might be a problem those.
Have you tried hooking BOTH sides of the loop to your sound card input? Unless you do, the loop is open and noisy. Try a piece of shielded audio cable. On one end, hook the center conductor of your mic input connector to the center connector of the cable. Hook the ground of the cable to the shield connector of the mic connector. On the far end of the audio cable hook the center conductor to the ungrounded side of the loop and the shield of the cable to the grounded side of the loop. This should GREATLY improve your signal to noise, while rejecting a lot of the local noise near your computer.
For even better signal reception, use coax to a loop outside of your house. Just google for VLF loops for construction info.
Also, you appear to be in a basement. Perhaps a metal water pipe may provide a decent ground.
Good luck, Glenn WA4AOS
The other side of the loop was connected via the ground of the electrical system, since the tuner was plugged in (but not turned on). But you're right, a direct connection would be better.
+vwestlife The ground provided by the electrical system is also the ground on everything on the electrical system and will e noisy compared to a dedicated connection across the loop.
Interesting video and it is neat that you were able to see signals from a modest setup. Radio Shack, if you can find one, use to carry a fairly decent audio cable; not great but OK
I have been tempted to build a rotatable loop that would be outside and tune it for ~135KHz for some of the LOWFER signals. as you probably know many of the NDB's have gone silent in favor of newer GPS navigation. I can still copy a number of them especially, in the dead of winter.
Regards,
Glenn
I remember having an Philips radio casette boombox in the early 2000's which had FM, AM and VLF. When I was a small kid i accidentally kicked on the VLF switch. I thought I heard UFO's back then and my prarents wouldn't believe me. Now I know why XD
Yarach That would be LW (Longwave), not VLF. Or possibly VHF, if it had TV audio or weatherband reception.
vwestlife LW it was indeed. Now I remember, Thanks for the info!
I noticed that if I use a cheap poorly shielded RCA cable to amplifier's line in without connecting the other end to anything I can hear a faint sound from our local AM stations.
I am a little confused. Did you use a long wire antenna outside when you received these signals? I also see that you used a AM loop antenna that is connected to the sound card. How did you hook this up? I was trying think on how you did it, but still it got me confused, and I really need a good indoor VLF antenna for my SDR. Please help me out. Thanks.
I used a combination of both the loop antenna and outdoor longwire antenna (although it's not really that long, only about 20 feet).
what does the morse code say?
pandaaa22 "VVV GBR" repeatedly... the "VVV" being a legacy of the World War II "V for Victory" slogan, and of course GBR being the station's call sign.
vwestlife VVV, in morse code jargon literally means that the station is idling, or testing.
GBR was the callsign of the Rugby Radio submarine communications transmitter. Actually if you stood under the antennas and had good hearing you could hear the morse as they acted as giant loudspeakers.
As a paranormal investigator I have a pecuniary interest in this software.
Tutorial please? because it looks like you are playing a wave file and not capturing what's coming from the mic jack or input. Does audio have to be recorded first then played back in SDR#?
No, you can do it live. This site has some basic info on setting up and using SDR Sharp: sites.google.com/site/g4zfqradio/connecting-soundcard-sdr-to-computer
+vwestlife hmm it doesn't explain what you're doing with a lead in the audio in. Also you're frequency graph shows frequencies higher then. What you would see if you're using you're sound card as input as like someone said here the graph only goes to 20khz when selecting sound card as input. It would be great if you showed us this with sound card as source, doing it live.
*****
You have to make sure your sound card supports and is correctly configured to a 96 kHz (or higher) sampling rate for recording. There should be an option in the sound card's settings somewhere. And there are other videos on RUclips about using a sound card to receive VLF signals, they may have more detailed info.
+vwestlife Okay thanks I will play around with it, I see that when you raise the sampling rate of the sound device in SDR# it does change the scale of freq. chart. I do see the waveform dropping down a little after 24Khz but thats becuase I didnt change my sound card settings, I will play with it some more. I've been catching up on all things RF and I find this pretty interesting. I'd like to see examples of how this method can pick up communications devices would use and possibly decode it.
ok, but what can You do with that signal? just sit there and listen to the noise? :)
There are FSK decoders you can use to turn the data transmissions into the text they were sending.
vwestlife Now that's a good answer :) I'd like to see that in action.
Marek Sysoł I imagine most of the interesting transmissions would be encrypted as well.
jamie marchant for sure, but seeing the text itself is exciting enough :)
Well at IDLE its sending the station call sign. IF there was a nuclear attack imminent the station would start sending SLBM launch info in the form of data and possibly even voice in a loop..
Wow! I'd like to have a super wide sound card to receive the mediumwave range! 🤓
Are these the signals that are beaching all of the whales and other aquatic animals that use sonar?
No.
Yes, animals are easily influenced by electromagnetic waves. Especially aquatic animals that use vibrations for direction
Where can I download this app?
I wonder if any other albums have such an audio artefact... Presumably many
Great video VW! Does anyone know what studio device was actually picking up the radio signals? I had an old guitar amplifier that would randomly pick up commercial am radio at certain times of the day (probably bad input filtering, or a grounding problem) but the article I read about TB stated that they recorded the guitar & bass directly into the console. It's strange that the engineers would not have heard this as they were listening to the isolated tracks on the master tape. This must have been discovered before someone isolated it in SDR.
Or maybe they were very much aware of it and left it in on purpose as an easter egg.
Have you been able to pick up any numbers stations or otherwise strange radio broadcasts in this way or a similar way?
No, numbers stations operate on shortwave (HF), which is well above the frequency range of VLF or LF.
I see, I thought shortwave was within the VLF frequency range. Have you ever picked any numbers stations up on your shortwave radios before? I wouldn't have any hope of ever finding any in my area.
LOLZpersonok Yes, Cuba still uses numbers stations a lot and I can hear them quite often on shortwave.
Can a person use this apparatus to detect weaponized infrasonic pulse generators?
How low on the spectrum can you broadcast voice/music? And is the Antenna required too large or can it be done at close range with a shorter antenna?
Voice transmissions are certainly possible in the VLF range, although that's not an efficient use of the bandwidth available. Shorter antennas are possible but won't give as good of reception (or signal coverage if transmitting).
How can you conect the rg85 coax to the computer microphone?? Thank you very much!
wow, very interesting video! thank you
This is awesome I have to try this, my computer has 2 sound cards one internal and a external because I upgraded it but the internal still works and the driver is still installed so I wonder if it will make a difference being Realtek and my external is creative and also I wonder if the morse code is on the vinyl version of tubular bells or do you recon it will be too noisy from dust and static etc
Excellent educational
This was a great video.
You can use 192 kHz sample rate to get up to 96 kHz
His sound card cant go that high, it only goes up to 96kHz
@@dlarge6502 I know, mine has 192 kHz
Not sure how safe it would be to do so, but you could also attach the antenna to your household wiring through the ground pin and or the copper piping in your house if you have it.
Also, have you ever tried to decode this data using a modem?
+AIO inc. The data is encrypted.
vwestlife
Decryption included? Would it be possible?
+AIO inc. decryption is illegal.
Nikola Begonja
Why? It's just time codes.
Hi y'all. I was wondering if I can use the sound card in my android phone any ideas? I think sharp++ works on the phone any idea how you can use the sound card 💋 and hugs
How do you actually connect the antenna to the mic input? What pin is the wire connected to? If I get a stereo lead with a minijack on the end and cut it down so I just have the two cables coming out, should I connect my antenna to that? But which core?
None of the explanations of this method online address this in any great detail :(
You connect it to the wire that goes to the tip of the plug. You may need to use a multimeter to find one which one that is. Or just try both and find out which one gives better reception.
VWestlife thanks, I have access to one so I can tone the lines.
VWestlife do I need to connect a ground anywhere? To the ground I guess (sleeve?)