What 50,000 watts of RF energy sounds like through a jumper cable

Re:What 50,000 watts of RF energy sounds like through a jump... by connorlee on Thursday February 11, 2016 @01:41AM (#11078588)

Amplitude Modulation, or AM, works by modulating the sound on the "peaks and valleys" of the frequency. If you were to look at the waveform of the carrier frequency, you would see it as variance in the "power levels" of the signal, going higher and lower depending on what's being sent.

Because of how AM works, you can actually hear what's being transmitted by causing an electrical arc. It's the same concept of hearing a "buzz" from high voltage power lines, except in a controlled fashion to produce sound.

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Re:What 50,000 watts of RF energy sounds like through a jump... by LesZedCB on Thursday February 11, 2016 @11:09AM (#11080970)

ElectroBOOM has a cool video[1] on youtube talking about some of that! His videos are some of my favorite.

[1] https://www.youtube.com/watch?v=L5E4NiP4hpM

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Re:What 50,000 watts of RF energy sounds like through a jump... by gus_massa on Thursday February 11, 2016 @01:30PM (#11081940)

This video I very interesting. You should submit it.

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Re:What 50,000 watts of RF energy sounds like through a jump... by JoeAltmaier on Thursday February 11, 2016 @11:51AM (#11081279)

The carrier frequency is way above the hearing range. So it has to be shifted to the audible range. That happens by clipping and filtering. The arcing must be doing that somehow. Probably clipping; the low-pass filtering is done by the air/your ear.

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Re:What 50,000 watts of RF energy sounds like through a jump... by malexw on Thursday February 11, 2016 @12:36PM (#11081568)

My guess is that the arc through air gap is functioning as both the detector and speaker here. I suspect that the arc can only be sustained in one direction, probably from ground to the cable, which would give us the required clipping. At the same time, I assume the arc is acting as a plasma speaker, and, as you say, the air and our ear provides the low-pass filtering.

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Re:What 50,000 watts of RF energy sounds like through a jump... by xhrpost on Thursday February 11, 2016 @10:14AM (#11080550)

Came here to ask this very question. Thank you. I take it then that a signal using frequency modulation or phase modulation (is that done anywhere?) wouldn't work then? Also, probably the same reason a ground loop in a home entertainment system will pick-up local AM stations. Edit: also, why does this work with the given RF frequencies which for AM are still much higher than audible sound frequencies?

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Re:What 50,000 watts of RF energy sounds like through a jump... by Already__Taken on Thursday February 11, 2016 @03:20AM (#11078931)

So could you tune into the singing tesla coils with an AM radio is that the same idea?

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Re:What 50,000 watts of RF energy sounds like through a jump... by pdkl95 on Thursday February 11, 2016 @07:35AM (#11079732)

You probably could, though I suspect you might need to re-tune between notes.

If you have an old CRT, you might be able to achieve a similar effect with Tempest for Eliza[1].

[1] http://www.erikyyy.de/tempest/

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Re:What 50,000 watts of RF energy sounds like through a jump... by jackhack on Thursday February 11, 2016 @02:50PM (#11082671)

Indeed. One of the more interesting projects I've seen uses a tesla coil discharge as a guitar amp: https://www.youtube.com/watch?v=glrPioGqu3s

A search for "singing Tesla coil" will turn up many more.

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