iPhone audio detectable with AM radio
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iPhone audio detectable with AM radio
1–10 of 68 posts
Re: iPhone audio detectable with AM radio
#2Wow.
I wonder how far from the phone this signal could be detected.
Re: iPhone audio detectable with AM radio
#3Pretty interesting.. many class D audio amps drive at frequencies above 100-200khz, so either the odd or even harmonics of that frequency sounds like where you would get the actual audio content showing up in the audible band (not sure if it’s odd or even that would be the right one). I want to try this on some other class D speakers.
Re: iPhone audio detectable with AM radio
#4Wow. I wonder how far from the phone this signal could be detected.
It depends on how noisy the surroundings are. In an office block with potentially many other iPhones and sources of interference, probably not far at all. Out in a suburban or rural setting probably much further.
I wonder if it'll tune into phone calls?
Re: iPhone audio detectable with AM radio
#5This is not surprising. We’ve been using AM and FM radios to debug circuits for decades. They can pick up oscillations and instabilities.
But the range is centimetres at best. So much so the antenna gets used as a fairly directional probe.
Re: iPhone audio detectable with AM radio
#6Wow. I wonder how far from the phone this signal could be detected.
He says in one of the comments that he was able to get a signal you could hear from around 20 feet away.
Re: iPhone audio detectable with AM radio
#7Re: iPhone audio detectable with AM radio
#8I'm surprised this wasn't discovered sooner. For a while, when I was working in Portland radio, there was an AM station that played recent indie releases on it. Needless to say, while it was the butt of countless hipster jokes, there was a sizable crop of people with both AM radios and iPhones on them, frequently operating at the same time.
Re: iPhone audio detectable with AM radio
#9Earlier quoted context omitted.
He says in one of the comments that he was able to get a signal you could hear from around 20 feet away.
I suspect that’s unlikely from my own experiences on this stuff. Perhaps 20-40cm is more likely.
If you are disregarding that detail of the story, why not dismiss the author outright?
Re: iPhone audio detectable with AM radio
#10This is not surprising. We’ve been using AM and FM radios to debug circuits for decades. They can pick up oscillations and instabilities. But the range is centimetres at best. So much so the antenna gets used as a fairly directional probe.
In a later tweet he says the signal is pretty strong and that he could detect it from 6 feet away