this is completely illegal.
Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
21–30 of 89 posts
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#22This is so bad, and dangerous. It outputs pwm from an unfiltered digital output, therefore generating a hell of harmonics on a wide set of frequencies, not just the one it's set to operate on. It can seriously jam not only broadcast FM transmission but also other services. Beware that airband is very close; any jamming on those frequencies can turn in huge fines if not landing the perpetrator straight to jail. Want t…
In real life, what would happen to a legitimate clueless hobbyist who tries this (with no ill intent or knowledge of what's happening) and gets caught? I'm assuming the real response is closer to "hey, don't do that, read this PDF" than it is to "straight to jail"?
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#23Earlier quoted context omitted.
Sigh, getting a amateur radio operator license is not difficult, and teaches people such wonderful concepts like avoiding interference with noisy transmitters. 1. If you are using a modulated square-wave without a filter, than the harmonics/overtones will be splattering the local spectrum. 2. Tools like KerberosSDR/KrakenSDR make triangulating illegal broadcasts rather trivial. 3. Keep in mind, some places have a $5k…
> Sigh, getting a amateur radio operator license is not difficult, It is if you are trying to run from someone who's liable to pluck your address out of a public database (like the one the FCC runs) and come after you, possibly with murderous intent. It is if the government persists in misgendering you because hating you is politically fashionable in some circles. I'm not arguing that it's conceptually difficult, but…
I haven't done it but I've heard you can use a PO box for your license.
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#24this is completely illegal.
So? It's a proof of concept.
Tinker away, laws be damned.
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#25This is so bad, and dangerous. It outputs pwm from an unfiltered digital output, therefore generating a hell of harmonics on a wide set of frequencies, not just the one it's set to operate on. It can seriously jam not only broadcast FM transmission but also other services. Beware that airband is very close; any jamming on those frequencies can turn in huge fines if not landing the perpetrator straight to jail. Want t…
In real life, what would happen to a legitimate clueless hobbyist who tries this (with no ill intent or knowledge of what's happening) and gets caught? I'm assuming the real response is closer to "hey, don't do that, read this PDF" than it is to "straight to jail"?
Basically, the FCC can slap you with an expensive fine when the local HAMs rat you out.
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#26Earlier quoted context omitted.
In real life, what would happen to a legitimate clueless hobbyist who tries this (with no ill intent or knowledge of what's happening) and gets caught? I'm assuming the real response is closer to "hey, don't do that, read this PDF" than it is to "straight to jail"?
Basically, the FCC can slap you with an expensive fine when the local HAMs rat you out.
I know nothing about how this all works, how do people know who did it / where it came from? I presume its possible to get a rough location but in a built up area I'd imagine its pretty much impossible to find the person that did it unless it's left running right?
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#27Earlier quoted context omitted.
In real life, what would happen to a legitimate clueless hobbyist who tries this (with no ill intent or knowledge of what's happening) and gets caught? I'm assuming the real response is closer to "hey, don't do that, read this PDF" than it is to "straight to jail"?
Basically, the FCC can slap you with an expensive fine when the local HAMs rat you out.
A 20cm antenna driven by a raspberry pi's current limited GPIOs won't be powerful enough to get picked up by anything more than a few dozen meters away, especially not powerful enough to get in the way of actual signals being transmitted by a more powerful transmitter
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#28Earlier quoted context omitted.
Basically, the FCC can slap you with an expensive fine when the local HAMs rat you out.
I know nothing about how this all works, how do people know who did it / where it came from? I presume its possible to get a rough location but in a built up area I'd imagine its pretty much impossible to find the person that did it unless it's left running right?
You can use radio triangulation to determine where the signal source is while it is transmitting
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#29Earlier quoted context omitted.
Basically, the FCC can slap you with an expensive fine when the local HAMs rat you out.
A 20cm antenna driven by a raspberry pi's current limited GPIOs won't be powerful enough to get picked up by anything more than a few dozen meters away, especially not powerful enough to get in the way of actual signals being transmitted by a more powerful transmitter
A 20cm antenna will be a 1/4 wave at 375 MHZ (and a half wave at 188Mhz, etc), and thus will be a very efficient radiator at many different frequencies.
Even a tiny signal can be enough to block the operation of a nearby police repeater (which is also trying to hear weak signals).
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#30Earlier quoted context omitted.
That’s cool and all, but getting an amateur radio license would not have allowed me to do what I want legally anyway which is run a low power music FM station broadcasting to common radios in my own apartment. I do use a filter but it wouldn’t matter if I didn’t, I don’t really care that I’m splattering the spectrum when the broadcast doesn’t even make it through my walls.
If I recall, license free 88.7MHz under 15mW transmitters for FM audio were very common in some zones.
I believe the EU limit is 50nW (at least it is in the EU country I live).