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Re:Turn Raspberry Pi’s GPIO into an FM Transmitter by BrandoElFollito on Saturday November 12, 2022 @01:04PM (#33575418)
One needs to be careful with such home made devices as they may clash with the officially assigned frequencies.

We had in France a similar story where a village was losing 3G/4G connectivity almost every day around 22:00. It seemed that there are interferences with something.

A special car was sent by the national regulation entity, it was trying to triangulate the source.

They found a house where the owner bought a jammer on AliExpress because he wanted his children to sleep and not go on internet. He thought it was only "for the house".

Re:Turn Raspberry Pi’s GPIO into an FM Transmitter by pvg on Saturday November 12, 2022 @01:18PM (#33575538)
A special car

These have a surprisingly long history, e.g.

https://en.wikipedia.org/wiki/Direction_finding#/media/File:...

Re:Turn Raspberry Pi’s GPIO into an FM Transmitter by avian on Saturday November 12, 2022 @02:06PM (#33576006)
Every mobile operator has stories like this. Back in the GSM times the common theme in Europe was people using illegaly imported devices made for the US market. The unlicensed 900 MHz band in the US fell right into the GSM band in Europe. Apparently the worst offenders were wireless security cameras.
Re:Turn Raspberry Pi’s GPIO into an FM Transmitter by Johnythree on Saturday November 12, 2022 @04:24PM (#33577238)
In my small town, the entire local TV reception was being wiped out by interference.

When the Radio Inspector came to check, he found a rechargeable torch sitting in it's charger bracket, which generated horrendous interference whenever the batteries reached full.

Re:Turn Raspberry Pi’s GPIO into an FM Transmitter by anthk on Saturday November 12, 2022 @07:43PM (#33578783)
I know the reverse of your story. And OLD TV from a grandma jamming an entire town:

https://www.popularmechanics.com/science/a34229436/old-tv-br...

Re:Turn Raspberry Pi’s GPIO into an FM Transmitter by Johnythree on Saturday November 12, 2022 @08:16PM (#33578943)
Yep, this was surprisingly common. When the picture tube in old B/W TVs lost emission, the EHT voltage increased to the point that it was constantly arcing and flashing over. But because the arcing was synchronised to the TV signal, it didn't cause much interference on the faulty TV set. But it did create a horrid rolling bar on any TV set nearby which was tuned to a different channel. So the old lady had no idea she was causing problems.

And there's a twist to this: ADSL data networks attempt to feed broadband signals over unshielded (and poorly balanced) phone lines, which means that they are intolerant of legitimate radio emissions from licensed services nearby.

The ADSL system attempts to compensate for conventional transmissions by dropping out those channels, but any wideband impulse causes the entire system to hang while it unsuccessfully tries to find a clear set of channels. So each pulse locks up the system for a few minutes while it renegotiates.

A variation on this is the ignition on the Postman's motor bike which wipes out all the ADSL in each street that he visits.

The bottom line of course is that ADSL was a horrible hack which attempts (and fails) to bypass the laws of physics.

Re:Turn Raspberry Pi’s GPIO into an FM Transmitter by BrandoElFollito on Sunday November 13, 2022 @03:51AM (#33581286)
On the other hand, I still remember the time I got an apartment, my furniture was not there yet but I ordered the ADSL+ line that came early.

There is quite something magical in switching an ISP box in the middle of the living room, awaiting for the synchronization and, behold, I am connected.

This first connection i ssomething I always long for (whether the satellite we had in my job, or fiber that comes at home, or getting rid of the ISP router to replace with mine).

Re:Turn Raspberry Pi’s GPIO into an FM Transmitter by anthk on Sunday November 13, 2022 @07:52AM (#33582587)
>And there's a twist to this: ADSL data networks attempt to feed broadband signals over unshielded (and poorly balanced) phone lines, which means that they are intolerant of legitimate radio emissions from licensed services nearby.

Copper wires in Spain I think, from the old phone days.