[Twisol]

> this is the same country that has the national power grid introduce "hum" (or whatever it is technically callled) in the signal so that a time reference can be decoded from it.

I don't think that's intentionally introduced. My understanding was that mains hum in any grid is an artifact of a noisy signal that just happens to be useful as a forensics fingerprint.

https://en.wikipedia.org/wiki/Mains_hum

[dylan604]

Yes, it seems I crossed a few streams in my head. Here's an article[0] talking about how the forensics is done because someone is creating a database of all of the fluctuations that give it the forensic finger print rather than it being deliberately injected.

[0]https://www.bbc.com/news/science-environment-20629671

[roywiggins]

I believe that the frequency actually is deliberately managed... to keep old clocks synced.

https://www.kccscientific.com/the-dirty-little-secret-about-...

[ErikCorry]

Fascinating