UVB-76
en.wikipedia.org
en.wikipedia.org
Is that a hoax, interference or something else?
The trade off is sometimes human error happens. It isn't really a big deal since the messages themselves are encrypted inside of a secure facility then transmitted to a non-secure area that handles the actual broadcast (since it would be stupid to put a massive transmitter in the room with your super secrets).
X:59:00 - Buzzing gets faster.
(X+1):00:00 - Normal buzzing resumes.
It can be speculated that Russian Perimeter (Dead Hand) system [0] may be one of the listeners.
If whole system (and world's fate) relies on a single buzzer, we have much bigger problems :)
It's said that it has connections to seismic and pressure sensors and can check whether communication to critical infrastructure is intact. So it keeps tabs on many heart-beat signals it seems. UVB-76 might be one of them.
Moving a low traffic radio station with an interesting sound just because a bunch of HAM radio guys doesn't make sense. It has to have some higher function to warrant the move.
With the new over the horizon radar systems Russia is deploying, I guess that signals from these would be evaluated too.
Going in to wild speculation territory, Russia's in-house CPUs would fit the bill for these kind of systems nicely.
Tune in to 4625 kHZ, and there it usually is, UVB-76, buzzing on all of its glory.
They also tracked the signal using TDoA: https://priyom.org/blog/real-buzzer-site-found!
It's almost more suspicious to be listening to a radio at all these days, so unless you needed coverage of areas without internet access it would make sense to just dump the numbers onto a .onion or similar.
Also, while number stations broadcast over the air, the signal might not terminate at a radio receiver. It might be picked up by another system and forwarded in a different form.
A similar model is used by Chinese FireDrake jammer. There are numerous broadcast stations for FireDrake and all are fed by the same satellite radio channel (one of the audio channels of the minority radio stations) which play extremely high intensity chinese classical music which loops perfectly and lasts 60:00 minutes sharp.
When they spot a transmission they don't like, they tune the ground station to it and blast with the music. Intensity of the music drowns out the other transmission. Interesting stuff.
Also, low tech stuff is extremely resilient to outside effects. Modern IP telephony will collapse if something bad occurs. POTS, won't sneeze at it probably.
You should've seen Terry Davis...
http://www.numbers-stations.com/media/sample-uvb76-logbook.p...
I got _very_ into number stations a few years ago. Still have a vague interest in them these days but there's not so much traffic now. Scared the crap out of myself when I first found them though!
There's all sorts of interesting/creepy stuff out there on the airwaves.
two threads from 2010: https://news.ycombinator.com/item?id=1632488
as far as how powerful the transmitter was, obviously the rogue transmission would be stronger for those closest to it.
That the public might be likely to observe more thoroughly makes it less of a coincidence.