It is still transmitting.
Since the mid-1970s a monotonic buzz has held 4625 kHz, roughly 25 times a minute. Nobody has ever officially explained it. Press play for a synthesized impression, or open a live WebSDR and tune 4625 kHz yourself.
Dossiers
16 dossiers, the codebreakers who made the numbers unbreakable, the radar designer behind the Woodpecker, the spies who listened, and the monitors who chronicled it all.
Stations
18 stations, transmitters and systems, the Buzzer on 4625 kHz, the Lincolnshire Poacher, the Duga radar, the Dead Hand, and the one-time pad.
Network
Who built what, who ran which station, who decoded whom, 53 people, stations and institutions, 95 documented ties.
Timeline
150+ verified events across world, Soviet, Western and espionage tracks, plus a life track for every dossier. With four guided tours.
Map
42 journeys across the globe, from Povarovo to the Duga array at Chernobyl-2, from Havana to a DIA desk in Washington.
On this day
What happened today in the history of UVB-76 and the numbers stations? A fresh moment from the archive, every day.
The Signal Game
67 questions, from a whisper on the band to a megawatt jammer. How far up the spectrum can you tune?
The Book
An eerie Cold-War-radio thriller, and the real, verifiable history behind every page of this site.