Henry Cooke: Numbers Stations: Cold War, short waves

For a period of time which coincided suspiciously closely with the Cold War, Europe's shortwave spectrum was full of mysterious radio stations which broadcast inscrutable strings of numbers, noises and tones.
This talk examines the history of the Numbers Stations and theories of what they might have been up to, using evocative archive recordings and a section where you can try your hand at decrypting a clandestine transmission.
Henry Cooke