numbers stations

“Numbers” stations on shortwave.

Since World War 1, foreign governments have been using shortwave to broadcast instructions to overseas operatives. Correct decoding of the messages relies on the possession of a codebook, or daily timepad.

This is achieved by transmitting a series of letters and numbers, sometimes using an automated synthesised voice, sometimes using Morse Code, and sometimes in a digital format.

Countries know to use or have used the “numbers” communications system includes: Cuba, Poland, Russia, North Korea, Israel, Czechoslovakia, Sweden, UK, and the USA.

Numbers stations have a great advantage over most forms of modern communications-they are completely anonymous. All an operative needs to do, is purchase a shortwave radio in the country in which they are located, and know the time and frequency of transmission.