Back in the days of Cold War espionage, foreign intelligence agencies used to communicate with agents on the field via shortwave radio. Radio transmitters placed at secret locations around the world would broadcast coded messages usually in the form of an automated voice reciting a string of numbers or letters. The message often began with a melody, or a set of beeps, or a buzz, followed by the actual coded message read aloud by a voice. Anyone with a radio receiver tuned into that frequency could hear it, but only the intended recipient with proper decoding instructions could decipher the message. For the rest of the listeners, they were just a string of random numbers. Ham radio operators, who frequently stumbled upon these secretive transmissions, called them “number stations”.
Photo credit: k'nash/Flickr
Read more »© Amusing Planet, 2017.
Comments