The Creepy, Encoded Broadcasts Of Numbers Stations
Numbers stations were first noticed during the Cold War, when some of the more "famous" ones were given proper names. The Lincolnshire Poacher station, for example, was named after its tendency to insert parts of an English folk song into its broadcast. Some of these stations were in use for decades, and though there are far fewer nowadays, it's still possible to tune in to one with a shortwave radio of your own.
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Key Facts In This Video
Shortwave radio frequencies sit just above the medium band typically used for AM radio. (0:25)
The Lincolnshire Poacher numbers station broadcast from the mid 1970s until 2008. (2:16)
It's generally thought that numbers stations are encrypted messages intended for spies. (3:22)