Numbers stations - radio ghost broadcasts

Numbers stations are mysterious radio broadcasts that have been broadcasting on shortwave radio since World War I. Their distinctive transmissions consist of computer-readable voices that deliver sequences of numbers and letters, often in various languages. Although they don't formally exist, many theories suggest they are used by government agencies to communicate with agents, as well as by smugglers. Receiving these stations requires specialized equipment, and their source remains unknown. Numbers stations broadcasting from Poland are also interesting.

You turn on the radio. You switch to shortwave. You search for a station. Finally, you find something. It's a strange station, though, because on the set frequency all you hear is a sequence of numbers: "one, one, one, three, sedum, two, six, three..."—and so on. You think to yourself, "Nonsense." But you continue listening, curious. Maybe they'll tell you the name of the station? Maybe they'll start a regular program?

But after a moment, all you hear is a short "The End." And silence—nothing's transmitting anymore.

If something like this has ever happened to you, you most likely picked up a numbers station.

Numbers stations are shortwave radio stations of unknown origin. Their broadcasts typically feature computer-generated voices reading out sequences of numbers, letters, or words. These are usually female voices, although male and even children's voices also occur. Messages are broadcast in various languages (including Polish). Sometimes, they also include audio signals or music.

These transmissions are nearly identical every time and appear to follow a specific schedule (though some stations appear suddenly and disappear just as quickly). They typically begin on the hour or when the timer hand reaches halfway through the hour. Numbers stations typically broadcast on multiple frequencies simultaneously—if reception is poor on one frequency, reception may be better on another.

Each numbers station begins its broadcast in a distinctive manner. This may be a special code (e.g., "Mike Adam Cynthia"), an initial set of digits (e.g., "250 250 250"), or a distinctive phrase (e.g., "Atención"). Sometimes stations play simple melodies. Then the actual code is transmitted. Then, again in a distinctive manner, the station announces the end of transmission (e.g., "end of transmission"), or sometimes a string of zeros (e.g., "00000 00000").

Only in isolated cases is it possible to determine the location from which numbers stations transmit. Formally, numbers stations do not exist, and no one fully knows what they are used for.