For years, shortwave radio enthusiasts have noted a curious phenomenon: radio stations that seem to pop-up out of nowhere, read a list of numbers, then disappear... sometimes forever.

Because the sole purpose of the broadcasts is apparently to read lists of numbers, shortwave junkies started calling them “numbers stations”... although as we shall see, other names might be appropriate. 

No one seems to know when the “numbers stations” started broadcasting. No one seems to know who’s behind them. Shortwave enthusiasts assume that someone somewhere knows the purpose behind the stations, but as far as I or anyone else knows, that purpose is a mystery. In fact, there’s not a lot about the numbers stations that we do know. In fact, all we can say for sure is:

The stations are sometimes transient, sometimes not: Some numbers stations appear to broadcast once, then disappear forever; others appear in certain places on the shortwave dial with clockwork regularity. In fact, certain stations appear with such regularity that broadcast schedules are posted on shortwave enthusiast websites.

The stations broadcast for hours... or minutes: Some numbers stations repeat their “messages” a few times and then sign off; other stations might repeat their messages for hours and hours.

The stations broadcast in many languages: Recordings and verified “sightings” have shown that numbers stations are broadcast in English, French, Spanish, German, Russian, Chinese, Hebrew... and just about every other major language you can think of.

The stations may read a list of numbers, letters, Morse code... or something else: Although each station seems to have its own particular “format”, there is wide overall variety in what “code” is actually broadcast. The broadcast might consist of a single number repeated over and over again (“12345”), or it could consist of a list of numbers (“070 – 214 – 427 – 819”), or a list of letters (“AAEBH”), which are usually, but not always, broadcast in the phonetic alphabet (“Alpha Alpha Echo Bravo Hotel”).

The stations usually use mechanized voices: The stations usually use the “voice” of a mechanized female. Children’s voices are sometimes used and male voices are rarely used (if ever). Why female voices? Who knows... It also seems that “live” human voices are used on very rare occasions.

The stations use music or sound as an “identifier”: Most broadcasts begin and end with a simple tune or some distinctive noise. This is presumably to help anyone searching for the station to easily pick it out from other stations broadcasting at similar frequencies. Stations typically use the same tune or noise as their “station ID”, and many stations are referred to by the identifier they play. One of the most famous numbers stations is the “Lincolnshire Poacher” station, so-called because that’s the tune it plays before, during and after a broadcast:

So – who’s behind the numbers stations? And what are they used for? Well, that’s the mystery. Shortwave radio stations aren’t something an individual can just throw together on a whim, so it would seem that governments are behind it. This is given even more credence by the fact that the first reports of numbers stations began during World War I, when radio broadcasting was extremely expensive and required far more expertise than it does today. Back then, most broadcasting equipment was built by hand and built to order. There wasn’t such a thing as “off the shelf” parts or automated equipment. Just as the first computers required custom-built components assembled by highly-trained engineers, so too did the early days of radio.

Even more evidence that governments are behind numbers stations comes from traffic patterns. Just as TV shows like 24 talk about an increase of “terrorist chatter” before a major attack, numbers stations often see an increase in the frequency and\or duration of messages before governments go to war or announce a major new policy. This was made especially clear with the fall of the Berlin Wall; after the collapse of East Germany, the number of German-language numbers stations dropped significantly.

So – if governments are behind the stations... what are they used for? The most logical assumption is that they are used to send messages to spies. After all, shortwave radios are pretty easy to buy almost anywhere, are simple to use, generally don’t require anything more complicated than batteries to operate, and (most importantly) don’t cause alarm with border patrol agents or police officers. A person carrying a shortwave radio could easily be a harmless tourist wanting the latest news from home or a homesick expat wanting to listen to cricket matches in the heart of darkest Africa... or he could be a CIA or MI-6 agent.

The “numbers stations are for spies” hypothesis has gotten a boost from two sources:

a) An article in Britain’s The Daily Telegraph newspaper from 1998, which quoted a spokesperson for the Department of Trade and Industry as saying that “These [numbers stations] are what you suppose they are. People shouldn’t be mystified by them. They are not for, shall we say, public consumption”. Interestingly, listening to numbers stations in the UK is illegal under the Wireless Telegraphy Act 1949.

b) Also in 1998, the United States began pursuing a legal case against several suspected Cuban spies. In 1995, the Miami-based spies were observed by the FBI tuning in to the “Atención” numbers station, which is broadcast out of Cuba. They wrote down the list of numbers, then entered them into a laptop computer to decode the messages. The FBI surreptitiously entered the apartment and copied the encryption program, which allowed them to decode messages on their own. Several of these messages were revealed in a public courtroom during the trial of the “Wasp Network”, as the spies were known: “Under no circumstances should [agents] German nor Castor fly with BTTR or another organization on days 24, 25, 26, and 27″.

There are other theories about the numbers stations. Some think that they are used by drug lords, pirates or other criminal types to exchange information. This almost certainly cannot be. While it’s possible, it’s unlikely given the cost and complexity of the setup, as well as the availability of safer (and cheaper!) alternatives like cellular or satellite phones.

While it’s almost a certainty that numbers stations are operated by governments, and almost a certainty that they are operated for spies... we may just never know the true origin of this man-made mystery. Everyone that might know has a guess, and everyone that does know isn’t talking.



published according to Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States licence