Listening intently to a steady stream of static, suddenly you hear a series of low tones followed by a robotic woman’s voice:
“Yankee… Hotel… Foxtrot… Yankee… Hotel… Foxtrot… Yankee… Hotel… Foxtrot…”
The static continues as a sheet of white noise in the background. The woman continues:
These strange series of words and numbers are not the crazy ramblings of a demented person. They are actual broadcasts from real “numbers stations.”
Numbers stations are shortwave radio transmitters that send out a constant stream of numbers, letters, words or song lyrics, all delivered by disembodied voices. The voices are male and female, young and old.
To many laypersons that hear number station transmissions for the first time, they sound eerie and distant, as if from a barren, lonely post-apocalyptic future. For governments and others that need to transmit messages to their agents in foreign countries, however, they are extremely valuable.
How Numbers Stations Operate
Number stations, sometimes called One-Way Voice Links (OWVL) broadcast a series of loops of numbers or letters. Inside the string of seemingly nonsensical characters is a code which, if you have the decoding mechanism, delivers secret messages across borders and long distances to foreign agents (spies).
The majority of number stations operate on shortwave radio. This is because shortwave has characteristics that make it easy to send a signal extremely long distances. Although different types of transmission equipment have been used, a regular shortwave transmitter anywhere from 10 kW power to 100 kW is the most common form.
Even though spies have access to high-tech modern equipment, many governments find it advantageous to continue to use old-fashioned shortwave radio. It raises less suspicion than a bank of expensive high-powered equipment. Shortwave radio is also better than modern conveniences like cell phones and e-mail because it does not leave a digital trail.
Recording of a German Numbers Station
Below is a recording of a German Numbers Station dubbed “G06″ or “G6″ at 4792KHz on Dec 11, 2009 at 19:36 ZULU time.
Number stations usually follow a consistent formula. Most broadcasts take place at the beginning or the bottom of an hour. Very often, the beginning of a broadcast will have a “signature” identifier or slogan—perhaps a saying or phrase; or clip of music, sounds or tones.
Usually there is only one message per each transmission. Just as the sign-on has a signature, sign-offs also have some sort of theme. For example, they may say the word “end” or repeat a series of zeros. You might also hear another snippet of music or sounds.
Number stations are broadcast out in the open but they don’t make any sense to most people. Some officials think they are nothing but a campaign of disinformation by governments to throw adversaries off their trail.
Some number stations operate for years:
- One of the most famous, “The Lincolnshire Poacher,” was never acknowledged by the British government although it operated day and night for decades. Its name was based on the fact that they played the first two bars of the folk song, “The Lincolnshire Poacher,” for each string of numbers.
- “Magnetic Fields” is named after the multi-million selling 1981 album from French electronic musician Jean Michel Jarre. Before and after each set of numbers, the “Magnetic Fields” station played a Jean Michel Jarre track.
- A Spanish-speaking numbers station emanating from Cuba began their transmissions with the declaration “Atención!”
Number stations have been around since World War I. One of the original uses was for countries to communicate with their spies working in foreign countries undercover. Many number stations broadcasts are encrypted with a one-time pad. A one-time pad is a type of encryption method that has a key that is used once and never again. They are considered unbreakable.
Numbers stations have been used by criminals like smugglers to help transport illegal contraband such as drugs across borders. It is widely believed, however, that most number stations are run by governments to communicate with agents. Further evidence of this is that most number station broadcasts are in the part of the shortwave band set aside for international use. This band is not available to most citizens that might contemplate using them for criminal activity.
The first official public accusation of using number stations to transmit information to spies was the “Atención!” station of Cuba. A United States Court espionage trial came after the arrest of several Cuban spies in 1998. Prosecutors in United States said they were decoding numbers that came over the “Atención!” number station.
The FBI went to one of the accused spy’s apartment in 1995, gathered computer decryption equipment, and used it to decode their messages. During the trial, the FBI translated some of the spy messages. Here is one example:
“Under no circumstances should agents German nor Castor fly with BTTR or another organization on days 24, 25, 26, and 27.”
“BTTR” represents the organization Brothers to the Rescue, an anti-Castro group. (Miami New Times Feb 01)
Perhaps the largest collection of number stations transmissions has been gathered by The Conet Project. They have assembled assorted transmissions onto CDs. The recordings have also been made available for free download for the nonprofit use of the general public.
Despite this, the band Wilco used several of the transmissions for a music album without permission. They were subsequently sued and eventually decided to settle out-of-court. They paid for the commercial use of the transmissions as well as legal costs. The Conet Project recordings have been used by noted music groups like Boards of Canada and Faith No More, and in commercial films like Vanilla Sky.
You should be able to pick up a copy of “The Conet Project” over at Amazon here.
Interference and Jamming
Interference and jamming of number stations takes place. Even though the stations are on open frequencies, jamming is somewhat difficult due to the limited number of transmitters available that are capable of jamming a transmission.
Nonetheless, there have been interferences recorded over the years:
- North Korea interfered with the Lincolnshire Poacher station in 2006.
- One dangerous jammer affected critical aeronautical transmissions in the Caribbean in 1990.
- A West German based numbers station interfered with Radio Moscow broadcasts.
- The Mossad station Uniform Lima X-ray clashed with the “Independent Voice of Zimbabwe” broadcasts.
A number of large jamming sessions took place in 2005 and 2006 from what is known as the “Chinese Music Station,” which emanates from the mainland of China. Many suspect it was an attempt to jam the broadcast of a Taiwanese station named “Sound of Hope.” There were no spoken numbers or letters as in a traditional numbers station broadcast – only a cacophonous mixture of music, songs, sounds, drums, and flutes. (IARU Region 1 report)
There have also been reported jammings of the Lincolnshire Poacher station in the 1990s, the CIA station “Cynthia,” and the Mossad station “EZI 1.”
Despite jamming attempts, interference, arrests, and trials over the years, numbers stations continue to survive. In a fast-paced, high-tech modern world, their low-tech, low-profile nature has worked to their advantage. It’s hard to believe James Bond may be getting his next assignment from a simple shortwave radio.
Nobody knows for sure who is transmitting the eerie, robotic numbers and letters across cities, towns, and borders into foreign countries. Many assert they are government agencies communicating to a far-flung spy network, or simply trying to outwit a rival country’s espionage effort. Others believe drug smugglers have learned to use technology to move their product.
All we know for sure is they will continue to send their eerie message across the void as they have for years, “5,2,8,4…6,2,9,7…4,1,6,2…8,8,5,3…”