Σταθμός αριθμών: Διαφορά μεταξύ των αναθεωρήσεων

Numbers stations appear and disappear continuously, although some stick to regular schedules, and their overall activity has increased slightly since the early [[1990s]]. It has been speculated that these stations operate as a simple and foolproof method for government agencies to communicate with [[spy|spies]] "in the field", using the transmitted codes as a [[one-time pad]] cryptosystem. As evidence, numbers stations have changed details of their broadcasts or produced "special", non-scheduled broadcasts in response to extrordinary political events, such as the [[Russian constitutional crisis of 1993]]. Others speculate that some of these stations may be related to illegal drug smuggling operations. Although no broadcaster or government will acknowledge or give a reason for their existence, a 1998 article in London's ''[[Daily Telegraph]]'' quoted a spokesperson for the [[Department of Trade and Industry]] (the government agency that regulates radio broadcasting in the [[United Kingdom]]) as saying, "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."

Errors at the transmission site, radio direction-finding, and a knowledge of shortwave radio propagation have also provided clues to number station locations. For example, the "Atención" station is presumed to be from [[Cuba]], andas a supposed error allowed [[Radio Habana Cuba]] to be carried on the frequency.

Numbers stations are often given nicknames by enthusiasts. These nicknames often reflect some distinctive element of the station. For example, "Lincolnshire Poacher", one of the best known numbers stations, supposed by many to be run by

[[MI6]], plays the first two bars of the [[folk song]] of that name before each string of numbers. "Magnetic Fields" plays music from French [[electronic music]]ian [[Jean Michel Jarre]] before and after each set of numbers. The "Atención" station begins its transmission with the Spanish-language phrase "¡Atención! ¡Atención!" And "Yosemite Sam" used a voice clip of the [[Warner Brothers]] [[cartoon]] character.

On some stations, such as "Yosemite Sam", tones can be heard in the background. It has been suggested that in such cases the voice may be an aid to tuning to the correct frequency, with the coded message being sent by [[modulation|modulating]] the tones, perhaps using a technology such as [[burst transmission]].