Spy Transmissions: By the Numbers

Posted on January 15, 2014


The January 15 issue of Radio World magazine contains my article on spy numbers stations.

Figure 2 Warrenton b1

The Warrenton Training Center, once a fixture in the Virgina countryside, is widely regarded by radio hobbyists to be the home of “Cynthia” the CIA’s spy numbers station. (Courtesy the Federation of American Scientists)

Spy numbers stations are anomalous radio stations which transmit coded messages in the shortwave bands. For years they were suspected to contain messages to covert agents working inside foreign countries. With the demise of the Cold War, the number of stations transmitting dropped, but there are still several that continue to this day.

This article is about the hobbyists who have long tracked these stations, compiling detailed logs and schedules and even photographed suspected transmission sites. Today, thanks to them and several high profile espionage cases, we know a lot more about the purpose and intent of these mysterious stations.

Spy Code Key

This chart, found amongst the belongings of one of Cuba’s most prolific spies in the USA, is believed to be the key to deciphering a Numbers Station message. (Courtesy Federal Bureau of Investigation)

There were many interesting hobbyists involved in many different aspects of tracking these anomalous and mysterious stations and logging their transmissions. Unfortunately I wasn’t able to interview all of them for the article but in the coming weeks I’ll add more information and conversations so check back often.