Gustav Siegfried Eins
Gustav Siegfried Eins (GS1) was a British black propaganda radio station during World War II operated by the Political Warfare Executive (PWE). It was the brainchild of Sefton Delmer, a former BBC German service announcer recruited by PWE in 1940, and claimed to be an illegal radio station operating within Nazi Germany. The callsign was based on the German Army phonetic alphabet for the letters GS, but had no meaning.
The programmes were recorded on glass disc at the Wavendon Tower studio then taken to the short wave radio stations at Signal Hill, Gawcott and Potsgrove.