 The "Nederlandse Seintoestellen Fabriek" (NSF) company established a professional transmitter and radio factory in Hilversum in the early 1920s, growing into the largest of its kind in the Netherlands.Following the defeat of Allied forces in the Netherlands in 1940, and its occupation by Nazi Germany, Hilversum became the headquarters of the German Army ("Heer") in the Netherlands..In 1948, NSF was taken over by Philips.