In 1990 Junghans brought the Mega 1 onto the market, the world’s first radio-controlled wristwatch. It receives the time from the DCF77 transmitter in Mainflingen, which is tied to the caesium clock of the national metrology institute in Braunschweig.
A Junghans brochure of 1990 promised for its MEGA radio-controlled clocks: Kein Nach- oder Umstellen der Uhr erforderlich. No resetting of the clock is needed. They even change to summer time and back by themselves.