Complex sentence: DCF77 is a longwave time signal and standard-frequency radio station, in service as a standard-frequency station since 1 January 1959; date and time information was added in June 1973.
Split into simpler sentences: DCF77 is a longwave time signal and standard-frequency radio station. DCF77 has been in service as a standard-frequency station since 1 January 1959; date and time information was added in June 1973.