Terms for subject Telegraphy containing frequency

English	German
four-frequency duplex telegraphy	Vierfrequenz-Duplextelegrafie
frequency shift keying	Frequenzumtastungstelegrafie
frequency shift telegraphy	Frequenzumtastungstelegrafie
scanning line frequency	Zeilenabtastfrequenz
set of voice-frequency multiplex telegraph circuits	Gruppe von Wechselstromtelegrafie-Leitungen
voice-frequency multiplex telegraphy	Wechselstromtelegrafie