...Modulated telegraphy. A carrier wave modulated at one or more audible frequencies, the audible frequency or frequencies or their combination with the carrier wave being keyed according to a telegraph code. 59 Type A3. Telephony. Waves resulting from the modulation of a carrier wave by frequencies corresponding...

...Modulated telegraphy. A carrier wave modulated at one or more audible frequencies, the audible frequency or frequencies or their combination with the carrier wave being keyed according to a telegraph code. 59 Type A3. Telephony. Waves resulting from the modulation of a carrier wave by frequencies corresponding...