Frequency-Shift Telegraphy

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Frequency-Shift Telegraphy

 

a method of transmitting electric telegraph signals over communications lines by means of alternating currents. It converts DC signals formed by telegraph apparatus into AC signals, which are then transmitted over the line (cable, radio-relay link, or the like). The channel equipment (seeMULTICHANNEL COMMUNICATION) produces from one to 24 or more channels within one standard voice-frequency telegraph channel (0.3–3.4 kilohertz). The signal in each channel of the system is transmitted on its own carrier frequency, usually by means of frequency modulation; amplitude and phase modulation are also sometimes used.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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