RTTY

Radioteletype (RTTY) is a telecommunications system consisting of two or more teleprinters using radio as the transmission medium.Early RTTY operators used equipment built for Bell System wire-linked Teletype(tm) systems. When ham radio operators began using this equipment for RTTY, they were required to sign agreements not to use the equipment for commercial purposes. This equipment was expensive and required periodic maintenance.
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Abbreviation for radio teletypewriter.

A teletypewriter employed in a communication system using radio circuits. Note: Such systems are spoken of as RATT systems. (188 )

RADIO TELETYPEWRITER (COMMUNICATIONS). RTTY