Slow-scan Television

Slow-scan television (SSTV) is a picture transmission method used mainly by amateur radio operators, to transmit and receive static pictures via radio in monochrome or color.

The concept of SSTV was introduced by Copthorne Macdonald in 1957-1958.  He developed the first SSTV system using an electrostatic monitor and a vidicon tube.  In those days it seemed sufficient to use 120 lines and about 120 pixels per line to transmit a black-and-white still picture within a 3 kHz phone channel.