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.
A technical term for SSTV is narrowband television. Broadcast television requires huge 5, 6 or 8 MHz wide channels, because it transmits 25 or 30 pictures per second (in the NTSC, PAL or SECAM systems), but SSTV usually takes up to only 3 kHz of bandwidth. It is a much slower method of still picture transmission, usually lasting from about eight seconds to a couple of minutes.


The concept of SSTV was introduced by Copthorn Macdonald in 1957–1958[1]. He developed the first SSTV system using an electrostatic monitor and a vidicon tube. 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. First live tests were performed on the 11 m citizen band.

Frequencies:

3kHz wide. 3.845, 3.857, 7.171, 14.230, 14.233, 21.340, 28.680, 145.5 MHz.