343-line television system
1930s analog standard-definition television resolution standard / From Wikipedia, the free encyclopedia
343-line is the number of scan lines in some early electronic monochrome analog television systems. Systems with this number of lines were used with 30 interlaced frames per second the United States by from 1935 to 1938,[1][2][3][4][5][6][7][8] and with 25 interlaced frames per second in the Soviet Union from 1937 onwards.[7][9] A similar system was under development in Poland in 1939.
TV cameras were based on the iconoscope, the primary camera tube used in American broadcasting from 1936 until 1946, when it was replaced by the image orthicon tube.[10][11] Earlier cameras used special spotlights or spinning disks to capture light from a single very brightly lit spot, and were not suitable for broadcasting of outdoor live events.
This early standard was soon replaced by 441-line systems.