Beautiful Pictures of Campfires

Saturday, 2 July 2011



Electromechanical broadcasts began in Germany in 1929, but were without sound until 1934. Network electronic service started on March 22, 1935, on 180 lines using telecine transmission of film, intermediate film system, or cameras using the Nipkow Disk. Transmissions using cameras based on the iconoscope began on January 15, 1936. The Berlin Summer Olympic Games were televised, using both all-electronic iconoscope-based cameras and intermediate film cameras, to Berlin and Hamburg in August 1936. Twenty-eight public television rooms were opened for anybody who did not own a television set. The Germans had a 441-line system on the air in February 1937, and during World War II brought it to France, where they broadcast from the Eiffel Tower.
The American Armed Forces Radio Network at the end of World War II, wishing to provide US TV programming to the occupation forces in Germany, used US TV receivers made to operate at 525 lines and 60 fields. US broadcast equipment was modified; they changed the vertical frequency to 50 Hz in accordance to the European mains frequency standard to avoid power line wiggles, changed the horizontal frequency from 15,750 Hz to 15,625 Hz a 0.5 microsecond change in the length of a line. With this signal, US TV receivers with only an adjustment to the vertical hold control had a 625 line (= 576 visual lines + 49 lines of non-visual synch and burst data), 50 field scan, which became the German standard. This AFN system, however, was not the later PAL standard native to Germany, as the displays themselves were not capable of displaying any more than the standard NTSC 486 visual lines, which effectively were even only 243 visible lines due to display-internal deinterlacing by means of alternatively discarding one field and applying line doubling on the result. Additionally, it still took until the 1960s for the PAL-specific YUV color system to be invented by Walter Bruch, with PAL operating at 576 visual lines.

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