Analog High-definition Television System - French 819-line (737i) System

French 819-line (737i) System

When Europe resumed TV transmissions after WWII (i.e. in the late 1940s and early 1950s) most countries standardized on a 576i (625-line) television system. The three exceptions were the British 405-line system, which had already been introduced in 1936, the French 819-line system developed by René Barthélemy, and the American 525-line system. During the 1940s Barthélemy reached 1015-lines and even 1042-lines. On November 20, 1948, François Mitterrand, the then Secretary of State for Information, decreed a broadcast standard of 819-lines; broadcasting began at the end of 1949 in this definition.

This was arguably the world's first high-definition television system, and, by today's standards, it could be called 737i (as it had 737-lines active) with a maximum theoretical resolution of 408×368-line pairs (which in digital terms can be expressed as equivalent to 816×737 pixels) with a 4:3 aspect ratio. It was used only in France by TF1, and in Monaco by Tele Monte Carlo. However, the theoretical picture quality far exceeded the capabilities of the equipment of its time, and each 819-line channel occupied a wide 14 MHz of VHF bandwidth.

By comparison, the modern 720p standard is 1280×720 pixels, of which the 4:3 portion would be 960×720 pixels, while PAL DVDs have a resolution of 720×576 pixels.

Television channels were arranged as follows:

Technical specifications of the broadcast television systems used with 819-lines.

System E implementation provided very good (near HDTV) picture quality but with an uneconomical use of bandwidth.

In addition, an adapted 819-line system known as System F was used in Belgium and Luxembourg. It allowed French 819-line programming to be broadcast on the 7 MHz VHF channels used in those countries, with a substantial cost in horizontal resolution (408×737). It was discontinued in Belgium in February 1968, and in Luxembourg in September 1971.

Despite some attempts to create a color SECAM version of the 819-line system, France abandoned it in favor of the Europe-wide standard of 625-lines (576i50), with the final 819-line transmissions from Paris in 1984. TMC in Monaco were the last broadcasters to transmit 819-line television, closing down their System E transmitter in 1985.

From the French government's point of view, the 819-line TV system had the great advantage that it prevented French citizens from being able to receive 'inappropriate' broadcasts from foreign countries. The switch to the accepted European wide 625-line standard looked to undermine that advantage, but this was sidestepped by adopting positive video modulation when the rest of the world had switched to negative modulation with all its advantages.

However, between 1976 and 1981 when French channel TF1 was switching area by area to the new analog 625-lines UHF network with SECAM color, some transmitters and gapfillers broadcasted the 819-line signal in UHF. When switching to 625-lines, most gapfillers did not change UHF channel (e.g. many gapfillers using this transmission located in French Alps near Grenoble, Mont Salève and Geneva began broadcasting on UHF channel 42, and continue to use this frequency to this day). They were switched to 625-lines in June 1981.