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567-line television system

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The 567-line television system was an experimental late 1940s[1][2][3] proposal by Philips of the Netherlands for a European television system, with some test transmissions being made from Eindhoven.

The first mention of the system appeared in an article from 1938, published in the Philips' technical bulletin, on a transportable demonstration TV station, running an at 50 fields (25 frames) per second,[4] but no more details were provided.[5] Most of the technology was to be borrowed from the American 525-lines system, the difference being the reduction of horizontal scan frequency from 15,750 to 14,175 Hz.[6] This would have meant that the American sound carrier frequency of 4.5 MHz above the picture carrier would have also been the standard for Europe, and hence a lot more common worldwide.

By 1950 some 567-line television sets were built and distributed to Philips employees for home testing.[7]

The 567-line system was proposed for international use but never adopted. Russian engineers had already shown how 525-lines could be easily adapted to a higher resolution by breaking with American 6 MHz channel bandwidth restrictions and moving the sound carrier up from 4.5 to 6.5 MHz, along with 625-line scanning. This 625-line system was eventually approved as CCIR System D.

Technical details

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Technical details[6]
Frame rate Interlace Field rate Line/frame Line rate Visual b/w Vision mod. Sound mod. Sound offset Channel b/w Vestigial sideband Aspect ratio
25 2/1 50 567 14175 Hz 4.2 MHz Neg. FM +4.5 MHz 6 MHz. LSB cut @ -0.75 MHz 4:3

References

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  1. ^ "Philips bringt ein neues Fernsehsystem". Funktechnik. No. 2. Austria. 1948.
  2. ^ "Philips bringt ein neues Fernsehsystem". Funktechnik. No. 2. Austria. 1948.
  3. ^ Leithäuser, G.; Winckel, F., eds. (1953). Fernsehen. doi:10.1007/978-3-642-92591-7. ISBN 978-3-642-92592-4. S2CID 244293816.
  4. ^ "Philips Netherland 567 line TV Standard" (in German). Radiomuseum.org. Retrieved 2011-06-20.
  5. ^ J. van der Mark (January 1938). "A transportable television installation" (PDF). Philips Technical Review. 3 (1): 2. The installation is suitable for the broadcasting of 25 pictures per second, with 405 or 567 lines per complete picture, while interlaced scanning is employed. (If 567 lines are used, a frequency spectrum must be dealt with which extends from about 50 cycles per second to about 5 × 106 cycles per second, for 405 lines the necessary frequency spectrum extends only to 2.5·106 cycles per second.
  6. ^ a b Scheida, W. (2006). "Fernsehen in Holland - in den Niederlanden". Virtuelles Museum des Fernsehens. Retrieved 2011-06-20.
  7. ^ "Philips TX594U - Television receiver for experimental broadcast, VHF channel 4 only, 567 lines". Radiomuseum.