Cannabaceae

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.

One thought on “Cannabaceae

  1. Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
    View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction

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