567-line television system
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
[edit]| 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
[edit]- ^ "Philips bringt ein neues Fernsehsystem". Funktechnik. No. 2. Austria. 1948.
- ^ "Philips bringt ein neues Fernsehsystem". Funktechnik. No. 2. Austria. 1948.
- ^ Leithäuser, G.; Winckel, F., eds. (1953). Fernsehen. doi:10.1007/978-3-642-92591-7. ISBN 978-3-642-92592-4. S2CID 244293816.
- ^ "Philips Netherland 567 line TV Standard" (in German). Radiomuseum.org. Retrieved 2011-06-20.
- ^ 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.
- ^ a b Scheida, W. (2006). "Fernsehen in Holland - in den Niederlanden". Virtuelles Museum des Fernsehens. Retrieved 2011-06-20.
- ^ "Philips TX594U - Television receiver for experimental broadcast, VHF channel 4 only, 567 lines". Radiomuseum.