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Prog scan on old TV

Discussion in 'Projectors, Screens & Video Processors' started by Jonesthegas, Jun 8, 2002.

  1. Jonesthegas

    Jonesthegas
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    Forgive my ignorance.

    Would an old TV (8 year old Panasonic) accept a de-interlaced signal from an external line doubler?
     
  2. Gordon @ Convergent AV

    Gordon @ Convergent AV
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  3. John Freeman

    John Freeman
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    If what your're asking is: Will a de-interlaced signal display correctly on an old tv; i.e. as a progressive signal; the answer is no. If what your're asking is: Will a de-interlaced signal display on an old tv at all; the answer is yes; it will just be displayed as an interlaced signal since that's all that the old tv's will display.
     
  4. Jonesthegas

    Jonesthegas
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    Thanks
     
  5. RichardA

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    Actually it's extremely unlikely that you'll get a usable picture at all on an old set.

    The input stages on most sets are designed for a specific scan rate (i.e. 15KHz horizontal and 50Hz vertical for interlaced PAL)

    If you put in Progressive scan the horizontal rate doubles to 32KHZ - unless the TV is specifically designed to handle this rate the best you can hope to see is two half width pictures on the screen (i.e. one complete picture on the left half, one complete picture on the right)

    What is more likely is that the TV will see the double speed syncs as the half line syncs within vertical blanking and will continually go into a V refresh, which will cause a pretty much blank screen and quite a squeal from the scan coils.

    Hope this helps!
     

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