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Old March 16th 14, 03:42 PM posted to uk.radio.amateur,rec.radio.amateur.equipment,rec.radio.amateur.misc
Ian Jackson[_2_] Ian Jackson[_2_] is offline
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First recorded activity by RadioBanter: Nov 2007
Posts: 568
Default Quad shield coax & dielectric?

In message , Jerry Stuckle
writes





HDTV requires a stronger signal than the old NTSC.


It really depends on how good your old analogue NTSC was. For a
noiseless picture, you would need around 43dB CNR, but pictures were
still more-than-watch-able at 25dB, and the picture was often still
lockable at ridiculously low CNRs (when you certainly wouldn't bother
watching it). Digital signals can work at SNRs down to around 15dB for
64QAM and 20dB for 256QAM (although if it's a little below this, and you
will suddenly get nothing).


--
Ian

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