ms6b+@andrew.cmu.edu (Marvin Sirbu) (03/19/90)
> >I hope the "clean break" approach wins out too. What a engineer's nightmare > >it would be to match up the side panels to the NTSC center. > I heard that the FCC said they wouldn't approve the standard unless its > backwards compatible...=-( The FCC has said broadcasters may have no more than an additional 6 MHz (not necessarily contiguous with their existing frequency allocation. They can use the allocation either to: 1. transmit the "additional" resolution and picture size to be added to the NTSC signal on their existing 6 MHz allocation. 2. transmit an _entire_ HDTV picture. Old sets will be serviced by continuing to broadcast the same programming using an NTSC signal on the original spectrum allocation. While at first glance it would seem easier to send HDTV using the full 12 MHz from both allocations (alternative 1), the problems of combining the two signals-- and living with the defects of existing NTSC-- are such that most technical proposals are along the lines of option 2. Option 2 has the additional virtue that after a few decades when no one has NTSC sets any more, the stations can stop broadcasting in NTSC altogether, and reuse the spectrum for some other purpose (more HDTV programs, land mobile radio, etc.)
3ksnn64@pur-ee.UUCP (Joe Cychosz) (03/20/90)
In article <Ma1D=8600io81=bFFx@andrew.cmu.edu> ms6b+@andrew.cmu.edu (Marvin Sirbu) writes: >> I heard that the FCC said they wouldn't approve the standard unless its >> backwards compatible...=-( >Option 2 has the additional virtue that after a few decades when no one >has NTSC sets any more, the stations can stop broadcasting in NTSC >altogether, and reuse the spectrum for some other purpose (more HDTV >programs, land mobile radio, etc.) How did the FCC handle the conversion of the FM band from around 40Mhz to its present location around 100Mhz?