[Jeffhs]

Originally Posted by Penthode

Alas. VITS is no longer broadcast. Analog TV broadcast included the vertical blanking interval to carry data such as VITS, Closed captions, Nielsen data etc. But DTV does not accommodate carriage of the VBI or vertical blanking interval. Only the active picture is broadcast with the ancilliary data carried as separate data packets ins the digital broadcast stream.

DTV receiver boxes and DVD players recreate VBI signals from the ancillary data. This is to provide a backward compatibility with older analog TV.

So we can now say V.I.T.S. - R.I.P.

I guess I have a lot to learn about digital TV. I was not aware of the fact that there are no VITS in broadcast DTV signals, although common sense tells us that since there is no vertical blanking bar in a DTV picture, and since DTV is completely different from NTSC analog, there is no need for VITS (at least as we used to know them in the analog NTSC era) any longer.

I also did not know that the data once carried by VITS in analog NTSC broadcasts are now contained in data packets nestled in the DTV stream itself.

Boy, how things have changed for TV since the DTV transition. No more VITS, no vertical/horizontal sync problems, no more worrying about convergence adjustments, the sets themselves are much smaller and slimmer than their NTSC counterparts, the pictures are much better in 16:9 ATSC digital than those in the old NTSC 4:3 standard . . . it's all new and different for people like myself who grew up with NTSC analog.

The backward compatibility with older NTSC analog TVs may be done away with sooner than we think, as more and more people replace their NTSC analog sets with digital flat screens. NTSC analog TV, after all, is no longer broadcast in the U. S. and now Canada, so the older TVs built for the NTSC standard are now obsolete. Some people, such as VK's own Doug Harland, drh4683 (where on earth is he hiding?), may continue to use older NTSC sets with converter boxes and antennas, but he is a collector, so he is going to want to keep his old sets going as long as possible.

For almost everyone else, however, once the old NTSC TV finally shows its last program and dies of a serious problem, it will be trashed ASAP and replaced with a flat screen. Remember also that most TV shops won't touch any television that is more than about five years old, and then only for warranty repairs on flat screens.

Tube-type or even solid-state NTSC TVs? Forget it. Many if not most of today's TV technicians (except those members of VK who work for TV shops, of course) don't know the first thing about working on very old TVs with picture tubes (CRTs) and vacuum tubes, so they would be stopped dead in their tracks, figuratively speaking, if one of these ever showed up in a 21st-century TV shop for service or repairs. I recall an old cartoon in a 1960s edition of, IIRC, the now long defunct Electronic Experimenter magazine. The cartoon showed two TV techs looking at a tube-powered TV that has just come into their shop for repair. One tech took the back off the set, saw the vacuum tubes in the chassis, and then, a bewildered look on his face, turned to the other tech and asked, "What the hell is a vacuum tube?"