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Re: NTSC Legalacy Formats

> The practice in broadcast is to turn off the subcarrier burst when a
> monochrome picture such as an old movie is being transmitted.  This causes
> color TV sets to revert to monochrome mode so you don't see false colors
> running through the image.

	That was the case many years ago but after a few color commercials
 that aired during monochrome shows went out (without the burst being restored
- it used to be a manual process) that practice ended. Now the general practice
is to have a proc before the exciter to ensure stable sync/burst and legal
levels. Most VTRs work better with burst also - many TBCs have lock problems
when the vtr is playing back a tape without burst. That used to cause us
headaches at HBO  because Cinemax had so many classic B&W features and the
TBC-2b's were finicky.

Rich Torpey

Thanks to Blake Jones for support of the TIG in 1998.
No product marketing allowed on the main TIG.  Contact rob at alegria.com
922 subscribers in 36 countries on Wed Feb 18 04:39:38 PST 1998 
complete information on the TIG website http://www.alegria.com/tig3/