Quick p.s.f. query

[Rafael Amador]

I have to disagree with you, Gary.
[gary adcock] “On Older Color sets when luma and chroma combined reached 90% white the harmonics in the signal would cause AUDIO interference when graphics or the random white shirt on screen allowed the signal drift into that area. Super White graphics can still cause this today – ( ever heard an audio buzz on a local car commercial when the Price is on screen?) “

This is one of the reasons why the signals must be “Broadcast Safe”, to avoid Chroma-Luma Intermodulation.
But this is nothing related with the 59,98 fps.

The time base was changed from 30 to 29’98 fps to avoid what is call the “Chroma Interference Pattern” produced by the color subcarrier. Nothing related with the signal levels.
That was like that in 1.983 when I learnt the NTSC system.

[gary adcock] “Since B&W sets at the time could not see any part of the Chroma signal it did not affect them, “
Curiously, when a B&W TV set display a signal containing Chroma, it rise the bright due to the Gamma.
Rafael

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