[Frank Raffaeli]

On Sep 19, 7:58 pm, "Green Xenon [Radium]"
wrote:
On Sep 3, 8:27 pm, isw wrote inhttp://groups.google.com/group/sci.electronics.basics/msg/6689f0d1e8e...:

Prolonged blacks can damage television transmitters, however (video
is inverted for transmission, so black requires full power from the
transmitter).

Why is video inverted for transmission?

There are exceptions. System L, still used in France, for example, has
peak white at max RF power. The analog audio sub-carrier is amplitude
modulated.

There is a digitally modulated sub-carrier for stereo audio (NICAM)