In article ,
charles wrote:
Do you mean by that the mains would have to be 10Hz away from 50? I've
seen 2 or 3 adrift on my meter here - but never that much.

If yiou are crating programmes using NTSC 525/60 in the UK, then the
maisn is 10Hz away from field frequency.

Right. Well, despite working in TV all my life, the number of times I saw
this done was near zero. More usual to standards convert it later.


But even then I'd be surprised if a tungsten filament lamp reacted at
all. Things like some fluorescents and discharge lamps are a different
matter if running at mains frequency. Which is why all the general
purpose studio luminairs were all tungsten.

yet a 10Hz beat was visible.

You'll have to be more specific. What lamps were in use? Which studio?

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Dave Plowman London SW
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