Old NTSC tricks: 240p?

[Tor Arntsen]

On 18 March 2015 at 19:18, tony duell <ard at p850ug1.demon.co.uk> wrote:

> Not part of the _video_ signal, but part of the overall signal : IIRC continental Europe (mostly?) put the sound
> carrier 5.5 MHz way from the video carrier, but the UK had a 6MHz offset.
>
> -tony

SECAM comes in two variants, one with a 5.5MHz sound carrier offset
and another with a 6.5MHz offset. The Russians apparently use a
variant of the latter - many years ago I visited a family living close
to the Russian border and they used to tune in to Russian TV on their
black&white TV. But they had a hard time getting picture and sound at
the same time, IIRC it was either one or the other. They would tune to
sound or video depending on what was on - there are some great
classical music programmes so presumably that's when they tuned to
sound only.

As for NTSC - 'never twice same color' - that sounds cumbersome, what
we learned in (TV repair!) school was 'Never The Same Colour' :-)
(PAL means Phase Alternating Line, except for the lines/frequency
differences it is really just NTSC but with the phase of the colour
subcarrier alternating every other line. Thus automatically cancelling
out transmission phase errors which would otherwise change the colour.
That's all really: NTSC with automatic colour phase error
cancellation.)

-Tor