On 24/02/2014 08:12, gareth wrote:

Picking up on your BW comment, AIUI, the Baird transmssions of 30 line
pictures
were also of the audio BW, and were transmitted as part of the normal
broadcast,
but not at the same time as the audio; it was either speech or video, but
not
simultaneously!

I read that.
You would think that it would be trivial to transmit on 2 channels; one
for the video and one for the sound.

The bloke who invented thermal socks should have thought of that.

Andy