Behind the scenes UK experimental colour transmission 1957

[ppppenguin]

Originally Posted by tubesrule

.....It's nearly impossible to run the frame rate of the television at a different frequency from the AC power. (at least for crt based sets) This is why all 50Hz power countries use a 50Hz field rate, and 60Hz countries use 60Hz.

Japan has both 50Hz and 60Hz power which must have made things a bit interesting for their TV service.

Colour made it impossible to use a mains (power line) locked field frequency. In the early days most systems relied on this to minimise the visibility of hum effects. Not sure which is more annoying; a slow moving hum bar or a 10Hz effect.