On Sat, 19 Apr 2014 22:03:33 +0100, Tim Streater wrote:

In article , Uncle Peter wrote:

On Sat, 19 Apr 2014 21:11:26 +0100, Vir Campestris
wrote:

On 19/04/2014 20:48, Uncle Peter wrote:
So how did TVs work properly when they used the mains as a guide to
frequency?

I'm not that old.

"Current" ones (ie solid state) lock to the flyback pulses in the
transmission, and don't take any notice of mains.

I'm 38, and I had a TV as a kid that had vertical and horizontal hold. Is
this anything to do with it?

Don't think so. I think that was just a manifestation of the fact that
component drift with temperature was worse back then. More recent CRT
tellies didn't have them - or they could lock on better.

I didn't have to adjust it with temperature. Once adjusted, it was fine when cold and warm. It would drift out after a few months.

--
Amanpreet was overheard at the hospital angrily say, "My wife just delivered twins!!!"
A passerby said, "So? You should be happy about that. Why are you so angry?"
"I want to know who the son of a bitch is that's the father of the second kid!"