cctech Digest, Vol 102, Issue 33

From:?ard at p850ug1.demon.co.uk (Tony Duell) Subject:?Re: UK versus US monitor question OK, I am sceptical. ?What do you mean by a 'long time ago'? Unti lthe coming of the National Grid, different areas would be supplied with mains at slightly differnet frequencies (even assuming it was supposed to be nominally 50Hz), and therre would eb no phase relationship at all. So usign that for any form of TV synchronisation is a non-starter. So that really limits us to post-WW2 TVs. The oldest book of schematics I have is dated 1953, but it contains models going back to 1948. Not one attempts to derrive the vertical sync signal from the mains as far as I can see. But I am a scientist... So while I have not found such a TV, I ?an't say they don't exist. So I would ask you to state the make and model of one or more TVs that derrived the vertcal sync signal from the mains, so that I can track down the scheamtics and see what they did. -tony