DVB-T receiver analogue composite video sync timing accuracy.

[dr pepper]

I was wondering if a dvb-t receiver as used in the UK and many other countries has an accurate sync o/p on the composite video connector.

Years back you could sync a xtal oscillator to the horizontal sync pulse from the bbc's analogue transmission using a sync seperator, I was reading some blurb on dvb-t, and it does mention a load of stuff on timing and accuracy, however I couldnt work out whether this means the video output is also 1 e-9 accurate.

Anyone here know?

 

[Nigel Goodwin]

I wouldn't imagine so, as there's need for it to be - and the composite signal is actually created inside the TV.

 

[dr pepper]

Yes thats what I thought, however reading an article on dvb it implies that the signals from different sources have to be spot on so switch overs can be done seamlessly and even specifies a rubidium standard must be used, so we know the transmitting end uses an accurate source, however I havent found out for sure if this accuracy appears in the decoded video output, I suspect it does but the decoder introduces its own pile of phase noise, like you say that wouldnt be improtant to the average jeremy kyle viewer.
Phase noise can be dealt with using a PLL.
A remember an article a long time ago that used a ferrite rod aerial to pick up the field from a tv lopty and synced it with a pll to an xtal osc.