Hi Magnus that may be the case in some countries I suppose. Surely the accuracy is only required at the end of the transmission link, the frames from different sources are then resynchronised, and it is not "necessary" to transmit nationwide accurately synced frames?? The UK is "privatised" and content distribution network and transmitters are no longer owned by the programme companies, and they probably have little say in this aspect except that it will depend upon the price they are willing to pay.......... hence the BBC engineer did not think it a "reliable form of frequency distribution in the UK"....this does not mean it might not be useful!
Alan ----- Original Message ----- From: "Magnus Danielson" <[email protected]> To: "Discussion of precise time and frequency measurement" <[email protected]> Sent: Sunday, June 14, 2009 12:31 PM Subject: Re: [time-nuts] Time/freq from digital TV > Alan Melia skrev: > > This may not relate to the USA but a couple of years back I had an > > interesting chat with a BBC engineer at an NPL Time and Frequency gathering > > at Teddington. His comment was along the lines of....."....well there is as > > you realise not need to sync lines and frames nationally now because all the > > network content travels digitally even though we have only just started a > > phased change-over. The frames and line syncs broadcast will be probably > > derived from a "good clock" but it will not be a single traceable unit as it > > was. There is no telling how good the clock is, though it will probably be > > better than absolutely necesary. > > Actually, this is still far from the thinking I have heard from other > sources. They essentially want everything traceable to TAI/UTC. > > Digital doesn't help, it makes it more acute actually. > > Cheers, > Magnus > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
