DIGITAL DELAY
Digital TV viewers who watched the 1999 New Year’s eve celebrations from the comfort of
their homes may have wondered why their neighbor’s fireworks and champagne corks went
off just a little too early. The answer comes from an engineer in England who discovered
that one of the unexpected benefits of switching to digital was that it gave him the
opportunity to see the year 2000 in twice.
Watching the festivities on the digital TV, he noticed that the countdown to midnight
shown on screen was running just behind the time shown an electronic digital clock
continually synchronized by radio with the atomic-based Standard Frequency Transmission
from Rugby. Tuning to the analogue broadcast of the same channel, he found the countdown
agreed precisely with the cesium-synchronized timepiece. When Big Ben struck at midnight,
the analogue was right on time but almost a second later it happened again on digital.
He attributes this time delay anomaly to analogue to digital conversion and he wonders
what the implications will be for broadcasters presenting an incorrect time in this era
of interactive shopping and TV banking.