[time-nuts] Time Signals on TV signals

Hal Murray hmurray at megapathdsl.net
Mon May 25 18:14:08 UTC 2009


> Why did TV stations stop broadcasting time signals? HDTV requirements?

One thing that may be relevant....

Many years ago, all the TV sources were kept in sync so there wasn't any 
glitch when they switched feeds.  The sync timing was distributed from at 
atomic clock at network headquarters.  The time of day probably piggybacked 
on that.

I remember an old NBS booklet describing it.  That was back in the late 70s.  
(It's probably a valuable collectors item now.)  I think HP and NBS used to 
publish a table of delays for several  major TV stations.  Somebody on this 
list will probably recognize that description.

The breakthrough that got around the timing requirement was frame buffers.  
(Thank Moore's law.)


> Could a cable company interfere with the time signals?

Thanks for the laugh.  :)

Cable companies do all sorts of strange things.


-- 
These are my opinions, not necessarily my employer's.  I hate spam.






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