Art Harris wrote:
Bill Baka wrote:
Art Harris wrote:
I don't know, but I just checked again and my Cable Box is dead on
with WWV.
Comcast? I don't have a box since I don't watch much television but
their channel listings channel is usually off by about 30 seconds.
Another channel that shows local weather is about 15 seconds
better but neither is dead on.

No, I have Cablevision. The time is dispalyed continuously directly on
the front of my cable box, not on the TV. And it's always dead on.

Art Harris

Most big facilities like that use GPS derived distributed master time
code for the whole plant.