[ntp:questions] Re: Which PBS station should I use for the time signal?
mrc at CAC.Washington.EDU
Wed Nov 16 17:00:13 UTC 2005
I think that it is a false presumption that the time signal sent by PBS is
accurate. As far as I can tell, it is set from some operator's watch and
*not* from an accurate timebase such as GPS or WWV.
In the Seattle area, PBS sets the time at least a minute fast, compared to
time from GPS.
For what it's worth, the time that DirecTV sends to its receivers is
pretty good, although I haven't checked it against GPS time. You may have
to hunt in the menus to find the time reported to 1 second resolution
since usually it just shows hh:mm
Most CDMA cell phone networks (Verizon, Sprint, etc.) transmit GPS time.
CDMA requires a precise timebase across the entire network and usually (I
have seen exceptions with isolated rural networks) they synchronize it
with good time. That is not the case for GSM or TDMA cell phone networks,
which are generally set from an operator's watch.
-- Mark --
Democracy is two wolves and a sheep deciding what to eat for lunch.
Liberty is a well-armed sheep contesting the vote.
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