[time-nuts] Why is holdover LED on HP 58503A not lit, when GPS lock is unlit too?
hmurray at megapathdsl.net
Sun Dec 18 20:34:44 EST 2016
drkirkby at kirkbymicrowave.co.uk said:
> I assume it wont start until it has tracked sufficient number of satellites.
There is a chicken-egg problem with getting started. The satellites tell you
where they are, but you need to know where they are and where you are in
order to calculate the Doppler offset so you know what frequency to listen to.
The difference between warm start and cold start is that for a warm start the
receiver has a 32KHz clock and has saved its last position and the satellite
orbit data in battery backed RAM.
These are my opinions. I hate spam.
More information about the time-nuts