[time-nuts] First success with very simple, very low cost GPSDO, under $8

Hal Murray hmurray at megapathdsl.net
Thu Apr 10 06:18:20 UTC 2014

tvb at LeapSecond.com said:
> You only need enough bits to cover the worst case OCXO frequency drift or
> the worst case GPS jitter error, per second. For example, if your OCXO stays
> accurate to 1 ppm it can't possibly drift more than 1 us per second.
> Similarly, it's a safe assumption that your GPS 1PPS stays within 1 us of
> correct time. Therefore, the maximum number of 100 ns ticks you will be off
> in any second is +/-10. So even a 8-bit counter is enough. Does this make
> sense now? 

Am I confused or did you forget to add the 2 errors to cover the case when 
they both happen during the same second?  2 us or a count of 20 is still 
tiny, even for an 8 bit counter.

These are my opinions.  I hate spam.

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