Best practices question

Hal Murray hmurray at
Wed Jun 26 09:35:47 UTC 2019

> I've been tracking this and to my knowledge there are no makers of
> high-precision WWVB receivers left, following the modulation change in 2012.
> You can get "atomic clocks" that do the AM part of the signal, but they have
> only 1-second resolution. They don't unpack the subsecond PM information.

You can get better that 1-second timing even if the on-air format doesn't 
provide it.  Consider a typical PPS from a GPS.  No sub-second bits, but you 
can clearly get good timing.

The same thing happens with the typical battery backed RTC/TOY clock.  You can 
only read to a second, but if you poll the register with the low order second 
bits you can get close to a second when they change.  Or get an interrupt.

These are my opinions.  I hate spam.

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