Forrest W. Christian wrote:
>> US-based time signal radio station:
>> http://en.wikipedia.org/wiki/WWVB
>>
>> For other countries, see:
>>
>> http://en.wikipedia.org/wiki/Atomic_clock#Radio_clocks
>>
> Actually, it's kinda tempting to put a GPS receiver in the clock.   Most
> people wouldn't even think about it, but since I integrate close to a
> thousand GPS modules a year into products I sell, coming up with a spare
> one wouldn't be a problem.   The newer MTK-based GPS modules shouldn't
> have a problem locking on often enough to be able to keep the clock
> accurate enough assuming a 20ppm crystal as the clock source.... even if
> it only had good time once every few days it would be great.

Forrest, I don't think I've ever seen your website. What kinds of products 
do you build/sell?


> In reality my intention would be to use the 60Hz line as the clock
> source.  Good, cheap, reliable, as long as you make sure you have a good
> schmitt-trigger on the input.

A long time ago, someone told me that because of this assumption, clocks 
that worked well in FRG went haywire in the GDR. You are really limiting 
your market with this decision. ;-)

Vitaliy 

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