[EAS] EAS time stamp usage

[Eric Adler]

Free-running crystal referenced*?  These clock reference systems are not there to 'keep time' for you, but so that you can adjust your time to maintain accuracy.  You should still be able to free run after a loss of such a system and remail as accurate as a free-running clock (which shouldn't be too far off).  I would think that a window of -5 minutes to +10 minutes or perhaps even +[message valid duration] should be plenty to account for this.  

* Yes, I realize that a certain EAS unit runs its clock on line frequency.  I cannot offer a good fix for this other than possibly making the line frequency source a double-conversion true-sine self-referenced UPS or redesigning the clock mechanism.  

Eric

-----Original Message-----

I suspect people will then complain about the expense of being 
install another radio (GPS, WWV) or Internet (NTP) or low-quality clock 
chips in equipment or something else. But the bigger problem is what if 
those better UTC clock sources aren't available or working after a 
catastophe. Just like EAS is a last resort message transmission, what is 
the last resort clock source? How will you cooperate with your other EAS 
partners?