It's really a matter of what you want for a reference. A Rubidium/Cesium/whatever reference will give you a very stable 10Mhz timing reference, but it *wont* give you the official time-of-day. Every so often, there are corrections to official world time and if you're using a stable timing reference you still have to code those changes into your clock.
When you use GPS or NTP, all of that global time update stuff is handled for you, but between updates your time will drift slightly though that amount of drift is probably milliseconds or less. It would be cool/amusing to monitor the drift in realtime versus a local atomic reference. I believe NTP monitors drift and attempts to correct for it and if drift is small enough it will periodically skip updates; my RasPi is logging about 20 NTP updates overnight. I recall some of the temp-controlled quartz-crystal ovens were holding +/- 0.1PPM , which is roughly 1 second per 100 days. Whereas an atomic source is on the order of 1 second per 30+ *years* . -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/ad4b61cc-70e7-44b8-917b-0999688e4a60%40googlegroups.com.
