On Thu, 18 Aug 2005, Chuck Harris wrote: > Phase lock the crystal to the 50/60 Hz powerline? The signal > seems to be ubiquitous.
I considered that. There are many problems: The person with the device may move from one place to another and may pick up anyone of three possible phases of power or different utilities (they are sync'ed?). In this case, it may become hard to constantly watch your phase and adjust. At best, you can make short temporal measurements based on stable signals and use that to look at you local crystal. But, on short time scales, the 60Hz wave has poor stability. It is controlled well on longer time scales (witness all the clocks using it), but we can't assure a stable environment to measure that against. 60Hz is also very low frequency. I wasn't sure I could pick it up reliably despite all my experience getting it when I don't want it! Worth thinking about, though (says the man with a 250KV three phase trunk outside his building...) -- Mike Ciholas (812) 476-2721 x101 CIHOLAS Enterprises (812) 476-2881 fax 255 S. Garvin St, Suite B [EMAIL PROTECTED] Evansville, IN 47713 http://www.ciholas.com _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
