[time-nuts] 60hz disciplined watch (really?)

[Robert Atkinson]

Hi,
I think this is incorrect,
1/ My ecodrive that I bought in the USA does not run 20% slow here in the UK
2/What about incandesent lamps and those with inverters?
3/ even a cheap crysal is better than than the mains unless you average over days. They vary the frequency (phase) slightly to load share.
 
Robert G8RPI.
--- On Wed, 20/4/11, Bill Hawkins <bill at iaxs.net> wrote:


From: Bill Hawkins <bill at iaxs.net>
Subject: Re: [time-nuts] 60hz disciplined watch (really?)
To: "'Discussion of precise time and frequency measurement'" <time-nuts at febo.com>
Date: Wednesday, 20 April, 2011, 19:33


Group,

Google can't find anything for "citizen ecodrive watch time sync 60 hz"
except a few where the "k" was left out of "60 khz". All of the watches
that synched received WWVB at 60 KHz.

The claim of 13 millisecond accuracy from line frequency is suspect. There
is no control of the power grid to that accuracy. It is not possible.
The weekly accuracy is measured in cycles. Variation during the day
can be seconds, losing during the day and gaining at night.

It seems to me that the filtering algorithm for 60 Hz would have severe
underflow problems with floating point math in a low power processor.

Bill Hawkins


_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.