[time-nuts] Mains Frequency -again

[Andy Talbot]

Since building my real time mains monitor, I've noticed just how far the
mains timing drifts, for days at a time.   Friday evening last week (10
days ago)  timing was running at [plus] +50 seconds, and was slowly dragged
back over the weekend to about +7s on teh Monday.  Over the week it wobbled
around, but on a slow downward trend.  By Friday evening (2 days ago) it
was -17s  and I watched it drop further.  Now, Sunday morning, it is -56
seconds

So in the space of eleven days the mains timing has drifted a total of
nearly two minutes.

There doesn't seem to be, anywhere,   a long term record of mains timing
error.  You can download frequency from the Gridwatch site, but not
timing.   And I wouldn't trust integration over such extended periods to
derive timing error.
perhaps it's time to add a serial output to my monitor and couple up an old
obsolete laptop

Andy
www.g4jnt.com