[time-nuts] More 60 Hz data/graphs

[Hal Murray]

I've moved the 60 Hz stuff from
  http://www.megapathdsl.net/~hmurray/time-nuts/
to
  http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/

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The main graph is now up to sightly over 4 days.
  http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz.png

Peak-to-peak is almost 8 seconds.

The slew rate is pretty fast in a few places.
  1 second in 1/2 hour at hour 64.
  4 seconds in 3 hours at hour 13.
  2.5 seconds in 3 hours at hour 44.
  7 seconds in 7 hours at hour 91.

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When I started, I picked 10 seconds as the sampling rate.  That was just a 
wild guess, but it seems to have worked out well.  That's 1/2 megabyte per 
day.  (I think I can trim a factor of 2.)

I plotted the frequency.  It's not as clean as the offset.  Here are 3 
graphs, measured over 10, 100, and 1000 seconds.
  http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz-f10.png
  http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz-f100.png
  http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz-f1000.png

Note the two big spikes on the 10 second graphs.  Those correspond to 2 
glitches in the raw data.  Both have 3 extra counts within a 10 second sample 
slot.
  http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz-g1.png
  http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz-g2.png

Note that they are close to 24 hours apart, at 6:30 to 7:00 AM Pacific local 
time (California).

Has anybody noticed things like this?  As a sustained slew rate, it's huge 
relative to the longer samples above.  But maybe steps like that are normal 
transients when somebody throws a big switch.  Or maybe they are glitches due 
to lightning/whatever.  I guess I'll have to connect up the audio port and 
grab a lot of raw data so I can inspect the area around glitches like these.

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This is the (python) code I'm using to collect the data:
  http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz.py
Edit daemon to 0 if you want to debug things.
It's got my directory hard wired in it.  (That should be easy to fix.)
If you improve it, please send things back to me and/or put your version on 
the web.

It's a quick hack, don't expect elegance.  It uses some Linux specific 
tricks.  I'll work on a version in c that will probably run on *BSD if 
anybody wants it.

----------

The raw log files include the 10 second deltas.  This is the hack I use to 
compute the 100 second and 1000 second data.
  http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/stretch-60Hz.py

If anybody wants it/them, I'll put the gnuplot files I use out there too.


-- 
These are my opinions, not necessarily my employer's.  I hate spam.