[time-nuts] Blackout in Europe and power line frequency jump

[Tom Van Baak]

> Your report, though, inspires me to look into more reliable and precise
ways
> to measure the frequency of one's local grid. I had not actually
considered
> monitoring electric fields "off the air" before, but it seems like this
> might be fairly practical.

One very simple method that I have used is plug in a
AC wall wart transformer with the 6 VAC secondary
going directly into a HP53131A frequency counter.
The serial data you get then looks like this:

53747.845696 59.996,154,495,1  Hz
53747.846854 59.999,588,387,2  Hz
53747.848012 60.001,434,856,1  Hz
53747.849172 60.001,288,258,8  Hz
53747.850330 60.002,697,145,5  Hz
53747.850330 N      : 36
53747.850330 STD DEV: 0.004,660,852,51 Hz
53747.850330 MEAN   : 60.004,606,291,05 Hz
53747.850330 MAX    : 60.020,723,348,6  Hz
53747.850330 MIN    : 59.996,154,495,1  Hz
53747.851489 60.006,143,055,9  Hz
53747.852646 60.001,106,173,4  Hz
53747.853805 60.003,317,733,6  Hz
53747.854963 60.000,519,248,1  Hz
53747.856122 59.997,117,006,6  Hz

which you can run as long as you like and process
the data as you see fit. In this particular example the
gate time was 100 s and so the statistics were hourly.

Another way is to use a surplus TrueTime TFDM:
http://www.leapsecond.com/pages/mains/

/tvb