[time-nuts] Weird TEC data

[Bill Hawkins]

Could you please explain how transformer phase lags could jump?

As I understand synchronous generators tied to a common grid, it
is not possible for them to have large phase angle differences
under normal conditions. Losing a whole cycle would cause forces
that could damage the machine.

What that means is, that if the two locations representing the
red and green traces are on the same grid then there should be
less than one cycle difference between them at all times.

NTP can't be causing the jumps because the difference increases
with time. You would see the displayed time difference change
as well.

Since that is not the result that you have, it is time to
calibrate your equipment. I'd start with the line frequency sensor
looking for dropped cycles.

It's possible that different computers running different other
programs could drop different numbers of points. What are they
doing when the steep drops in difference occur?

Is anyone else running a similar experiment?

Bill Hawkins


-----Original Message-----
From: Poul-Henning Kamp
Sent: Thursday, August 04, 2011 1:13 AM

The jumps in the difference looks a lot like transformer phase-lag
in the grid, but the real test is to collect more data and see if
you ever see the difference move the other way.