[time-nuts] Allan variance by sine-wave fitting

[Tom Van Baak]

> BTW: Do you know the cause of the oscillations in the 5065 vs BVA plot?

The ADEV wiggles aren't visible with normal tau 1 s measurements. But since the TimePod can go down to tau 1 ms, when I first measure a standard I like to run at that resolution so effects like this show up. Once that's done, 1 ms resolution is overkill.

In this case it appears to be power supply noise. Attached are the ADEV, PN, and TDEV plots.

The spur at 120 Hz is massive; there's also a bit at 240 Hz; almost nothing at 60 Hz. When integrated these cause the bumps you see in the ADEV plot. It's best seen as a bump at ~4 ms in the TDEV plot.

Note the cute little spur at 137 Hz. Not sure what causes the one at ~3630 Hz.

/tvb
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