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Calibration & battery update 2023-12-13

A project log for Remarkably Accurate Quartz Clock

Shooting for 10 sec/year accuracy with an ATmega and software-based, temperature-aware frequency correction

gaborGabor 12/13/2023 at 10:360 Comments

After the last tuning on September 27, the watch started to drift faster than before. I tuned again after only 2 weeks, on October 11. It ws 0.5 sec late; the error went from -6.85 to to -7.25 PPM.


In the 2 months since then, the clock has grown late again, but only by less than a second. Not tuning yet.


Battery measurements show a steady, slow slide:

2023-10-25: 2.988 V
2023-11-08: 2.984 V
2023-12-13: 2.970 V

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