[time-nuts] FA2 internal OCXO warm-up time

[Mark Sims]

I did a test of the FA2 internal OCXO warm up time.  I powered mine down for 4 fours and then powered it up and measured the frequency as it warmed up.  It looks like it takes 45 minutes to stabilize.  

Note that it took a week of constant power for the oscillator drift rate to settle down.  The drift on mine seems to be around 0.00025 Hz/day.  I need to do a longer test to better weed out temperature sensitivity.

BG7TBL internal oscillator warm up time:

Minutes   Freq error
0         221 Hz
1         17 HZ
2         0.2760 Hz
3         0.0500 Hz
4         0.0350 Hz
5         0.0240 Hz
10        0.0130 Hz
15        0.0080 Hz
20        0.0060 Hz
25        0.0050 Hz
30        0.0042 Hz
35        0.0040 Hz
40        0.0034 Hz
45        0.0021 Hz <--- stable
50        0.0025 Hz
55        0.0022 Hz
60        0.0020 Hz