I had a lab A/C hiccup today and temperature went beyond normal tight limits. But this provided an accidental test of Thunderbolt response to ambient temperature changes. Note TBolt is GPS locked, not in hold-over or free-running mode.

Phase is Thunderbolt 10 MHz output compared to lab standard (cesium, etc.). Temperature is from lab ambient air temperature sensor. Note these are actual external readings, not internal TBolt phase or temp readings.

Plot scale is ±15 ns on left (blue) and 22 to 25 °C on right (red).

24 hours of measured phase and lab temperature.

6 selected hours from above.