[time-nuts] Achievable temperature stability for Thunderbolt environment?

[Arnold Tibus]

Hi Achim,

I have very stable thermal conditions in my house. The temperature
indicated by the box (internal sensor) does stay stable within 50 mK/d
when the sun is not shining with very slow ripple. On sunny days the
in-box temperature does climb up by about 350 to 450 mK (less then 100
mK/h) and will come back to the stable floor in about 12 to 14 hours.
Today it was sunny from 11h30 to 15h30, raising the temperature by 300
mK to 29.25 °C. The box has no housing (yet) and is sitting on the to of
my rack.

The influence to the EFC-Voltage is still visible (around 50 µV) but
with a delay of close to 2 hours.

Arnold, DK2WT

Am 15.01.2011 17:36, schrieb Achim Vollhardt:
> Hi list,
> as my Thunderbolt is now nicely cooking for a few weeks now, I am
> wondering what a typically achievable ambient temperature
> stability/variation is in your setups.
> 
> Of course, a more stable environment is better, but currently I am
> struggling to achieve more than +-0.5 K variation on the temperature
> reading on a weekend.. during working days (when I am around in the
> lab), the variations are as much as 3 times higher.
> 
> I am just wondering, if I should rather worry more about high
> temperature gradients rather than excursions from a mean value, as slow
> variation can be compensated by the control loop while for quick
> changes, the loop is just too slow :)
> 
> 73s Achim, DH2VA