[time-nuts] Temperature stability for Thunderbolt: results
holrum at hotmail.com
Wed Jan 26 15:54:07 UTC 2011
BTW, once you have the ability to control the Tbolt temperature you can get the oscillator aging and temperature coefficients. You should first run (or have already run) the '&a' oscillator autotune to get a good value for the oscillator control voltage gain.
Once the unit temperature is stable, then the '&' command will show the oscillator aging. You should have several of hours of data on the screen for it to be valid. The DAC voltage plot should show a rising (or falling trend).
To get a valid oscillator temperature coefficient you should first stabilize the unit's temperature. Then turn off the temperature control and let the unit heat up. Then adjust the plot view to show a range of temperature on the screen that is rising and fairly linear (i.e. trim off the ends). The '&' command oscillator temperature coefficient should be fairly accurate.
Note that without temperature control the '&' command oscillator aging/tempco parameters don't have much validity...
More information about the time-nuts