Hi The gotcha here is that an un-cooled piece of gear will heat up and cool down as it's work load changes. There is no "magic bullet" that keeps the temperature constant with zero airflow in a normal design. Yes, I'm old enough to remember oil cooled computers. Still no constant temperature and you have turbulence.
Bob On Dec 16, 2012, at 8:40 PM, Magnus Danielson <[email protected]> wrote: > On 12/17/2012 02:21 AM, Bob Camp wrote: >> Hi >> >> When you blow on a TCXO you are setting up variable airflow. A fan produces >> a constant airflow. A variable flow gives you a variable temperature. A >> constant flow keeps things pretty uniform. >> >> Environnemental chambers have pretty massive airflow. TCXO's and OCXO's do >> quite well inside them. > > The trouble with airflows over a TCXO or OCXO compared to still air, is that > you provide a better connectivity to the ambient air and it's variations. > Hence, I get to monitor the AC in the building or testlab that way. Just > tossing very mild isolation and it is almost quiet in comparison. A good > quality environmental chamber doesn't have drastic "puffs" of heat-up, where > as lesser onces do that. When testing TCXOs I learned more about the > environment chamber in use than on the TCXO itself... > > Again, your mileage WILL vary. > > Oh, I do know some folks that are looking into the effect of turbulence of > forced air on crystal "noise". I could find some flaws in their line of > reasoning. > > Cheers, > Magnus > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
