[time-nuts] Z3805A cooling requirements?

[Bob Camp]

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 <magnus at rubidium.dyndns.org> 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
> 
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