[ntp:questions] NTPD can take 10 hours to achieve stability

Richard B. Gilbert rgilbert88 at comcast.net
Wed Apr 20 20:13:19 UTC 2011


On 4/20/2011 3:42 PM, Chris Adams wrote:
> Once upon a time, David Lord<dlord at lordynet.org>  said:
>> There are designs for temperature control of the motherboard
>> xtal and alternative of using an external 14.31818 MHz clock
>> source. Some of my motherboards even have an external source
>> connector.
>
> I have one server (really an old desktop motherboard turned to personal
> server use) that holds consistent drift, even when the temperature
> fluctuates (we had an air conditioner fail last week).  The drift file
> consistently shows -0.2xx (-0.217 at the moment).  I guess it is just
> blind luck that this mboard crystal is better than most?
>

It's more likely to be the case and ventilation fan.  If the quartz 
crystal is kept at a more or less constant temperature, the oscillator 
will maintain a more or less uniform output frequency.  If you REALLY 
want a stable frequency output, you put the whole thing in an "oven" 
which will maintain it at a constant temperature.  Don't plan on baking 
pizza in it, the "constant temperature" mentioned above would probably 
be something in the range 100 to 150 degrees Fahrenheit.




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