On Sun, Feb 12, 2012 at 19:03, Chuck Swiger <[email protected]> wrote: > On Feb 12, 2012, at 9:36 AM, unruh wrote: >> The clock crystal ages, and suffers internal crystal "cracks" >> migrations, etc, which change the frequency of the crystal. Thus even in >> a temperature controlled oven, the crystal frequency will change, but >> much of the crystal frequency change is driven by temperature changes. > > Agreed, temperature swings will have a major impact on the crystal frequency.
Well, I know what you're saying but we're talking on the order of 1 PPM / degree C. > You might be able to improve the stability of the crystal by ensuring good > airflow and cooling via HVAC as needed. And I suppose you could adjust the > rate by changing the HVAC set-point, but I don't think the benefit is worth > it. > > I'd be more likely switch to an OXCO + GPS on a PCI/PCIe card if such as > needed. That's OCXO, oven controlled crystal oscillator. Why X for crystal? Christ if I know. There's a great article at http://en.wikipedia.org/wiki/Crystal_oscillator that includes a table of abbreviations you can refer to. Cheers, Dave Hart _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
