Long-term aging of oscillators

The authors report aging results for more than 40 oscillators, from a variety of sources, for periods ranging from 1 yr to more than 10 yr. The aging data were accumulated with an automated aging facility. The oscillators that have been tested include temperature-compensated crystal oscillators (TCXOs) and oven-controlled crystal oscillators (OCXOs). The TCXOs were maintained in a controlled temperature environment. Several of the TCXOs were built for a gun-launched sensor application and have been shown to be capable of surviving more than 30000-g shock levels of 12-ms duration. The aging results for these ruggedized TXCOs are surprisingly good (<2*10/sup -10//d). The better OCXOs exhibit long term aging of a few parts in 10/sup 12//d.<>