Re: Quartz crystal accuracy over time
Yes they do age over time. The ones in digital clocks seem to be terrible. They are cut differently to other crystals as well apparently. I have a Casio watch from the 1980s that loses about 10 minutes a week.
Based on my observation of a large bag of 40m calling frequency crystals (7030KHz) which were dated early 1980s, they have drifted down by quite a bit with the correct load capacitance.
Usually you can add some capacitance to the circuit to tune them rather than replace the crystals however.
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