This helps keep this site FREE for everyone. Oscillator drift can be related directly to frequency stability. Drift is the unwanted and unwarrented change in frequency measured over seconds, minutes or hours. Hz over seconds would not necessarily be noticeable. Sources of oscillator drift Assuming quality components are used throughout the oscillator the principal cause would most likely be thermal considerations.
Voltage regulation is another consideration along with mechanical stability.
Before considering other possibilities of oscillator drift let's look at the causes listed here. As I said thermal considerations play a major part in oscillator drift. Consider just one example in close detail using nominal yet highly accurate figures, an oscillator designed for operation at precisely 7 Mhz. For this part we will assume neither the trimmer nor the inductor vary in value. Re-read all that if necessary, it's a mouthful.