Alan Melia wrote: > Maybe this is not "aging" you are looking at...parts in 10^9 over a few > days
I agree. Aging is the forest and you are watching the trees. The adjustment pot could also have some mechanical relaxation issues that work like delayed hysteresis. The 10811 designers had fits getting the piston trimmer capacitor to behave. Originally, you would adjust the frequency and then it would walk off. Turned out to be the lubricant in the cap was migrating around. >>> I had always thought that crystals changed frequency consistently in one >> direction as they age. That is until recently. I was trying to get the This is not always true any more than the idea that aging always keeps getting better and better with time. It is probably more valid for low performance crystals that have substantial contamination that is trying to reach equilibrium. High quality crystals are so clean that this mechanism is negligible. Instead, the built in stress of the crystal is being relieved, but cracks can propagate like a cracked windshield. Thus nothing is particularly predictable. (Any predictable aging mechanism will be identified and eliminated in a good fab). Rick Karlquist N6RK _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
