On Dienstag, 26. April 2022 23:20:34 CEST Lux, Jim wrote: > That's the MCXO - uses third harmonic and fundamental to measure the > temperature. Q-Tech sells them. Or, more properly, has them in their > catalog and may be happy to quote a price and delivery. The datasheet > revisions are >5 years ago, except for the Space version which was > updated a couple years ago. They're fairly good temp stability (a few > ppb over -40 to +90) and lower power than a OCXO of comparable > performance.
Neat. Well, they're certainly not on their stock list (nor the TCXO ultra- miniature that would drop into a rasPi). > The fancy temperature compensation doesn't say anything > about aging, of course. It seems that aging is a thing with this particular implementation, seeing that they can use a reference to tune it out. But they also seem to have implemented a scheme that determines aging by taking the crystal out of the synthesis loop for a little while. The data-sheet dooesn't really say if it's only active at start-up nor whether the continuous correction requires a reference. > It's unclear whether cycling the temperature up > and down at room temp makes an oscillator age faster than one held at a > constant higher oven temp. The control loop I implemented for my self-ovenized rasPi can do linear sweeps of the temperature (usually across the turnover point to determine or refine the control parameters, you can set both the slope and the span). I have no hard data, but my impression is that both the sweeping itself and especially the ramp speed contribute to an accelerated drift that takes a few days to subside when returning to constant temperature. Regarts, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ SD adaptations for KORG EX-800 and Poly-800MkII V0.9: http://Synth.Stromeko.net/Downloads.html#KorgSDada _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
