Jeffrey Pawlan wrote: > > On Thu, 29 Nov 2007, David Forbes wrote: >> It might be more fun to require that an OCXO be designed and built by >> the DIY-er out of commercially available crystals and resistors. That >> way, it's an engineering challenge instead of a procurement >> challenge, since IEEE is about engineering. >> -- > > I second David's suggestion! The only REAL challenge would be to design the > circuitry. Otherwise this is just a "rack & stack" project which is not > engineering. >
I think it's a fantastic challenge. I imagine starting with a design goal something like tvb's original leapsecond goal. It would be kind of cool to have a $100 clock that met that criteria. I don't think an off-the shelf OCXO timebase will be competitive at this price point. I'm not aware of an inexpensive SC-cut oscillator. I think the parameters for the contest need to be tightened up. Temperature and environment are enemies for this kind of clock, I hope they specify the operating environment and time period for evaluation. I think that I would start by looking at 32kHz watch crystals, I've often wondered how good a timebase you can make out of one. The tempco is a parabola around 25C with a max slope of something like 0.05 PPM/C, so they are naturally a pretty good timebase with good aging characteristics. The crystals are really tiny, maybe insulating it with a material that has an interesting heat of fusion along with a micro to model the physics of the parabolic shape of the crystal performance. jeff _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
