Hi Mouser shows 16 items tighter than +/- 20 ppm accuracy. Six of them are in stock and less than $1 in single piece quantities. The cheapest is 39 cents.
Bob On Jan 17, 2013, at 7:38 PM, WB6BNQ <wb6...@cox.net> wrote: > Hi Ed, > > I seriously doubt you will be able to pull the 10 MHz crystal tht far off. > International Crystal Manufacturering (ICM) > > http://www.icmfg.com/ > > still makes crystals for a reasonable amount (about $25) cut to order. That > may > be far easier than all the time you would spend bending and pushing things > around > trying stretch components. > > Bill....WB6BNQ > > > Ed Breya wrote: > >> I've got to make a very clean 10.05944444... MHz VCXO for a redo of one >> of my old circuits. I previously used a 10 MHz ceramic resonator, which >> was easy enough to push around in frequency. Of course, I have a couple >> dozen of those somewhere, but can't find them now that I need them >> again. I figured I'd just pull the ones out of the old circuit, but >> since I did find a whole bunch of 10 MHz quartz crystals, I'd like to >> revisit whether I can push one of those that far with decent results. As >> I recall, the results of my previous experiments in doing this were less >> than satisfactory, which is why I went with the ceramics. >> >> This would be a change of 60 kHz out of 10 MHz, or 0.6 percent - a >> helluva lot for a crystal. The frequency will be exactly phase locked to >> a reference. It doesn't need to have extremely high in-circuit Q or >> long-term stability - just tunable to that magic number - the PLL will >> do the rest. A conventional varicap circuit will provide the VCO-ness, >> while the tuning range just needs to be enough to accommodate drift and >> the initial setting. The power gain element will be a 74HC04 or 74HC86 >> section. The PLL reference will be 59.44444... kHz - way above the >> necessary loop BW. >> >> Has anyone successfully pushed a quartz crystal that far off, with >> reliable (still sort of a sharp resonance) operation and no spurious >> modes? Any ideas? If this isn't practical, I'll just go back to the >> ceramic resonator (which worked just fine), but I'd like to settle it >> once and for all. >> >> Ed >> >> _______________________________________________ >> 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. > > > _______________________________________________ > 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. _______________________________________________ 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.