Hi The gotcha with all this is the temperature coefficient. If they all have roughly the same +100 ppm / C tempco (which they might), then the typical lab temperature swing of 2 to 4 C will have them out in the 200 to 400 ppm range (and more or less tracking each other ….).
1 LSB on a 16 bit part is 15 ppm. Again relative to the reference involved. On a typical GPSDO, this *probably* is 5V (but maybe not …. ). We are chasing something in the 5 to 10 LSB range. Even if the two “full scales” line up, the reference in the $5 meter is likey to get in the way. Better to spend $100 on a HP 3456 ….. Bob > On Sep 5, 2020, at 3:33 PM, Perry Sandeen via time-nuts > <[email protected]> wrote: > > Learned members, > Wrote: > Well, I could measure the EFC voltage every other day and if it'schanging, > then it's the OCXO that’s drifting, if not (or not inaccordance to the DAC > graph) it's the DAC itself. > > One can buy 5 digit LED meters on ebay for $5 each +shipping. > > While I wouldn't necessarily trust their accuracy, at that price one could > buy 3 or 4 and continuously measure several variables. > Regards, > Perrier > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
