Hi WWVB DSO’s were a pretty common thing back in the 70’s and 80’s. You could hold fractions of a ppm with them. With manual intervention / scheduling you could get into the “couple ppb” range on a good week.
Comparative numbers would be 1x10^-11 on a GPSDO. All the same qualifiers about “is that really this or that” apply equally (or more so) to it’s WWVB cousin. Bob > On Feb 24, 2016, at 5:22 PM, Hal Murray <[email protected]> wrote: > > >> From what others on the list have said before, WWVB offers performance >> that's at least a couple orders of magnitude worse than GPS, even if you >> correct for all of the expected diurnal variations in LF propagation. Given >> that a fairly pedestrian GPS module offers a nominal PPS accuracy of ~10ns >> for $25... > > Yes. But it would be fun to measure the diurnal variations. > > I thought WWVB was actually good at that. It's ground wave rather than > bouncing off the ionosphere. But I'd like to measure both WWVB and WWV. > > Has anybody built a WWV(B)DSO? You would need a stable oscillator so you > could average over days or weeks rather than hours. I'm thinking of a > surplus rubidium. Maybe a manual screwdriver adjustment would be good enough > and a PIC/AVR to make a PPS and fake GPRMC. > > > > -- > These are my opinions. I hate spam. > > > > _______________________________________________ > 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. _______________________________________________ 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.
