Tom, Btw part of my frustration with this is that we sometimes get calls from customers asking why they need our or others' GPSDOs for a couple 100 dollars when they can buy a CW or uBlox doing "the same thing" for a fraction of the cost.
Most of them come back to us after evaluating these NCOs and finding that its not the same thing. You get what you pay for I guess.. Said Sent From iPhone > On Aug 19, 2014, at 13:01, "Tom Van Baak (lab)" <[email protected]> wrote: > > Hal, as long as you maintain long-term phase lock it's a disciplined > oscillator. So, yes, a carrier tracking WWVB receiver with sufficiently > stable flywheel LO is a WWVBDO. > > Said, too-short or too-long 100 ns cycles is one thing. Still ok for many > applications. But tell me more about extra or missing pulses in the ublox-7. > That sounds like a show stopper to me. > > /tvb (i5s) > >> On Aug 19, 2014, at 2:05 PM, Hal Murray <[email protected]> wrote: >> >> >> [email protected] said: >>> its not a GPSDO though, not even a simple one :) >>> It does not discipline an oscillator. It generates the output by >>> mathematically calculating how many phases it has to add/drop in a second, >>> then digitally adds/drops/extends/retards the phase of the output clock to >>> achieve an average of number of desired clock cycles. >> >> Is there something about the term GPSDO that says I have to do the "D" in >> the >> analog domain rather than the digital domain? >> >> I agree that current technology doesn't give results that are useful for >> many >> applications that currently use GPSDOs. What if the clock ran at a GHz? 10 >> GHz? Sure, it would have spurs, but would it be useful for some >> applications? >> >> Is a GPSDO still a GPSDO if the D/A driving the VCXO only has a few bits? >> How many bits does it need to be a real GPSDO? >> >> Is a battery powered wall clock listening to WWVB at 2 AM a WWVDO? It's got >> a pretty good ADEV if you go out far enough. >> >> -- >> 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. _______________________________________________ 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.
