Hi As mentioned multiple times in the archives. As you get into the single digit milliseconds, the human eye simply can’t keep up. A watch that is 1 ns off and one that is 1 ms off are both “good enough” if you are looking at it with a normal eyeball.
>From a design standpoint 1 ms / day / week is *way* different that 1 ns over >the same sort of period. Design constraints *do* make a big difference. It’s important in any project to get them sorted early. If you are spending $5K on a CSAC, tossing in another $100 on a GPS isn’t going to even get into the roundoff error. You *will* need the GPS gizmo to keep the CSAC calibrated. It is only a question of how often the beast gets used. Bob > On Jan 28, 2018, at 7:45 PM, Ronald Held <[email protected]> wrote: > > Bob: > Right now I own nothing that outputs a GPS PPS. GPS watches I own do > not have that option. Maybe for infrequent resets, an independent > GPS unit is better from a design and construction POV? > Ronald > > > > Hi > > A GPS PPS output will (most likely) be more accurate than the CSAC > each time you go back to dock with the charger. A GPS module to do > everything you would ever want to do is a sub $100 sort of item. You > would still need a bit of hardware to “glue” things together (but not a lot) > and some code running on the MCU of your choice to supervise the process. > > Accuracy wise, a GPS PPS is *very* hard to beat. > > Bob > _______________________________________________ > 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.
