Wolfgang It would help if you would let us know what equipment other than a scope you have. Also what resolution you would want to achieve. One time set up or want to use repeatedly. Bert Kehren In a message dated 4/19/2012 4:53:40 P.M. Eastern Daylight Time, saidj...@aol.com writes:
Depends on the scope.. if your scope has 100ps A-to-B measurement resolution, then waiting 5 minutes in this scenario would give 0.83ns drift, with 100ps uncertainty IF your oscillators were synced to ~3ppt which is very tough to do with a free-running OCXO (It would be unrealistic to get that stability from the two sources if they are free running). A more realistic scenario would give say 100ns drift in 5 minutes, then a 0.1ns resolution on the scope would give a very accurate reading in just 5 minutes (100ns +/-0.1ns = +/-0.1% error). The result would be 3.33E-010, +/-3.33E-013. Who needs more resolution than that as the OCXO will likely wander much more than that in 5 minutes.. bye, Said In a message dated 4/19/2012 12:52:07 Pacific Daylight Time, azelio.bori...@screen.it writes: Yes, and, as you can see, you have to wait 1 hour. On Thu, Apr 19, 2012 at 9:49 PM, <saidj...@aol.com> wrote: > Hi Wolfgang, > > one of the easiest and very accurate ways to do this is simply to measure > the drift of the two 10MHz signals on an oscilloscope. Adjust the OCXO so > that this drift between the two traces is as slow as you can get it. Then > simply measure it over time. Use one signal for trigger, the other to > display > if you only have a one channel scope. > > If you get say 10ns drift over 1 hour (which you can easily measure even > with the cheapest scopes), that is a resolution of 10ns/3600s = 2.78E012. > > Or in other words 27.7uHz! > > This has been discussed before and documented in the time nuts archives > some time ago. > > bye, > Said > _______________________________________________ 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.