Hi Tom, true, that decision has to be made, and there is probably some cut-off phase difference where the 1PPS position is just reset. But I would have expected the PRS10 designers to bound the frequency change to something less than several parts to the E-10 when the loop time constant is set to 7 hours. Even a frequency error of 1.0E-011 would have drifted the 1PPS at a rate of 36ns per hour, so by the 7'th hour it would have been back on track (since I set a 7 hour loop time constant that would have worked well). I just did not expect such a drastic frequency adjustment from the Rb, and would think most people would not mind a slower drift rate while also having less of a frequency error. After all the 1PPS was "off course" for a long time already anyways - otherwise the error would have been much smaller. bye, Said In a message dated 4/24/2008 20:48:04 Pacific Daylight Time, [EMAIL PROTECTED] writes:
If you're lucky, the GPSDO gives you an option whereby you can program your threshold; your "expectation". But internally every GPSDO has to make a decision about when to jump vs. when to drift. Whether it's hardcoded or programmable is the question. See section 5.1.1 of the Trimble Thunderbolt manual for a good example of how this can be done. /tvb **************Need a new ride? Check out the largest site for U.S. used car listings at AOL Autos. (http://autos.aol.com/used?NCID=aolcmp00300000002851) _______________________________________________ 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.