Hi The variation you see is dependent on a number of things. One of them is space weather. If you do your run during a very active period ( typically peak sun spots) you may see some very dramatic swings on a single band device.
Bob > On May 30, 2022, at 3:00 AM, Erik Kaashoek via time-nuts > <time-nuts@lists.febo.com> wrote: > > Further evaluation did shown the time differences between the 3 GPS modules > was due to difference in the trigger level setting of the timer/counter and > difference in length of GPS antenna cables. > After removal of the phase drift due to Rb frequency offset the attached > image shows the phase differences of the 3 modules versus a Rb reference. > The two ATGM modules are very consistent over a 2.8 hours period. The NEO-7M > varies wildly with phase errors above 100 ns. Possibly due to a somewhat > less optimal antenna position. > It seems phase variations over time in the order of 10-20 ns are indeed > unavoidable, even with a good antenna. > Erik. > <3GPS_phase_difference.png>_______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com