I ordered an inexpensive BG7TBL GPS disciplined clock (www.ebay.com/itm/121530825744). The unit includes both a 10 MHz and a 1 PPS output. Is there any reason to favor using one or the other reference signal for the B200, or would the results in terms of frequency stability and accuracy be exactly the same with either reference? Is there any configuration that needs to be done for the B200 to use an external clock reference? Thanks in advance. Andy

Andrew, 10MHz is a frequency reference, PPS is a time reference…its an important distinction. You use 10 MHz to discipline the oscillators in connected equipment so that they having matching and accurate frequency. You use PPS to coordinate time (As in wall clock) between devices, often in connection with a UTC time value emitted via the RS232 port on the GPSDO. The PPS signal is already synchronous to the 10MHz clock in such a way that all connected devices will sample a PPS edge on the same 10MHz clock edge. -Ian On Jun 10, 2015, at 6:20 PM, Andrew Clegg via USRP-users <usrp-users@lists.ettus.com> wrote: > I ordered an inexpensive BG7TBL GPS disciplined clock (www.ebay.com/itm/121530825744). The unit includes both a 10 MHz and a 1 PPS output. Is there any reason to favor using one or the other reference signal for the B200, or would the results in terms of frequency stability and accuracy be exactly the same with either reference? Is there any configuration that needs to be done for the B200 to use an external clock reference? > > Thanks in advance. > > Andy > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

On 10.06.2015 18:20, Andrew Clegg via USRP-users wrote: > I ordered an inexpensive BG7TBL GPS disciplined clock > (www.ebay.com/itm/121530825744). The unit includes both a 10 MHz and a > 1 PPS output. Is there any reason to favor using one or the other > reference signal for the B200, or would the results in terms of > frequency stability and accuracy be exactly the same with either > reference? Is there any configuration that needs to be done for the B200 > to use an external clock reference? The B200 allows you to use both. You will need to set the time and clock sources to 'external'. If you had to choose (which it doesn't seem you do), the 10 MHz reference would be better suited for frequency stability, but doesn't provide any kind of time reference, which you'd need, e.g., for synchronizing devices in time. Cheers, Martin