Matt Ettus wrote:
What are your PLL settings? If you minimize the R divide ratio, you can eliminate this. The larger R divide will put you further from right on frequency, but the DDC will put you right back in the right place.
Yes. You can also try setting the frequency to 1575 rather than 1575.42; this results in more favorable PLL settings by default, and then one can remove the frequency offset at baseband as a separate frequency translation step. How sudden are the shifts and how often do they happen? Do they look like frequency spikes (phase steps) or frequency steps (phase ramps)? If the dbsrx PLL were to slip occasionally, I guess one would expect the former, not the latter. Could try feeding the dbsrx with a nice strong tone from a signal generator to get a better view of its phase purity once it's been through the entire USRP chain. Some TCXOs suffer from sudden jumps over temperature, but this doesn't match your experience, since the TCXO is on the motherboard and would affect both dbsrx's equally. Cheers, Peter Monta _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
