On 02/12/11 07:10 AM, Nakajo Tomoyuki wrote: > Dear All, > > Please tell me the phase stability of 100MHz clock in USRP2 when the > 100MHz clock is locked to an external 10MHz reference signal. > > I have measured the temporal variation of phase difference between two > USRP2 outputs when a 10MHz signal is fed into PPS IN ports of two > USRP2s. The input signal of each USRP2 is fed by a same oscillator where > the output frequency is set to 26MHz. The result indicates the phase > difference varies from 0 to 2pi radians in about 100msec. This similar > result is obtained in the case a 10MHz signal is not fed into PPS IN > port. I think this observed temporal variation of phase difference is > too rapid, therefore, suspect the 100MHz clocks are unlocked to the > external 10MHz signal. > > Best regards, > Nakajo Tomoyuki > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > Are you configuring your UHD sink to use the extneral ref clock?
Does your external reference meet the hardware requirements: http://files.ettus.com/uhd_docs/manual/html/usrp2.html#ref-clock-10mhz Have you measured the phase noise of your reference? -- Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
