On Thu, Oct 14, 2010 at 12:13 PM, Steven Clark <[email protected]>wrote:
> Hi all- > > I have a multi-usrp setup with 2 USRP 1s and 4 WBX daughtercards. I have > performed the clock synching described here: > http://gnuradio.org/redmine/wiki/1/MultiUsrp > > I'm doing 4-channel receive, using a power splitter to send the same CW > signal into all 4 d'cards, and tuning them all identically. > > 3 of the 4 channels are nicely phase-locked. The 4th seems a little...off. > > ClockMasterUSRP (Serial #5821): Side A: "red" channel > ClockMasterUSRP (Serial #5821): Side B: "green" channel > ClockSlaveUSRP (Serial #2087): Side A: "blue" channel > ClockSlaveUSRP (Serial #2087): Side B: "black" channel <--- problem > with this guy > > Please see these 3 images to see the problem: > http://picasaweb.google.com/steven.p.clark/MultiUsrpGlitches?feat=directlink > > You can see the problem in both the frequency domain, and in the time > domain. > > I tried swapping daughtercards around, and the problem is not tied to any > one daughtercard, but rather to slave USRP side B. > > Any idea what could be causing this? Shouldn't the same clock be going to > both sides of the USRP? (why does blue look fine, but black does not?) > > -Steven > Solved....see if you can spot the problem: self.usrp_master.tune(0, self.wbx0_subdev, freq) self.usrp_master.tune(1, self.wbx1_subdev, freq) self.usrp_slave.tune(0, self.wbx2_subdev, freq) self.usrp_slave.tune(0, self.wbx3_subdev, freq) /facepalm (The final line's 0 should be a 1. the daughtercards were getting tuned properly, but the 4th DDC was not). Everything looks fine now. Sorry for suspecting the hardware, Matt! -Steven
_______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
