On Tue, May 16, 2023 at 8:35 PM Marcus D. Leech <[email protected]> wrote: > > On 16/05/2023 20:31, Michael Toussaint wrote: > > Hi, > > > > I am testing the LO synching on a single N321 using the 2 Tx channels > > on the N321. > > > > I have followed the LO setup steps from the knowledge base, > > https://kb.ettus.com/USRP_N320/N321_LO_Distribution, to distribute the > > LO. (Sample Python code used for setup below) > > > > I am using separate streamers for each Tx channel and noticing a delay > > between the 2 channels executing. > Yeah, using separate streamers, the code doesn't attempt synchronization > across two streamers. You'll need a single > two-channel streamer--that's the "synchronization paradigm" that has > been in UHD for over a decade...
Separate streamers shouldn't be a problem. I use them regularly in synchronized mode. If both streamers have the same time spec, the radio should start them both in sync. That said, it won't hurt to test with a single streamer. > > The Tx channels do not appear to be synchronized, we're measuring > > anywhere from 0.5ns to 4ns of delay across the channels. The master clock cycle on the N321 is between 4 and 5 ns. This is also the D/A (and A/D) clock cycle. When you are seeing a relative delay of 0.5ns this is about one tenth of a D/A sample interval. Or, from another perspective, this represents a difference of about 4 inches of cable length (if the relative delay had an analog cause). So, the channels are definitely synchronized to some degree - I don't have a guess at why the synchronization is not tighter. _______________________________________________ USRP-users mailing list -- [email protected] To unsubscribe send an email to [email protected]
