Hi, I am using N310 with external LO. I still want to use the digital LO offset. However, it appears that when the LO is set to external the digital LO offset is ignored. Am I missing something or is this the intended behavior? UHD 4.6 Eugene Eugene Grayver, Ph.D. Principal Engineer 310-336-1274

On 07/02/2025 16:55, Eugene Grayver wrote: > Hi, > > I am using N310 with external LO.  I still want to use the digital LO > offset.  However, it appears that when the LO is set to external the > digital LO offset is ignored.  Am I missing something or is this the > intended behavior?  UHD 4.6 > > Eugene > This doesn't *sound* like design intent, but, maybe? Have you tried it with an earlier UHD, just in case this is a version issue?

Hi This was my mistake. Turns out the offset is handled correctly. However, I think there is a bug for the N310 for setting up external LO. It works if you specify the external LO in device arguments. However, if you set it using a function call at run time the function call is apparently simply ignored And the internal source is used. This bug reveals another bug which is related to using internal for the first two channels, and external for the last two channels. If the external LO signal is not applied to either of the RF channel pairs, UHD fails with a low level error that apparently comes from the embedded arm, micro controller inside the analog devices chip. I don’t envy ettus having to test all these quarter cases Eugene Get Outlook for iOS<https://aka.ms/o0ukef> ________________________________ From: Eugene Grayver Sent: Friday, February 7, 2025 1:55:38 PM To: usrp-users <usrp-users@lists.ettus.com> Subject: LO offset with external LO Hi, I am using N310 with external LO. I still want to use the digital LO offset. However, it appears that when the LO is set to external the digital LO offset is ignored. Am I missing something or is this the intended behavior? UHD 4.6 Eugene Eugene Grayver, Ph.D. Principal Engineer 310-336-1274

Hey Eugene, if you can summarize a bug report and put it on github.com/EttusResearch/uhd, that'll help here. Thanks! --M On Tue, Feb 11, 2025 at 6:45 AM Eugene Grayver <eugene.grayver@aero.org> wrote: > Hi > This was my mistake. Turns out the offset is handled correctly. However, > I think there is a bug for the N310 for setting up external LO. It works if > you specify the external LO in device arguments. However, if you set it > using a function call at run time the function call is apparently simply > ignored And the internal source is used. > This bug reveals another bug which is related to using internal for the > first two channels, and external for the last two channels. If the external > LO signal is not applied to either of the RF channel pairs, UHD fails with > a low level error that apparently comes from the embedded arm, micro > controller inside the analog devices chip. > I don’t envy ettus having to test all these quarter cases > Eugene > > > Get Outlook for iOS <https://aka.ms/o0ukef> > ------------------------------ > *From:* Eugene Grayver > *Sent:* Friday, February 7, 2025 1:55:38 PM > *To:* usrp-users <usrp-users@lists.ettus.com> > *Subject:* LO offset with external LO > > Hi, > > I am using N310 with external LO. I still want to use the digital LO > offset. However, it appears that when the LO is set to external the > digital LO offset is ignored. Am I missing something or is this the > intended behavior? UHD 4.6 > > Eugene > > > Eugene Grayver, Ph.D. > Principal Engineer > 310-336-1274 > _______________________________________________ > USRP-users mailing list -- usrp-users@lists.ettus.com > To unsubscribe send an email to usrp-users-leave@lists.ettus.com >