Well, according to your description, you could transmit a carrier from TX to RX (through an attenuator) with both sides set to the same frequency. Your received signal should look like a sine wave at the frequency of the offset.
On Mon, Mar 25, 2019 at 9:16 AM Michael R. Freedman via USRP-users < usrp-users@lists.ettus.com> wrote: > Hello, > > Do you have any suggestions as to how to measure the frequency delta > between the transmit channel and the receive channel? > > As I sat down to do this, I realized I have no real way to do that. > > > Mike > > > > > > On 03/24/2019 03:23 PM, Marcus D. Leech via USRP-users wrote: > > On 03/24/2019 02:39 PM, Freedman, Michael - 1008 - MITLL via USRP-users > wrote: > > It is not just a phase offset. It is a frequency offset. The phase drifts > between the two. I can tolerate a phase offset at startup. A freq offset > however is causing problems. > > Mike > > Sent from my iPhone > > On Mar 24, 2019, at 4:28 AM, Marcus Müller <marcus.muel...@ettus.com> > <marcus.muel...@ettus.com> wrote: > > Can you elaborate on what "not coherent" means to you – the relative > phase should be constant after each tune, but if you don't tune > simultaneously, i.e. with timed commands, random at each tune. > > Best regards, > Marcus > > Also, what version of UHD? What hardware rev of UBX cards? > > > On Sat, 2019-03-23 at 17:06 -0400, Michael R. Freedman via USRP-users > wrote: > > Hello, > > > I have an issue where I tune both the TX and RX side of a UBX40 card > in > an X310 to the same frequency and find that the transmitted signal > and > what is received are not coherent. I am using an external 10MHz > reference and have tried the documented suggestions. > > at 150MHz it is coherent. > > at 155MHz it is NOT coherent. > > > I have tried setting the dboard_clock_rate to 20MHz. This made the > problem appear at 150MHz as well. I've tried integer_n tuning. > > I have verified that the ref_lock and lo_lock are both true. > > > Any suggestions? > > > Mike > > > _______________________________________________ > USRP-users mailing > listUSRP-users@lists.ettus.comhttp://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > > > > _______________________________________________ > USRP-users mailing > listUSRP-users@lists.ettus.comhttp://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > > > > > _______________________________________________ > USRP-users mailing > listUSRP-users@lists.ettus.comhttp://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >
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