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.mueller@ettus.com> <mailto:marcus.mueller@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 list
 USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com>
 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

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Any thoughts on this? Mike On 03/25/2019 01:04 PM, Michael R. Freedman via USRP-users wrote: > > Marcus, > >    190Hz is what we calculated.  I have attached a text file with the > data we used.  This is a single UBX40 tuned to 155MHz sampling at 2MHz. > > > Mike > > > On 03/25/2019 12:34 PM, Nick Foster wrote: >> 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 <mailto: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.mueller@ettus.com> <mailto:marcus.mueller@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 list >>>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>> >>>> >>>> _______________________________________________ >>>> USRP-users mailing list >>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>> >>> >>> >>> _______________________________________________ >>> USRP-users mailing list >>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >> >> _______________________________________________ >> USRP-users mailing list >> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >> http://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

190Hz is what we calculated.  I have attached a text file with the 

 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.mueller@ettus.com>  <mailto:marcus.mueller@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 list
 USRP-users@lists.ettus.com  <mailto:USRP-users@lists.ettus.com>
 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

 _______________________________________________
 USRP-users mailing list
 USRP-users@lists.ettus.com  <mailto:USRP-users@lists.ettus.com>
 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

 _______________________________________________
 USRP-users mailing list
 USRP-users@lists.ettus.com  <mailto:USRP-users@lists.ettus.com>
 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

 _______________________________________________
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On 03/27/2019 10:41 AM, Michael R. Freedman via USRP-users wrote: > > Any thoughts on this? > > > Mike > Given that in this case, the incoming carrier will be fighting DC-offset removal rather hard, I wonder if this is a weird artifact of DC-offset removal? If you use offset tuning on the RX, do you still see a significant phase roll? > > On 03/25/2019 01:04 PM, Michael R. Freedman via USRP-users wrote: >> >> Marcus, >> >> 190Hz is what we calculated. I have attached a text file with the >> data we used. This is a single UBX40 tuned to 155MHz sampling at 2MHz. >> >> >> Mike >> >> >> On 03/25/2019 12:34 PM, Nick Foster wrote: >>> 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 <mailto: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.mueller@ettus.com> <mailto:marcus.mueller@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 list >>>>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>>> >>>>> >>>>> _______________________________________________ >>>>> USRP-users mailing list >>>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>> >>>> >>>> >>>> _______________________________________________ >>>> USRP-users mailing list >>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>> >>> _______________________________________________ >>> USRP-users mailing list >>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>> http://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 > > > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

 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.mueller@ettus.com> <mailto:marcus.mueller@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 list
 USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com>
 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

 _______________________________________________
 USRP-users mailing list
 USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com>
 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

 _______________________________________________
 USRP-users mailing list
 USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com>
 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

 _______________________________________________
 USRP-users mailing list
 USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com>
 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

Marcus, I tried a 10MHz LOOffset with no change.  I also tried it at 1155.0MHz and 1160.0MHz.  At 1155 the phase rolls... at 1160 it does not. Mike On 03/27/2019 11:10 AM, Marcus D. Leech via USRP-users wrote: > On 03/27/2019 10:41 AM, Michael R. Freedman via USRP-users wrote: >> >> Any thoughts on this? >> >> >> Mike >> > Given that in this case, the incoming carrier will be fighting > DC-offset removal rather hard, I wonder if this is a weird artifact of > DC-offset >   removal? > > If you use offset tuning on the RX, do you still see a significant > phase roll? > > >> >> On 03/25/2019 01:04 PM, Michael R. Freedman via USRP-users wrote: >>> >>> Marcus, >>> >>>    190Hz is what we calculated.  I have attached a text file with >>> the data we used.  This is a single UBX40 tuned to 155MHz sampling >>> at 2MHz. >>> >>> >>> Mike >>> >>> >>> On 03/25/2019 12:34 PM, Nick Foster wrote: >>>> 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 <mailto: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.mueller@ettus.com> <mailto:marcus.mueller@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 list >>>>>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> USRP-users mailing list >>>>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> USRP-users mailing list >>>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>> >>>> _______________________________________________ >>>> USRP-users mailing list >>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>> http://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 >> >> >> >> _______________________________________________ >> USRP-users mailing list >> USRP-users@lists.ettus.com >> http://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

190Hz is what we calculated.  I have attached a text file with 

 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.mueller@ettus.com>  <mailto:marcus.mueller@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 list
 USRP-users@lists.ettus.com  <mailto:USRP-users@lists.ettus.com>
 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

 _______________________________________________
 USRP-users mailing list
 USRP-users@lists.ettus.com  <mailto:USRP-users@lists.ettus.com>
 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

 _______________________________________________
 USRP-users mailing list
 USRP-users@lists.ettus.com  <mailto:USRP-users@lists.ettus.com>
 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

 _______________________________________________
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 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

On 03/27/2019 03:39 PM, Michael R. Freedman via USRP-users wrote: > > Marcus, > > > I tried a 10MHz LOOffset with no change. I also tried it at 1155.0MHz > and 1160.0MHz. At 1155 the phase rolls... at 1160 it does not. > > > Mike > Could you give us a dump of uhd_usrp_probe for an X310 that displays this issue? What version of UHD? Also, to be clear, this is within a *single* X310, correct? > > On 03/27/2019 11:10 AM, Marcus D. Leech via USRP-users wrote: >> On 03/27/2019 10:41 AM, Michael R. Freedman via USRP-users wrote: >>> >>> Any thoughts on this? >>> >>> >>> Mike >>> >> Given that in this case, the incoming carrier will be fighting >> DC-offset removal rather hard, I wonder if this is a weird artifact >> of DC-offset >> removal? >> >> If you use offset tuning on the RX, do you still see a significant >> phase roll? >> >> >>> >>> On 03/25/2019 01:04 PM, Michael R. Freedman via USRP-users wrote: >>>> >>>> Marcus, >>>> >>>> 190Hz is what we calculated. I have attached a text file with >>>> the data we used. This is a single UBX40 tuned to 155MHz sampling >>>> at 2MHz. >>>> >>>> >>>> Mike >>>> >>>> >>>> On 03/25/2019 12:34 PM, Nick Foster wrote: >>>>> 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 <mailto: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.mueller@ettus.com> <mailto:marcus.mueller@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 list >>>>>>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>>>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> USRP-users mailing list >>>>>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>>>> >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> USRP-users mailing list >>>>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>>> >>>>> _______________________________________________ >>>>> USRP-users mailing list >>>>> USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> >>>>> http://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 >>> >>> >>> >>> _______________________________________________ >>> USRP-users mailing list >>> USRP-users@lists.ettus.com >>> http://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 > > > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com