Hello Kunal, Please keep the mailing list included so that others can assist in answering the questions or learn from the responses. The set_rx_dc_offset function still exists. Here is the C++ API for that function. http://files.ettus.com/manual/classuhd_1_1usrp_1_1multi__usrp.html# a7beb49c1a04a81b3e7569db482453746
The page you link to contains mostly C++ code examples, so my guess would be that the previous author (four years ago) was making changes to the gr-uhd source code to set the DC and IQ offsets manually. The functions also are exposed in gr-uhd in C++ and python: https://www.gnuradio.org/doc/doxygen/classgr_1_1uhd_1_1usrp__source.html# ae3a31eb295e486c17c9e3d4b051e2ba8 https://www.gnuradio.org/doc/sphinx/uhd_blocks.html# gnuradio.uhd.usrp_source_sptr.set_dc_offset In order to use these you'll have to add either Python or C++ code to your GNU Radio flowgraph. If you really want to make these changes in UHD we can point you into the source, but it's going to be much simpler and easier to do so using the existing APIs. Regards, Derek On Tue, May 22, 2018 at 5:22 PM, kunal sankhe <kunal.2...@gmail.com> wrote: > Hi Derek, > > Thanks for the prompt reply. > > I have tested with both USRP N210 + WBX daughterboard and USRP B210, but > it does not seem the dc offset and IQ imbalance are disabled in both the > cases. I am referring a section '*Parameter estimation and UHD > implementation*' from the website http://shannon.ece.ufl > .edu:6528/index.php/USRP_Transceiver_Tuning_and_Calibration. I am trying > to reproduce similar results as shown by FFT spectra when receiver dc > offset is enabled and disabled. > > They have used a function *set_rx_dc_offset()* to disable DC offset. > However, this function seems to be replaced with *set_auto_dc_offset() *in > USRP Source block. > > *What difference in the spectrum are you expecting? What signals are you > observing while doing these tests?* > > Answer: I am expecting a rise in the dc value in the spectrum, when DC > offset calibration is disabled. I am simply connecting USRP sink with FFT > sink connected to it. No signal has been transmitted. > > Again, if I want to force these changes in the UHD code > (usrp_source_impl.cc and usrp_source_impl.h), what changes do I need to > make? > > > Thanks, > Kunal > > > On Tue, May 22, 2018 at 11:25 AM, Derek Kozel <derek.ko...@ettus.com> > wrote: > >> Hello Kunal, >> >> What daughterboard do you have? I do not believe that there is an IQ >> balance function on the N210. Those functions apply to the E31x, B2xx, and >> possibly N310 USRPs. There should be a DC notch filter which is selected on >> and off, but I would have to check to see if that applies to the N210. >> >> What difference in the spectrum are you expecting? What signals are you >> observing while doing these tests? >> >> Regards, >> Derek >> >> On Tue, May 22, 2018 at 4:06 PM, kunal sankhe via USRP-users < >> usrp-users@lists.ettus.com> wrote: >> >>> Hi, >>> >>> I want to disable automatic calibration of DC offset and IQ imbalance in >>> USRP Source block. >>> >>> I am aware that I need to pass bool value 'false' as the argument to >>> *set_auto_dc_offset* and *set_auto_iq_balance*. The USRP Source block >>> itself provide this facility in the tab *FE Corrections*. However, it >>> does not seem to work. By providing 0 (boolean false) value in Enable DC >>> Offset Correction and Enable IQ Imbalance Correction do not disable the >>> automation DC offset and IQ Imbalance correction. I tested this with USRP >>> N210 by simply using USRP Source block centered at frequency 915MHz >>> connected with WX GUI FFT Sink. The spectrum plot does not show any changes >>> in both cases. >>> >>> If I want to force these changes in the UHD code (usrp_source_impl.cc >>> and usrp_source_impl.h), what changes do I need to make? >>> >>> >>> Thanks, >>> Kunal >>> >>> >>> >>> >>> >>> _______________________________________________ >>> USRP-users mailing list >>> USRP-users@lists.ettus.com >>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>> >>> >> >
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