Hi all, We observe different behaviour using the E320 radio with the UHD: USRP_SOURCE block and the RFNoC Radio block with a low sampling rate. We are attempting to set the sampling rate to 25 kHz for both blocks. In the UHD block, we achieve this by configuring the sampling rate to 25 kHz. Similarly, in the RFNoC block, we set the sampling rate of the RFNoC radio block to 25 kHz and the output rate of the DDC to 25 kHz. When we look at the output of the blocks, we effectively observe a signal of 25 kHz in the UHD block, while in the RFNoC radio block, we observe a larger bandwidth of approximately 250 kHz. How can we correctly configure both the Radio and DDC blocks in RFNoC to have an output of 25 KHz? Is it possible? Kind Regards, Maria

On 06/05/2025 10:12, Maria Muñoz wrote: > Hi all, > > We observe different behaviour using the E320 radio with the UHD: > USRP_SOURCE block and the RFNoC Radio block with a low sampling rate. > We are attempting to set the sampling rate to 25 kHz for both blocks. > In the UHD block, we achieve this by configuring the sampling rate to > 25 kHz. Similarly, in the RFNoC block, we set the sampling rate of the > RFNoC radio block to 25 kHz and the output rate of the DDC to 25 kHz. > When we look at the output of the blocks, we effectively observe a > signal of 25 kHz in the UHD block, while in the RFNoC radio block, we > observe a larger bandwidth of approximately 250 kHz. > How can we correctly configure both the Radio and DDC blocks in RFNoC > to have an output of 25 KHz? Is it possible? > > Kind Regards, > > Maria > > _______________________________________________ > USRP-users mailing list -- usrp-users@lists.ettus.com > To unsubscribe send an email to usrp-users-leave@lists.ettus.com Since the lowest master clock rate in the E320 is 250kHz, a *POSSIBLE* configuration is to run the radio at that master-clock,   and the DDC block with an appropriate decimation factor. What you might be able to do is to run your ordinary "multi_usrp" UHD code with the logging level turned up, so that it   *might* tell how it is configuring the RFNoC blocks inside the radio.  Remember it has been the case for quite some time   that multi-usrp now lives *ON TOP* of RFNoC, and simply configures RFNoC blocks in the USRP hardware appropriately. https://kb.ettus.com/The_UHD_logging_facility

This is correct! The simplest way for you to deal with this is to set the RFNoC Radio Block rate to something larger (like 10 Msps), and the output rate of the DDC to 25 kHz. RFNoC will take care of configuring the resampling accordingly. --M On Wed, May 7, 2025 at 12:05 AM Marcus D. Leech <patchvonbraun@gmail.com> wrote: > On 06/05/2025 10:12, Maria Muñoz wrote: > > Hi all, > > > > We observe different behaviour using the E320 radio with the UHD: > > USRP_SOURCE block and the RFNoC Radio block with a low sampling rate. > > We are attempting to set the sampling rate to 25 kHz for both blocks. > > In the UHD block, we achieve this by configuring the sampling rate to > > 25 kHz. Similarly, in the RFNoC block, we set the sampling rate of the > > RFNoC radio block to 25 kHz and the output rate of the DDC to 25 kHz. > > When we look at the output of the blocks, we effectively observe a > > signal of 25 kHz in the UHD block, while in the RFNoC radio block, we > > observe a larger bandwidth of approximately 250 kHz. > > How can we correctly configure both the Radio and DDC blocks in RFNoC > > to have an output of 25 KHz? Is it possible? > > > > Kind Regards, > > > > Maria > > > > _______________________________________________ > > USRP-users mailing list -- usrp-users@lists.ettus.com > > To unsubscribe send an email to usrp-users-leave@lists.ettus.com > Since the lowest master clock rate in the E320 is 250kHz, a *POSSIBLE* > configuration is to run the radio at that master-clock, > and the DDC block with an appropriate decimation factor. > > What you might be able to do is to run your ordinary "multi_usrp" UHD > code with the logging level turned up, so that it > *might* tell how it is configuring the RFNoC blocks inside the > radio. Remember it has been the case for quite some time > that multi-usrp now lives *ON TOP* of RFNoC, and simply configures > RFNoC blocks in the USRP hardware appropriately. > > https://kb.ettus.com/The_UHD_logging_facility > > _______________________________________________ > USRP-users mailing list -- usrp-users@lists.ettus.com > To unsubscribe send an email to usrp-users-leave@lists.ettus.com >