Hi Everyone, I just had a quick question. What does set_bandwidth() actually do on a USRP sink block in GNU Radio? I know that for the B2x0 series, there isn't a tune-able TX filter (you get the full bandwidth that your sample rate supports), so I'm wondering if this is just a vestigial API call in some cases. Namely, I'm wondering if set_bandwidth() is meant for the RX side (i.e., doing band pass filtering for received signals). FYI, I am currently using an E310 for this application. Also, is there a list of daughtercards / products that do have a filter on the front-end (both for TX and RX)? -- Peter Witkowski pwitkowski@gmail.com

On 02/02/2016 04:10 PM, Peter Witkowski via USRP-users wrote: > Hi Everyone, > > I just had a quick question. What does set_bandwidth() actually do on > a USRP sink block in GNU Radio? I know that for the B2x0 series, > there isn't a tune-able TX filter (you get the full bandwidth that > your sample rate supports), so I'm wondering if this is just a > vestigial API call in some cases. Namely, I'm wondering if > set_bandwidth() is meant for the RX side (i.e., doing band pass > filtering for received signals). > > FYI, I am currently using an E310 for this application. Also, is there > a list of daughtercards / products that do have a filter on the > front-end (both for TX and RX)? > > -- > Peter Witkowski > pwitkowski@gmail.com <mailto:pwitkowski@gmail.com> > The set_bandwidth() call does nothing on a number of cards, and I think that it only does anything for RX. Off the top of my head: TV_RX2 DBS_RX2 B2xx WBX/SBX/UBX/CBX all have fixed-bandwidth baseband filtering.

In fact on B2xx and E3xx there are tunable analog TX and RX filters in the radio, but S/W support via UHD has only very recently been added. Previously they were configured automatically to a width that was appropriate to go with the configured sample rate. You should double check my recollection, but I believe all 3.9.x versions of UHD should now work in this respect for TX filtering, i.e you manually configure the analog filter bandwidth. Martin et al can talk to the UHD API enhancements they added in better detail to do this, beyond set_bandwidth. -Ian On Feb 2, 2016, at 1:26 PM, Marcus D. Leech via USRP-users <usrp-users@lists.ettus.com> wrote: > On 02/02/2016 04:10 PM, Peter Witkowski via USRP-users wrote: >> Hi Everyone, >> >> I just had a quick question. What does set_bandwidth() actually do on a USRP sink block in GNU Radio? I know that for the B2x0 series, there isn't a tune-able TX filter (you get the full bandwidth that your sample rate supports), so I'm wondering if this is just a vestigial API call in some cases. Namely, I'm wondering if set_bandwidth() is meant for the RX side (i.e., doing band pass filtering for received signals). >> >> FYI, I am currently using an E310 for this application. Also, is there a list of daughtercards / products that do have a filter on the front-end (both for TX and RX)? >> >> -- >> Peter Witkowski >> pwitkowski@gmail.com >> > The set_bandwidth() call does nothing on a number of cards, and I think that it only does anything for RX. Off the top of my head: > > TV_RX2 > DBS_RX2 > B2xx > > WBX/SBX/UBX/CBX all have fixed-bandwidth baseband filtering. > > > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

On 02/03/2016 01:08 PM, Ian Buckley via USRP-users wrote: > In fact on B2xx and E3xx there are tunable analog TX and RX filters in > the radio, but S/W support via UHD has only very recently been added. > Previously they were configured automatically to a width that was > appropriate to go with the configured sample rate. > > You should double check my recollection, but I believe all 3.9.x > versions of UHD should now work in this respect for TX filtering, i.e > you manually configure the analog filter bandwidth. > > Martin et al can talk to the UHD API enhancements they added in better > detail to do this, beyond set_bandwidth. Yep, all of the above is correct. 3.9.x added actual support for this feature on the AD9361-based devices (i.e., B2xx and E310). Cheers, Maritn

On 02/03/2016 01:08 PM, Ian Buckley via USRP-users wrote: > In fact on B2xx and E3xx there are tunable analog TX and RX filters in > the radio, but S/W support via UHD has only very recently been added. > Previously they were configured automatically to a width that was > appropriate to go with the configured sample rate. > > You should double check my recollection, but I believe all 3.9.x > versions of UHD should now work in this respect for TX filtering, i.e > you manually configure the analog filter bandwidth. > > Martin et al can talk to the UHD API enhancements they added in better > detail to do this, beyond set_bandwidth. Yep, all of the above is correct. 3.9.x added actual support for this feature on the AD9361-based devices (i.e., B2xx and E310). Cheers, M