# Set\_bandwidth on UHD called from osmosdr

**URL:** <https://www.ruby-forum.com/t/set-bandwidth-on-uhd-called-from-osmosdr/242439>\
**Category:** GNU Radio\
**Created:** [June 24, 2015, 4:17am UTC](https://www.ruby-forum.com/t/set-bandwidth-on-uhd-called-from-osmosdr/242439 "2015-06-24T04:17:57Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Detlef\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58f4c7/32.png) [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\
**Post date:** [June 24, 2015, 4:17am UTC](https://www.ruby-forum.com/t/set-bandwidth-on-uhd-called-from-osmosdr/242439/1 "2015-06-24T04:17:57Z")

</div>

The osmosdr source/sink blocks provide a “bandwidth” field, which  
defaults to 0. Previously on B2xx this field would have no effect,  
because up  
until this point, the setting of the analog bandwidth on B2xx did  
nothing. Now it does.

It looks like trying to set a bandwidth of 0 on B2xx clips to minimum  
bandwidth (about 1MHz or so, from the resulting spectrum). Not sure what  
the correct behavior here is. Should there be a magical numeric  
value (perhaps 0) that means “set it to some sensible default, given the  
sample-rate”, should users of the osmocom source blocks always just  
set the bandwidth field to something like 0.8\*sample-rate, and then  
for hardware for which analog bandwidth is settable it will do  
“something sensible”??

I don’t know what the correct answer is, just got caught by this with  
one of my simple\_ra users with a B200, and the very-latest UHD drivers.