On Thu, 2011-08-04 at 12:54 +0300, Sivan Toledo wrote: > How is gain distributed when the UHD USRP block is told to set the > total gain to a particular value? > > I am using GRC with UHD controlling a USRP with a Flex400 daughter > board. I set the gain in the GRC block to 20dB, which results in the > line "self.uhd_usrp_source_0.set_gain(20, 0)" in the Python output > file. > > My understanding is that the codec on the USRP has an internal PGA > whose gain can be set between 0 and 20dB and that the Flex400's mixer > also has a PGA whose gain can be set between 0 and 45dB. > > Does this mean that I can set the gain in the USRP source block to > anywhere between 0 and 65dB (with the driver deciding how to > distribute the gain between the two PGAs), or is there a way to > control separately the two PGAs?
UHD handles gain distribution generally from the front end inward, for best NF. You can control individual gains like so: self.uhd_usrp_source_0.set_gain(20, "PGA0", 0) You can get a list of gain controls with: self.uhd_usrp_source_0.get_gain_names(0) --n > > Thanks, Sivan Toledo > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
