On Fri, 2008-12-05 at 08:09 -0800, dan s wrote: > I've been using a waveform driver with known amplitude to calibrate > the counts reading on the USRP/LFRX when I use the usrp_cfile_rx.py > script file with decimation of 32 (2 MHz sampling). > > I performed the calibration using 0dB gain on the USRP, and 10 dB gain > for various frequencies from 10 to 150kHz. The difference in measured > voltage between 0dB and 10dB was about a factor of 3.04 for all > frequencies. > > I know that the voltage gain with 10dB should be a factor of 3.2. > Does anyone know if this is purely in an ideal state? I'm guessing > that is the case and my setup is working properly?
10dB power delta is ~3.16 factor in amplitude change. An amplitude change of 3.04 is 20*log10(3.04)=9.65 dB. The AD9862 datasheet says the PGA gain error is +-0.3 dB. I suspect if you look at the tolerances in your measurement setup you'll find you are within spec. -Johnathan _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
