On Mon, Mar 23, 2009 at 12:58:17PM -0400, Erich Stuntebeck wrote: > The daughterboard gain was set to the mid-point. > > I don't have the range of the time domain samples as I did the FFT > processing in real-time and discarded the raw data. The data was > collected using a script I wrote to link the USRP block with a custom > processing block that I wrote. This custom block take the FFT of the > incoming data and outputs the amplitude of the appropriate bin. It > determines the appropriate bin based on a given frequency as an input, > and searches a few neighboring bins in case of clock errors to select > the bin nearby with the maximum amplitude. > > I'm using the firmware without the half-band filter. > > The signal generator is an Agilent 33220A. I don't have a spectrum > analyzer, but I do have two of the 33220A's and they both perform the > same way so I'm guessing its not a calibration issue with the signal > generator.
Thanks, Erich. Without seeing the time domain samples, I'm guessing that the gain is too low and/or the input is too low, and that what you're seeing is the result of only a few of the least significant bits moving in received samples. That is, you're not using the full dynamic range of the signal processing pipeline. I suggest running it again with the Rx gain set to its maximum value. Let us know how it turns out. Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
