My HW configuration: USRP1 with DBSRX, no input signal. Using the script to plot FFT usrp_fft.py -f 1003.25M -d 8 -g 72 I see two spurious spikes at 1000 MHz and 1004 MHz (the next one is at 1008 MHz). http://www.nabble.com/file/p23854396/fft_no%2Bsignal.png Where does these spurious signals come from? In the thread "Spurious Spikes Seen with usrp_fft.py" http://www.nabble.com/Spurious-Spikes-Seen-with-us... one of the explanations is the 64MHz clock, but then the spikes should be in 64MHz intervals. On the picture below with 0dBm CW input signal at 1015 MHz you can see the spurious spike is significantly strong. Reducing the gain removes the both signals - the CW and the spurious. http://www.nabble.com/file/p23854396/fft_with_signal.png Does anyone have experience how to remove/suppress the spurious signals? -- View this message in context: http://www.nabble.com/spurious-spikes-in-FFT-tp238... Sent from the GnuRadio mailing list archive at Nabble.com.
on 2009-06-03 18:10