[Discuss-gnuradio] usrp_fft.py question and benchmark related question

[John Andrews]

Hi,
Can we change the DDC value to 0 in usrp_fft.py? Why is this not 0 as one would expect to input the center frequency same as the baseband frequency; i.e. if I know that my signal is on a carrier at 2.4G then I would use usrp_fft.py to display the spectrum by having the center frequency as 2.4G instead of typing in 2.404G (as DDC is -4M).

In benchmark_tx/rx programs do I have to account for this DDC=-4.0M? If one USRP is transmitting at 2.4G ( ./benchmark_tx.py -f 2400M ) then should I have the receiving USRP receiving at 2.404G ( ./benchmark_rx.py -f 2404M )?

Thanks