On Thu, Feb 12, 2009 at 1:20 PM, Bruhtesfa Ebrahim <li...@ruby-forum.com> wrote:
> What makes it strange is the dependence on gain.when the linear gain in > the spectrum panel(usrp_fft.py)is set to 0,the signal at the center(the > DC)is 5dB higher than the noise level.When I increase the gain, the > difference between the DC and noise level keeps decreasing and finally > the DC level is equal to the noise level. > Specifically, for a linear gain >=20, the signal around DC is not > visible(it is equal to the noise level). Actually, what you're now describing is more like not receiving any signal at all--the small line at DC is residual DC offset from the ADC, and the noise is simply that, noise that gets amplified according to the gain setting. At a certain point the noise power exceeds the small DC offset. Johnathan _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
