On Sat, Apr 30, 2011 at 3:47 PM, Stefan Gofferje
<address@hidden> wrote:
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On 04/30/2011 05:38 PM, Marcus D. Leech wrote:
> The bandwidth is used to determine both the axis labels, and the correct
> decimation parameters
> to use to produce the desired display rate. The center frequency is
> purely used set axis labels.
>
> I'd still recommend posting your .GRC file here.
I ran an audio_source -> qtgui_sink and it looked fine to me. I also took your grc xml here and ran that and saw the four spikes as expected.
The setting of the center frequency is only to set the axis labels, it won't do any translating of the signal or anything. Remember in this case and with your audio source one, the signal is real, so you will only have spectral components from -22.05 to 22.05 kHz and the spectrum will be symmetric around 0 Hz. So "translating" this up to 22.05 kHz won't really do anything for you since you have no information over 22.05 kHz, anyways.
Tom
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