> I found sine waves will be terribly distorted when they are generated at
> relatively high frequency(above 5khz) from signal source in GRC. I set the
> sampl_rate of scope sink to 2Ghz(high enough, I think), and there are always
> spikes on generated sine wave. This problem is especially distinct when
> generated sine wave reaches 20Khz and the waveform displayed on scope sink
> is almost "saw wave". There will be nothing to dispaly if I keep on
> increasing frequency to 1Mhz. Is there anybody who met this problem before?
> or it might only be the display problem in GRC? I guess it might be the
> problem of scope sink which could not achieve that high sweep (sampling)
> rate even I set it correctly.
>
> Attached are snapshot of generated sine waves at different frequencies:
Your plots are probably fine, depending on what is your sampling rate (Fs). Think of it this way: if you display a