Here we have zoomed in around the distortion component near 1.1 MHz. Note that the plot has auto-scaled to show more vertical resolution, given that there is less dynamic range in the data.

Zoomed ADC Signal Spectrum

However, aside from being able to pin down the frequency and amplitude of this component more accurately, this plot really doesn’t show us anything new; we just see more grass around the distortion.

Next, let’s look at the frequency list…