Fast Fourier Transform

Hi all,
I have some problems with FFT.
I have one column for the time and one column with some values from -140 to +140. Then I have a Window Function node and the FFT node. At the end I have a Line Chart.
If I execute and open view, I get an unexpected wave.
My window function is on hamming.
And it doesn’t matter what sample rate I enter, it’s every time the same wave.

Hi Manuel,

I have worked with FFT using other tools than KNIME Analytics Platform. Could you provide the workflow?