Metric Halo SpectraFoo - Manual (Page 93)

Signal Generator
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Figure 8.7: Dithered 16 bit signal
FFT Synchronization
Each of the frequencies of the generated signals can be synchronized to the analyzer width, allowing you to
generate test tones that can be analyzed with no FFT windowing for the best level accuracy.
Figure 8.8: Synchronization Controls
Synchronization is enabled by checking the Synchronize checkbox.
When synchronization is turned on the generator will not sweep the sine parameters – it will only use the
parameters entered in the start column. The parameters for the two noise sources will continue to sweep.
If you have turned on synchronization you can select the “Rectangular” window for the system analyzer. This
window will allow the analyzer to recognize that the synchronized sines fit exactly into one analyzer spectral
line.
To select the rectangular analyzer window:
1. If the FFT Window window is not visible, make it visible using the Show FFT Window Control command
from the Window menu.
Figure 8.9: Selecting the Rectangular window from the FFT Window library