| Fourier Analyzer: A Fourier analyzer displays the frequency spectrum of an incoming signal. The Fourier analyzer is the analog counterpart to the frequency meter. By default, Fourier analyzers operate during both Stop mode and Run mode. You can place between one and three Fourier analyzers and move them freely about the simulation window. If you select a Fourier analyzer before entering Run mode, you can tweak its display during Run mode by typing control-O to open the Fourier analyzer's Properties Box and then modifying its properties. In the Properties Box, you can set the range of displayed frequencies by choosing a lower-bound frequency from one pull-down menu and the upper-bound frequency from the other pull-down menu. Remember that setting a smaller range also increases the frequency resolution of the display. You can increase the displayed power of weak incoming signals by setting the amplification factor above 1.0, or decrease the displayed power of strong signals by setting the amplification below 1.0. The refresh time tells you how often the simulator refreshes the Fourier analyzer's display. If you have difficulty obtaining a steady display, you can set a high refresh time and freeze the display for one or two seconds at a time. Finally, you can decide if the Fourier analyzer will work in Stop mode. The Fourier analyzer is one of four wave measurement tools in Sound Lab.