The Source Palette allows you to set the frequency and power level of the input source. This source is always at the input of the cascaded system, which may or may not be the currently displayed system page. The Solve button causes a single analysis of the system at the indicated parameters. If the system has a tunable mixer you can step the frequency up or down by the step size defined in the mixer. If the LO Track button is check, the tunable mixer LO will track the input frequency. If the button is unchecked, the input frequency will change but the LO will remain fixed.