Abstract: An automated process and device for testing both C.W. and swept output signal modulation of a system or unit under test. The invention conditions the output signals to be compatible for measurement, measures incremental cycle periods of the signals using a continuous time counter, converts raw signal data into formatted tables, calculates prescribed parameters relating to the signals, aligns the calculated prescribed parameters relating to the signals, computes incremental signal frequencies from the incremental cycle periods as measured, substarts the incremental signal frequencies from the predicted signal frequencies to form a frequency residual model, constructs a curve using the incremental signal frequencies, and displays the curve. A prediction model is created and used to predict expected results. The prediction model defines ideal behavior of both C.W. and swept signals from a unit under test.