A low cost, low power and lightweight swept sine wave analysis system that is affordable to engineers, university laboratories and students, providing accurate magnitude and phase response measurements over a wide bandwidth is described. An analog mixer mixes a local oscillator signal with an amplified input signal allowing AC signal coupling between input stages. This minimizes errors due to DC and low frequency drift. A computer graphical interface is used for controlling the acquisition hardware in real time, displaying results on the computer screen, and making the graphical results and numerical results immediately available for inclusion in documentation or spreadsheet applications.