The 3202R Dual Channel Tunable Filter is an all solid-state variable rack-mounting electronic filter with low-pass, high-pass, band-pass, and band-reject capabilities plus continuous tuning range of 20Hz to 2MHz. The basic frequency response characteristic of this filter very closely approximates a fourth-order Butterworth with maximal flatness for cleanest filtering in the Frequency Domain. To meet the requirements of Time Domain, a switch changes the basic response to simple R-C to provide superior pulse or complex (transient) signal filtering. Pass band gain is unity and single-channel attenuation slope is 24 dB per octave. The individual channels may be interconnected to obtain band-pass and band-reject modes or to achieve 48 dB per octave high-pass or low-pass slopes.