• Cutoff Tunable Range: 0.03Hz to 1MHz • Attenuation: 48dB/Octave • Filter Modes: Low-Pass and High-Pass • Response: Butterworth and Bessel • Input Gain (pre-filter): 50dB in 10dB Steps • Output Gain (post-filter): 20dB in 0.1dB Steps • Input Type: Differential and Single-Ended • Gain Only Mode: 70dB Pre-Amplifier The Krohn-Hite Model 38 Butterworth/Bessel, plug-in filter card is one of a family of filter cards used in Krohn-Hite Programmable Filter System Mainframes. It is carefully designed with the user in mind, providing ease of operation, reliability and price competitiveness. The 38 provides a tunable frequency range from 0.03Hz to 1MHz in the low-pass mode and 0.03Hz to 300kHz in the high-pass mode. Both modes are extended down to 0.003Hz with the 002 option. The frequency response characteristic is either maximally flat (Butterworth) for clean filtering in the frequency domain, or linear phase (Bessel) to provide superior pulse or complex filtering is operator selectable. The 38 is an 8-pole, wide range, low-pass/high-pass filter or an amplifier providing gains to 70dB in 0.1dB steps. The 38 will accept input signals of ±10V peak at 0dB gain and has selectable ac or dc coupling. Overload detectors are standard and assist the user in detecting input signals or incorrect gain settings.