The Model 35 is a low-pass, Butterworth (maximally flat) filler card, used in the Models 3905B and 3916B mainframes, providing 24GB/octave rolloff with a minimum stopband attenuation of up to lOOdB. The Model 35 covers the frequency range of 170Hz to 25.6MHz with 2Vz digits of resolution. The filter card has selectable AC or DC coupling and selectable 1M or 50 ohm impedance. Programmable input gains of up to 20dB and output gains of up to 26dB are standard. The Mode135 also has the capability to be configured in an Amplifier By-Pass mode to operate as an amplifier, by-passing the filter. This gives the user the ability to amplify without filtering when so desired. The Model 35 is one of many Krohn-Hite filter cards used in conjunction with two GPIB programmable mainframes; the 3 1/2' high Model 3905B (5 plug-in card chassis) or the Model 3916B (16 plug-in card chassis).