The Filter-3 board is a module for the SCA-23 board. It consists of a four-pole lowpass filter and two adjustable two-pole filers.
The characteristics of the lowpass filter are established by four capacitors and a resistor network. It can be configured for any standard design and cutoff. Normal configuration is Chebyshev, 1 db ripple, 3500 Hz.
The adjustable filters are set for about 500 Hz. One filter adjusts below the center to provide either boost, flat or cut and the other filter has the same function above the cutoff. The frequency response can be tailored for the system.
An option block allows the use of either or both filters.
The Filter-3 can be integrated into other systems that have a high input impedance.