Abstract: A digital partial response filter is disclosed. The digital partial response filter has particular application in an FM subcarrier (SCA) digital data transmission system wherein digital data is frequency modulated on an F.M. subcarrier. The partial response digital filter includes a digital memory wherein digitized samples of the partial response channel response to a representative input digital data symbol are stored and digital adding means for cumulatively summing the digitized samples in groups so as to produce the partial response channel response to an input digital data stream.

Abstract: A single screw extruder, comprising a rotatable core means in an extruder barrel, is provided with spaced-apart discontinuous helical flights arranged on the rotatable core means with each flight centered in the channel formed by the preceding flights, the flights being formed by lands on the core means, and each land having a traversed axial length of about one diameter unit of the core means. The extruder is particularly useful in filler compounding of solid polyolefins, the blending of different polyolefins, and the reacting of monomers with polyolefins such as in extruder grafting.