A paper by Leconte, Penick, Schramm and Wier discusses the system aspects of 8‐kc program circuits over carrier facilities and outlines the functions of several filters and networks. This paper describes in detail two of the filters and one network. These are: The channel selecting crystal band pass filter used at program terminals of all broad‐band carrier systems, The band elimination filter which blocks the program at branching points on type K carrier systems, The network used at branching points on type K carrier systems to simulate the phase shift of the band elimination filter.