Signal coupling apparatus for combining CATV and telephone signals onto a single cable for transmission to an impulse pay-per-view converter device. The apparatus includes a bidirectional CATV signal port, a bidirectional telephone signal port, and a bidirectional composite signal port for transmitting and receiving composite signals including telephone and CATV signals. The apparatus further includes a circuit having a first isolating portion for isolating the CATV signal port from telephone signals present on the telephone and composite signal ports, and a second isolating portion for isolating the telephone signal port from CATV signals present on the CATV and composite signal ports.