Motorola Signal Booster 4-Port BDA-S4 Cable Modem TV HDTV Amplifier The BDA-S4 is a bi-directional cable TV amplifier designed for use in homes. Boosts signal by 12x. This is the 4-port commercial version of the Motorola Signal Booster 484095-001-00. A passive return path supports multiple broadband devices such as set-top boxes and cable modems. Meets all applicable IEEE surge standards for all output ports, which enhances system reliability. Weather seal and protective coating allow use of the amplifier for indoor or outdoor applications.