A filter system that filters WCS signals received by a satellite radio antenna if the WCS signals have a high enough signal strength where they could overwhelm the satellite radio signals and prevent the satellite radio from operating. The filter system includes a coupling circuit that couples off a small portion of the signal received by the antenna and sends it to a detector that detects the signal strength of the coupled off portion of the signal. If the signal strength exceeds a predetermined threshold, the detector provides a control signal to a switch that directs the signal received by the antenna to a WCS filter to filter out the WCS signals, where the switch otherwise causes the signal received by the antenna to be sent directly to the radio.