If ingress signals and noise are causing problems in your reverse path, Communication Associates Reverse Ingress Attenuator can help. Available in two models that combine a sharp cutoff highpass filter with an attenuator, the RIA eliminates ingress below either 10MHz or 6 MHz and provides up to 9 dB of flat attenuation in 1 dB steps. Available in 0 dB through 9 dB attenuator values.

U.S. Patent No. 7,177,143 B1