Abstract: A gain variance and ingress reduction system reduces the overall ingress of interferers for an entire CATV system return transmission path and allows a reduction in subscriber terminal return transmitter power. The system places a calculated loss at each subscriber tap location. By placing these losses at each subscriber location, the headend receives a more consistent return transmission path gain thereby reducing the terminal return transmitter power range requirement. In addition, the losses reduce return transmission path ingress.

Abstract: A thermoelectric cooler temperature control circuit provides a periodic control signal having a substantially constant peak-to-peak magnitude and an average value dependent on a sensed temperature to be regulated. The control signal is coupled to control the heating or cooling of a thermoelectric cooler. In a preferred embodiment, complementary positive and negative going control signal pulse streams are provided. A switch selectively couples one of the complementary pulse streams to cool the thermolectric cooler or the other stream to heat the cooler. The control signal pulse streams can be pulse width modulated signals.