Abstract: A digital finite impulse response (FIR) filter having a shift register for receiving a digital signal, a counter for counting pulses in a sampling signal and a look-up table read-only memory (ROM) having address inputs coupled to the outputs of the stages of the FIR filter and to the outputs from the counter. The output of the ROM forms the filtered signal. This digital filter approach allows for a balance between cost and performance and is inherently flexible due to the programmable nature of its core device (ROM).

Abstract: A device for tapping the line power of a cable television distribution system. The device is intended for connection to a standard port of a cable tap. The device includes a threaded portion for connection to the port, a housing and an output connector mounted to the housing. Disposed within the housing is a module containing electronics forming a low pass filter to remove the line power from the RF television signal. The module is slidably mounted to extend out of the housing and is biased into engagement with the hot side of the port. The mounting of the electronics within a slidable module permits the low pass filter to be in close proximity to the port so as to eliminate interference with the television signal. The slidable housing also permits the device to be used with ports which differ in depth.