Abstract: A removable plug-in board for dividing incoming radio frequency (RF) to an external port and providing alternating current (AC) signals to a CATV system amplifier contains a radio frequency choke or inductor for passing the AC power signal, a high pass filter for passing the radio frequency signal and either a directional coupler or a splitter. This plug-in board is inserted into a motherboard on which is mounted amplification circuitry and power supply and divider circuitry. The plug-in board routes RF signals arriving on an input port of the amplifier motherboard through the directional coupler to the amplification circuitry, while additionally tapping off and feeding the incoming RF signals to a second output port of the amplifier motherboard.

Abstract: A node (100) for a communications system includes a forward distribution amplifier within a housing (600). Plug-in modules (200,400) can be removably attached to the forward distribution amplifier within the same housing (600) to change the functionality of the node (100). For example, the plug-in module can be a reverse amplifier module (200) for adding reverse signal processing function or an optical module (400) for adding optical capabilities.

Abstract: A cable television system employs two-way communication between a headend and at least one subscriber terminal. The two-way communication is provided by having separate frequency bands for each communication path. The frequency bands do not overlap and the higher frequency band is used for subscriber terminal to headend transmissions. A line amplifier is provided that employs two diplex filters each connected to both a forward and reverse amplifier. The high pass portions of the diplex filters are formed from both lumped and distributed components.

Abstract: A combination surge and diplex filter is provided for a CATV distribution amplifier. In a first preferred implementation, an integrated surge and high pass filter section is provided when the CATV amplifier is used only in the forward direction. Provision is made for a plug-in low pass filter section which is matched to the high pass filter section. The plug-in low pass section is used to form a diplex filter if the reverse direction capability of the CATV system is required from the distribution amplifier. In a second preferred implementation, the integrated surge and high pass filter section is segmented into a surge filter segment which is designed as a divisible part of the high pass filter section. A plug-in module is then provided with a high pass filter segment having those components of the high pass filter section which were not necessary for surge protection and a low pass filter section matched to the high pass filter section.