By Gaylord G. Rogeness, Anaconda CATV
A cable repeater trunk amplifier station design in common use today consists of a flat (or nearly flat) frequency response, fixed gain preamplifier and poweramplifier, separated from each other and from the station input and output connectors by various loss networks. Refer to the block diagram in Figure 1. The networks introducing loss provide the functions of cable equalization, gain and slope controls, bridging and AGC amplifier and power takeoff, and frequency division multiplex filters, all of which are necessary for cable repeater amplifier station performance. Apportioning the magnitude of loss in these networks in the station design should be done in a manner which, in the limit, allows the ultimate station noise figure to approach the value of the preamplifier (Ar) noise figure and the station distortion values to approach the values of the poweramplifier (A2) distortion. Fixed gain amplifiers Ar and A2 will be referred to as IC (hybrid integrated circuit) amplifiers throughout the paper, although the analysis is general and applies to discrete component amplifiers as well.