Data signal lever control circuit - filters out pilot signal to compare with reference and give correcting signal

摘要

The level control circuit, for data signals, has a comparator to compare the actual and required levels of the transmitted pilot signal and to initiate the production of a control signal according to the result of the comparison. The incoming signal mixture is passed to two filters to separate the pilot signal from the rest. The pilot signal is rectified and mixed with the filtered data signal. The mixer's output is passed to a regulated stage that controls the level of the data signals. The regulated stage is controlled by the comparator's output.