Abstract: A method and apparatus are provided for determining the fidelity of one or more communications channels with high efficiency and resolution with particularly advantageous application to digital communications in a radio communications environment where portable radios roaming across multiple RF site coverage areas strive to monitor the optimal control channel having the highest signal fidelity under current receiving conditions. The radio collects signal fidelity information for alternative communications channel in very short time intervals without missing important messages on a communications channel currently being monitored by that radio. Signal fidelity of the alternative communications channel is calculated without the radio being synchronized either at a digital bit or frame level to the alternative communications channel. The fidelity calculation provides information both about the accuracy (i.e., the digital value of a received digital pulse) and the quality (i.e.