Some important features to be looked at in a radio receiver are its sensitivity, selectivity, fidelity, adjacent channel and image interference, automatic volume control (AVC), squelch and signal to noise ratio. Sensitivity is the ability of the radio receiver to pick up weak signals. Lower the signal needed in the antenna circuit to have good audio output, higher the sensitivity of the radio. Sensitivity may range from microvolts to millivolts of signal in the antenna circuit and depends on the number of amplification stages in the radio and their quality. Selectivity is the ability of a radio receiver to separate the signal of the intended station from those operating on other frequencies. We need the reception bandwidth to be narrow. Yet it should not cut off the upper and lower audio frequencies modulating the received signal. Selectivity can be improved by having more tuned circuits of higher quality in the receiver. Fidelity is the quality of reproduction of the received signal in the output. High fidelity would mean lower distortion introduced by the radio in the received signal.
