AmplifierCircuits

AM Radio Circuits AM radio began with the first, experimental broadcast on Christmas Eve of 1906 by Canadian experimenter Reginald Fessenden, and was used for small-scale voice and music broadcasts up until World War I. AM radio technology is simpler than Frequency Modulated (FM) radio, Digital Audio Broadcast (DAB), Satellite Radio or HD (digital) Radio. An AM receiver detects amplitude variations in the radio waves at a particular frequency. It then amplifies changes in the signal voltage to drive a loudspeaker or earphones. The earliest crystal radio receivers used a crystal diode detector with no a mplification.  As a result, many broadcast stations are required as a condition of license to reduce their broadcasting power significantly (or use directional antennas) after sunset, or even to suspend broadcasting entirely during nighttime hours.  Medium-wave and short-wave radio signals act differently during daytime and nighttime.  However, in the late ...