An AM radio station transmits sine waves using an antenna. The transmitted sine waves are modulated by encoding information onto them using amplitude modulation. Amplitude modulation involves overlaying a sine wave produced by a person's voice onto the transmit wave to vary its amplitude. When received by an antenna, the AM signal is demodulated and amplified so the encoded audio can be played over speakers.

1. AM Transmission How Radio transmits and receives AM signals

2. AM Transmissions Radio broadcasting sends sine waves into the atmosphere with an antenna. RADIO STATION

3. The transmitted sine waves are modulated, by information is encoded on to them. There are 3 kinds of methods: 1. Pulse Modulation 2. Frequency Modulation 3. Amplitude Modulation

4. AMPLITUDE MODULATION The sine wave produced by a person’s voice is overlaid onto the transmit wave to vary its amplitude. - Sine wave A person’s voice - -AM Signal

5. Radio Receiver Speaker Antenna Demodulator Amplifier Tuner

6. ANTENNA AND TUNER The antenna picks up the electromagnetic waves in the atmosphere. And converts them into electrical signals. These signals get sent to the tuner in the radio. The tuner sorts through the many waves the antenna receives and selects the desired sine wave.

7. DEMODULATOR The demodulator is controlled by an apparatus called ‘diode’. The diode only allows a current to flow in one direct and not the other. This alters the sine wave, and clips its current flow in the opposite direction.

8. AMPLIFIER The amplifier increases the modulated wave for it to be processed bythe audio apparatus.