How does am and FM station work?

Answer 1

Both AM and FM radio operate in signal waves. Picture a beach. The ocean waves on this beach come in very regularly at 1000 waves every hour exactly, and every wave is exactly 5 feet high. AM (Amplitude Modulation) and FM (Frequency Modulation) have something in common and something different. Can you guess what those things are? They're right in the names. They both have "modulation" in common. Modulation is, in a nutshell, a change. Our beach needs some sort of change in the waves to carry a message. A change is needed in order to produce a sound on a radio, and that change can be done in two different ways: Oo! Oo! Can I guess the first one? Amplitude! Amplitude is the height of our beach waves. On our beach, we notice that some of the waves are getting lower and higher than the 5 foot waves we are used to seeing. Some of them are tiny 6 inch waves and others are huge 20 foot monster waves. On an AM radio, tiny radio waves will produce a small sound and the high radio waves produce a loud sound. The waves always come in 1000 waves per hour (or frequency) on AM Beach, and a radio set to receive a certain station will pick up only a certain frequency of waves. Let's relax on FM beach. Again, normally we have exactly 1000 waves per hour and exactly 5 foot swells. Now we notice that the waves are coming in more frequently or less frequently than 1000 per hour. Sometimes 900 waves per hour and sometimes up to 1100 waves per hour. But the waves are always 5 feet tall. Now we've changed or modulated the frequency. A lower frequency will produce a small sound in FM radio, and a higher frequency will produce a louder sound. AM has the advantage of a larger transmission distance, and FM has the advantage of more clarity.