Amplitude+and+Frequency+Vibrato+(AM-FM)

Amplitude and Frequency Vibrato

The two types of radios that you listen to are the Amplitude Modulation and Frequency Modulation, better known as, AM and FM.

AM deals with the the amplitude signals sent by radio stations, and the FM deals with the pitch frequency sent by the radio stations. The best way to identify the difference between the two is to listen for the static. If you hear it, then you are most likely listening to AM. The reason you hear all the static is because they are the amplitude waves, meaning you can hear it when the radio receives those exact signals. The amplitude isn't strong enough by the time it reaches your radio. The waves tend to be closer to Earth during the daylight hours, and higher in the sky later in the evening.

FM waves are a little more complicated than the AM waves. Radio stations prefer FM waves over AM waves because when the waves meet a barrier, only the amplitude of the radio waves get distort, whereas the frequency waves don't, which carry the actual data (voice). Despite this fact, Marine and Air Force individuals use the AM radio waves because they travel a wider range than the FM radio waves.

On the website, you can listen to the difference between the AM frequency and the FM frequency. To listen to how a AM sounds like, click on //Play amplitude vibrato// and to listen to how the FM radio waves, click //Play frequency vibrato. **Caution: The sound produced by these waves might not be pleasant to some people.** //

http://webphysics.davidson.edu/faculty/dmb/Vibrato/vibtrem.html

This applet was designed by Dan Boye.