Sienna LE V6-3.0L (1MZ-FE) (1998)
Radio, Stereo, and Compact Disc: Description and Operation
1. RADIO WAVE BAND
The radio wave bands used in radio broadcasting are as follows:
2. SERVICE AREA
There are great differences in the size of the service area for AM and FM monaural. Sometimes FM stereo broadcasts cannot be received even
through AM comes in very clearly.
Not only does FM stereo have the smallest service area, but it also picks up static and other types of interference ("noise") easily.
3. RECEPTION PROBLEMS
Besides the problem of static, there are also the problems called "fading", "multipath" and "fade out". These problems are caused not by electrical
noise but by the nature of the radio waves themselves.
a. Fading
Besides electrical interference, AM broadcasts are also susceptible to other types of interference, especially at night. This is because AM radio
waves bounce off the ionosphere at night. These radio waves then interfere with the signals from the same transmitter that reach the vehicle's
antenna directly. This type of interference is called "fading".
b. Multipath
One type of interference caused by bouncing of radio waves off obstructions is called "multipath". Multipath occurs when a signal from the
broadcast transmitter antenna bounces off buildings and mountains and interferes with the signal that is received directly.