Radio, Stereo, and Compact Disc: Description and Operation

1. RADIO WAVE BAND
The radio wave bands used in radio broadcasting are as shown.




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

HINT: 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 the bouncing of radio waves off of obstructions is called "multipath". Multipat occurs when a signal from the broadcast transmitter antenna bounces off buildings and mountains and interferes with the signal that is received directly




c. Fade Out
Because FM radio waves are of higher frequencies than AM radio waves, they bounce off buildings, mountains, and other obstructions. For this reason, FM signals often seem to gradually disappear or fade away as the vehicle goes behind a building or other obstruction. This is called "fade out".

4. COMPACT DISC PLAYER
Compact Disc (hereafter called "CD") Players use a laser beam pick-up to read the digital signals recorded on the CD and reproduce analog signals of the music, etc. There are 4.7 in. (12 cm) and 3.2 in. (8 cm) discs in the CD player.

HINT: Never attempt to disassemble or oil any part of the player unit.
Do not insert any object other than a disc into the magazine.

NOTE: CD players use an invisible laser beam which could cause hazardous radiation exposure. Be sure to operate the player correctly as instructed.




5. TAPE PLAYER/HEAD CLEANING
a. Raise the cassette door with your finger. Next, using a pencil or like object, push in the guide.
b. Using a cleaning pen or cotton applicator soaked in cleaner, clean the head surface, pinch rollers and capstans.




6. CD PLAVER/DISC CLEANING
If the disc gets dirty, clean the disc by wiping the surfaces from the center to outside in the radial directions with a soft cloth.

NOTE: Do not use a conventional record cleaner or anti-static preservative.