5–15
Interior Features
Audio System
FM characteristics
An FM broadcast range is usually about
40—50 km (25—30 miles) from the
source. Because of extra coding needed to
break the sound into two channels, stereo
FM has even less range than monaural
(non-stereo) FM.
FM Station
40—50km
(25—30 miles)
Signals from an FM transmitter are similar
to beams of light because they do not
bend around corners, but they do re À ect.
Unlike AM signals, FM signals cannot
travel beyond the horizon. Therefore, FM
stations cannot be received at the great
distances possible with AM reception.
AM wave FM wave
FM wave
100—200 km (60—120 miles)Ionosphere
Atmospheric conditions can also affect
FM reception. High humidity will cause
poor reception. However, cloudy days may
provide better reception than clear days. Multipath noise
Since FM signals can be re À ected by
obstructions, it is possible to receive both
the direct signal and the re À ected signal
at the same time. This causes a slight
delay in reception and may be heard as a
broken sound or a distortion. This problem
may also be encountered when in close
proximity to the transmitter.
Reflected wave
Direct
Flutter/Skip noise
Signals from an FM transmitter move in
straight lines and become weak in valleys
between tall buildings, mountains, and
other obstacles. When a vehicle passes
through such an area, the reception
conditions may change suddenly, resulting
in annoying noise.
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5–16
Interior Features
Audio System
Weak signal noise
In suburban areas, broadcast signals
become weak because of distance from the
transmitter. Reception in such fringe areas
is characterized by sound breakup.
Strong signal noise
This occurs very close to a transmitter
tower. The broadcast signals are extremely
strong, so the result is noise and sound
breakup at the radio receiver.
Station drift noise
When a vehicle reaches the area of two
strong stations broadcasting at similar
frequencies, the original station may be
temporarily lost and the second station
picked up. At this time there will be some
noise from this disturbance.
Station 2
88.3 MHz Station 1
88.1 MHz
Operating Tips for CD Player
Condensation phenomenon
Immediately after turning on the heater
when the vehicle is cold, the CD or
optical components (prism and lens) in
the CD player may become clouded with
condensation. At this time, the CD will
eject immediately when placed in the unit.
A clouded CD can be corrected simply by
wiping it with a soft cloth. Clouded optical
components will clear naturally in about
an hour. Wait for normal operation to
return before attempting to use the unit.
Handling the CD player
The following precautions should be
observed.
y Do not use deformed or cracked CDs.
The disc may not eject resulting in a
malfunction.
y Do not use non-conventional discs such
as heart-shaped, octagonal discs, etc.
The disc may not eject resulting in a
malfunction.
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