INSPECTION PROCEDURE 9: Noise is Present while Moving (FM)
.
DIAGNOSIS 1. The signal becomes weak as the distance from the station's transmission
antenna increases. The signal strength received depends on the signal strength
of the transmitting station and intervening obstructions such as buildings and
hills. Generally speaking, the area of good reception is approximately 20 - 25
km (12 - 16 miles) for stereo reception, and 30 - 40 km (19 - 25 miles) for
monaural reception.
Fi
g. 136: Identif
ying Ins
pection Procedure (Noise Is Present While Movin
g
(Fm)) 1 Of 2
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. The signal will becomes weak when an area of shadow from the transmitting
antenna (places
where there are obst
ruct
ions suc
h as m
ountains or buildings
NOTE: FM waves have the same properties as light, and can be
deflected and blocked. FM signal reception is severely
degraded in the shadow of obstructions such as buildings
or mountains. An FM receiver will then only receive a
reflected signal.
2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Radio With Tape Player & Cd Player - Endeavor
between the station transmitter and the vehicle), and noise will appear. < This
is called first fading, and gives a steady buzzing noise. >
3. If a direct signal hits the antenna at the same time as a signal reflected by
obstructions such as mountains or buildings, interference of the two signals
will generate noise. When moving, noise will appear each time the vehicle's
antenna passes through this kind of obstructed area. The strength and interval
of the noise varies according to the signal strength and the conditions of
deflection. < This is called multipath noise, and is a repetitive buzzing. >
Fig. 137: Identif
ying Ins
pection Procedure (Noise Is Present While Movin
g
(Fm)) 2 Of 2
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. Since FM stereo transmission and reception has a weaker field than monaural,
it is often accompanied by a hissing noise.
After taking measures to prevent the noise, check that no noise occurs.
5. Change to a different station with a stronger wave to boost resistance to
interference.
6. Su
ppress hi
gh tones to reduce noise.
2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Radio With Tape Player & Cd Player - Endeavor
