Mitsubishi Eclipse Workshop Manual page 681

AUDIO SYSTEM
-
Troubleshooting
54-43
Noise sometimes appears
on
FM during traveling'
o
*
About multipath noise and fading
noise
Because
the frequency of FM waves is extreme-
ly high,
it
is highly susceptible
to effects
from
geolögical formations
and
buildings. These
öttects disrupt the broadcast signal and
obstruct
reception
in
several ways.
o
Multipath noise
This describes
the
echo
that
occurs
when the
broadcast signal
is reflected by a
large obstruc-
tion and enters
the
receiver
with a
sligrht
time
delay relative
to the
direct signal
(repetitious
buzzing).
.
Fading noise
This
ü
a buzzing noise
that occurs when
the
broadcast bearn
is
disrupted
by
obstructing
objects and
the
signal strength fluctuates
intri-
cately
within a narrow
range.
@
Mitrubishi
Moton Gorporation Apr.
1991
Check
the motor antenna itself.
(Refer
to D-1, 2.)
ls the antenna
completely extended?
Does
the problem clear
up
when retuned?
Due to
electrical field conditions.
(Multrpath notse*. fadrng
notse'
).
Does
the problem
appear
only in
certain
locat'ons änd
only
wlth certain stations?
Are
connectors properly connected?
Static
electricity noise:
Bodv static electric
from the shock
absörber rubber bushings used
to
orevent vibration.
tires, etc. occurs
because of separation
from the
earth. causing a
buzzing noise.
Since no measures can be
taken on
the radio side, steps should be
taken
to discharge the static
electricitv of
the vehicle body-
Does noise appear
when the radio
switch is
turned
on wnit'e
the vehicle is stopped
and
the
iäoio
's
struck
while tuned away
f
rom
a
station?
ls
the radio body correctly earthed?
(G
trre
mountini
screw
ti!htened
securely?)
Tighten the screw securelY.
lf rust is
present ol the antenna
earth
sciew,
clean and
tighten
the
earth securelY.
ls
the antenna correctly earthed? (lf noise
appears
when the antenna
is
moved,
this means
thö earth is not securely
connected.)
Repair
or replace radio.
Check connectcr connecllons.
PWUE9010