Mitsubishi Eclipse Workshop Manual page 675

AUDIO SYSTEM
- Troubleshooting
54-37
A-3
| Mixed
with
noise,
only
at
night (AMl.
:
_'- ,'j,
t
The
following factors can be considered as possible
causes
of
noise appearing
at
night.
1.
Factors due
to signal conditions: Due
to the fact
that
long-distance signals
are more easily
re-
ceived at night, even stations that are received
without problem during the day may experience
interference
in a general worsening of reception
conditions. The weaker
a
station
is the
more
susceptible it is
to interference,
and a change
to
a
different station
or the appearance of a beating
sound* may
occur.
Beat sound*:
Two
signals close
in
frequency
interfere
with
each other.'creating a repetitious
high-pitched sound. This sound is generated not
only by sound signals but by electricalwaves
as
well.
2.
Factors due
to vehicle noise: Alternator
noise
may be
a
cause.
ls
the noise still
obvious even
with
the lamps
OFF?
Do
the following
measures
elirninate
the
noise?
o Tune to
a
station
with
a
strong
signal.
o Tune
to
a
station
with
a
strong
signal
without completely
extending the antenna.
Does
the
noise fade away when
the vehicle harness is moved awav
from the radio
chassrs?
(if
the harness is not in the
proper
position).
lf there is more noise than
other
radios,
consult
a
service center.
@Mitsubishi
MotorGorpontion
Apt.
1991
PWUE9010