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CONDITIONS FREOUENTLY
MISTAKEN
FOR
MALFUNCTION
Noise: There are
a
variety
of
noises
relating to the
operation
of a hifi
unit.
These
are
generally
divided
into two
types;
(1) the unit is faulty
(a
transistor
or
part
has deteriorated) and
(2)
an
external
source
is adding
to the unit.
When
a
hifi
unit
produces an unpleasant noise,
it
is
often
assumed
that
the
unit
is
faulty, but statistical
records indicate
that
the majority
of
noises
pro-
WATCH
FOR
THE FOLLOWING
CONDITIONS;
THESE
ARE ALSO APT TO
BE
MISTAKEN
FOR MALFUNCTIONS.
duced
in high-fi
acoustic
units result from external
sources
of
noise: Due
to
the inherent high
sensi
tivity
and the high
fidelity
in
reproduction,
the
unit
amplifies and reproduces extraneous
noises,
however small,
into
definite output noise.
If
your
receiver produces
a
noise, check according
to
the
following table and trace out the
source
of
noise
for the appropriate corrective
action.
SYMPTIOM
SUSPECTED SOURCE
OF
NOISE
DIAGNOSIS
AND
REMEDY
TA
F
o
o
G
(D
o
F
=
z
l.IJ
F
:
z
ul
I
=
Continuous or
intermittent
noise
like
ijjjij
or
zzzzzz.
.Static
(lightning)
.
Fluorescent
lamp,
motor,
or
thermostat
may be in
use
in house
or
in the
vicinity
of
the
house.
ln
many
cases,
it
is
very
diff
icult to
remove the
source
of
noise.
ln
order
to
make
the
radio input
larger than
the
noise level, set
up a
good
outdoor
antenna
and
make
a
complete grounding.
When a
station
is
tuned
in,
hum is
mixed
in
the
pro-
gram.
. Poor fluorescent lamp,
motor, or
electric
heater
may
be
in
use
in
house
or
near
the
house.
Reversing
the line plug may
occasionally alleviate this
noise
problem. Usually
it
is
very diff
icult
to
eliminate
the
noise.
Hissing sound noise
in
AM
(medium wave)
reception.
.
The
frequency
of
an
adjacent
station
is
interfering
with that
of
the
station
being
tuned
in
{10kHz
beat interference).
.
TV
set is
on in
the
same house
with
the
rece
iver-
lmpossible
to
remove such
interference.
lf
the
case
of
such noise
is
in
the
TV
set, increase
the
distance
be-
tween the
TV
set
and
receiver.
Static
noise
(in
particular,
when
automobiles
run
close
to
the
house).
'White
noise generated
from
automobile
engi nes.
.
High
frequency
sewing
machine or
weld-
ing machine being
used
near
your
house.
ln
an
area
surrounded
by
hills or
high buildings,
the
FM input
signals
are very weak, Thus the noise
limiter
in
the
circuit
loses
its
function.
Set up an FM
outdoor
antenna having many
director
elements.
Reception
of FM
stereo
program contains
more
noise
than FM
mono
pro-
gram.
. Note
that
the
service area
covered
by
an
FM
stereo broadcast is
about
50%
of
that
of
a
regular
mono
broadcast.
lncreasing
FM input
signal may alleviate this
problem.
Use
an exclusive
FM outdoor
antenna instead
of
the
indoor T-type
antenna.
@
o
tr
o
O
UJ
tr
(,
=
J
o-
z
TIJ
I
=
Hum or buzz.
When
switched
to
radio
recep-
tion,
the
noise
disappears.
Poor
connection of
shielded
wire.
(a)
Jack
connection
is
loose.
(b)
Line cord
of
fluorescent lamp
is near the
shielded
wire.
(c)
Poor
grounding.
(d)
Ham transmitting station or
TV
transmit-
ting station
is near
your
house.
(el
Correct the conditions
stated
in
(a),
(b),
(c)
or
(d).
ln
case
of
(e),
report
it
to
an
official
activity.
Output
tone quality
is
poor
and mixed
with
noise.
Treble
is
not
clear.
stylus
wears
out.
(a)
Record
wears
out.
(b)
Dust
adheres
to stylus.
(c)
Stylus
is
improperly mounted.
(d)
stylus
pressure is
not.proper.
(e)
The
TREBLE
level
is
too
high.
Check (a)
through
(e)
and
correct
the
condition.
Lower the
TREBLE
level.
SYMPTOM
SUSPECTED SOURCE
OF
NOISE
DIAGNOSIS
AND
REMEDY
Power
is not
turned
on
although the power
switch
is
set
to
ON.
Fuse
blows.
(a)
Line plug
is
loose,
(b)
Check
(a)
and (b) and
correct
the
condition.
Power
ON but
speakers
produce no sound.
Blown-out
PROTECTION
fuse.
Replace
with
the supplied PROTECTION
fuse.
ln
playing
a
record,
in-
creasing
the volume
causes
howling.
.
Distance between
the
turntable and
the
speakers is
too
short.
'The
place
on
which
the
turntable
or
speakers are
set
is
unstable.
Change
the
distance
or
rearrange
the
installation
increase
of the unit
and
speakers.
(lnstalling
the
turntable
on a firm,
solid
stand
may
alleviate
this
problem.)
Do
not
enhance
the
BASS
sound
level excessively.
20
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