
CONDITIONS FREOUENTLY MISTAKEN FOR MALFUNCTION
Ir{oise: There are a variety of noises relating to the
operation of a hi-fi 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 hi-fi unit produces an unpleasant noise, it is
often assumed that the unit is faulty, but statistical
records indicate that the majority of noises pro-
SYMPTOM SUSPECTED SOURCE.OF NOISE DIAGNOSIS AND REMEDY
a
O
o
o
cc
6
o
F
(9
z
2
IIJ
2
z
Lrl
I
Continuous or intermittent
noise like jjjjjj or zzzzzz. .Static (lightning)
" Fluorescent lamp, motor, or thermostat
may be in use in house or in the vici nity of
the house.
ln many cases, it is very difficult 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 electri c
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 difficult to eliminate
the noise.
Hissing sound noise in AM
(medium wave ) reception. The frequency of arr 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
re cei ver .
lmpossible to remove such interference. lf the cause of
such noise is in the TV set, increase the distance be-
tween the TV set and receiver.
Stati c noise (in particular,
when automobi les run
close to the house).
White noise generated from automobile
en gi nes.
Radio frequency sewi ng 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 probrem.
Use an exclusive FM outdoor antenna instead of the
indoor T-type antenna.
o
o
E
o
O
uJ
tr
(9
z
;
o-
z
u,l
r
=
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 or fluorescent lamp is near the
shielded wire. (c).
. Poor gro und ing. (d ) .
. Ham transmitti ng station or TV transmit.
ti ng station is near your house. (e).
Correct the conditions stated in (a), (b), (c) or (d).ln
case of (e), report it to an off icial activity .
Output tone quality is
poor and mixed wi th noise.
Treble is not clear.
Stylus wears out. (a)
Record wears out. (b)
Dust adheres to stylus. (c)
Stylus is improperly mounted. (d)
Tracking force is not proper. (e)
The TREBLE level is too high.
Check (a) through (e)and correct the conditi on.
Lower the TREBLE level.
WATCH FOR THE FOLLOWING CONDITIONS; THESE ARE ALSO APT TO BE MISTAKEN FOR MALFUNCTIONS.
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 conditi on.
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 al leviate this
problem.)
Do not enhance the BASS sound level excessively.
duced in hi-fi acoustic units result from external
sources of noise: Due to the inherent high
sensitivity 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.
t3