Pioneer TX-9500II User manual

- AM/FM STEREO TUNER
- OPERATING INSTRUCTIONS

FEATURES
Highly Sensitive FM Front End
Rejection of spurious signals, images and other types of
interference
is strongly enhanced by the 5-gang variable
capacitor tuning circuit and three high gain, low noise dual
gate MOS FET devices. This design also reduces phase
distortion in the front end, leadingto linear phase response
in the RF stage. Inclusion of a buffer amplifier in the local
oscillator circuit prevents interference under strong signal
input conditions, ensuring enjoyment of stable FM recep-
tion.
Convenient Recording Facilities
High quality recordingsfrom FM broadcasts depend inlarge
measure on proper recording level settings and correct
FM antenna direction. The REC LEVEL
CHECK switch on
the TX-9500U activates a built-in 440Hz tone burst signal
corresponding to a 50% modulated FM level which can be
used as a reference for setting
the recording level controls
on the tape deck. In addition to determining levels prior to
recording, this feature can be used for correct balance
control settings on a stereo system, since an equal signal is
Selectable Bandwidth IF Amplifier
provided to both stereo channels.
An FM MULTIPATH switch
is included which produces an
IF amplifier response can be selected for wide or narrow audible signal that can be effectively employed for deter-
bandwidth according to signal conditions. In the wideband
mining the optimum FM antenna direction. This
can
mode, a newly developed SAW (surface acoustic wave)
also be monitored with an oscilloscope^
filter and 4 pole phase linear filter are utilized. These
possess excellent group delay time flatness characteristics
High Performance AM Tuner with Newly
and provide superior phase response in comparison to
conventional ceramic filters. Nearly ideal wide phase
response and selectivity are realized together with ultra low
distortion.
In the narrow band mode, a
10 element ceramic filter is
switched in to provide ultra high selectivity. This setting
allows comfortable reception in locations where there is
strongadjacent interference to the desired station.
Automatic Pilot Signal Cancelling Circuit
Earlier multiplex circuit designs employed 19kHz pilot
signal blocking filters and thus exhibited
a hintof reduction
in frequency response at the high end of the band. This
drawback is overcome by a newly developed PLL IC which
includes an automatic pilot signal cancelling circuit. Since
carrier leakage can also be amply suppressed, the new
device actually extends frequency response at high fre-
quencies. The demodulator includes a negative feedback
(NFB) circuit for improved SN ratio and minimum distor-
tion.
Developed IC
The AM section incorporates a 3-gang variable capacitor
tuned type RF amplifier circuit and a highly sensitive, low
distortion IC. Together with possessing superb imagingand
IF rejection properties, selectivity and frequency response
become advanced to new levels. Optimum AGC voltage
is
supplied to each section, providing stable reception with
low spurious interference and distortion even in localities
with strongfield strengthconditions.
AF IC Includes Built-in Muting Circuit
Full NFB is applied in the wide dynamic range differential
direct coupled audio frequency amplifier circuit, while the
muting circuit incorporates the most recent electronic
circuit technology. By including both these circuits in a
newly developed
IC, low distortion and high S/N are
realized which approach the values associated with test
instrumentation. Smooth, noise-free reception
is thus
assured.
CONTENTS
................
Features ............................ 2 Listening to Broadcasts 6
...................
Installation Cautions .................. 3 Effective Operation 8
..................
Connection Diagram ................... 3 FM-Dolby Reception 10
........................
Connections ......................... 4 Specifications 11
Antenna Connections .................. 4 Conditions Frequently Mistaken
....................
i Front Panel Facilities 6
forMalfunction 12
..................

PIONEER
INSTALLATION CAUTIONS
To ensure long term reliable performance, avoid installing the TX-9500II in locations such as the following:
Locationsto be avoided
Dlrect sunlight, radiators or other heat sources. Above or near
h~ghpowerstereo amplifiers or power transformers.
Sites subject to poor ventilation, high humidity or moisture.
Dusty locations
0 Where AM radio or TV set is being used simultaneously.
Locations where alcohol, insect sprays or volatile materials are
used or stored.
Possibledetrimental effects
External heating can cause deterioration of circuit components
and may prevent stable operatron.
*Corrosion of terminal contacts wh~chcan lead to faulty connec-
tions. Humidity and moisture can aiso cause defective ~nsulation,
present the risk of leakage currents and ovrrl~b
,.$ j ,' . -rcult
components.
Internal accumulations of dust can absorb molsture and lead to
faulty insulation.
Mutual interference can occur from oscillator circuits used in
these products.
Appearance and fin~shof front panel can be damaged.
T TYPE
---FM DE-EMPHASISSWITCH AM ANTENNA FM ANTENNA FM OUTDOOR
Normally, set thtr switch to "75~s." (indooror outdoor) (ifstationsare nearby) ANTENNA
Be sure to set
it to "25~s." only when DISCRETE 4CHANNEL
listenmg to an FM broadcast (pre- FM ADAPTOR
emphasis. 25~s)with aDolby system.
See page
10
rJ
B8QQ
GROUND
pb
30@
OSClLLOSCOPE TAPE DECK STEREO AMPLlFlE R
"The word "Dolby" is a trademark of Dolby Laboratories Inc.

CONNECTIONS
Connection Notes
Output level at the OUTPUT (VARIABLE)
jacks is adjustable with the front panel OUTPUT
LEVEL control. Output level at the FIXED
jacks is not adjustable.
Upper jack of each pair is for the left
(L) chan-
nel and lower jack for the right
(R) channel. As
stereo amplifier and tape deck are also provided
with
L and R channel jacks, use care to connect
the channels correctly (L to L and R to
R) in
order to obtain proper stereo reproduction.
Plug connecting cords firmly into the jacks.
Loose connections can cause absence of sound
or noise.
Do not bundle input and output cords with
power and speaker cords. Also avoid using
longer cords than necessary. These practices can
result in noise, impaired sound quality and
possible operating difficulties.
CONNECTIONS
TO STEREO AMPLIFIER
Use the accessory connecting cords to connect the
OUTPUT (VARIABLE)jacks with the tuner jacks
of a stereo amplifier.
CONNECTIONS TO TAPE DECK
A tape deck can be connected directly to the
TX-9500I.I to allow recording from broadcasts.
Connect the recording input (LINE INPUT) jacks
of the tape deck to the OUTPUT (FIXED)jacks.
ANTENNA
STEREO AMPLIFIER
Right channel
Ls-N 8 1
9
TUNER INPUT JACKS
Fig. 1
TX-9500fl
TAPE DECK
RECORDING JACKS
Fig. 2
FM ANTENNAS
FM broadcast signals deteriorate in mountainous
areas, amid tall buildings, within metal framed
structures and similar locations. In locations where
signals
are weak, reflected signals from mountains
and man-made structures can be picked up by the
antenna to produce multipath distortion. For these
reasons, both the antenna and
its installation site
must be selected according to ambient conditions
and signal strength. See additional description of
multipath distortion on Page
8.
Outdoor FM Antennas
An outdoor
FM antenna is recommended to obtain
an input signal with which the
TX-9500II can
display its full performance capabilities.
While listening to an
FM station (see FM
Reception on Page 6), determine the antenna
Outdoor FM antenna
(special antenna)
300It FM feeder
300R FM feeder terminals
Fig. 3

direction for optimum reception, then install it
securely.
According to type of antenna, employ 300ohm
feeder or 75ohm coaxial cable for connection.
B
300ohm feeder: This is suitable in locations where
75a coaxial cable
external noise is not a problem and if the distance
A
between the antenna &d the TX-9500II is short.
Connect to the 300ohm
BAL terminals as shown
in Fig. 3.
75ohm coaxial cable: Recommended in locations
where external noise is incurred due to street
traffic, high voltage power lines or other causes.
Also employed if distance between antenna and
TX-9500I.l is relatively large. Connect to the
75ohm
UNBAL terminal as shown in Fig. 4.
NOTE:
Consult a reliable audio dealer regarding FM antenna and
75ohm cable.installation.
T Type Dipole FM Antenna
The accessoryT type FM antenna can be employed
in locations where FM signals are strong, suchas
those near transmitting stations or within wooden
structures. As shown in Fig.
3, connect the T type
FM antenna to the 300ohm BAL terminals. While
listening to FM stations, open the antenna to a
T shape, rotate it 180" todetermine where the best
reception is obtained, then attach it to a wall or
ceiling.
AM ANTENNAS
While listening to AM stations (see AM Reception
on Page
7), move the rear panel ferrite bar antenna
and position it for best reception.
In cases when the bar antenna is insufficient for
adequate reception, an indoor AM antenna can
be made from a length (5to
6 meters) of vinyl
insulated wire. As shown in Fig.
6, connect one
end of the wire to the AM antenna terminal and
suspend the free end from a
wall or ceiling at as
high a location as possible.
If reception is still difficult with an indoor
antenna, use vinyl insulated wire to erect an
outdoor
AM antenna between two supports as
shown in Fig. 6.
GROUNDING
From aspects of both safety and reduced noise, if
possible employ a ground as showv in Fig.
6.
Connect the ground lead to the GND terminal of
the TX-9500II. Consult a qualified electrician
regarding proper grounding techniques.
75Ct UNBAL terminal
Strip the coaxial cable
as shown in
(A)
Loosen the screws end
insert the cable
(8)
Tighten all screws for a
firm connection (C)
Fig. 4
Move bar antenna
end position it for
best reception
Fig. 5
Outdoor AM antenna
Groun
I
I
Fig. 6

FRONT PANEL FACILITIES
POWER SWITCH ----- --- SIGNAL METER-------- --a-
Set to ON position to turn on power. Pilot lamp will light. Employ when tuning AM and FM stations. Optimum
'
tuning point occurs when maximum meter deflection
toward the right
is obtained.
IF BAND SWITCH
----.".
------!
FM IF (intermediate frequency) passband can be set to
1
for wide or narrow.
i
WIDE: Normally set switch to this position.
NARROW: If adjacent station interference
is a pro- ,
blem at the WIDE setting, set switch to
this position.
See further description under the heading "IF BAND
Switch" on Page
8.
1
I
MULTIPATHIREC LEVEL CHECK SWITCH
Single lever operates bothMULTIPATHand REC LEVEL
CHECK switches. With the FUNCTION switch at FM, set
as required for the application. Be sure to return it to the
OFF position when it
is not beingused.
MULTIPATH ON: Multipath sound becomes audible
from speakers. When installing FM
antenna, select antenna location and
direction so as to minimize this sound.
See additional description under the
heading "FM Multipath ~istdrtionl'on
Page
8.
OFF: Normallyset switch to this position.
REC LEVEL CHECK ON: Use this position for setting
recording levels of tape deck. A
440Hz
signal (level corresponding to 50% FM
modulation) is produced at approxi-
mately
1.7 second intervals.
I L I
t I
J
i
! , 3
I I
I
-" .-
$1 i
$7 -" -
I
MEMORY MARKERS-
i
Convenient for designating most often tuned in stations.
Slide markers with fingertip to desired positions.
OUTPUT LEVEL CONTROL L
Adjusts level at OUTPUT (VARIABLE) jacks. Clockwise
rotation increases output level. See "OUTPUT jacks and
OUTPUT LEVEL control" on Page
8.
FM RECEPTION
1. SetFUNCTION switch to FM AUTO.
2. Set MULTIPATHIREC LEVEL CHECK switch
to OFF.
3. Normally set the MUTING switch to 1 position.
0
However, in locations where signals are very
weak, set switch toOFF.
a
4. Set IF BAND switch to WIDE. If reception of
desired station is difficult due to interference
from an adjacent station, set this switch to
NARROW.
5. Turn the TUNING knob to select desired sta-
tion. Tune for maximum deflection of the
SIGNAL meter toward the right and center of
scale indication
on the TUNING meter, as
shown in Fig. 7. The STEREO indicator lights
duririg FM stereo reception. It does not light
during monophonic reception.
If signals are weak or noisy, it may be advisable
to set to FM MONO.
If comparatively high frequency noise becomes
objectionable during FM stereo reception, set
switch to FM NOISE FILTER.
SIGNAL METER TUNING METER
Fig. 7

-TUNING METER ,-FM STEREO INDICATOR
Use when tuning FM stations. First tune for maximum
,
With the FUNCTION switch set to Fhl AUTO (or FM
deflect~onof the SIGNAL meter (toward the right), then
f
NOISE FILTER), the indicator will ligii, ti ring stereo
tune carefully so that the meter indicates center of scale
1
signal reception.
(optimumtuning point).
i
%
I i----FUNCTION SWITCH
Switch for selecting type of reception.
AM
: AM broadcast reception.
FM AUTO: FM stereo reception. Ifbroadcast
is FM
mono, the mono mode
is automatically
selected.
FM NOISE FILTER: Set to this position if compara-
tively high frequency noise becomes
objectionable during FM stereo reception.
Note that some loss of stereo separation
occursat this position.
FM MONO: FM monophonic reception. Set to this
position
if reception at FM AUTO posi-
tion
is noisy or signals weak.
---
MUTING SWITCH
1
Controls circuit for cancelling bothersome interstation 1
noise when tuning FM stations to provide a comfortable
t-TUNING KNOB
tuningoperation. Knob for selecting stations. Refer to the SIGNAL meter
2 : Set to this position to receive only strong when tuning AM stations and to both SIGNAL and
stations. TUNING meterswhen tuning FMstations.
1 : If desired station cannot be received at position
2, set switch to this position.
OFF: Set to this position in locations where signals
are extremely weak.
See "MUTING Switch" on Page
8 for additional descrip-
tion.
AM RECEPTION
4
1. Set FUNCTION switch to AM.
If the stereo amplifier is connected to the OUT-
2. Turn the TUNING knob to select desired sta- PUT (VARIABLE) jacks, volume can be adjusted
tion. Tune for maximum deflection of the
by the OUTPUT LEVEL control.
SIGNAL meter toward the right,
as shown in
Fig. 8.
NOTE:
If sensitivity is poor or reception noisy when listening to
FM or AM Receptions, refer toPage 4 "Antenna Connec-
tions" and inspect again the antenna installation.
SIGNAL METER
Fig. 8

EFFECTIVE OPERATION
OUTPUT JACKS AND OUTPUT LEVEL
CONTROL
Output level at the OUTPUT (VARIABLE) jacks
can be adjusted by the front panel OUTPUT
LEVEL control. In addition to the VARIABLE
jacks, the FIXED jacks are provided with a fixed
level output.
Employing VARIABLE Jacks
By connecting these to a stereo amplifier, the
OUTPUT LEVEL control can be used to adjust
the TX-9500II output to match those of other
components connected to the stereo amplifier.
This conveniently simplifies operation of thestereo
amplifier in that iteliminates the need for readjust-
ing its volume control when selecting program
sources.
CICC.,
MUTING SWITCH
Fig. 9
An annoying interstation noise becomes audible
on the FM band when tuning between stations.
The muting circuit cancels this noise to allow
comfortable station tuning. Muting degree can be
selected in
2 steps according to signal strength.
Set switch to position
1 in locations where trans-
mitting stations are at comparatively inter-
mediate distances.
When transmitting stations are comparatively
nearby (or when a weak adjacent station is
present) set the switch toposition
2.
In locations where signals are very weak, set the
MUTING switch to OFF. Although noise will be
increased, it will be possible to receive distant
and weak signal stations.
IF BAND SWITCH
The IF passband of the TX-950011
is selectable for
NARROW and WIDE modes. If an adjacent station
interferes with a desired station, set switch to
NARROW to increase selectivity and avoid mixed
signal problems. For example, if a strong station is
adjacent to a desired station, set the MUTING
switch to
1 or OFF, then set IF BAND switch to
NARROW to permit reception of the desired
station. Conversely, when adjacent station effects
are absent, set this switch to WIDE in order to
obtain better quality reception.
REC LEVEL
CHECK
Proper recording level setting of the tape deck is
required for producing good quality recordings
from
FM broadcasts. This is ordinarily quite
difficult since the output level of
FM broadcasts
varies continuously.
By setting the REC LEVEL CHECK switch to ON,
a 440Hz reference signal at level corresponding to
50%FM modulation is produced. Optimum record-
ing levels can then be set regardless of the program.
Setting Recording Level
1. Connect tape deck.
2. Set FUNCTION switch to FM position and tune
in desired station.
3. Set REC LEVEL CHECK switch to ON. A
440Hz signal will be produced atapproximately
1.7 second intervals at the OUTPUT (FIXED
and VARIABLE),jacks.
4. Adjust recording levels of the tape deck so that
its level meters deflect in the following ranges:
Open reel deck: 0 to
+2dB
6 Cassette deck: Approxin~ately-2dB
5, Set REC LEVEL CHECK switch to upper (OFF)
position and record
FM program.
Since the output level of this signal is the same for
left and right channels, it can also be employed as
a convenient reference signal for adjusting the left
and right channel balance of the stereo system
connected to the OUTPUTjacks.
FM MULTIPATH DISTORTION
Multipath distortion occurs when FM signals are
reflected from interfering objects and enter the
antenna from various directions, as shown in Fig.
10. Due to the different distances travelled by the
reflected signals, the slight time difference with
which they strike the antenna causes mutual inter-
ference. This results in phase distortion,distortion
of received sound, reduced channel separation and
SN ratio. Especially in locations where signals
are weak, these effects become easily incurred.
In order to minimize multipath distortion, use a
sharply directional antenna and adjust antenna
height and direction according to the following
steps.
Adjustment Using MULTIPATH Switch
1. Set FUNCTION switch to FM AUTO and tune
in FM station (it is not necessary to use the rear
panel MULTIPATHjacks).
2. With the MULTIPATH switch set to ON, the
multipath sound
(AM synthesis of FM signal
reflections) can be heard from both left and
right channels.

PIONEER
3. Adjust antenna position and direction to mini-
mize the multipath sound.
4. After completing adjustment, set MULTIPATH
switch to OFF. Normal FM stereo broadcasts
can then be enjoyed.
Adjustment Using Oscilloscope
1. As shown in Fig. 11, use good quality shielded
cable to connect
VERT (lower) and HORIZ
(upper) MULTIPATH jacks to the vertical and
horizontal input terminals of an oscilloscope.
2. Set FUNCTION switch to FM AUTO, tune in an
FM station and adjust oscilloscope for a wave-
form display on the CRT.
3. Adjust antenna direction so that vertical wave-
form component becomes minimized as shown
in Fig. 12-A.
NOTES:
When multipath distortion is reduced, the horizontal
component becomes nearly linear as shown in
Fig.
- 12-A. if present in large amount, a vertical corn-
ponent (amplitude waveform) becomes apparent as in
Fig. 12-B.
If horizontal axisgain is insufficientfor easy waveform
observation when employing an oscilloscope for adjust-
ment, instead ofconnecting the oscilloscope horizontal
input to the
MULTIPATH HORIZ jack, connect it to
the OUTPUT VARIABLE L jack. In this case, the
horizontal axis gain can then be adjusted with the
OUTPUT LEVEL control.
Since adjustment with the aid of an oscilloscope can
also be performed together with that using the MULTI-
PATH switch, more precise antenna direction can be
determined.
Optimum multipath detector operation is when
SIGNAL meter deflection is below
4.5 of the scale
indication.
FM DET OUTPUT JACKS
In locations where discrete four channel FM
programs are being broadcast, an adaptor for this
format can be connected to these jacks.
ANTENNA
INSTALLATION
Use care that feeder
or cable does not
contact other struc-
4m above
Best installation
site
is in an open
1.5m-2m
More than'
Use care that
or cable doc
contact other
feeder
?S not
struc-
area awav from
/ - /
TRA
AN7
Fig. 10
OSCl LLOSCOPE
VERT
TERMI-
? NAL I
Fig. 11
Fig. 12
traffic noise. /
/

FM-DOLBY RECEPTION
The FM DE-EMPHASISswitch is provided to allow
reception of FM-Dolby broadcasts in locations
where these programs are being transmitted.
A
separately sold adaptor must be connected to the
stereo amplifier in this case, then proceed accord-
ing to the following steps.
1. As shown in Fig. 13, connect Dolby NR adaptor
to the tape (record
& play) jacks of the stereo
amplifier.
2. Set rear panel FM DE-EMPHASIS switch to
25~s.
3. Set TAPE MONITOR switch of stereo amplifier
to ON.
4. Set FUNCTION switch to FM position and use
the TUNING knob to tune in FM-Dolby broad-
cast. Tuning is performed in the same manner
as
described in "FM Reception".
5. Operate adaptor and set for reception. Adjust
volume
and tone with the controls of the stereo
amplifier.
NOTES:
0 Refer to the Dolby NR adaptor operating instructions
regarding connection and operation.
When not listening to FM-Dolby broadcasts, be sure
to
set the FM DE-EMPHASIS switch to 75us.
FM DE-EMPHASIS SWITCH
1. Loosen lower screw, remove plastic cover and
set switch to 25~s.
2. Loosen upper screw, rotate plastic cover 180"
and use this screw to secure.
DOLBY NR ADAPTOR
Fig. 13
ALLEN HEX WRENCH
The accessory Allen hex wrench is provided for
ALLEN
removing the TUNING knob or tightening its set-
screw in event it becomes loose.
If required, loosen the setscrew by inserting the
wrench into the hole on the side
of the knob and
turning the wrench counterclockwise. Be particu-
TUNING
larly careful not to scratch the front panel when
employing the wrench.

SPECIFICATIONS
Semiconductors
FETs
.............. 5
ICs
............... 15
Transistors
........... 12
Diodes
.............. 19
FMSection
............. Circuitry MOS FET 2-stage RF ampli-
fier, 5-gangvariable capacitor,
IF Band Selector, Wide-band
linear detector, doublebal-
anced NFB type PLL MPX
built-in pilot signal 'auto
-
canceller.
Usable Sensitivity
....... MONO: 8.8dBf (1 SpV)
50dB QuietingSensitivity
. . MONO: 13.2dBf (2.5pV)
STEREO: 36.ldBf (35pV)
Signal-to-Noise Ratio
at 65dBf
........... MONO: 82dB
STEREO: 77dB
Distortionat 65dBf. MONO: WIDE NARROW
.....
lOOHz 0.05% 0.07%
1kHz 0.05% 0.07%
lOkHz 0.07% 0.1%
15kHz 0.12%
-
STEREO:
lOOHz 0.1% 0.3%
1kHz 0.07% 0.25%
10kHz 0.2% 0.5%
15kHz 0.5%
-
Capture Ratio. ................. 0.8dB 2.0dB
Alternate Channel Selectivity.
....... 35dB 85dB
......... StereoSeparation 1 kHz: 5OdB 45dB
-
SOHz to '15kHz: 35dB 30dB
Frequency Response
..... 20Hz to 10kHz_t0.2dB
20Hz to 1
S~HZ;\:~B
Spurious Response Ratio . . 1 1OdB
Image Response Ratio
.... 120dB
IF Response Ratio ...... 105dB
- AM Suppression Ratio .... 65dB
MutingThreshold
....... 19.2dBf(5pV), 34.1dBf(28pV)
Subcarrier Product Ratio
. . 77dB
SCA Rejection Ratio
..... 62dB
Antenna Input
......... 300ohmsbalanced
75ohms unbalanced
AM Section
Circuitry
............. 1 stage RF amplifier 3-gang
variable capacitor
Sensitivity
IHF, ferrite antenna
... 300uVIm
IHF, exteinal antenna
. . 1SpV
Selectivity
............ 30dB
Signal-to-Noise Ratio.
.... 55dB
Image Response Ratio
.... 70dB .
IF Response Ratio ...... 65dB
Antenna
............. Built-in
antenna
Audio Section
ferrite loopstick
Output (Levelllmpedance)
..... FM (100% MOD.) FIXED: 650rnV/4.2ki2
VARIABLE: 50mV to
1.3V13.6kSl
..... AM (30%MOD.) FIXED: 200mV/4.2kS2
VARIABLE: 15mV to
400mVl3.6 kCl
Miscellaneous
Power Requirements
..... 120V 60Hz only.
Power Consumption
..... 25W
Dimensions
........... 420(W)x150(H)x395(D) mrn
16-9116x5-718x15-9/16in
Weight
.............. Without Package:
9.5kg (201b 15oz)
With Package:
11.Okg (241b
4 oz)
Furnished Parts
FM T-type antenna ......................... 1
Operating Instructions
....................... 1
................
Connection Cord with Pin Plugs 1
Hex. Wrench (used for fasteningTuning knob)
....... 1
NOTE:
Specifications and the design subject lo possible modifica-
tion without notice due to improuements.

AM/FM STEREO TUNER
FR FRM END Ass'y AW0 -023
POWER SUPPLY Ass'y
AWR - 128 (UL- dpp-d model,)
AWR - 123 tCSA-dppmved rodeb)
§ ----.--------
l r

CONDITIONS FREQUENTLY MISTAKEN FOR MALFUNCTION
If your stereo system appears to malfunction, first
check such things
as the controls (power switch,
function selector, tape monitor, etc.) and connect-
ing cords (components connected correctly).
Noise: 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
SYMPTOM
Continuous or intermittent
noise like
jjjjij or tzzzzz.
When a station is tuned in,
hum is mixed in the pro-
gram.
H~ssingsound noise in AM
(medium wave) receptcon.
Static noise (in particular,
when automobiles run
close to the house).
Reception of FM stereo
program contains more
noise than FM mono pro-
gram.
often assumed that the unit is faulty, but statistical
records indicate that the majority of noises pro-
duced in hi-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
tuner produces a noise, check according to the
following table and trace out the source of noise
for the appropriate corrective action.
SUSPECTED SOURCE OF NOISE DIAGNOSIS AND REMEDY
Static (lightning)
Fluorescent lamp, motor, or thermostat
may be in use in house or in the vicinity of
the house.
In many cases, it is very difficult toremove the
source of noise. In order to make the radio
input larger than the noise level, set up a good
outdoor antenna and make a complete groun.
ding.
0 Poor fluorescent lamp. motor, or electric
heater may be in use in house or near the
house.
Reversing the line plug may occasionally al-
leviate this noise problem. Usually it is very
difficult toeliminate the noise.
8 The frequency of an adjacent station is
interfering with that of the station being
tuned in(1OkH.zbeat interference).
0 TV set is on in the same house with the
tuner.
Impossible to remove such interference. Ifthe
cause of such noise
is the TV set, increase the
distancebetween the
TV set and tuner.
0 White noise generated from automobile en-
gines.
High frequency sewing machine or welding
machinebeingused near your house.
PIONEER ELECTRONIC CORPORATION
4- 1. Meguro I -Chome. Meguro-ku. Tokyo 1 53. Japan
U.S. PIONEER ELECTRONICS COFIPORATION
85 Oxford Dr~ve,Moonach~e.New Jersey 07074. U S.A.
PIONEER ELECTRONIC [EUROPE) N.V.
Lu~thagen-Haven 9. 2030 Antwerp, Belgwm
PIONEER ELECTRONICS AUSTRALIA mv. LTO.
178-1 84 Boundary Road,Eraes~da,V~ctor~a 3195, Austral~a
Printed inJapan
Inan area surroundedby hills or high buildings.
the
FM input signals are very weak. Thus the
noise limiter inthe circuit loses
its function. Set
up an FM outdoor antenna having many direc.
tor elements.
Note that the servicearea covered by an FM
stereo broadcast
is about 50% of that of a
regular mono broadcast.
Increasing the
FM input signal may alleviate
this problem. Use an FM outdoor antenna
insteadof the indoor T-type antenna.