Pioneer SX-700L User manual

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to
SYNTHESIZED
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STEREORECEIVER
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MODELSX-7OOLCOMES
IN TWO
VERSIONS
DISTINGUISHED
AS FOLLOWS.
Type Voltage Remarks
HE 22OV and 240V (Switchable) Europe model
HB 22OV and 24OV (Switchable) United Kingdommodel
o This servicemanual is applicable
to the HE type. Whenrepairing
the HB type, please
see
page
26.
CONTENTS
1,SPECIFICATIONS
2, FRONTPANEL FACILITIES
3. BLOCKDIAGRAM
4. CIRCUIT DESCRIPTIONS
. .
5. PARTSLOCATION
6. DIAL CORD
STRINGING
7. ADJUSTMENTS
3
4
6
7
11
12
13
8. P,C.BOARDS
CONNECTION
DIAGRAM 16
9. SCHEMATIC
DIAGRAM 19
10.
ELECTRICAL
PARTS
LIST . 21
11.
PACKING 23
12.EXPLODEDVIEW 24
13.
SUPPLEMENTS
FOR HB TYPE 26
Line
Voltage
Selection
Line
voltagecan
be
changed
withfollowing
steps.
1. Disconnect
the
ACpower
cord.
2. Remove
thebonnetcase.
3. Take outthe
fuse
fromthe
fuse
assembly.
4. Re-install
the fuse in the correct
voltageindication.
5. Stick
the
linevoltagelabelonthe
rear
panel.
Part No. Desctiption
Rearpanel
FU2 (HE type only)
for 24OV position
for 22OV position
AAX-193
AAX-192 220Vlabel
24OVlabel
rT=T-11
FuseT1
.6A250V
(FU1)

I1.SPEC|FtCAT|ONS
Amplifier
Section
Continuous
power
output
of
40watts*
per
chan.
nel,
min.,at
8ohms
from
20Hertz
to 20,000
Hertz
with
no
more
\han
0.2%
total
harmonic
distort
ion.
Continuous
Power
Output
at l kHz (both
channels
driven)
T.H.D.O.2%,8ohms. . . 45
watts
per
channel
TotalHarmonic
distortion
(20 Hertz
to 20.0O0
Hertz,
8ohms, fromAUX)
20wattsper
channel
power
output
. . . . Nomore
than
0.07%
f
ntermoduf
ationDistortion
(50
Hertz
: 7,O00Hertz
=4 : 1.
8 ohms,fromAUX)
continuousrated
power
output . . . Nomore
than
0.2%
20watts
per
channel
power
output
. . . . .No morethan0.OT/o
Damping
Factor
(1,000
Hertz,
I ohmsl 30
I
nput(Sensitivity/lmpedance)
PHoNo . .2.smV/bo
kitohms
AUX,TAPEPLAY. .... 150mV/50kilohms
Phono
Overload
Lever
(T.H.D.0.1%,
1,000H2)
. . 150mV
Output
(Level)
TAPEREC 150mV
FrequencyResponse
PHONO
(RIAA
Equalization)
. . . . . 30Hzto 15,000H210.5d8
AUX,TAPE
PLAY . 7Hzto 6O,0OOHz:l
dB
ToneControl
BASS. .....t8d8(100H2)
TREBLE ....18d8(10kHz)
Loudness
Contour
(Volume
control
setat-40dB positionl
+10d8
fi00H2)
HumandNoise
(lHF,
short.circuited,
A network)
PHONO ....70d8
AUX.TAPE
PLAY . . loodB
HumandNoise
(DlN,
continuous
power/SOmW)
PHONO .....67dB/62d8
AUX,TAPEPLAY. ...87d8/66d8
FMTuner
Section
Usable
Sensitivity
(lHF) . 12dBt.2.2uyl
50dBQuieting
Sensitivity
MONO 17.2dBt
(4ttYl
STEREO 37.ZdBf
(40rrV)
Sensitivity
(DlN)
MONO .....2ttV
STEBEO SOpV
Signal-to-Noise
Ratio
MONO ....78d8(at60dBf)
STEREO . . 72dB
(at
75dBfl
S)(-7OOL
Signal-to-Noise
Ratio
(DlN)
MONO ...75dB(at60dBf)
STEREO . . 60dB
(ar
TsdBf)
Distortion
(at
65dBf
)
MONO lkHz. ...0.5%
STEREO lkHz. ...0.3%
CaptureRatio
. ......2.Sdg
AlrernateChannelSelectivity(400kHz) .. ..S0d8
StereoSeparation
lkHz . 45dB
Frequency
Response .. .. 30Hztol5kHzr0.bdB
SpuriousResponseRatio. ......70d8
lmageResponse
Ratio . . .45dB
lFResponseRatio. ....g(HB
AMSuppressionRatio ...SOdB
Antenna
Input 300ohms
balanced,
75ohms
unbalanced
MWTuner
Section
Sensitivity (
lH
F,ferrite
antennô) . . 27O1N
lm
(lHF,
ext.
antennaf 10;rV
Selectivity . .25d8
Signal-to-NoiseRatio ....52d8
lmage
ResponseRatio . .32d8
lFResponseRatio. ....4Od8
Antenna ..... Ferriteloopstickantenna
LWTuner
Section
Sensitivity (lHF,
ferrite
antenna) . . .450frV/m
(lHF,
ext.
antenna) 20pV
Selectivity .....25d8
Signal-to-NoiseRatio .....52d8
lmageResponseRatio ....20d8
lFResponseRatio. ....30d8
Antenna .... Ferriteloopstickantenna
Miscellaneous
Power
Requirements HE
model a.c.22OV,5Ol6OHz
HBmodel . . . a.c.240V,50/60H2
PowerConsumption ...240W
Dimensions .. .. . 420(W)
x94(H)
x36t(D)mm
16-9/16(Wl
x 3-11116(Hl
x 14-3116(Dl in
Weight
{without
package) . . . 7.1k9
(151b
11oz}
FurnishedParts
Operatinginstructions .....1
FMT-typeantenna .......1
*Measured pursuant to the Federal Trcde Commission's Tradc
Regulation rule on Power Output Claims for Amplifiers.
NOTE:
Specifications and the design subject to possible modifications
without notice due to improvements.
o
o

DIAGRAM
RF AMP MIXER IÊT C.F IF AMP C Frc(
TA7303P)
FM MULÎIPLEX OECOOER
I
MUTIN6
6ATE
AUDIO
AMP SECTION
I rc(NJM4ssaoxl
| -
L
AUX PHONES
I
str PowÊR ( oN-slar{o8Y)
s2,5: FuNCltOlr
(LW
- MW
- FM - PHONO.AUX
'
53: TAFE frOtrTOR {ON'0ÈÊ )
s4-r: LouoNEs9 (oN -0FÊ |
54-2r FM MUI|NG { ON-OFF)
_.r I
.^^., l.To TUNTNGVoLTAG€ |
'2"" I GE{ERATToNcrRcurT
--J I
REC R
TAPEL
PLAYR
LE\EL DIAGRAM TO POWER
AMP
TO EO AMP
SPEAK€R
RL:ao
t1?.9V/8^' -4 a
L--
AM TUNER
Iru 3 .'"- Lrlf i.,p gc! T :
ss oJ leBf----r JÉf\lJ{lEI-Ll--.i sz
C F IF AMP IF AMP
TUNINGVOLTAGEGENERATION
CIRCUIÎ
t--
v 83) Q5)8qeU\?oræ)(&)(3r)GaGS€' MAxuaL
rN F-iuilE eb È6
È eY
si ai eq s az sr
v oul VoLTAOE
SYNTHESTZER
LSr rLC72O7r MUrE
8uc MEMO CHr CH2 CH3 CH4 CH5 CH6 CH7
lHE SAMEAS THE LEFT CHANNEL

@ TUNING
KNOB
Use
this
knob
to tune
into broadcasting
stations'
@ HEADPHONE
JACK
Plug your headphones
into this iack when you want to
listen
to a program
source
in private'
NOTE:
When the headphones
ptug is connected
to this
iack' the sounct
will no tonger
beheardthroughthespeakers'
@ BASS
AND
TREBLE
CONTROLS
Use
these
controls
to adiust
the bass
andthe treble'lf
you turn the bass
control to the rightfrom its center
position'
you will be
able
to emphasize
thesound
in the
low-frequency
range'
Conversefy'
turning
this
control
left
from thecenter
position'
youwilt attenuate
thesound
in
the
low-frequency
range'
You can
use
thetrebl-e
control
to adjust
the
sound
inthe
high'frequency
range'
o FUNCTIoN
INDICATORS
TheLW'MWorFMindicator|ightsinIinewiththeposi-
tion selected
by the function selector'
c) BALANCE
CONTROL
Use
this control to balance
the volume
of the le{t and
right channels'
lf the sound
appears
to belouder
on the
right,
it means
that the
volume
of the-right
channel
is
higher.
Turn
the
balance
control
to the
left
and
adjust'
Conversely,
if tfre
sound
appears
to belouder
onthe
left'
it means
that tne volume
of the left channel
ishigher'
Therefore,
turn the balance
control to the right and
adjust.
GD
FM
MUTING
SWITCH
When
this switch
is released
and
anFM broadcast
tuned
in, the muting
circuitis activated
inside
to suppress
the
annoVing
interstation
noise between
the broadcasting
frequencies
for noise-free
reception'
When
thebroadcast'
ing station
isfar away
or whenreceiving
a station
in a
fringe
area,
set
th; switch
to theOFF position
and
then
tune in. lf there
is a broadcasting
station
with a strong
signat
teuet
on the air nextto a station
whose
program
you want to receive'
you may not be able
to tune ln
satisfactorily
O'"tu" the sound
witl bedrowned
out by
thestronger
signals'
In cases
like
this'set
the FM muting
switch
to orr iJep'essed
position)
t"d '"1.t
l1^'lll
muting circuit doesnot work when the tuner is recelvlng
AM (LW, MW) broadcasts'
@ LOUDNESS
SWITCH
When
listening
to aperformance
with the
volume
control
turneddown, depress
this switchand the bass
will be
volume
control
is
turned
down'
@ VOLUME
CONTROL
Use this control to adjust the output levelto the speakers
and headphones.
Turn it clockwise to increase
the output
level.
No sound
will beheard
if you setit to "0"'
@ FUNCTION
SELECTOR
six-7clClL
LW Set
here
when
receiving
anLWbroaocasr'
MW . . . . . Set
herewhen
receiving
an
MW.broad-cast'
FM . . . . . Sethere
when receiving
an FM braodcast'
PHONO. . ' Set here
when playingrecords
on a turntable
connected
to the PHONO iacks'
AUX . . . . Set herewhen listening
to a program
source
which is
connected
to the AUX iacks'
NOTE:
Setthe
switch to the
OFF position
vvhen
listening
to recordsor
broadcasts'
etc'setected
bYthefunction selector'
o
o

2.
FRONTPANEL
FACILITIES
O poweR
swtrcH
When
thisswitch
is
set
to ON position.
power
issupplied
to thereceiver's
main
circuits.
The
unit'spower
switch
is
geared
to selecting
the transformer,s
secondary
and so
even
at
STAND-BYposition,
the
unit,s
circuitry
will work
aslong
asthepower
cordis
connected
to the
power
out_
let.For
thisreason,
the
programmed
broadcasting
stations
willnotbe
erased.
Disconnect
the power
cord from thepower
ouiletwhen
youdo not plan
to use
the
unitfor along
period
of time.
When
it has
been
disconnected,
thebroadcasting
stations
remainprogrammed
forabout
3days.
@ FM
STEREO
INDICATOR
This indicator lights up when receivingan FM stereo
program.
@ SICruAL
METER/PRESET
FREOUENCY
DISPLAY
METER
@ueuoRy
swtrcH
This is depressed
to preset a broadcasting
station in a
preset switch (memory operation). When presettang
the
frequency of a station in one of the preset switches,
depress
the preset
switch with thisswitch in the depressed
position.
€) D|AL
POTNTER
This
pointer
indicates
the
broadcasting
stations.
@pReser swtrcHEs
Depressthese switches when calling out preset broad_
casting
stations
and when presetting
these
stations.
When
one of the switches is depressed,
it lightsand it remains
lighted
during
call-out.
One switch can be used
to preset
one FM station
and one
LW or MW station.To call out the preset
station,
first set
the function selector to the frequency band and then
depress
the preset
switches.
The broadcasting
station can
be checked by the position of the pointer on the preset
frequency
displaymeter.
Depress
one switch onfy to call out a station. lf two or
more switches are depressed
simultaneously,
the broad-
casting
stationmay not becalled
out.
O MANUAL
swtrcH
This switchis depressed
when
tuningin a station
with
the
tuning
knob.
When
it is
depressed
when
changing
from
preset
tuningto manual
tuning,
the preset
switch
light
goes
off and
the
dial
pointer
lights.
NOTE:
When one of the preset switches is depressed.it is not possible to
tune in a station using the tuning knob. lwhen the diat pointer
illuminatîon goes off, it means that tuning is not possiblewith
the tuning knob.)
I

Isx-7ClClL
. BUC(pin 3)
This is the LSI memory backup control ter-
minal. All functions apart from memory hold are
inhibited when alow level
input signalisapplied.
o FM (pin 5)
The SX-700L is switchedto FM receptionmode
when a low level input signal is applied to this
terminal. This FM mode is maintained evenif the
terminal issubsequently
switchedto high level
(low
levelholdtime: 5ms.minimum).
o ÏiW-1pin o;
Likewise, the SX-700L is switched to AM-MW
reception mode when a low level signal
is applied
to pin 6. This receptionmodeismaintainedeven
if
the terminal is subsequentlyswitchedto high level
(low level
holdtime: 5ms.minimum).
o LW (pin 7)
Furthermore, switchingto the AM-LW reception
mode is achievedby applying a low level signal to
pin 7, and is maintained even if the terminal is
subsequently switched to high level (low level hold
time: 5ms.minimum).
o CV out (pin 10)
An analog switch output terminal where
tuning voltage output signalappears.
o CV in (pin 11)
An analog switch input terminal to which
R-2R ladderoutput voltage
is applied. the
o ManuT\rne(pin 12)
An analog switch input terminal to which the
tuning voltage modified by the manual tuning
variableresistor
isapplied.
o S-Curve
(pin 13)
The AFC (Automatic Frequency Control)
control signal input to which the FM and AM
S-curvevoltages
areapplied.(This S-curve
describes
the variation in DC level for the FM detector
while tuning to and away from a particular
station).
o MANU (pin 16)
The SX-700L is switched to manual tuning
mode when a low level input signalis applied to
this terminal, but switched back to presettuning
mode if any one of the CH1 to CH? terminals is
switchedto low level.
o MEMO (pin 17)
This terminal is switched to memory enable
4. CIRCUIT DESCRIPTIONS
4.1 TUNER
CIRCUIT
The tuner section of the SX-700L featuresan
electronic tuning system where the conventional
tuning capacitor has been replaced by variable
capacitance diodes (vari-caps). In addition to
manual tuning, it is also possibleto preset 7 FM
stationsand 7 AM stations(including MW and LW
stations).
FMTuner
The front-end consistsof a J-FET RF amplifier
(single stage),and also includes 3 vari-capsin a
tuning circuit correspondingto a 3-ganged
tuning
capacitor. DC voltages generated in the tuning
voltage generator circuit are applied to these
vari-caps,and aremodified by the variable
resistor
coupled to the TUNING knob during manual
tuning. During preset tuning, the required DC
voltage level is read out from the voltage syn-
thesizerLSI (LC7207).
The IF stageconsistsof 2 dual-element
ceramic
filters, a single-transistor IF amplifier, and an IC
(T47303P). This stageis usedin the amplification
and detection of the IF signal.
The stereo decoder stage incorporatesthe PLL
MPXrC
(H41156W-P).
AM Tuner
The AM tuner consists of 4 transistors, and
includes2 vari-caps in a tuning circuit correspond-
ing to a 2-gangedtuning capacitor to cope with the
2 bands
(LW: 150kHz- }ïOkHz, andMW: 525kHz
- 1605kHz).
4.2 ELECTRONIC
TUNING SYSTEM
The LSI (LC72O7)
incorporatedin the SX-700L
electronic tuning system outlined in Fig. 4-1 is a
special 42-pin DIP package
C-MOSLSI developed
expressly
for usein the LW/MW/FM tuner voltage
synthesizerelectronictuning system.
The major terminal functions are summarized
below.
. CRl (pin 1)
The oscillator circuit used to determine the
fundamental clock pulsefor the systemis formed
by connectingan RC time constant circuit to this
pin.
o CR2(pin 2)
The timer circuit is formed by connecting
another RC time constant circuit to pin 2. This
circuit is then usedin determining the pulse
width
of the MUTE output signalemployed during band
switching.
the
o
I

tuning to and away ftom a parbicular
frequency).
'Since the AM tuner cannot obtain an S-curve
voltage from the detector, a separate FM ratio
detector is employed to provide the S-curve
voltage.
o Fine Tuning
This function involves fine tuning adjustment
apart from the AFC 10-bit data compensation.
The output from pin 23 (F-Tune) is obtained asa
8-step
pulse
width modulation signal
corresponding
to the pin 13 input. This signalis then integrated
and addedto the ladderresistor
output voltage
for
fine tuning purposes.
Note that the AFC circuit is
not activated
during manualtuning mode.
o FetchMode
This iunction is used to re-alignthe center of
the S-curvewith the preset
voltageby "swinging"
the voltage when the preset voltage is displaced
from the S-curve
AFC rangeas a result of tuner
drift. This voltage swing is gradually increased in
both directions up to a maximum of t8 steps
(approx. t56mV) to retrieve the S-curve.If the
S-curve is not retrieved by this measure, the
voltage is returned to the original preset voltage.
o Memory Hold
Whenpin 3 (BUC) of the LSI isswitched
to low
level, all functions except internal memory hold
areinhibited. The memory is held by a very small
current (approx. 50pA) in this case. Since the
POWERswitch in the SX-700L isconnected
to the
secondar5l
side of the power transformer, the LSI
is still supplied with power with the POWER
switch in the STAND BY position. In this case,
pin 3 is switched to low level, resulting in the
memory contents being preservedby a very small
current. Furthermore, if the AC power mains is
cut off altogether,the memorieswill be preserved
for about 3 days by charge stored in a capacitor
in the LSI power supply circuit.
Muting
Control
The muting output signal obtained from pin
22 (MUTE) is usedin eliminating unwanted noise
generatedduring band switching and presettuning
operations. The SX-700L employs a ground-
connectedmuting gatetransistorconnectedto the
tuner section output circuit to mute out these
unwantednoises.
NOTE:
The muting circuit employed in muting the inter-station
noiseduring FM tuning k incorporated in the TA7303 IC,
and is turned on and off by the FM MUTING switch.
10
Preset
Frequency
DisplayMeter
Since the tuning frequencies selected during
preset tuning mode are set irrespective of the
tuning dial position, an independent method is
used in the SX-700L to show the frequency of
the selected preset frequency. Since the tuning
voltageis usedto determine the tuning frequency,
it may also be used to drive the signal strength
meter, the readingin this case
indicatingthe tuned
frequency.By incorporatingan automatic selection
circuit in this meter, the meter will operate as a
signal strength meter during manual tuning, and as
the preset frequency display meter during preset
tuning mode.
o Automatic MeterSelection
Circuit
The operating principle of this circuit is ouilined
in Fig.4-2. During manual
tuning, pin 20 (M-ND)
is switched to low level, resulting in Q20b being
turned on. The Q205 collector voltage is con-
sequently increased, resulting in the base voltage
for Q4L2 and Q413 being switched to high level
via D426. Q413 will be turned off since it is a
PNPtransistor,while Q412, an NPN transistor
will
be tumed on. The tuning voltage is thereby
blocked, and the meter thus employed asa signal
strengthmeter.
During preset tuning mode, Q20b is turned
off, resulting in a drop in the collector voltage.
D426 will thus become non-conductive, resulting
in the base voltage for Q472 and Q41B being
switched to low level. Q412 will thus be turned
off and Q413 turned on, resulting in the meter
operating asthe preset frequency display meter.
Fig.4-2 Automatic
Meter
Selection
Circuit
4.3 AUDIO AMPLIFIER
SECTION
The EQ amplifier is an NFB type with one IC
(NJM4558DX)in both L andR channels.
The power amplifier is quasi-complementary
SEPP circuit features a differential amplifier in
the first stage,in corporatesthe tone control cir-
cuits in the NFB loop.

Iconnected to the R-2R ladder resistor for D-A
(
digital-analog)
conversion'
o VSS
(pin 35)
The LSI groundterminal'
. cHl -ffi (pin36 -Pin42)
minimum).
NOTE:
ïii automatic search tuning function -inco,rporated in
ine t'czzoz LSI is not u"nà in the SX-700L' Further-
Àore, description of functions of non-used terminals
has
beendeleted-
sx-7clclL
automatically). The SX'?00L has been desigrred
;;t*" un- to 1 FM frequencies,11$ 7 AM fre'
;;";Â (including both MW and LW broadcastins
frequencies).
o Preset Memory
The preset memory for manuall{ tÏl"d stations
involves A-D conversion
(to a 10-bit digital code)'
u"J tft" storage of an approximate value,
in the LSI
i;;;il;s a îesolution-of approx' 1/4000 when
ii" ti"""tuning function described later is in-
cluded).-- Oigii"f encoding of the tuning voltage is
achieîed in the following way' The LSI 10-bit
up/down counter code output obtained from pin
;E';. pin 34 (B10 - 81) is D-A converted
(digital
"od" ôrru"rted into analog quantity) by the R-2R
fuAJ"t resistor,and then compared
with the tuning
voltage (during manual tuning mode) by a voltage
"àÀpî*uiot, tLe result being applied to pin 18
(M-U/D).
If the ladder resistor output voltage is lower
than the tuning voltage (manual tuning)' the pin
ig l"p"t is swilched to high level, resulting in the
LSI lb-bit up/down counter counting up and the
ladder resistor output voltage being increased'
ti tfre ladder resistoi output voltage is higher than
ihe tuning voltage, a low level input- is applied to
pi" fg, rËsulting in the 10'bit up/down counter
counting down, and the ladder resistor output
vottæe "Ueing
decreased'
In this way' the up/down
"orrrrl", 10-bit code is immediately approximated
;; ;h" tuning voltage (manual tuning)' and then
frequencY.
o Direct Tuning bY Memory Read'Out
Band
Switching
(
LW/MW/FM)
FUNCTION switch operationresultsin one of
the band designator
terminats
pin 5 Fq)' pi" g
ffi, ;; pi"T [f,W)
ueing
lonnecte!,P.f:t1
ii:.' :'#"ilâ io'
t# reueJ),
therebv,.switching
ifr;
bï-zôôï-ilth" selected
band'
Although,an1?
remainsonduringnormaloperation'-itisturned
;;i;h"" the POWERswitch is set
to STAND BY'
;;;;; the AC line Power suPPlY is cut' so
;;*;;t is stopped during memorv. hold mode'
il;;y t"a"ci"i the power consumptionlevel'
Manual
Tuning
The SX-700L is switched to manual tuning
^"Jwhen pin 16 (M-ANU) is.switched to low
ilu"f uv turniàg the MANUAL switch on' '- ïd;" the TUNING knob is turned' the variable
resistorcoupled to the TUNING knob isactivated'
,àr"ru"g in a changein the DC voltage applied to
pin 12 (Manu Tune)' Th
via an analog switch inct
and aPPears
again at Pin
'equency. During manual
-iND) is switched to low
reing
turned on to light uP
the dial Pointer LED'
Preset
Tuning
Whenthe MEMORY switch andPRESET
switch
are both tumed on togt
broadcasting frequencY
?00L memory' And w
onlY isturned on, abroa
stored in the memory r
o

VOLlAGE
COMPARATOR
f:
Y
PRESET SWITCBES
Fig.
4-1 Electronic
Tuning
System
mode while the input signalis maintained at low
level.
o M-U/D
(pin
18)
o M-IND(pin 2o)
This output terminalis switched
to low level
during manual tuning mode, ,"rrtiirrg in the
appearance
of an
indicator
output
signal.
o VDD (pin 2t)
The
LSIpower
supply
terminal.
o MUTE (pin 22)
This isthe muting control signal
output terminal
where a high level output signal app"u.s during
preset
tuning and bandswitchingoperations.
o F-Tune(pin 28)
o Vref (pin 24)
Referencevoltage.
o 810 - 81 (pin 2b- pin 84)
The 10-bit up/down counter output terminals
R-2R LADDER RESISÎOR
10-8IT UPlOOWN COUNTER

ISX-7OOL
NOTE:
c The fi marh found on some component parts indicates
the importance of the safety factor of the part. There-
fore, when replacing, be sure to use parts of identical
designation. Push
knob
(1-7)
AAD.298
Push
knob (MANUAL)
AAD.299
Knob {TUNING}
AAA{)69
-Front panelassembly
ANB.9OO
Push
knob
AAD.179
Tuningshaftassembly
AXA-274
switch
(TAPE MONITOR}
ASG-221
Slide
rotary
switch
(FUNCTTON)
ASE{08
24anged
push
switch
(FM
MUTING,LOUDNESS)
ASG-242
Variable
resistor
(VOLUME)
ACT-128
relief
AEC-327
A Ac socket
AKP026
AC power cord
ADG-O41
Terminal(SPEAKERS)
AKE.O48
EO AMP assembly
GWF-133
Tuner/AF assembly
GWM-165
5. PARTS LOCATION
Front
PanelView
Pushknob (MEMORY)
AAD-299
AAD-2OO
Knob
AAB.244
FrontViewwith Panel
Removed
lndicator assembly
GWX.sO1
Signalmeter
AAW.I26
I
r\ Leverswitch (POWER
- ASK-522
Phone
jack(PHONES)
AKN-O29
Variable
resistor
(BASS,
TBEBLE}
ACT-129
Rear
Panel
View
Bar-antennaassembly
ATX-O19
Terminal
(ANTENNA)
AKA-OO7
Terminal(PHONO)
AKB-062
Terminal
(AUX,
TAP
AKB{64
Top View
Fuseassembly
GWX-502
,\ Fuse
(T2.5A
250V)
AEK4O3
,{ Fuse
(T1.6A
250V}
- AEK4Os
7fr
Fuse
(T250mA
250V)
- AEK{37
A Fuse
(T3.15A
250V)
AEK442
Variable
resistor
(BALANCE)
ACl-O22
o
t
Bonnet case
-) .'':
::.;;

O Turn the tuning resistorshaft fulley counter-clock-
wise. @ Fix thetuning
drumto thetuning
resistor
shaft
sothattheset-screw
is
uppermost.
O Tieone
end
of the
dial
cord.
o
o
(E
o
Windthe
cord
around
the
tuning
shaft3 times.
Wind
the
cord2-112
turnaroundthe
tuning
drum.
Tieittothespringso
that
it is
tensioned.
Turn the tuningshaftclockwiseas
faras
it will go.
(D Align the dial pointer with the ending
point of the
dial scale. (D Pass the cord over it.
Finally
applythelocking
paint
to theknotof thecord
and
thedial
pointer
connection.
6.DIAL CORDSTRINGING
a

)7.
ADJUSTMENTS
7.1 TUNERSECTION
Ttrning Voltage
o Setthe FUNCTION selector
to the MW position, the MANUAL switch to the ON position.
o Turn the TUNING knob counter-clockwiseas
far asit will go.
FM T\rner
o Connectthe FM SG(FM signal
generator)
to the FM ANTENNA 300O terminal viaa 3004 dummy
antenna.
o Setthe FUNCTION selector to the FM position, FM MUTING switch to the OFF position.
Step FUNCTION Adiustment
point Adjustment method
1MW (no
input) vR201-b Obtain a reading of DCl.5V (within tsOmvl between terminal no.42 and
ground,
2FM (no input) V8201-c Obtain a reading of DCGV (within t50mV) between terminal no.42 and
ground.
Step FM SG (400H2.
t75kHz DEV.I Position of
dial pointor \djustment
point Adiustment method
Frequency Level
1106MHz 106d8 1O6MHz cT403 Obtain maximum deflection of the signal
meter.
2T402
Obtain maximum demodulated output (at TAPE REC
terminal).
3
106MHz 20dB 106MHz
cT403
4cT401
5cr402
6T401
7
9OMHz 20dB 90MHz
L403
IL401
9L402
10 Repeatsteps
3 to I until the maximum sensitivity.
11 98MHz
(Fin
tune
to sX-700L)
20dB 98MHz T402 Obtain minimum distortion in the demodulatd output
66dB (TAPE
RECterminall.
12 No signal 98MHz VR2O3 Obtain a reading
of DC4.75V (within tsOmv )between
terminal
no.9 and
ground.
o
il

8. P. C. BOARD CONNECTIONDIAGRAM
EQAMP
Ass'y
GWF-133
SWITCH
Ass'y
GWX-500
.\ .,
'n: "D: 'Dj
| ' ," vwi ,r$:_ _ .
' 1!ilrr n':LLY
INDICAT0R
Ass'y
GWX-50't

External
Appearance
of Transistors
andlcs
254798
Type No
Lot No
2Serc1
2SC535
LC7207
characteristics.
2S4850
2SC1735
AC 220V
50/60H2
Lot No
hre
8
7
UNSWlTCHED
2OOW
MAX
STAMPEO
ON
THE
BACK(E
orF)
Ar KrA2 K2 At
Kt
A2
K2

TUNER/AF
AMP
Ass'y
GWM
-165
i
+
,,:
d""
"'
' *"df
Ir-fr i;a;;r 1";
,, ,.3r TlY'iBoo. L I È
,+t_::
tlt ' lr t tl I I JT.
.t'FEA_trJJ
o
o
-- -";",a l
/Q; I
. {
STEREo) I
Liili it'it:i
tt""
t-l*
rftlî
î1,
lnql I I
î"r1i
I J dr
I--T--

FM Multiplex Decoder
Circuit
o Connectthe MPX SG(FM multiplex signal
generator)
to the FM
r Set the FM SG output to 98MHz and 66dB (modulation mode
this position.
SGexternal modulator terminal.
to external), and tune the SX-?00L to
T2 (L)(Bar-antenna
LW
Core)
1
(FM
ANT.
Coit)
T401
(FM
ANT.
trimmerl
Voltage
ADJ.)
vR201-b
(AM
Tuning
Voltage
ADJ.)
CT403
{FMLocalOSC.
trimmer}
L4o3
(FM
Local
osc.coiD
T401
(FM
lFTransformerl
T402
(FM
DET.
Transformerl
VR4Ol
(FM
PLL
VCO
ADJ.)
No.6
(PLL
VCO
TP)
CT405
(AM-MW
ANT.
Trimmr'rr--@tp
CT4O4
(AM-LW
ANT.Trimm
T2
(M)
(Bar-an
MW
Core)
VR2O2
(AM
AFC
ADJ.}
L405(AM-MW
Local
OSC.
Coit)
T403(B)(AM
S-CurveADJ.)
L406
(AM-LW
Local
OSC.Coill
No.9
(AFC
TP)
VR2O3
(FM
AFC
ADJ.}
I
Stap FM MPX SG Adiustment
point Adiustment mothod
1No signal
(unmodulated) VR4Ol Obtain a l9kHz (within tSOHzl signal at terminal no.6.
2Main:
1kHz,L+R,
t67.5kHzDEV.
Pilot:
1gkHz,
t7.SkHz
DEV.
T401
(byupto 90" in
eitherdirection) Reducedistortion in the ourput {TAPE REC terminal) to a minimum.
Fig.
7-1 ïuner Adjustment

D7.
ADJUSTMENTS
7.1 TUNER
SECTION
Ttrning Voltage
o Set
the FUNCTION selector
to the MW position, the MANUAL switchto the ON position.
r Turn the TUNING knob counter-clockwiseas
far asit will eo.
FM Tunet
o Connectthe FM SG(FM signal
generator)
to the
antenna.
o Setthe FUNCTION selector
to the FM position,
FM ANTENNA 300Çlterminal viaa 300S2
dummy
FM MUTING switch to the OFF position'
Step FUNCTION Adlustmenl
point Adiustmsnt method
1MW (no
input) vR201-b Obtain a readingof DC1.5V (within r50mv) between terminal no.42 and
ground.
2FM (no input) V8201-c Obtain a reading of DC6V (within l50mV) between terminal no.42 and
ground,
Step FM SG
(40OHz,
t75kHz DEV.) Position of
dial poantel \djustment Adjustment method
Frequency Level POrnr
1106MHz 106d8 106MHz cT403 Obtain maximum deflection of the signal
meter.
2T402
Obtain maximum demodulated output (at TAPE REC
terminall
.
3
106MHz 2(HB 106MHz
cT403
4cT401
5cr402
6T401
7
9OMHz 20dB 9OMHz
L403
8L401
I1402
10 Bepeatsteps
3 to 9 until the maximum sensitivity.
11 98MHz
(Fin
tune
tosx-700L)
20dB 98MHz T402 Obtain minimum distortion in the demodulated output
(TAPE REC
terminal).
66dB
12 No signal 98MHz VR2O3 Obtain
a reading
of DC4.75V (within 150mV )between
terminal
no.9 and
ground.
o
o

IS
Adiustment method
obtain a 19kHz (within lsoHz) signal
at terminal no'6'
Step FM MPX SG
-Adiustment
Point
1No signal
(unmodulated) VR4Ol
Beducedistortion in the ou(put (TAPE REC terminal) to a minimum'
2Main:
1kHz,
L+R,
t67.skHz
DEV.
Pilot:1gkHz,
r7.SkHz
DEV.
T401
(byupto 9o" in
either
direction)
FM Multiplex Decoder Circuit
o Connect the MPX SG
(FM
o Set the FM SG outPut to
this position.
T2
IM
{Bar-an
MW
Core)
L405
(AM-MW
Local
OSC.Coil)
multiplex signal
generator)
to the FM
98MHz and 66dB (modulation mode SGexternalmodulator terminal.
to external), and tune the SX-?00L to
T2 (L)(Bar-antenna LWCorel
(FM
RF
Coil)
vR201.b
(AM
Tuning
Voltage
ADJ.)
CT403
(FMLocal
OSC.trimmerl
L403
(FMLocat
OSC.
Coit)
T401(FMlF Transformerl
No.6
(PLL
VCO
Tp)
VR2O2
(AM
AFCADJ.)
T403
(B)(AM
S-Curve
ADJ.)
L406
(AM-LW
LocalOSC.Coil)
No.9
(AFC
TP)
VR2O3
(FM
AFC
ADJ.)
5Ta02
/6\ | | | tf-UDET.Transformer)
VR4Ol
w(FM
PLL
VCO
ADJ.)
Fig.7-1 TunerAdjustment