Pioneer TX-9500II User manual

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Type Voltage Remarks
KC 120V
only CSA (Canada)
approved with de-emphasis
selectorswitch
(25psl75psl
KU 120V
only UL (U.S.A.) approved with de-emphasis
selectorswitch
l25trs/75psl
HG 22OY and 240V (Switchabte) SEMKO (Sweden),
NEMKO (Norway), DEMKO (Denmark)
and El (Finland)
approved
S110V,
120V,
22OV
and
240V
(Switchabte) Generalexport model with de-emphasis
selectorswitch
l25ysl50ps/75psl
TX-g'5ClCltr
MODEL
TX-gsOOII
COMES
tNFOUR
VERSIONS
DISTINGUISHED
AS
FOLLOWS:
. Service
informations
forTX-9500II/KU
isdescribed
onpage
5through
52inthismanual.
o Forservacing
of Kc, SandHGtypes
please
refer
to TX-9500II/KUmanual
with theexception
of
descriptions
inthe
"Additional
ServiceManual"
(p.53-p.86).
CONTENTS
1.
2.
3.
4.
5.
CONNECTION
DIAGRAM
SPECIFICATIONS
BLOCK
DIAGRAM
5
6
7
I
FRONT
PANEL
FACILITIES
CIRCUIT
DESCRIPTIONS
5.1 AMTuner
5.2 FM
Tuner
DISASSEMBLY
5.3 REC
LEVEL
CHECK
5.4 Power
Supply
CircuitSignal
Generator
Circuit
11
11
15
6.
7.
15
16
20
21
PARTS
LOCATION
7.1 Front
Panel
View
7.2 Front View with Panel
Removed 17
18
19
7.3 Top
View
7.4 RearPanel
View
8. DIAL
CORD
STRINGING

9. ADJUSTMENTS
9.1 FMSection 22
9.2 AMSection 26
10. EXPLODED
VIEWS
10.1 TopSide 27
1O.2 Bottom
Side. 29
10.3 Nomenclature
of Screws,
Washersand
Nut ... . . . 31
11. PACKING 32
12. SCHEMATIC
DIAGRAMS,
P.C.BOARD
PATTERNS
AND
PARTSLIST
12.1 Schematic
Diagramand
Miscellaneous
PartsList 33
12.2 FMFront
End
(AWB-023)
. 36
12.3 AMFM
lFAssembly
(AWE-070)
... 37
12.4 MPXAF Assembly
(AWD-009) 45
12.5 PowerSupply
Assembly
(AWR'128) 50
Additional
Service
Manual
1. CONTRAST
OF
MISCELLANEOUS
PARTS 54
*
2. KCTYPE
2.1 Schematic
Diagram
and
Miscellaneous
PartsList
2.2 PowerSupply
Assembly
(AWR-I29)
2.3 Packing
3. HGTYPE
3.1 Schematic
Diagramand
Miscellaneous
PartsList
3.2 MPXAF Assembly
(AWD-008)
3.3 Power
Supply
Assembly
(AWR'I30)
3.4 Packing
4. STYPE
4.1 Schematic
Diagramand
Miscellaneous
PartsList
4.2 MPX
AF Assembly
(AWD-010)
4.3 Power Supply
Assembly
(AWR-I31)
.. ..
4.4 Switch Assembly
(AWX-113)
..
4.5 Packing
56
59
61
62
65
70
73
74
77
82
85
86

1.
SPEC|FtCATIONS
Semiconductors 5
15
FETS
lCs
Transistors ......12
Diodes ....19
FM Section
Circuitry . . . MOS FET 2-stageRF ampli-
fier,
5-gang
variable
capacitor,
lF Band
Selector,Wide-band
linear detector, doublebal-
anced
NFB type PLL MPX
built-in p ilot signal auto
cancel
ler.
UsableSensitivity
. . MONO: 8.8dBf
(1.59V)
50dB
Quieting
Sensitivity. . MONO: 13.2dBf
(2.5tN)
STEREO:36.1dBf
(35pV)
Signal-to-Noise
Ratio
at65dBf MONO: 82dB
STEREO:71dB
Distortion
at
65dBf MoNo: wlDE NARRow
100H2 0.05% O.OIY,
l kHz 0.05% O.jlY'
10kHz O.07o/o 0.1Yo
15kHz 0.12Y"
STEREO:
100H2 0.17o O.3Vo
l kHz 0.07o/o 0.25%
lOkHz 0.2Yo 0.5%o
15kHz O.57o
Capture
Ratio.. . 0.8d8 2.0d8
AlternateChannel
Selectivity. . . 35dB 85dB
StereoSeparation.. ..lkHz: 50dB 45dB
50Hz
to 15kHz: 35dB 30dB
Frequency
Response 20Hzto 10kHz+0.2dB
2oHz
to
r
stHzloo']aa
SpuriousResponseRatio
. . 11OdB
lmage
ResponseRatio. . . . 120d8
lF ResponseRatio . 105dB
AMSuppression
Ratio
. . . . 65dB
Muting
Threshold . . 19.2dBf(5
ttY),34.1d8f(28pv)
Subcarrier
Product
Ratio
. . 11dB
SCAReiection
Ratio
. . . . . 62dB
Antennalnput
. ... 30Oohmsbalanced
75ohmsunbalanced
TX-s|5clCltr
AM Section
Circuitry ...lstageRFamplifier3-gang
variablecapacitor
Sensitivity
lHF,ferriteantenna
.. . 300pV
lHF,
external
antenna. . 15pV
Selectivity . . 30dB
Signal-to-Noise
Ratio.. . . . 55dB
lmage
ResponseRatio
. . . . 70dB
lF ResoonseRatio.. .... 65dB
Antenna ... Built-in ferrite loopstick
antenna
Audio Section
Output
(
Level/lm
pedance)
FM
('100%
MOD.) FIXED: 650mV/4.2kO
VARIABLE:50mVto
1.3V/3.6ks2
AM (30%
MOD.) . FIXED: 2OOnYl4.2kQ
VARIABLE:
'l5mV
to
400mV/3.6kO
Miscellaneous
Power
Requirements 120V60Hz
only.
PowerConsumption
. . . . . 25W
Dimensions . a20(W)x150(H)x395(D)
mrr
16-9
|
16x5-7
18x1
5-9l1
6 in
Weight .... WithoutPackage:
9.5kg
(201b
15oz)
WithPackage:
11.0kg
(241b
4 oz)
Furnished
Parts
FMT-typeantenna ....1
Operatinglnstructions ......1
ConnectionCordwithPinPlugs .....I
Hex.Wrench
(used
forfasteningTuning
knob). . . . . . . 1
NOTE:
Specifications
and.the
designsubject
topossible
modifica-
tionwithout
notice.
/r
l

2.CONNECTION
DIAGRAM
FM DE.EMPHASIS
SWITCH
Normafly, set this s,witch to "75tts."
Be sure to set it to "25ps." only when
listening to an FM broadcast (pre-
emphasis:25psl with a Dolby* system.
TX-9500[
GROUND
OSCILLOSCOPE
*
The
word
"Dolby" isatrademarkof Dolbv LaboratoriesInc.
TTYPE
FMANTENNA FMOUTDOOR
(ifstations
are
nearby) ANTENNA
AM ANTENNA
(indoor or outdoorl
>t
DISCRETE
4CHANNEL
FM ADAPTOR
!
{t
I
-)
I
I *-J-=
rl I
i----
AM FERRITE
BAR
ANTENNA
CONVE]\
OUTLET
coupledv
power sr'\,
t- |
tl
t=J
:NlENr
iT (not
Iwith
witch)
"l
lr
_JTII
power
lf-
lls
tl
I lr5
L-
oosoo16;sO
b'ossoifdon
TAPEDECK STEREOAMPLIFIER

3. FRONTPANELFACILITIES
POWERSWITCH
Setto ONposition
to turnonpower.
Pilotlamp
will light.
MULTIPATH ON: Multipath sound becomesaudible
from speakers.When installing FM
antenna, select antenna location and
directionso as to minimizethis sound.
Normally
setswitchto this
position.
RECLEVEL CHECKON: Usethis position
for setting
recordinglevelsof tape deck. A 44OHz
signal
(level
correspondingto 50% FM
modulation) is produced at approxi-
mately1.7
second
intervals.
SIGNAL
METER
Employ when tuningAM
tuning point occurs
when
toward
therightisobtained.
and FM stations.
Optimum
maximum meter deflection
TUNING
Usewhen
deflection
tune carel
(optimum
MUTING
Controls
noise
whr
tuning
opr
2:
OFF:
PILOT
LAMP
IF BAND
SWITCH
FM lF (intermediate
forwide
ornarrow. frequency)
passband
canbe setto
WIDE: Normally
setswitchto this
position.
NARROW: lf adjacentstation
interference
isa pro-
blemat the WIDE setting,setswitchto
this
position.
MULTTPATH/RECLEVEL
CHECKSWTTCH MEMORY
MARKERS
Single
leveroperatesbothMULTIPATH
andRECLEVEL
CHECK
switches.Withthe FUNCTION
switchat FM,
set
asrequiredfor the application.Besureto returnit to the
OFFposition when
it isnotbeing
used.
tFBAND
INDICATOR
Convenient
for designating
most
oftentuned
in stations.
Slidemarkers
with fingertip
to desired
positions.
OUTPUT
LEVEL
CONTROL
Adjusts
levelatOUTPUT
(VARIABLE)
jacks.
Clockwise
rotationincreasesoutputlevel.
OFF:

;.Optimum
' deflection
TUNINGMETER
Usewhen
tuning
FM stations.Firsttunefor maximum
deflection
of theSIGNAL
meter
(tov,ard
the
right),
then
tune carefullysothat the meterindicates
centerof scale
(optimum
tuning
point).
oraorueen
srEFEo
ruNEr
il-9500]l
MUTING
SWITCH
Controls circuit for cancellingbothersomeinterstation
noisewhentuning FM stations to provide a comfortable
tuningoperation.
TX-s|5ClCltr
FM STEREO
INDICATOR
with the FUNCTTON
switch
set
to FM AUTO (or FM
NOISE
FILTER),
the indicaror
will light
during
stereo
signal
reception.
FUNCTION
SWITCH
Switch
for selecting
type
of reception.
AM: AM broadcast
reception.
FM AUTO: FM stereoreception.
lf broadcast
isFM
mono, the mono modeisautomatically
selected.
FM NOISE
FILTER: Ser to this position
if compara-
tively high frequency noise becomes
objectionable
during
FM
stereo
reception.
Note that someloss
of stereo
separation
occurs
atthis
position.
FM MONO: FM monophonic
reception.
Set to this
position
if reception
at FM AUTO posi-
tionis
noisy
or signals
weak.
TUNING
KNOB
Knob for selecting
stations.Refer
to theSIGNAL
meter
when tuning AM stations
and to both SIGNAL and
TUNING
meterswhen
tuningFM
stations.
)ICATOR
)'
-_l
I
___l
Clockwise
2:
1:
OFF:
Set to this position to receiveonly strong
stations.
lf desired
stationcannot
bereceivedatposition
2,setswitch to this
position.
Setto this position
in locationswheresignals
areextremelyweak.
a

4. BLOCK DIAGRAM
FI,{
FRONT
END
l'-- Rr -; -- RFam; - f1i*"
!. crq rctr*@l -5.@l
r4
I lr'€i
,F I lrefl
+
It--- --i--L-- --_ --/ t L--r
ISWITCHES.
S'a^t ' FUNCTI0N
1.
AM 7. Fl
Sz,r,b
: MUTING
1 OFF 7.
S:a'd ' f40DE
1.IIULTiPA
S4a,b
' lF BAND
NARROW
<-
(.
vJ
55
FX
I
L
15o
t
3000
L
CND
Loca
| 0SC
POW
ER
0N<--) OFF
DE-
ENPHA:
flixer
1 Buffen
F11IF AHPLIFIER
& DETECTOR
t- WIDE
n*ftr;--rtr;-\
L=Jr=LL4Ld
Frf r Yr r7
--t ---1 --1 --1
Ceramic
f
ilfen
NARROW
Cer^am
ic
filfer^
e
J1A
TUNING
meter'
FM
detecton
T
WIDE
rnd.
NARROW
lnd
J
FI1IFAMP
IC
MUTINGCONTR
CIRCUIT
SIGNAL mefer-
L
AI1 TUNER __J
Al1
Our

SWITCHES.
S'a^ t :
S2,r,
b i
S34-
d :
FU
NCTION
1.
AM 2 FI'1 AUTO
3, FI"]
I1PXNOISE
FILTER 4. FM
I4ONO
IlUTI
NG
1 OFF ?. 1 3.2
11O
DE
1.IIULTIPATH
ON 2.
OFF 3.
REC
LEVEICHECK
ON
S4a,b ' lF BAND
NARROW
E WIDE
(. ' POWER
0N
--+ 0FF
56 : DE-
ENPltnSf
S 25aS
*-t5l.5
Separ
at
ion adL
U:- --J
-IFIER-&
DETECTOR
FM
detecl-on
- *+-;"rt I
1--th-Xl I r'rct' :
T1PX
DEMODULATOR OUTPUT
LEVEL OUTPUT
,\i
AF MUTING CIRCUIT
lrVARIABTE
RJ
L-r
FIXED
Rr
r ULTIPATH
HORIZ
(DtT
OUT)
VERT
.J5
#c-->AC LINE
S,
q
t6 o Stn
5os
o
Q+va
3
L.PF.
3AF
MUT.
IC
-_Jl REC
LEVEL
OSC.
l--r--.l
rLs.- --i
I o q.^
I "JU
l*r
L------r'\ |
src I I
S'a
L
l__ __ L _)
POWER
SUPPLY

5.CIRCUIT
DESCRIPTIONS
5.1 AM TUNER
The major components of the AM tuner are the
3-gangedvariable capacitor, a newly developed IC
(HA1197), and an AM ceramic filter. A block
diagram
of the HAlL97 isshown in Fig. 1.
This IC consists of an RF amplifier first stage,
followed by a mixer stage which also includes a
self-oscillating local oscillator, the IF amplifier 3rd
and 4th stages,and a detector circuit final stage.
The AGC (Automatic Gain Control) receivesan
AGC voltage from the output of the detector cir-
cuit, and applies it to the RF amplifier and IF
amplifier stages.The advantage
of the HA1197 isa
large
reduction in the distortion at low frequencies.
Whereas
the distortion at 100H2 was 1.57oin the
previous HA1138, this figure has beenreduced to
0.4Vo
(LOOHz)
in the HA1197.
TX-s|E'clcltr
5.2 FMTUNER
FM Front-end
The FM front end is composedof a tuning circuit
employing a 5-gangvariable
capacitor,a 2-stageRF
amplifier a mixer employing dual gateMOS FETs,
and a local oscillator with buffer. An equiva-
lent of a cascode amplifier is produced by AC
grounding gate-2 of the dual gate MOS FET,
allowing stable RF amplification at high gain.
The output signal of the RF amplifier is applied to
gate-l of the mixer stage
MOS FET, while the local
oscillator output signal is applied to gate-2. This
technique minimizes input power from the local
oscillator,resultingin low mutual interferenceeven
if the receivedsignalinput level is high.
A variation of a Clapp circuit forms the local
oscillator. Inclusion of a buffer amplifier between
local oscillator and mixer reduceslocal oscillator
load, eliminating distortion of the oscillation wave-
form. Drawing effect of the local oscillator is also
eliminated.
AF out
Fig.
1 Blockdiagram
of HAl197
2nd RFamp
FM75O UNBAL.
t-
FM
3OOOBAL.
L
Ceramicfilter
ANT
ToSIGNAL Meter
AGC line
1stRF
amp.
Localoscillator
Fig.
2 Circuitof FMfront
end