Pioneer TX-520 User manual

^{æffiHf.$WË#ffiffi,
STEREO
TUNER
o This
service
manual
is
applicableto the KUtype.
o Whenrepairing
theYP,S andS/G
types,
please
see
paç 25.
o Ce
manuel
d'instruction
serefère
aumode deréglage,enfrançais.
o Este
manualdeservicio
tratadelmétodo
deajusteescritoenespafrol.
1.
2.
3.
4.
5.
6.
7.
8.
9. ELECTRICALPARTS LIST
10.
EXPLODEDVIEW
11.
PACKING
12.ADJUSTMENTS
nÉcuce
AJUSTE
ADDITIONAL
SERVICEMANUAL
(FOR
YP,SANDS/GTYPES)
ORDER
NO.
ART-653-O
MODELTX€20 COMES
IN FIVEVERSIONS
DTSTINGUISHED
ASFOLLOWS;
Type Voltage Remarks
KU AC120V
only U.S.A.
model
YP AC240V
only Australiamodel
s/G AC110V,
12OV,22OV
and
24OY
(Switchabte) U.S,
Military model
sACI10V.120V,
22OV
and24OV
(Switchabtel Generalexport model
ss AC110V, 12OV,22OVand 240V (Switchablel Soutch Africa model
CONTENTS
SPECIFICATIONS
FRONT
PANELFACILITIES
.
BLOCKDIAGRAM
CIRCUIT
DESCRIPTIONS
PARTSLOCATION
DIAL
CORDSTRINGING
P.C.
BOARDSCONNECTIONDIAGRAM
SCHEMATICDIAGRAM
2
3
4
4
5
6
7
I
11
13
14
15
18
21
25
PICINEEFI ELEGTFICINIC CCTFIPCIFIATICIN 4-1. Mesuno 1-chome. Mesuno-ku,
Tokyo 1s3. Jêp6n
U.a. FfCINIIE| IIICTF|CINIC3 CC'FIFC,F|AIIC'N €'5 Oxf o.d Odve. Moonechre. New Je€ey O7O74, U S A
Plcrl\lllFl ILCCTFICINIC (E!,FIC,PE, N.V. Lurchagen-H6ven 9, 2O3O AnEwerp, Elelgrum
FfCrTvllF| ILICTF|CINaCa ALTaTFIALIA PTY. LTEI. 17A-1e4 Boundê.v Floêd. Eln6esrde. VicEonr6 3195. Au6b6li6 =H@
MAR.
1981
Printed
in
Japan

3. BLOCK DIAGRAM
FI
tooo
AM TUNER
FM
IF AMP A OETECTOR I
75n
GilO
(
FT,|
MPXSTEREO OEIT|oOULAIOR
Ic(HAil56wl
INOICATORS
Ftl +B +--i- V.R.
+8
AM +B---:o I
4. CIRCUIT DESCRIPTIONS
FMTuner
The FM front end is comprised of a J-FET
(2SK168) single+tate RF amplifier, an NPN
transistor mixer, and an NPN transistor modified
Clapp local oscillator.
The IF stageconsists of 2 dualclement ceramic
filters, a single transistor amplifrer element, and an
IF system IC (PA3001-A) which incorporates
the IF limiter amplifier, FM detector, and the FM
muting circuit.
FM Multiplex Stereo
Decoder
The stereo decoder stage employs an FM MpX
IC (HA1156W-P), while the subcarrier signals
(frequencies above l9kHz) are removed by an
-18d8/oct. active filter consisting of a pNp
transistor. This active filter also sewes as an
amplifier for frequencies within its passband,
and eliminates crosstalk.
FM IF SYSTEM
Ic
(PA300r-a
)
AMTuner
This employs a 2-ganged tuning capacitor, a
dualclement ceramic filter, and an IC (HA119T)
consisting of a RF amplifier, mixer, 2-stage IF
amplifier, detector and AGC circuit.
Signal
Strength lndicator
The TX-520 signal strength meter is a b-point
LED display meter driven by the meter drive IC
(L81416). The signal meter drive signalsfrom
the FM and AM tuner sections are applied to a
set of 5 voltage comparators which are activated
according to the difference between the applied
signal level and the respective reference vottage
levels allotted to each comparator, resulting
in the LEDs(1-5) being
lighted.
METER DRIVE
IC
(
L81416
)
Fig.
4-1 Signal
indicator
circuit

2. FRONT PANEL FACILITIES
o POWERSWITCH
When
this switchisset
to the ON position,power is
sup-
plied
to thetuner's
maincircuits.
Theunit's
power
switch
isgeared
to selecting
thetransformer's
secondary
andso
even
at theSTAND'BY
position,
theunit'scircuitry
will
work as
long
asthe
power
cord
is
connected
to the
power
outlet.
Disconnect
the power cord from the poweroutlet when
you do not plan to usethe
unitfor along
period
of time'
€) FUNCTION
SWITCH
When listening
to an FM broadcast
- Setthe function
switch
to theOUT (
r )position.
When listening
to an AM broadcast
- Set the function
switch
to thedepressed
( ^ )position.
@ FM MUTING
SWITCH
Whenselecting
an FM broadcasting
station,
this switch
removes
the irritating
noise
between
stations'
lt should
normally
be
inthe
ONPosition.
When
thesignal
is
weak
andthere
is
a great
deal
of noise
or distortion
with thisswitch
ON,making
it difficultto
hear,then it should
be pressed
to put it in the OFF
position (in this case
mono reproduction
is obtained)'
@rurutruc
KNoB
Turn
this
to select
abroadcasting
station
(FM
or AM)'
@ otnu
scALE
This indicates
the frequencY
(FMor
AMI'
upper
number
(88
- 108)
-
lower
number
(55
- 160)
-
@ otal PoINTER
This moves
right
or left when
thetuningknobis turned.
Line it up with the frequency
of the station
you wantto
listen
to.
O stcruel lNDlcAToR
This
indicates
thestrength
of thesignal
from the (AM
or
FM) broadcasting
stationto which you are presently
listening.
The larger
the numberof the lamps
lit up,the
stronger
the signal
(a
strongsignal
indicates
that reception
conditions
areoptimum).
G) TUNEDINDICATOR
This lights
up whenan FM broadcasting
station
isbeing
received.
This lamp doesnot light up when an AM
broadcast
is
being
received'
@ STEREO
INDICATOR
This
lamp
lightsup automatically
when
an FM broadcast
isin stereo.
lt does
notlight
up
when
theFMMUTING
switch
issetto OFF.
@ FM T.TYPE
ANTENNA
This antenna permits FM broadcasts
to be heard until a
regular
FM antenna
isinstalled.
NOTE:
When the broadcasting
station is far away' or in case
of weak
signats
btockedby mountains,
it might not be possible
to receive,
FM broadcasts
with this
antenna'
ln such
a case'
pleaseinstall
anantenna
exclusivelY
for FM uæoutdoors'
of thebroadcasting
station
frequencY
ofFM
station
frequency
of AM
station

1.SPEC|FlcATloNs
FMTuner
Section
Usable
Sensitivity . . 10'8dBf
(1.9r..V)
5(HBQuietingSensitivitY
MONO ..17.3dBf(4.0sV)
STEBEO 39.2dBf
(50svl
Signal-to-Noise
Ratio
(at
65dBf)
MoNo " " 75d8
STEBEO ....70dB
Dislortion
(at
65dBf)
MONO .-'.1kHz;0.1o/o
STEREO ....1kH2;O.2o/o
Capture
Ratio . ldB
AlternateGhannel
Selectivity
(400kHz) .60d8
Stereo Separation
lkHz. .....40d8
Selestivity .....25d8
Signal
to Noise
Ratio . . .50d8
lmageResponse
Ratio . . .40d8
lFResponseRatio. ...70dB
Antenna ,.. Ferriteloopstickantenna
Audio Section
Output (
Level/lmpedance) 650mV/3.6kO
FM
(100%
MOD)
AM (30%
MOD) lSOmV
Frequency
Besponse
. .
Spurious
Response
Batio .30Hz
totstnzlo'f
oa
Miscellaneous
PowerRequirements .... AC120V,50/60H2
PowerConsumption ....llw
Dimensions ... 420(W)x
94(H)x254(D)mm
16-9/16(W)x 3-11116(H)
x 10(D)in
Weight
(Without
Package)
FurnishedParts 3.2k9
(6lb
13oz)
FM T-type
antenna
Operating
Instructions
NOTE:
Specifications and the design subiect to possiblemodifica-
tion without notice due to improvements.
lmageResponseRatio ...55d8
lF
ResponseRatio.. ...80d8
AM Suppression
Ratio . .55dB
MutingThreshold ...19.2d8f (5pV)
Antenna
lnput . . 3(X)ohmsbalanced,
75ohms
unbalanced
AM Tuner Section
Sensitivity
IHF ferriteantenna 300frV/m
lHFexternalantenna. .....30pV

3
2
,r
()( T.tl,T
:?1,
iil-L+;l
iQr4 Qt2 QTQO 09 ,
HAl156W.P
T4 T2 1C4 VCITCi vRl
TC5VC3
\Æ2 rc2
,:* '" I]'Ki
HJ
[&ti,,,'
., .;
'- -1.r H l-a
9iç+d
ti R?6
3.46X
1? r
,.:F?ll4l(
)
-l
-
-
*3-rrr--
Ll "t'*
# **=
ffi ffi* Ëâ ffi
@ ffi fÈ, t'",,"
'cà ,,,1
.
"r€]",|Ê;f:Ë
r , Y#lu,T --i-- *Rfi,.-,,",^"
::l'i [:'na4pu- 33/50
''fJ.,fti Tc ] ' ,,1Ëlfff
ibJi ffi #
i '_b€lf,r".;,ld;
ff;* #
Èf - | | Jù*;";;;','J_hË;EE ili;
@ 's'T-ffi,'"':io
i i :t':"f-'il.;{îfl,ryF #l , '!{:,,,,
PA3001-A
HAl 197 2SA726S
2s'c2575
I
E
3
2
1
7. P.C.BOARDS
CONNECTION
DIAGRAM
ATUNER Ass'y(cWt- | SZ)
Q4 Q5 02 Q3
ExternalAppearance
of Transistors
and lCs
2sKt6B 2sc461
2Sc53s
E
i "____,f--* i 0iz aEe j:
ï'ffiLJffi
'
-:
ll -,.",,.$j.'ilgji'
ffiÆiffi#':,.,ï*fu ri.,-
r;___-t I i I e ,,:7- 16i,o0K
at2 zsc461 ll , .--_ fir:T
. "..^'lffil.jfl"TE* ffi-g *tq"- + L+=j-s- *4*l-.=*=*-#i,lo-.,:...-.,1.rcai**.{fi|.-,:*.-Æ

6
DIAL POINTER SWITCH Ass'Y
(cws-346)
LED Ass'y (GwX-634)
zscxt45A
Tl:POWER TRANSFORMER
r------\ Rtoo 2 2M.(t/2w)
LBl4t6
PL2
aV I OOmA
PLI
AVO3A
AC | 20V
5
4

5. PARTS LOCATION
Front
Panel
View
Front panel
assemblY
ANM-005 r
Rear
Panel
View
Strain relief
AEG76O
Terminal
(ANTEN
AKA.O14
TopView
Dial pointer assembly
AAF-I11
* * LamP with wires
AEL-l55
A * Power
transformer
ATT-790
A i* Pushswitch
(POWER)
ASG-s16
** l€mp
AEL-108
Switch
NOTES:
CTheAmarhfound'onsomecomponentpartsindicatestheimportanceofthe
safetyfactoroftnepart'Therefore,whenreplacing,besuretotnepartsofidentical
designntion.
oForyourPartsstochControl,thefætmovingitemsareindicatedwiththe
marhs ** and *
i7 cawsnALLY MovES FASTER
THAN *
This
clasification
snitt-UeTdiueted
byeach
distibutorbecarse
it depende
onmodel
number,
temperature,
humidity,
etc'
base
AEC-741
KNOb
(TUNING}
AAA.O71
Knob
(FUNCTION,
FM
MUTING}
AAD.268
Terminal
(AM
STEREOOUTI
AKB-O76
Strain reliel
AEC-327
ACpower
cord
ADG.Os2
ADE.O34
Tuning
shaft
assembly
AXA-292
* * Push
switch
(FUNCTION,
FM
MUTING)
ASG-261
LED assembly
cwx-638
Top
GWs346

Dial
Pointer
6. DIAL CORD
STRINGING
1. Removethe top cover and front panel'
2. Remove the tuning drum from the shaft of the
tuning caPacitor'
3. fie one end ot it'e cord to the stud A located
inside the tuning drum'
4. Rotate tfte tuinË-capacitor right,around until -' ifr" ,otot bladesa"" tutty intermeshed'
5.
6;;;" thetunintdnrm
back:"IÎ,tÏ t^TT::
"' Jupu"itot shaft, Àaking sure-
that the secunng
t"i"* B facesdirectlY uPwar-d'
6. Pass
the cord o"i Utt""gtt the small opening in
the circumt"'""àt of lrre tuning drum (see
diagram), ""a tf'"tt take it over pulleys C' D
and E in that sequence'
z. friiJtrt" "o'a Jtà"ttd thetuningshaft 3 times'
8.Pass
it over
p"ff"V f' *ii.d il."t9lÎd thetuning
drum 2 times, iiJ littutty tie it to the spring
ttà.t C so
that it istensioned'
9. Tum the tuning shaft, and check that the cord
movessmoothly.
10. Cut off any excess
eord'
ii. T;-ù; tuning shaft counter'clockwise
asfar as
it will go'
12. Alig the dial p"i"t"" wrth the starting point --' ;; A" dial scaie, and then passthe cord over
it.
13. Check that t'tre diat pointer is in line with the - - starting point of the dial scale'
14. Finally appty ttr" locking paint to the cord
securing positions (stud A and spring hook G)
and the dial Pointer connecuon'

9. ELECTRICAL PARTS LIST
NOlES;
o llhen ord,ering resisfors, first convert resistance ualuecinto code form asshown in
the following examples.
Ex. 1 Wen there are 2 effectiue digits (any digit apart from O),such æ 56O ohm
and 47h ohm (tolerance is shown by J=5%, and K=lO% ).
56Oa 56 x lol
57ka 47 x 103 561
. .. .. RD%PS
E[tE J
473.,.., RD%PS
EAAB
J
-
o.sa 0R5.. .... RN2H
@rE6 K
rsl 010
.. .... æsrP
@a@
K
Ex. 2 Wen there are 3 effectiue d,igits (tuch as in high precision metal film
resistots),
5.62ha 562x 10' 562r . .. . RN%SR
@6@ln
F
c The I mark found, on some component parts indicates the importance of the
safety factor of the part. Therefore, when replacing, be sure to use parts of
ide
ntical desi gnati
on.
o For your Parts Stoch Control, the fast mouing items are indicated with the
marhs ** and * .
** GENERALLY MOVES FASTER THAN *
This classification shall be adjwted by each distibutor because it depends on
model number, temperature, humidity, etc.
Miscellaneous
Parts
I
Mark Part No, Symbol & Description Part No. Symbol & Description
A
3
A * ATT-790
*i AEL-108
** AEL-I55
a ACN{29
ADG452
ADE-O34
GWE-l
52
GWS-346
GWX-638
AKB076
Tuner
Assembly
(GWE-I
52)
CAPACITORS
Mark Part No.
T1 Power transformer
PLI Lamp assembly
PLz Lamp with wires
R100 Carboncomposition
resistor (2.2M1%Vll
AC power cord
Output cords with phono plugs
Tuner assembly
Switch assembly
LED assembly
Terminal
(AM STEREO OUTI
Symbol & Description
c37,C39
c30,c:]1
g2,c5, cl 1, C13,eA7,C52.
CU,
c56,C69
cl4, Cl5,C17,
C18,C20,C22,
C23,
c26,C29,C49,C50,C71
c24
c51,C57,C68
c58
æ2
c33
c34
c16,æ5,U3,U4
c27,C60,e,61
c19
u6,62
c25
c55
c63
c28
cæ
cæ,67
c65
u5
c36,C70
CKDYB
222K50
CKDYX273M25
CKDYF
1032
50
CKDYF4732
50
CKDYX473M
25
CKDYF223250
cosA 331K 50
cosA 511J
50
CEA
R33M
50L
CEA
OlOMsOL
CEA
R47M
50L
CEA
OlOM
50L
CEA
2R2M
50L
CEA
lOOM
50L
CEA4TOM
1OL
CEA4R7M
35L
CEA
101M
25L
CEA221
M16L
CEA221M25L
CEA
471M
16L
CEA
471
M25L
CEA3R3M
50L
CEA
1O1M
16L
-
ACK-OI2
ACM-006
ccDUJ
O90D50
CGB
R47K
5OO
ccDzM 050Ds0
ccDSL 060D50
ccDcH 080D50
ccDcH 1
50J
50
ccDRH 150J
50
ccDUJ 150JsO
ccDcH 330Js0
ccDsl 101J
50
Tuning capacitor
Ceramictrimmer
VC
TCXI
c1
c10
c59
u
c7
c9
c6
c3
c8
c12
ccDsL 221J50 c21
CKDYB561K
50 C38,C40
CKDYB
102K
50 C53
CKDYB122K
û U8
CKDYB182K
50 CA1
,CA2
-11

(
rr AcPo7g
RD%PM
trBtrJ
RNz4PO
trODDF
SEMICONDUCTORS
Mark Pan No.
VRI Semifixed
(5k-B)
Rl-R4, R6-R25, R27-R34,
R36-R67, R74-R78, R80-R87
R26,R35
RESISTORS
NOTE:When ordering resisfons,
conuert the resistance
value
into codeform, and thenrewrite the portno. as
before.
Mark Pan No. Symbol & D6cription
OTHERS
Mark PartNo. Symbol& Dercription
* * ASG-261 Push
switch
(FUNCTION,FM
MUTING)
AKA-O14 Terminal4-p (ANTENNAI
PMZ3OPOGOFMC Screw3X 6
VBZ3OP100FZK Screw3
X 1O
SwitchAssembly
(GWS-346)
Mark PartNo. Symbol& Dcc.iption
A ** 496€,15 Push
switch
(POWERI
LEDAssembly
(GWX-638)
NOTE:When ordeing resrstors, conuert the resistance ualue
into code form, and then rewite the part no. as before.
Mark PartNo. Symbol& Dæcription
Symbol & D$cription
** 2SK168
** 2SC535
** 2SC461
** PA3001-A
** HAt156Wf
** 25A7265
** (2SA7501
** HAl197
A ** zsoego
A ** (zsogrs,
** L81416
** 2SC945A
** (2SC257st
* 1082
r (srB0102l
* KZL130
* 152076
* (1S15551
* 1152473''
COILS,
FILTERS
Mark Part ltlo.
o1
a2
03,o4,o12
o5
o6
07,o8
o9
010
013
011,O14
01
,o2
D3
D13,Dl4
RDy.PM
trtrtrJ
* AEL-337
* AEL334
R68-R73
D4-D9 LED(Greenl
D10 LED
(Red)
I
I
A
^
Symbol& Dæcrlption
ATEO49
AT8.()66
ATEOOS
124428
AT8623
ATFO53
ATF-I21
ATFO38
T2 FM
det.
transformer
T3 AMosc.coil
T4 FM lF transformer
L6 RF
chokecoil
L7 Bar-antenna
assembly
Fl ,F2 FM
ceramic
filter
F3 AMceramic
filter
F4 AM lFfilter
'1
2