Yamaha T-80 User manual

STEREO TUNER
I(FRON+ PANEL
HCONTENTS
.........................
TOSRVICE PERSONAL 1
.............................
SPEClFICATlONS 1
...............................
REARPANELS 2
.....................
DISASSEMBLY PROCEDURES 3
.............................
INTERNALVIEW 4
.............
.............
ADJUSTMENT ... 4 19
BLOCKDIAGRAM
............................. 10
PRINTEDClRGUlT BOARD ................... 11 13
WIRING DIAGRAM ......................... 14. 15
SCHEMATIC DIAGRAM ...................... 16. 17
EXPLODED VIEW ............................. 18
PARTS LIST ............................ 19 27
NIPPON GAKKl CO., LTD . HAMAMATSU . JAPAN
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WTO SERVICE PERSONAL
1. Critical Compnentt Information.
Components having special characteristics are marked
A and must be replaced with parts having specifications
equal tothose originally installed.
2.
LeakageCurrent Measurement (For 120V Model Only).
When service has been completed,
it is imperativethat you verify that all exposed conductivesurfaces are properly
insulatedfrom supply circuits.
EQUIPMENT AC LEAKAGE TESTER
@ Meter impedance should be equivalent to 1500 UNDER TEST or EQUIVALENT
ohm shuntedby 0.1 5pF.
@
Leakage current must not exceed 0.5mA.
B
Be sure to test for leakage with the AC plug in
WALL
both polarities. OUTLET INSULATING TABLE -
IISPECIFSCATIONS
FM SECTION
Tuning Range ............. 87.6 - 108.OMHz
50dB Quieting Sensitivity
............ Mono (DX) 1.6pV (15.3dBf)
......... (NR ON) 1.2pV (12.8dBf)
Stereo (DX) ............ 20pV (37.2dBf)
..........
(NR ON) 1OpV (3i.2dBf)
hbleSensitivity
(IHFMono) 75a ........ .0.9~V(10.3dBf)
UsableSensitivity (DIN)
............ Mono (SIN26dB).
.l .OpV (E)
............ Stereo (SIN46dB) .3.OpV (E)
I-e Rarpoma Ratio ............... 9548
................ IF Rslponro Ratio .l 15dB
............ Spurious R-ms Ratio.
.l l OdB
............... AMSuppression Ratio 70dB
Capture Ratio
Local
....................... 1.2dB
Alternate Channel Selectivity
DX ................. .85dB (U,C,R,A)
Selectivity (twoSignak)(DIN40kHz Dev.)
...................... DX 70dB (E)
Adjacent ChannelSelsctivity
DX .................. 20dB (U,C,R,A)
Signal to Noise Ratio (IHF)
................ Mono .94dB (U,C,R,A)
............... Stereo :86dB (U,C,R,A)
Signalto Nobe Ratio
...........
(DIN-Weighted) Mono 88dB (E)
.......... Stereo. 80dB (E)
Harmonic Distortion
.
Mono 100Hz. .DX0.03%, Local 0.02% (U,C,R,A)
.. 1kHz .DX0.15%, Local 0,03%(U,C,R,A)
6kHz .. .DX0.4%, Local 0.06% (U,C,R,A)
Stereo lM3Hz . .DX0.5%, Local 0.04% (U,C,R,A)
1kHz .. .DXO.5%, Local 0.03% (U,C,R,A)
6kHz. . .DX0.8%, Local 0.07% IU,C,R,AI
(4OkHz Dev)
Stereo 100Hz ...... DX0.5%, Local 0.05% (E)
l kHz ....... DX 0.5%. Local 0.04% (El
.....
6.3kHz. OX 0.5%, Local 0.08% (E)
Strreo Separation (IkHz)(Local)
mkHz. a........ .65dB
1kHz. .......... .65dB (U,C,R,A)
60dB (E)
10kHz ........... 50dB (U,C,R,A)
40dB (E)
F-affiy Raporar
0+O.~d9 . 50Hz to lOkHz ...............
-0.3
Subcarrier Product Ratio
............. 65dB
MetatSaturation Level ......... -3mV(75dBf)
AM SECTION
Tuning Range ........ .510 - 1620kHz (U,C,R)
513 - 1620kHz (E.A,R)
UsableSansitivity ................. ,250pV
Selectivity.. .................... 30dB
Signal to
NobRatio. ............... 55dB
Image RwnseRatio ............... 40dB
Spurious Response Ratio. ............. 50dB
Distortion (400Hz).
................. 0.2%
AUDIO SECTION
Output' Levelllmpedance (HIGH)
FM(100%MOD, 1kHz)
.... 1V/2ka(U,C,R,A)
1.6VI2kS2 (E)
.........
FM (30%MOD, 400Hz) 0.3VIZkn
..... REC CAL (50%MOD, 333Hz) 0.5V12kn .,
Output Level/lmpedanee(LOW) i
FM (100%MOD, IkHz) . . 0.5VI2.5ka (U,C,R,A)
0.8V12.5kn (E)
AM (100%MOD, l kHzl ....... 0.15V12.5kSZ
REC CAL (50%MOD, 333Hz) ... 0.25VI2.5kn
GENERAL
Power Supply
........
U.S. & Canadian Models 120V, 60Hz
.........
General Model. l1
01120V, 50/60Hz
220/240V, 50/60Hz
............
EuropeanModel. 220V, 50Hz
+,.K , 240V, 50Hz
............
Australian Model 240V. 50Hz
Power Cbnspmption-
U.S. & Canadian Models ............. 13W
..................
General Model. 13W
.
.................
EuropeanModel. 13W
................. Australian Model 12W
Dimemion(WX~D) . 435 X 93.5 X 357rnm (U,C,R,A)
(17-718" X 3-1 132" X 14-1116")
435 X 93.7 X 357mm (E)
(19-118" X 3-1/32'' X 14-1/16")
Weight-. ........................ 5kg
(Illbs)
Specificationssubject to change without notice
MARKET
U: U.S.-Model
C: ~anadbnModel
R: General Model
,>.
:'. .,-: --, ' '. , . ., ..:r ~g&+>*%&&&gF$g-&?;~2
A: Australian Model
J: Japanese Model
- . -- . -.
. -.
.,- .> . -1..

WREAR PANELS
U .S .& CANADIAN MODEL
EUROPEAN MODEL
GENERAL MODEL
AUSTRALIAN MODEL

POWER TRANSFORMER
U. S.
& Canadian models: GA67130
European model: GA67140
General model: GA67120
Australian model
: GA67150
TUNER CIRCUIT BOARD
AM LOOP ANTENNA
FRONT END ClRCUIT BOARD
POWER SWITCH (SW203)
IC114 : LC6502C-638
IC113:LC7210
KEYBOARD UNITCIRCUIT BOARD
LED FREQUENCY
& SIGNAL INDICATOR
1. Before Adjustment
1) Start adjustment approximately
5 minutes after the
power switch is pushed on in order to stabilize the
operationof circuit.
2) Adjust the OSC coil and IFT using high-frequencyor
nonferrousscrewdriver.
3) Adjust the FM section first. After that, adjust the AM
section.
4) Set the switches to the following positions unless
otherwisespecified.
TUNING MODE.
................. AUTO
RECCAL
...................... OFF
5) Be sure to make adjustment after installing the
bottom cover.
6) For connection with OUT PUT, use HIGHterminal.
< LineVoltage Checkup >
Check to see if the specified voltage is provided across
each terminal and
E inthe tuner circuit board.
2. Measuring InstrumentsAbbreviation
FMSG
............... FMsignal generator
SSG
................. Stereo signal generator
AM SG
............... AM signal generator
OSC
................. Oscilloscope
DlST M .............. Distortion meter
FC
.................. Frequency counter
ACVM
............... AC voltmeter
Center meter ........... Ji00036 or equivalent
DCVM
............... DC voltmeter
< FM Tuner Section >
@ Use 19kHz L.P.F for OUTPUT L and R terminalsand
make auditory compensation. Then connect the os-
cilloscope, AC voltmeter and distortion meter.
@ To check the optimum tuning point during adjust-
ment, connect the auxiliary center meter (Ji00036or
equivalent, current sensitivity: 250pA)
as shown in
the figure.
@ The accuracy of FM SG should be within +l kHz.
N Vcc T.M

"NOTE: 70dBp = 75.4dBf, 60dBp = 65.4dBf.
of auxiliary center tocheck again. If
meter
is positioned the pointer
is posi-
at zero (center).
pointer of auxiliary
center meter posi-
tioned at zero (center)
R197 and.J150 to
force stereo mode.
2. Adjust untilthe
frequency across
5
98MHz + l kHz aural distortion
is
LOCAL mode.
PLLinput phase
adjustment
+ 12 (.l1501
19K (C169)
300~2 FM
ANT
OUTPUT
FC
terminals C169
and
E becomes
19kHz i? lOHz.
FM SG
Stereo
( L-R)
modulation
OSC
l ncrease output to
maximum. Remove
FC and
2.2M52 resistor.

output is increased
to maximum.
R channel alone:
adjust
OUTPUT
Lch VR103 until
output is increased
level to minimum.
9% modulation
98MHz + l kHz
open across
itivity
is deterio-
d with FM ATT
98MHz + l kHz 10kHz
output differs
between when the
FM NR switch is at
ON and OFF position.

< AM Tuner Section >
Connect the AM loop antenna to the AM ANT terminals.
0 Connect the AM dummy used for adjustment to AM SG.
The accuracy of AM SG should be within kO.1 kHz.
i
i adjustment
l
l l I
1 up when tuned..
0
3 Auto reserarch
receptioncon-
f irmation
By shorting across the terminals TP(K4) and TPITG) in
i-2. ,-:;ode,AM
1,08OkHz, FM 92.6 MHz and FM 98.OMHz are automatic:;;..\! stored
into preset memories 8 to 10 respectively.
AM ANT AMSG TUNING Make sure that auto
search
reception can
UP, DOWN be made w~ththe
400Hz 30%modu- TUNING button for
lation both UP and DOWN
adjustment, re-
adjust VR204.
Sensitivity con-
I firmation
l
i
TUNING MODE
SW -+AUTO
< Digital Control Section >
AM ANT AM SG
630kHz r 0.1 kHz
' 1440kHz + 0.1kMz
1080kHz + 0.1kHz
(400Hz30%modu-
lation)
switches and con- indicator above the PRESET
ed, respectively. .In the same way, store the AM
The TUNING MODE
LED turns
manuallmono MODE switch to
operation con-
be made with the
TUNING button for
UP and DOWN oper-
ations. Also confirm
that when
FM is re-
ceived,forced mon-
1
/OUTPUT OSC,DlSTM
! LorR
I
I
I
VR204 Adjust so that all sig-
I nal indicators light
Confirm sensitivity
by checking to see if
tuning
is made at the
standard values.
2 / Fun-scalesignal
i I level indicator
,?'
1 When VR210 has
I been turnedafter
AM ANT AM SG
/1080kHz t 0.1kHz\
58dB~~orlower
58dBb or lower
58dBb or lower
. ~
Who?sensitivity
is improper, ad-
just as described
in steps
(l l to (5).

quency indicator. (When FM is
or "-" switch.
switch
is pressed,the following 3
memory opera- frequency in P2 is displayed and
tion confirma- the
P2 LED turns on.
seconds have
-r When the POWER switch is
ON MODE switch to turned on, the frequency in
P1
INITlALSTATION
is displayed without respect to
the frequency which
is displayed
before the
POWER switch is
turned off.Therefore, before
turning off the
P~WER switch,
display afrequency which has
. After 5 or more ~t this time, confirm that the
seconds have pass- frequency in
P1 is displayedand
ed, turn on the

TUNER CIRCUIT BOARD
I Connect resistor
across R467to 5268,
Full-scallesignal
level indicator
1 Separation adiustrnent 1
l adiustment Center Meter
(Ji 00036 or equivalent)
m

7FM FRONT-END SECTION DC
NFB MPX DECODER SECTION

CIRCUIT BOARD
(Panern Side)
FRONT END CIRCUIT BOARD