Yamaha K-1020 User manual

$
,t^ STEREO
CASSETTE
DECK
K-l
0n
I FRONT PANEL
;
aIJITPORTANTNOTICE
This manualhasbecn
providcd
for the use
of authorized
Yamaha
Retailersandtheirservice
personnel.
It has
beenassumedthat basicservicc
proccdures
inhcrantto the industry,andmore
specifically
Yamaha
Products,arealrcadyknown
and
understood
by the
users,
and
have
thereforc
notbeenrcstatcd.
WARNING: Failureto follow appropriateserviceandsafety
procedures
whcn
servicingthis
product
may resultin personal iniury, dcstructionof expcnsivccomponents
and failure of the
product
to perform asspecificd.
For
thescreasons,weadviscall
Yamaha
product
owners
that all serviccrequiredshouldbe performed by anauthorizcdYamahaRetaileror the
dppointed
rervice
reprerentativc.
IMPORTANT: The prescntation
or salc of this manualto any individual
or firm doesnot constitute
authorization,ccrtification,
recognition
of any applicable
technicalcapabilitites,or
establishaprinciple agentrelationshipof anyform.
Thc data provided is belicvedto be accurateand applicableto the unit/s indicatcdon the covcr.
The
rcscarch,engineering,and scrvice departments
of Yamaha arecontinuallystriving
to improveYamaha
products.
Modifications
are,therefore,
inevitable
andchangesin specificationare
subjectto changewithout
notice
or obliSationto retrofit. Shouldany discrepancyappcarto exist,
please
contactthedistributor's
Servicc
Division.
Staticdischargcscandestroyexperrsivecomponents.Discharge
anystaticelectricity
your
body mayhave
accumulatedby grounding
yourself
to the
ground
bussin theunit (heavy
gauge
black
wires
connectto thisbuss).
Turn the unit OFF duringdisassemblyand parts replacement.Recheck
all work before
youapply power
to th€unit.
I
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I CONTENTS
TOSERVICEPERSONEL ........1
REARPANELS... .....1
BLOCKDIAGRAM ......2
SPEC|F|CAT|ONS. ......3
INTERNALVIEW. ......3
DISASSEMBLYPROCEDURES. ..... 4-6
MECHANICALADJUSTMENTS. 7-9
ELECTRICALADJUSTMENTS. ....9-11
LSIDATA
TABLES 12
TIMINGCHART .......13
PRINTED
CIRCUIT
BOARD
(Pattern
Side) . . 14
- 17
wtRtNG .. .. .. . 18
fcBLocK ..19-21
SCHEMATICDIAGRAM .....22,23
PARTSLTST. .24-36
SINCEI'87
@YAMAHA
NIPPONGAKKICO.,LTD.HAMAMATSU,
JAPAN
2.5k533
El@PrintedinJapan.
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2.
K-ro2()
I TO SERVICEPER,SONNET
CnticalComponents
I
nformation.
Components having special
characteristics
are marked '
and must be replaced
with partshaving
specifications
equal
to those
originally
installed.
Leakage
CurrentMeasurement
(For l20V ModelOnlv)
When servicehas been completed, it is imperarive
ihat yo,
verify that all exposed conductive surfaces
are properly
insulated
from supply
circuits.
Meter impedance
should be equivalent
to 1
5O0ohm shunreo
by 0.1
5r F
Leakage
current
must not exceed
0.5mA.
Be sureto test
for leakagewith
the AC plug in tjoth polaIrres.
I REAR PANELS
U.S.A.
& Canadian
models
Generalmodel
British
& Australian
models
European
model
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K-|o20
T SPECIFICATIONS
Type 4-track.2-channelstereo Input Sonsitivity Impedance
Li
ne 40 mV/30 k-ohms
Head R & P Heads:Combination,PureSendustwith
triple-laminated
core
Erase
Heads:lon-platingFerrite,Double-gap Output Level/Load Impedance
Line
Head
ohones
Channel
Separation
(31
5O
Hz)
CrossTalk i'125 Hzl
Motors Capstan: DCServo
Motor
Reel: Flattorque DC Motor
Assist:
DC Motor
360 mV/47 k-ohms
3.6 mW/8 ohms
40 dB
60 dB
Wow & Flutter No morethan +0.06%
(W.Peak);
No morethan 0.03%
(W.RMS)
PowerSupplios
U.S.& CanadianModels
EuropeanModel
British& Australian
Models
General
Model
12OV
AC,6OHZ
22OVAC, 50HZ
24OV
AC,5OHZ
11
0
I120 I
220 1240VAC. 50/60H2
Fast
Wind Time About 70 seconds/45
seconds
(High
Speed
winding) (C-6O)
Frequency Response
Normaltape(-2OdB)
Chrome
tape(-2OdB)
Metal
tape
(-20d8)
Power
Consumption 28 watts
20 to 18.O00H2
t 3 dB
20 to 20,000H2
+ 3 dB
20 to 23,000H2
t 3 dB
Dimensions{WxHxD} 435 x 134 x 380 mm
17I la" x 5-1
14"
x 15"
Weight 7.6kg {16 lbs.
12oz.}
Signalto Noise
Ratio
Dolby oft
Dolby B on
Dolby C on
dbx on
Morethan 59 dB
Morethan 67 dB
Morethan 75 dB
More
than 95 dB
Specificationsare subject to changewithout notice.
(u)......
(c)
......U.S.A.model
Canadian
model
Harmonic
Distortion
Normal
tape
Chrome
tape
lvletal
tape
Lessthan 0.5%
Lessthan 0.5%
Less
than 0.8%
(A)..........
Australian
model
(G)..........
Europeanmodel
(B)
...... Britishmodel
(R1..........
General
model
I INTTNNAL
VIEW
O PoWER TRANSFoRMER
U.S.A.
& Canadianmodels:
GA68590
Europeanmodel: GA68600
Australian& Britishmodels:
GA68610
Generalmodel: G468620
€)
powEn
clRcurrBoARD
(1)
@
vnrru
crRcurr
BoARD
(1)
()dbx Circuit Board
@ Ootby Circuir Board
@cnpsreru
MoroR
(D
neelMoroR
@
nssrsrMoroR
Op-COM lC: LM6402G-494
@powEa
crRculr
BoARD
3

K-ro2()
I DISASSEMBLY
PR,OCEDURES
1. Adjustment of mechanismunit and replacementof
head
parts.
a. Remove
the cassette lid.
b. Remove2 screws
O in f ig. 'l and removethe blind
Plate.
c. Remove 4 screws
@ in Fig. 1 and removethe front
pl
ate.
* In this state, the head can be adjustedand its parts
canbe replaced.
Fis.1
d. Remove2 screws
O in Fig.
2 andreplace
the record/
playback
head.
e. Removethe screw @ in f ig. 2 and replacethe erase
head.
f. Removethe E ring @ in f ig.2 and replace
the supply
side
pinch roller.
g. Remove
the E ring @ in f ig.2 and replacethe take-
up side
pinch roller.
h. Bemovethe washer
O in f ig.2 and replace
the idler.
. Hsd wiring diagram
{viewed
from the
u
nderside)
Bemoval
of mechanismunit
Remove 5 screws
@ in f ig. 3 and remove the top
cover.
Remove
the cassette lid.
c. Disconnectconnectors
#1
Fis.4.
Fis 3
through rfi, +7 and #8 in
. CONNECTOR
WIRING
oA, G,B models .R model .U, C models BL
2.
d-
b.
d.R
m
CassetteLid
Voltage R. A, G, A mod.l! otrl
rr)RE lF6frE;'Tfil \
t, BE - 312
1
E: G model-
RE: A, B models
Fig.2

d.
I
:
I
i
i
I
;
i
i
!A
Remove 4 screws
€) in f ig. 5 and pull out
mechanism
unit gradually to the rear. Replacementof capstan motor Removethe mechanismunit.
Remove4 screws
@ in f lg. 6 and remove
the back-
plate.
O WIRING
OF MECHANISM
UNIT
the 3.
a.
b.
Fig.5 r''
/
I
J
A
I
I
I
i
j
{
i
. Srtting flywhsl belt
(viryed trom the rsr)
Fig.6
SensorCircuit Board
Reel Motor - Lavel

^
\A
F
c. Remove3 screws
molor. [) in Fig.7 and replacethe capstan
Fig.7
4. Replacement of reel
motor
a. Removethe mechanism
unit.
b. Remove2 screws
@ in Fig.8 and remove
the blind
Plate.
c. Removethe reelbaseasshown in Fig. 8.
" Note that coil springs
of the supply reel and takeup
reelaredifferent.
Supplyside:Silver
Take-upside:
Green
d. Remove the back
plate (Refer
to Fig. 6.)
e. Remove the washer
@ in f ig. 8 and remove the
flywheel (take-up
side).
K-ro20
Remove 2 screws
@ and nuts @ in Fig. 9 and
removethe reelmotor installation
plate.
Remove 2 screws
@ ln fig.9 and replace
the reel
motor.
ReelMotor lnstallation
Plate
Fig.9
5. Replacement
of assistmotor
a. Removethe top cover.
b. Remove the blind plate.
c. Remove2 screws
@ in f ig. 10and removethe assist
motor installation
plate.
d. Remove2 screws
@ in f ig. 10 and
replacethe
assist
motor.
Assist
Motor
lnstallation
Plate
Assist
Motor
Fis.
l0
s.
6
Capstan
Motor
Pushthe reelbase
to the rear
and remove
the ring.
Fig.
I

K-ro20
I MECHANICALADJUSTMENTS
1. Before adjustment
o Since head magnetization, dust accumulations,
etc.
arelikely to introduce error in the various
character-
istics,
it isvery important that the headsare
properly
demagnetized
and
cleaned.
2. lnstruments
required
. Head
Gauge
(M-300)
o Audio
frequencyoscillator
. Oscilloscope
. Mirror
Cassette
{MC-109C}
a Torquemeter
o Wow/fluttermeter
o D.C.V.M.
(DC
Voltagemeter)
. A.C.V.M.
(AC
Voltagemeter)
{/^r
2-r'1
.^
t
Adlustm€nt
at€m Tape Test Point Instrument
required Mode %H".l:iH:,lAdiustmenti natine I Remarks
1Check clear-
ance between
take-up side
pinch roller
and capstan
shaft.
PAUSE Fig. A More than O.5
2Panch Roller
Timing B
Fig
I STOP lWith head base
I jpushed up,
j icheck timing at
I which pinch
I lrollers on
I isuoolv side and
I itake-up side
] lcontact capstan
]
Take-up side Pinc
]
roller should start
I
rotating first.
I
l
lli timing ot both
lsides is samultane-
]ous or supply side
precedes, adj.ust'
lment rsrequrreo.
I
t--
Height of re-
cord/playback
h€ad and tape
guide
ig.o
A.C.V.M.
Oscilloscope
t\,
ir- ""t*tt"
(MC-109C)
-T"rq*t*
(Cassette type)
Repeat adj
ustment
in steps 3 to 6 and
apply screw lock
parnt upon comp-
letion of adjust-
r9!!.
Adjust by using
spacer as shown in
Fig. H.
f" "Ot.n t.t" "P
torque, read the
center of deflec-
tron.
Headgauge L
(M
3oo) I I
1l
Headgauge I lwithM300
(M-3OO) I lblock placed
I lverticallY on re'
I lcord/Playback
I lhead, adjust so
I lthat M 3OO
I lgurg" and block
i ]oecomes Parallel
I l(Fis.
E)
-n."as"ffi
(M-300) i i
PB
Supply side ]
Head gauge should
oinch rotler I
passthrough smoothlV
height adiust- lwathout i.ts
block con-
ing screw (Fig. Jtacting pinch roller
c) lguide. (Fig. F)
n.i. rtn aa- Eavback output of L
justing screw ]and R is maximum
(Fig. C) jand Phase difference
I lshould be minimum
I I
(Phase difference less
I lthan 60")
r lTape should move in
1 lthe center of erase
lhead smoothlY'
lCapstan (suppty side)
I lshould move smoothlv.
rv"""u,-"
Fr -T- --ffi?,"'c,'
REWtorque, i ]35-559/cm
take up torque 1 i FF, REW torque
and back tensi- I
more than 7oglcm
on torque. Back tension: I Back tenslorl:
lAdjustleaf ]5-1Og/cm
spring (5 steps) ]
i{Fie. t) I
4Reco
rdlpl a
V'
back head tilt
angle
5SupplV side
pinch roller
height
Fig.F
6Azimuth 1OkHz,
-10d8
(MTT-
114)
LINE
OUT
7Check Posr
tion of erase
head and tape
movement.
Check each
9Check FF
and BEW tak€
uP t im€s
AC-512
712,22a
c-60
I I l
Normal; Less than u5
I I seconds
I I High speed: Less than
I I I ssseconds
Check speed ls€mr f'xed varr I3OOO
+.:Hz
whileplaying ar,leresrstorat J -rc
jback 3kHz test the back of the I
tape. lg_apstglt
Motor. I
(Fiq. J)
t0 Tape speed 3kHz,
-10dB
(MTT-
111)
LINE
OUT Wow,/f lutter
meter Frequen
cy counter
PB
Wow/ F
lutter
3ooo
+.,
!uz
I
Lessthan O.O5% ]
Check wow/flutter
(WRMS) while confirming
3kHz frequency
with wow/flutter
meter counter.

-1
l^.
I
I
I
Il'o?lJ"li3l
'";,TlI
clearaoce l6190r.
K-ro2()
Fig.
B
Fig.
c
t-rg. E
Difference
beMeen A .nd B
Less than l/2
*Make sure to reconfirm after sdjustment
Adjust by beoding head base
contscting part of supply side
pinch roller.
'Confirm clearance and t;ming atter
acljustment.
There should
bea clear-
ance between lhe pinch arm and
head base
on both supply and t6ke-
up srdes.
Take-up Side Pinch Roller
-\
a
Tape
Supply Side Pinch Roller
Height Adjust Scrw
Capstan
Fig.A
Fig.
D
Er€g
Head
\ ..'
Hesd Fix Screw
r^ Tilt Angle Adjust Scrw
--
---A:' @
' Be sura to tighten the head fixing scrfl securely,
' Be sureio apply scrw lck painr to each adjusiing
scrry after sdjustment.
,/a\
(t@])
\7
Head Gauge
M.300e
y"'
il I .il||ti----
It | .il|t I
il t ililtl
ll L- .t | "r-_I_----'
[r -_:-J I
l_-----
Head Gauge
M-300
Adjust so that the same
clearance is obtained at
the upper and lwor parts.
E
;;;;;* Take-up
side
Pinch
Floller
Fig.F Fis.
G

K-ro2()
' Usespacer
to adjust the h8sd heighl Fig. HFig.I
Capslsn Moto.
Fig.J
I ELECTRI
CAL ADJUSTMENTS
O PLAYBACK
ADJUSTMENTS
* Makesureto use
a new tape of I
ECstandards
for atest
taDe.
Alignmenttape
Normal TDK AC223 or YAMAHA NR 60
CrO2 TDK AC512 or YAMAHA CR 60
METAL TDK ACl12 or YAMAHA MR 60
o Proceed
with the playback adjustmentsafter having
finished
the mechanical
adjustments.
] (dbx
circuit I I
{dbx
circuit i
I 1 board) 1-____1 I board) I
. RECORDINGADJUSTMENT
. Proceedwith the recording
adiustments
after havingfinished the playback
adjustments.
{
t
uHe8d
Hei0hr
Orivcr
/
/
(]-\
\\\ \\ \
F;f *r;,-.";;-l-;""- -j-,*l1;l*-[ Tffr# JW";;11
E.o^-" r J;';iat-r-I D.cr/M frtorl *roir'il- o.rfoc --
i iDc.offset lrP2{B)-E i I I vR102(R) i
i-t-lFr"yb".ki'^
r - i{tztzc l Lrrveou-f-eivnr---trl uRlon-L)
-i 36otls--v --
I I | 1stsa, \ i (Acvort/da I I vR1o4(R) I t-g.o+tdBv)
i I I \toonwo/m/ I I rvteter) I l
F_+ _+ _ __ f__t _ I
I s ietayuacr
rrequency Mrr.3s6u I r-rr.re
oui I ; 6nt i t-f---T;"*;,"*;'"
J i r".oonre
confirmation I {3t80
+70ps1 i 1 1 lshoutd
bewrthin
specifi-
response
conTtrmatton (J tUU
+ /Ups, 1 i lshould
bewtthin speciti-
I ],.I,.r';',,tuo|,,I I i ] lcationinFie'K
a ldbx rc 1 Tpl -rp2 D.C.V.M. 1
Srop 1 vRTOt i 15
t 2mVD.C.
I I (dbx
circuit ] {dbx
circuit
t-Aai-'tf"ntT , " -"t^Tt T..rj:l:jt- ,. . ' M"".u,"-"nt Jnai"tln"',tl *;- *.*,--
["n".n=."";r lL^;F;;* faoa*".AppryarkHz
sine*;-]u"*.tLr-r l*aaE
r"n-*,-i -'-l
Meter OUT signal
from LINE lN so iVR5O4
{R) I
(red}
should I
r 1(+4.5dBl I rLiNE l-Au;it that LINE OUT voltasers I ltisf't. I
r ltno
uott j li-,i"
]fll$,"."", $'J*,i,'-iyJrlirtase
is
I lrisht i
fF;k L"*f oscillator f,ppty" rri. rinu
*u* fvnsor tr-r I ooe,"g-"n, -iwrt"n nllnsrEn
-----l
Meter signal
from LINE lN so 1VR502
(R) i(redl should FADER isdecreasedL l
l(OdB) 1 that LINE OUT voltage i tliStrt. and R segments
i 'is 360mV (-gdBV). L aroundOdBshould
I 1 fade
out almostsimul-
* Use360mV
(-9dBV) for 0dBas
the
standardlevelof
this
unit.
. \')A
9
8ek Teosion (5 iteps)
at Playback mode @
@@
l(OdB) 1 that LINE OUT voltage I llight. and R segments
is
360mV {-gdBV}. ] around OdBshould
' , I L fade
out almostsimur- i
_l _ taneousty. I

AE^1",'J#""'F*"
,'.t i'H[lT:l'I '.]" i - %":::1:i:::'
loo,;:H""p
Ratins
i "".*1
li-5Lnso'"+Tnrrraillp;c.v.n,r.- rnrc israseolust* -Fjg: ---noiu.trotn",1
lation level ]TP6 ] LMaximum
(VR107) lt-t tO oscitlation
' Set
VRl 19and 12Oall I 1
output is
I the way to the teft. I t
;;;;r.
OUT ,TAPE (RECat minimum), set lFi102 (R) i 13mV imize
biasleak.
I I I BIAS ADJUST to maxi- I l
, 1 mum and measurebias I i I
I leakat LINE OUT when I i I
--- -] -t- - -- -l 4t"" i1I tt t""ilt --l-- - tlrililnu'n'
3 ,BrAS
LeakMErAL
ir-rruE
nc.v ru. tIFg_ IHL;;tflttpe["d -[:19119q-!3;,1.r';; -lnJr,"-'"
*.rn,ni
ll
I I I recording
and monitoring I I
AC-223
INPUT LINE A.C.V.M.
lsrcNnr- T
(1
kHz,
1
0kHz,
-20d Bl
simultaneouslv{TAPE
mode)by using a metal
the standardlevel)
3-rRecord
the signaland
adjustso
that the same
levelasthe above ilr
level
is
obtained.
I
rRecord
andplayback
a
l kHz (-20d8) signal
and read
the level.
Recordand playback
a
10kHz (-20dB) signal
andadjust
so
that the
same
level
asthe above
:-!,
level is obtained
SetMETAL (AC-712) and
DerformBIAS TEST.
Frequency
response
shouldsatisfy
Fig.
N.
I'l''ir'rili.
i
i"ii.ii
r*
lguency
is
used
for
adiustment.
Bias
],,191":l"l
may
indi-
Each
adjustmentin
Steps4and6should
becomplited.Con-
I simultaneously
{TAPE I I
I I mode)by using
a
metal I I
litape.li
rrllltane'il
ia-n""*Ji"s-iara-firvF-e.cl.rv. inic l,r,s"wilrgl"aiio "s
-ft*iri lr_jlto.sae
- ---rh;;r.
I Levet ilNpuT OUT TAPE 1 themidpoint. lVR1t2 (R) i lthis
unir
(Through) SIGNAL ___-NR-+ ,zApplyalkHzsinewavel (equivat,
i L ,(lkHz, iLtNEtnudio oFF I sisnal
from
LINElN so I i vn). tt
t i 1-20d8) jlN ifrequency I I that
LINE
OUT
voltage
I L used,stir
i I I j
osilaror i I is
36mV
(-29dBV). I lin
revetr
* "r-l
) 4 Becording tAC-712 ILINE A.C.V.M. REC 1,'r,SetVR119and 120as lVR11l {L) 10.5d8 Thereferencetapeof ]
Level INPUT OUT TAPE the midpoint. lVR112 (R) thisunit isAC-720
(Throush) 9]9.ryAL -- -ryl_* ,zApply-alkHzsine-waveI (equivalenttoTDK. I
ilii
(equivalent
to TDK- {
MA). lf other tapeis j
used,slightdifference j
in levelresults. I
I 1(Through) TSIGNALT___ -L______lNR-+ jZAnOlvalkHzsinewave | (equivalentt,
i L ,(lkHz, iL|NE tnudio oFF I sisnal
f
rom LINE lN so I i MA). lf othe
I i 1-20d8) jlN ifrequency I I that LINE OUT voltage i used,stightd
t i 1-20d8) 1lN lfrequency I I that LINE OUT voltage I i used,slightdifference
i I t lositlaror i l.'ts36mv.(-29dBv).. I ]inrevel
results.
A
I
1.
I
i i i l''1:::t'.ii;:l1ti#"ll
i i i issfxt.,lfifi:i*n'^l
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tne lKHz re- LVR119 (Ll I Frequency IASORBiT signalis
jBIAS TINPUT OUT I jTAPE ] cord/playbacklevel VR120 (R) response lltHz and 10kHz,
use
(METAL)
ls-tGNALI I i}1. i.^lsl"g
1): I tloulg
saj- iql.kf
, sisnar.and
a
I I I i"iii"t'"a.' I I i i
l=:--]--- -i=----- i' i .- --+----f:- -f- - --r -----1
5 Recording AC-712 LlNEIA.C.V.M. REC lil.Applya lkHzsinewave 1VR121
(L) l+0.5d8 Eachadiustmentin i
Level
(dbx) INfUT OUT I TAPE I signal
from LINE lN so ,VR122 (R) step
4 shoutd be I
i]9.ryAl__-_t_______ry.R* ] thatLI.NEoUTvoltase
I "ompteted. I
{1kHz, jttwE
laraio rdbx I is36mV
(-29dBV). I 1 l
-2odB) I
lN lf.equency ,
z
Recordthe signaland 1 I
losillator ] adiustsothat thereis I I I
j I I I I notevetdiffersncewhenl I l
I I I I I sounce/rRpeis 1 I I I
r j I I I li*it"t'J I I ]
r
^r^ - '-
- '':--;+rrruEincnnn
il^;:_
-l*"t-frtirH.[- ty.ltgttlir.o*r"u ]l,p"rt!,rrr,,
--1
6 Recordins LC^/12 lTnPe cord/playbacklevel VR120 (R) response jttHz ana 10kHz,
u
iNR * I (Step
4). I shouldsat- la lkHz signaland
a
ritH.,
- 1 | lcjir ]:a,h-""5.i'uno
prayback
a j ;;;;";js.t ]iriti, '"""
*r'"'
lokHz, I 1 I j 1OkHz(-20dB) signal I fad.iustinsrecording/
i-20d8)
i I I l:*""i1::l::,*"":*:"1 I l*::l::li::':::-:v
samelevelasthe above I ]response
andconfirm
:1r
level
isobtained. ] lthat eachrating
is
1 I I I I 1 I I lcateanerror'
i__f __.____ ._+_ +_ _l ) _
j z jRecorarns
lnc-sr-l-trvEfAcv.rvr.
-fnrc--fr-,n-"o,oi"alt"yb;.k; ivnrrs
(l-)
lFreque"cv
lAroneirtig"ar
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i lPlf, ,lT:llT, iourI irner I III:^hr-g9?l:1911
rvRl16(")
li:'el'.-^ illl:,:{_19,k1.;
y*
(CrOr) SIGNAL t I J and readthe level.
(A lshould sat- a lkHz siqnaland a
- (1kHz, -LtNEIffiio -- I ' slight
differenceresults ]
isfy f ig.tvl. ]tokHz oni when
1OkHz, lN I
f.eouencv ] as
record/playback
level i 1 'adjusting
recording,
1-20d8) i l^";ri.'^,' i I of thisunitissettoAC- i i lolavbackfreorrencv
lN I
frequencv ] as
record/playback
level
i I 'ad,usting
recording/
'ositiator ] ofthis
unit
is
set
to
AC- : lplayback
f
requency
i I i I 712.1 i I lresponseandconfirm
i ] i lrZlapply
a 10kHz signal i I ithat
eachrating
is
i I 1 from
LINElN so that I I lsatisfied.tfother
LINEOUT
voltage
is i I lf
r."qr"n"y
isusedfor
36mV
(-29dBV:vol- I I tadjustment.
Bias
indi-
tage
20dB
lowerthan I I lcator
mayindicate
an
Recording
IBrAS
l(Normal)
REC
TAPE vR1 17 (L)
vR118 (R)
BIAS Test
(LOW)
BIAS Test
(H
igh
)
BIAS
TEST
REC
BIAS
ADJ
Center. VR109
AC-112 TP3 A.C.V.M :O
t S.V

.Y
f"Pil'Jfl""1
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'Jmj'Hn::li'.*1 %"n',fi::!'
loo';:l.i:""'l
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lz tLnso*ii-rvrrraL
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E cnrvr.-
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level ]TP6 j jMaximum
{VR1o7} 1L110 oscillation I i
i I ] j Set
VR119and
12O
all i I
outputis i I
] ithe
wayto tl'e leltr I Tal'T1n\ ] _ _
:t lBrAtL;k METaltinrF-n.ct.M. -RE--fwirr' ". "s*r "pprl"o-_lriror tr-r ir-1.,G"n lAdiust
soasto minill
I OUT ITAPE 1(REC
at
minimum),set IFi102
(R) itgmV lmize
biasleak. I
I , i A|ASADJUST
to maxi- I I
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I I I ,leak
atLINE
OUT
when I r
i I recordingandmonitoring 1 I i f
I ; simultaneouslv(TAPE I I 1 I
mode)bYusingametal I
t___i
l-i-ip"^^- s-lA-c.zlz-I-NrEcvlra. TnrC
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ot-l
] Level INPUT OUT TAPE the midpornt. ]VR112 (R) thisunit isAC-72O I
(Throughl SIGNAL - -_-NR -) lz Appty a lkHz sine
wave I (equivalent
to TDK- |
(lkHz, LtNa-A;G----oFF , signai
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I I l-20d8) ltN I
frequencv I I that LINE OUT voltage I i lused,
slightdifference i
i I I I losiliator l._
rs
36mV.{-29dBV).
. I i ]in
lever
results. 1
I i I I 1 I llr-,Recordthesisnal
and I i
I I I I I I I adiustso.thatthereis I i I 1
1 I i I I I lglgye..lgilJgluncewhenl i I
I I I I I I SoURcE/rAPEis I i
I I I I t i lswitched. I I I 1
T5 lE""ord,ns
-lnc'zriftru-ln.c.V.r'4. -1nec [r epplvi lkHtr;" ;"*IvArzi tr-t ,to.sae ie""r'uui*t'n*ii" - l
i JLevel
(dbx)
iINPUT
IOUT
I ITAPE I signar
from
LINE
lN
so 1VR122
(R)I step
4
should
be I
I I ISIGNAL i I NR + I that LINE OUT voltaqe I comDleted. I
I i [kHz, [LtNETArdi.----iao" I is
gemv
(-29dBV).
- { j
-20d8) ;
lN lf.equency ,
2
Recordthe signal and 1 I
I I I I losillator i adlustsothattherers I i I ]
j I I I I I nolevel differencewhenl I
i I f i I i isounce/taeei' 1 1 1 i
i i i I I i jswitched 1 1 1 I
'- --lr-rrrrifncv-rrrr. lnic f
t
co'r"- rn.tH' iu- Ivnirs rl-r
frr.qru""v In"oneiirisnurir- -l i6lRecordins lAC-712
I letaS IINPUT lour ] lrRpe I cord/playback
level lvntzo (R)lresponse llkHz
and10kHz.
use l
I I(METAL) SIGNAL ] I lry! - l_lsteo
a). i ishoutd
sar, ]alkHz sisnar
and
a ]
SIGNAL] I lrun- I lStepO).' i ishouldsat, ]alkHzsisnat anda
(lkHz, i i iOf r l.zrRecord
and playback
a I isfy Fig.L. jl0kHz onewhen
I 10kHz, I I I 10 kHz {-20d8) signal I I Ladiusting
recording/
-20d8) ] I I I andadjust
so
that the I I lotayback
frequency
I i i I J same
level
astheabove I lresponse
and
confirm
I I I I i!; levelisobtained. I lthat eachratingis
i I j I I I lsatisfied.lfotherfre_
I I I I I I llY"n:roys1lror
I I I I I I lquencyisusedfor
1 I I I i ] ] ladiustment.Bias
liIl]lllindicatormayindi.
I I I I I - -L 1 rcateanerror'
F""*dt"s-ltcfEttNE fncv nlr. [nEc
- -]i,n"-rai"o or"vui"t--i*vR1it(L)
j
F'"or-"y ]-e-one'r
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;is;;r ]vdr
ro
ini 1
r."'ponr" 'lkHz
andlo-kHz,use
{Cr02) ISIGNAL I I I i and readthe level.
(A lshould sat- ja lkHz sisnal
anda
i(lkHz, lLtfUelnudio 1 I slightdifference
results I jisfy Fig.M. l'lOkHz
onewhen
llOkHz, ltN I
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record/playback
level I j ladjusting
recording/
'-20d8) I lositiator
' I 1 of thisunit rs
setto AC- I playback f
requency
| 1 I 1 | 712.1 i I lresponseandconfirm
I 1 | I j@Apply
a lOkHz sisnal i I lthat eachratins is
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I
\\
l
n'.
')
)
LINE OUT voltageis I ]f requency
is
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for
36mV (-29dBV: vol- I I ladjustment.
Bias
indi-
tage
20dB lowerthan i I )cator
may indicate
an
the standard
level) 1 I Jerror
3\
r.;1
,"iiiil\o-,''',,
Becord
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ng
BIAS
l'*"..'""
BIAS
Test
{LOW)
S Test
lH
igh
)
A.C.V.M. TAPE
BIAS
I EJ I
REC
BIAS
ADJ
Center
r9Record the signaland
adiust sothat the same
level
as
the above O
level
isobtained.
-lrRecord and playback a
lkHz {-20d8) signal
and read the level.
.2,Becord and playback a
10kHz (-20dB) signal
and adjust so thar the
same level as the above
'-1,
level is obtained.
SetMETAL (AC-712)
and
vRi17 (L) Frequency
Ri 18 (R) responSe
shouldsatisfy
Fig.
N.
3O
t 5mV Eachadjustmentin
Steps4and6should
be
complited.
Con-
firm adj
ustmentis
madewithin 12
aduation
when BIAS
TEST is
performed
th othertape
lAc-512,2231
.
Ac-223
INPUT
SIGNAL
(1
kHz,
1
0kHz,
-20d8)
perform BIAS TEST
VR1
09 Inorita

. PLAYBACK
FREOUENCY
RESPONSE
NR 'THROUGH
. RECORDINGFREOUENCY
RESPONSE
NR 'THROUGH
METAL
CrOz
NORMAL . 3dB
t4k
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Fig.
N
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j_i
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. TESTPOINT rL NE-
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I
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,ob T-
| 0 f ,02
TNI lNl
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fL'ff:itr l
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R;
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K-r(Jzg
I LSr DATA TABLES
. LM6402G-494
O
MODEVSOUTPUT
L..... Low level
H .....Highlevel
- .....Holding
premde
*" .....
L changeswhen operation
is
ON.
H changesat initial REC.
' .....
L changes
when TAPE is
selected.
H changeswhen SOURCE isselected
Note
I
I
i
I
lr2
I
I
h-
II
CLOCK, Microcomputer(800 kHz)
I +5V
I
LSE INPUT, Reelstand
{Take-up}
PULSE INPUT, Reel stand
(Supply)
KEY SCAN INPUT
Speed
Control of ReelMotor 2
Speed
Cont'ol of Reel Motor 1
AssistMotor Control
Reel
Motor Control
LINE
MUTE
OUTPUTSignal
MONITOR SWSignal
RECMUTE OUTPUT Siqnal
REC BIAS OUTPUT Signal
CLOCK, Microcomputer (800kHz)
{1 figure)KEY SCAN 1
DISPLAY (2 figure)KEY SCAN 2
DIGIT (3 f
igure)
KEY SCAN 3
OUTPUT (4fisure)KEY SCAN 4
RESET,
Microcomputer (Reset at "L" level)
%--l- orspr-nv
orcrr
(oott
rev scnr.rs
--
D1 NORMALTAPE
METAL TAPE
a.MEMOBY
b.
BtAs i:l::
c. tri
d. :<
e.
TAPE
f. O_M REPEAT
g. FULL REPEAT
_, REC, " TEST
REC MUTE
LINE
MUTE
rt-Ay- cuE TIEVIW
LIHH
FF j rrr !os"!.r
i-l -t--
REEL.R
REEL
REEL
Tr:
Tt: I
T.
r3,
T+:
I
KE
Tr:
Tz:
Te:
t3

ITIMING CHART
MOVEMENT
MODE
KEY
OPERATION
srop
+ il,t"".[ilfi Y
--o--
p
LA
y
----o-
MECHANISM ^
MOVEMENT -T
Kz
REEL R
HI REEL F
ASIST R
ASIST F
II REEL
lz REEL 2
T1
: Reversingdue to assistmotor stop... About 14
msec
T2: Playoperation time . . . About 300 msec
T3
: Delay of play
+ STOP
. . . About 15 mesc
Ta: Reelmotor running time beforeshifting out of the
previous
mode . . . About 50 msec
STOP o---------c- REW -
MECHANISM
MOVEMENT
T5
: Operation
timeof STOP
-+REW.
. . About90msec
T6
; Delay before fast forward voltage
. .. About 260
msec
Tr : Delay before
high speed
fast forwardvoltage. ..
About
300msec
{
l>ruHl
-Tl=-
Ir
ll
Ko
ccF
of
ol Kr
zj-
Lll J
atro
F
o-
F
f,
o
(Jn3
a",tt
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OPERATION
Go BIAS
GI REC MUTE
G: MONITOR
G: LINE MUTE
HI REEL F
MOVEMENT
MODE
laFn ontreE llDt n vl
ll
ii
MECHANTSM IMECHANISM
MOVEMENT IMOVEMENT
STOP {--l< REC/ 6-/+ REC
ll/-or\tTdE
I
I
I
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4-o--PLAY -
MECHANISM
MOVEMENT
FTdFI
I|H,lbNnoRl
I
fI\
PAUSE MECHANISM
MOVEMENT
T1
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mute
delay
. . .About25psec
T2
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switchingmute
. . .About50msec
T3:Operation of PAUSE
-+
PLAY
...About
150
msec
Ta: REC mutedelav
...
About
250msec
(to
wait
tilrunning is
stabilized)
Tr : PLAY operation
.. .About
300msec
T6
: Line
mutedelay
. . .About 250msec
t3

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