Mechanical Adjustments; Before Adjustment; Instruments Required - Yamaha K-1020 Service Manual

K-ro20
I MECHANICAL ADJUSTMENTS
1. Before adjustment
o S i nce h e a d m ag ne ti za t ion, dus t ac c um ul atio ns , etc .
a re l i kely t o int r o du ce er r or in t he v ar io us c ha rac ter -
i s t i cs , i t is v er y impo r tant t hat t he h ead s are pro per ly
d e magn e t iz ed an d c lea ned.
2. lnstruments required
.
H e ad Ga u ge ( M - 3 00 )
o A u di o fr e qu e nc y o s c i l l at o r
.
Osci l l osc op e
.
M i rr or C a s s e t t e { MC - 1 0 9C }
a Torque meter
o Wow/flutter meter
o D . C .V .M . ( D C V o l t a g em e t e r )
. A .C .V . M . ( A C V o l t a g em e t e r )
{ /^r
2-r '1
.^
t
Adlustm€nt
at€m
Tape
Test
Po in t
Instrument
required
M o d e %H".l:iH:, lAdiustmenti
natine
I
Remarks
1
Che c k cle ar -
an ce
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t a ke - up sid e
p in ch
roll er
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P AUSE
F ig. A M o re th an O.5
2
Pa n c h R o l l e r
Ti m i n g
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F ig
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jpushed up,
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l
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l s i d es i s s a mu l tan e-
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l m en t
r s r eq ur r eo .
I
t--
He i gh t o f r e -
c o rd / p l a y b a ck
h € a d a n d t a p e
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ig .o
A .C. V.M.
O scilloscope
t\, ir-
""t*tt"
( MC-109C)
- T "r q*t *
( Cassett e t ype)
R e pe at a dj us tm en t
i n s tep s 3 to 6 a n d
a p pl y s c re w l o c k
p a rn t u po n c o mp -
l e ti on o f a dj u s t-
r9!!.
A dj u s t by us i n g
sp a ce r a s s h ow n i n
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tor q ue , re a d the
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tr o n.
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L
(M 3 oo )
I I
1 l
He a dgauge
I
lwithM300
( M - 3O O)
I
lblock plac ed
I
lvert icall Y on re'
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I
lhead, adjus t so
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I
lgur g" and bloc k
i
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I
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-n."as"ffi
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i i
PB
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oi nch rotl e r
I p as s thr o ug h s m oo thl V
height ad i us t-
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ing sc rew (F i g .
J tac ti ng
p i n ch ro l l e r
c )
l g ui d e. ( Fi g . F )
n.i. rtn aa - Eav b ac k ou tp u t
o f L
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( F ig. C ) j a nd Ph as e di ffe re nc e
I
l s ho ul d be m i n i mu m
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( Ph as e d i ffer en c e l es s
I
l tha n 6 0" )
r
l T ap e s ho ul d m o ve i n
1
l the ce n te r o f e ra s e
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I
l s ho ul d
mo v e sm o oth l v .
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--ffi?,"'c,'
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i ]3 5 -5 59 /c m
t ake up torque
1
i F F, R EW to rq u e
and bac k tensi -
I mo r e th a n 7o gl c m
on torque.
Back tens i o n: I Bac k te ns l o rl :
lAdjus tleaf
]5- 1O g /c m
spring (5 ste ps ) ]
i{F ie. t)
I
4
R e co rd l p l a V '
b a ck h e a d t il t
a n g l e
5
S u p p l V s i d e
p i n ch ro l l e r
h e i g h t
Fig .F
6 A zi m ut h 1 O kH z,
-1 0 d 8
( MT T -
1 1 4 )
L INE
O UT
7
C h e ck P o sr
t i o n o f e ra se
h e a d a n d t ap e
m o ve m e n t .
Ch eck e ac h
9
Ch e c k F F
an d B E W ta k€
uP t i m € s
AC-512
71 2,22 a
c -6 0
I I
l N o r ma l ; Le s s th a n u 5
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s e co n ds
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H i g h s pe ed : L es s th a n
I I I
ssseconds
Chec k s peed
ls €mr
f
'x e d
v a rr
I3 OOO
+ .:H z
whileplay ing ar ,l eres r s tor a t
J
- r c
jback 3k Hz tes t the bac k o f th e
I
t ape.
lg_apstgl t M o to r .
I
(F iq. J )
t 0
Tape speed 3 kH z,
-10 d B
(MT T -
1 11 )
L INE
O UT
W o w,/ f lutt er
m e ter Fr equen
cy c ount er
PB
W o w / F l u t t er
3ooo +., !uz
I Le s s th a n O .O5 %
] C h e ck w ow /fl u tte r
( WR M S)
w hi l e c on fi r mi n g
3 k H z fre qu e nc y
w i th w ow /fl u tter
me ter c ou nte r.