Yamaha K-1020 Service Manual page 8

K-ro20
I MECHANICAL ADJUSTMENTS
1. Before adjustment
o S i nce he a d magnet ization, dus t ac cumulations , etc.
are likely to introduce err or in the vari ous charac ter-
istics, it is very import ant that t he heads are pro perly
demagn etized and cleaned.
2. lnstruments required
.
H ead Gau ge (M-3 00 )
o A udio freq ue ncy o sci l l ator
.
Osci l loscop e
.
Mirror C asse tte {MC -10 9C }
a Torque meter
o Wow/flutter meter
o D . C. V .M. (D C Vo lta ge meter)
. A .C . V .M . (AC Vo lta ge meter)
{ /^r
2- r'1
.^
t
Adlustm€nt
at€m
Tape
Test
Po in t
Instrument
required
Mo d e %H".l:iH:, lAdiustmenti
natine
I
Remarks
1
C he ck cle a r -
a nc e
be tw e e n
ta ke - u p sid e
p in ch
r o lle r
a n d ca ps ta n
sh a f t.
PA USE
Fi g. A Mo re than O.5
2
Panch R o ll er
Ti mi ng
B
Fi g
I S TOP
lW it h head bas e
I
jp u s h ed up,
j ic h e ck tim i ng a t
I
wh ic h pi nc h
I
lr o ller s o n
I
isu o o lv s i de and
I
ita ke -up s ide
]
lco n ta c t
c aps tan
] T ake- up side Pinc
] r oller should s tar t
I r otating fir st.
I
l
lli tim ing ot both
lsides is sa multane-
]ous or sup ply sid e
pr ecedes, adj.ust'
lment
r s requr r eo.
I
t--
Hei ght of r e -
c ord/pla yb a ck
h€ad an d tap e
gui de
i g.o
A . C.V. M.
Oscillo sc o pe
t\, ir-
""t*tt"
( M C-1 0 9 C)
- T"r q *t *
( Ca ss e tt e typ e )
R epeat adj ustment
in steps 3 to 6 and
apply sc rew lock
par nt upon com p-
letion of adjust-
r9!!.
Adjust by using
spac er as show n in
F ig. H .
f"
"Ot.n
t.t"
"P
tor que, read the
center of deflec-
tr on.
He a dg a u g e
L
(M 3oo)
I I
1 l
He a dg a u g e
I
lwit hM 300
( M - 3OO)
I
lb lo ck pl ac e d
I
lve rt ic al l Y on r e'
I lco rd / Pl ay ba c k
I
lh e ad , adj us t s o
I lth a t M 3OO
I
lg u rg " and bl oc k
i
]o e co m es Paral l el
I
l(Fis. E)
-n."as"ffi
(M- 3 0 0)
i i
PB
Suppl y side
] H ead gauge sho uld
o inc h rotler
I pass thr ough s moothlV
h eig ht ad ius t-
lwa tho ut
i.ts block con-
i ng s c re w ( Fig.
Jtacting
pinc h roller
c )
lguide. ( F ig. F )
n.i. rtn aa- Eavback output
of L
j us ti ng s crew ]and R is maximum
(F ig. C ) jand Phase difference
I
lshould b e minimum
I I
( Phase differ ence less
I
lthan 60")
r
lT ape should move in
1
lthe center of er ase
lhead smoothlY'
lC apstan (suppty side)
I
lshould
m ove smoothlv.
rv"""u,-"
Fr -T-
--ffi?,"'c,'
RE Wtorque,
i ]35- 559/cm
t a ke u p torqu e
1
i F F , R EW torq ue
a n d bac k ten s i-
I m ore than 7oglcm
o n t orque.
Bac k tension: I Back tenslor l:
l Adj us tl eaf
]5- 1Og/cm
s pri ng (5 steps) ]
i{ Fi e. t)
I
4
R eco rd l pl a V '
bac k h e a d til t
angl e
5
Suppl V si de
pinc h ro ll er
h ei ght
Fig . F
6 A zim uth 1O kHz,
-1 0 d 8
(M TT-
1 1 4 )
L I NE
O UT
7
C hec k P osr
ti on o f er ase
head a nd t a pe
m ovem e nt.
C h e ck ea ch
9
Check F F
and B EW ta k€
uP t i m €s
AC-512
712,22a
c -60
I I
l N or mal; Less th an u 5
I I
seconds
I I
H igh speed : Le ss than
I I I
sssec onds
Ch e c k s p eed
l s €mr
f
'xed
var r
I3O OO
+.:H z
wh il epl ay i ng ar,l eres rstor at
J
- rc
jb a ck 3k H z tes t the ba c k of the
I
t a pe .
l g_a ps tglt Motor .
I
(F iq . J )
t0
Tape speed 3 kHz,
- 10 d B
( MTT -
1 1 1 )
LI NE
OUT
W o w,/ f lu tt e r
m e t er Fre q u en
cy co u n te r
P B
Wow / F l utte r
3ooo +., !uz
I Less than O.O5%
] C heck wow /flutter
( WRM S)
w hile confir ming
3k Hz fr equency
w ith w ow/flutter
m eter c ounter.