Hitachi HT-L55 Serviceanleitung Seite 6

HITACHI HT-155
ADJUSTMENTS
1.
Ouartz lock phase adjustment
lFig.
9l
This adlustment
is
carried
out when the quartz lock
is
loose,
the speed of rotation is irregular and the speed
in-
dìcator flashes on and
off.
( 1
)
Connect the + side of a
DC
voltmeter to
TP
1
O0
(No. 8
pin of
lCOl), and the
-
side
to
earth
(R12).
Set
the
measurement
range
to
3
-
5V.
(2) Make the cabinet
to
horizontal, and rotate
the platter
at
33
1/3 rpm.
(3)After
rotation has stabilized. adjust
R
1
2
such that the
voltmenter
readings are as in the
following
table:
Ambient
Temperature
For33 1/3
rpm
For
45
rpm
5'C
-
20'C
1.4 -rO.1V
t.+-.8ill
20'c -
35'C
1.3
+0.1V
t.s--oîiluu
2.
Linear
tracking adjustment
Carried
out when replacing tone arm
P152.
Move
the
tone arm
up,
and connect a
DC
voltmeter between TPOl
and earth (the 2 terminals of
R53)
as
in Fig.
1O.
Next,
turn the sensor
position adjusting screw in
Fig.
11,
and adjust such
that the
DC voltmeter reads
6 -r
0.5V.
After
adjustment,
turn the sensor position
adjusting
screw 180" to
the
right
(half-turn).
3.
Stylus
lowering position adjustment (Fig. 11)
This adjustment is
carried
out when the tone arm
does
not lower onto the lead-in groove of the
record, or when
replacing the tone arm
(1)
Play
the auto-in
adjustment groove on Hitachi Test
Re-
cord
HT-SE (Parr No.
2561131
)
(side
A).
(2)
Move
the tone arm
inward,
and adjust the stylus low-
ering position
adjustment
screw
with a
screwdriver
such
that the
stylus lowers
to
the count
15 position.
(3) lf the stylus is too far
out,
turn the screw to the
right
(
\
);
if it
is
îoo far
in,
turn the screw to the left
(f
).
One turn of
the screw
moves
the
stylus
tip
approx. 0.7
mm.
4.
Return
sensitivity check
(1)
Play
the return sensitivity check groove on
HT-SE (Part
No.2561131)(side
B),
and verify that the
arm
plays
up to count
1
8.
(2) Play the return snsitivity check groove
on HT-SE (Part
No.
2561
1
31
)
(side A),
and verify that the arm returns
atcount3-6.
SCTCW
der Abtastnadel
de pointe
Fis.9
Abb.9
Fis.lO
Abb. 10
Fig.
11
Abb. î
I
î
^'
<
When
di
Bei
Ouand
Linear
Lineares
Mécanisme
-6-