Technics SC-CH570 Service Manual

RS-CH770
HEAD
AZIMUTH
ADJUSTMENT
(DECK
1/2)
(L-ch)
Bubdsieyé
1.
Connect
the
measuring
instrument
as
shown
in
Fig.
3.
or
EVM
2.
Replace
azimuth
screws
for
both
forward
and
reverse
direction
after
removing
(R-ch)
Siete}
the
screw-locking
bond
left
on
the
head
base.
Fine
adjust
t
of
azimuth
can
not
be
performed
with
remaining
the
bond
on
°
justment
of
a
f°)
p
g
AGND
.
the head base.
(Supply
part
No.
of
azimuth
adjusting
screw:
RHD17015)
3,
Playback
the
azimuth
adjustment
portion
(8
kHz,
-20
dB)
of
test
tape
(QZZCFM).
Adjust
the
azimuth
adjusting
screw
until
the
outputs
of
the
L/R-ch
R/P. HEAD (Deck 2)
are maximized. (Refer to Fig. 4.)
Make
sure
that
the
difference
in
the
peak
level
between
the
left
and
right
E.
HEAD
(Deck
2)
P,
HEAD
(Deck
1)
channels does not exceed 0.5 dB.
4. Perform the same adjustment in reverse playback mode.
Check
of
the
level
difference
forward
and
reverse
directions
5,
Playback
the
playback
gain
adjustment
portion
(315
Hz,
0
dB)
of
test
tape
(QZZCFM).
Check
if
level
difference
between
forward
and
reverse
direction
is
within
1.5
dB.
;
Azimuth
Screw
Azimuth
Screw
6.
After
the
adjustment,
apply
screwlock
to
the
azimuth
adjusting
screw.
(Forward)
(Reverse)
Fig. 4
Fig. 3
TAPE SPEED ADJUSTMENT (DECK 1/2)
Note: When connecting the unit to other system components for testing, short
the
section
between
the
test
points
and
Eieand
turn
on
the
entire
system.
(The
unit
is
set
to
the
TEST
mode,
and
either
the
DECK1
or
DECK2
indicators will blink.)
Normal speed (Standard value: 3000 + 45 Hz)
1. Playback the middle portion of the test tape (QZZCWAT). (L-ch) Bubdsieyé
2.
Adjust
Deck
1
=
VR801
and
Deck
2
=
VR803
for
the
output
value
shown
or
E
‘
below.
(Refer
to
Fig.
2)
(R-ch)
[Gee
requency
counter
O+
Adjustment target: 3000 + 15 Hz (NORMAL speed
i
9
(
peed)
GND
a
Deel
Standard value: 3000 + 45 Hz (NORMAL speed)
High
speed
[Set
the
unit
to
forward
(FWD)
mode.]
Fig.
5
3. Playback the middie portion on the test tape (QZZCWAT).
4. Press the one touch tape edit (High) button.
This will set the high speed mode.
5.
At
that
time,
check
if
the
output
from
DECK
1
is
within
the
standard
value.
Standard value: 5000 = 600 Hz (HIGH speed) —_—|
6.
Adjust
VR802
so
that
the
output
frequency
of
DECK
2
is
within
+
30
Hz
for
the value of the output frequency of DECK 1. (Refer to Fig. 2.)
Note: When connecting the unit to other system components, disconnect the
short between the test points ULd0] and —ubgtud.
PLAYBACK GAIN ADJUSTMENT (DECK1/2)
1.
Find
the
start
of
the
315
Hz/0
dB
section
of
the
test
tape
(QZZCFM),
insert
the
(L-ch)
Mibscterd
tape
into
Deck1
and
2,
and
play
it
back
(FWD)
or
EVM
3.
Adjust
Deck
2
:
VR102
(L-ch)
[VR103
(R-ch)]
and
Deck
1:
VR104
(L-ch)
(R-ch)
@ibedstes3}
K_]
[VR101 (R-ch)] so that the output is within the standard value. (Refer to Fig. 2.)
©
Fig. 6
[Standard value : 280 mV+ 15 mV |
ERASE CURRENT CONFIRMATION (DECK2)
1. Insert the blank tape into Deck2, and press the REC PAUSE button.
3.
Check
if
the
output
at
this
time
between
the
erase
current
confirmation
point
TP301
kab
and
PuGsteg
(the output
on
both
edged
of
R313) is
withinthe
standard
— Erase
Head
value.
(Refer
to
Fig.
7.)
Standard value EVM reading
Normaltape :85+25mA (85 + 25 mV)
CrO2tape :150+25mA (150+ 25 mV)
TP302
Metaltape :185+25mA (185+ 25 mV)
sedate dikes a he a
Note: The test tape is not required when confirming the erase current. Fig. 7
istitiei tins
46=

Technics SC-CH570 Specifications

General

Brand	Technics
Model	SC-CH570
Category	Stereo System
Language	English