Dual C 822 Serviceanleitung Seite 22

'i
Mechanical section
General
notes
The
item
numbeTs
stated refer
to
the
llsts
of replacement parts and
ex-
ploded
diagrams
below-
1.
Removing
the
housing and
the
base
plate
Remove the
f
our
machine
screws
2
and the
f
our washers 3.
Withdraw
the housing 1
from the
rear.
ln
order
to
remove the
base
plate. the
six machine screws 53 on the
lower section
of
the
unit
must be
loosened.
2.
Removing
the front trimplate
Remove the houslng
1 as
described
above.
The
six
head
screws 19, three on
the front trimplate
upper sectjon
and
three
on the lower section must be removed.The
fronttrimplate
6 can now
be
removed.
3.
Removing
the
cover
When carrying out
repairs on
the mechanical section, we recommend
that
the cover
1O8
remowed-
The
most practical method of
removing
the
above
parts
is
to proceed
as
follows:
Loosen
mounting
srews
of holder
11O .
Remove holder
11O
together
with
head
dust cover 112.
Disconnect cable connectors
of
leads
to
the
LED
plate
105 and
photo electric cell plate
118 and
open
wiring
haTness.
Unlock
mounting
tab
L of
cover
1O8.
Femove cover
1OB
carefully.
4.
Motor
a)
Feplacing the
motor
ln
order
to
replace
the motor
172, Ihe
motor
belt
and the
f
lat belt
must
f
irstly be removed
f ro
m
t he dr rve
pulley
1
73
-
Loosen
mo
unting
screws
of
holder 110. Remove holder 110
with
head dust cover
112
and
unlock mounting tab L
of
cover
1O8 (clo
not
remove).
Unlock motor
bracket 155. Remove
the three rnountino
screws
of mounting
set 147. Remove
the motor
172.
Unsolder
the
connection
leads
from the printed
clrcuit
board.
Loosen
the grub
screw
and remove the drive
pulley
173. Place the
drive pulley
173 onto the spindle
of
the new motor
172. Set
a
clearance
of approximately 1 mm
between
the drive pulley
173
and
the motor retalning plate and then tighten the grub
screw.
Solder
on
the connection
leads
to
the
printed
circuit
board
(red =
+).
lnsert the motor into
the unit
and
lock
in
with
the
f
ixing
screws.
Fit
the
flat
belt
and
motor belt
to
the drive
pulley
173.
b)
Motor
speed - tape
speed
Measurement procedure ls the
same as
that
described
in
section
6. "WOW and flutter". The
tape speed
may be set
with
the
aid
of an insulated screwdrlver at the
rear
of
the
motor.
The
speed
is correctly adjusted when
a
maximum deviation of
-
1
to + 0.5
%
is
measured
5.
Drive belts
I
n order to change defective drive
be
ts,you should proceed
as
follows
(refer
to
belt diagram):
The motor belt
A
and the
counter
belt B can be removed
or
replaced
without further difficuitV.
Remove the
f
lat belt C
an
the drive pulley.
Loosen
mounting
screws
of
holder
1
10. Bemove holder
1
10 together
with
head
dust cover
112
and
unlock rnounting tab L of
cover 108
(do
not
remove).
Unlock motor bracket
155.
The
flat
belt C may
nowbe
replaced.
Drawoutthe flywheel
164
from
the
beari ng bush
.
Attentionl The plastic
washer 166
at
the
f
ront
s
de
od
the
unit wrll
drop off.
The
tape-up
belt D
mav now be
replaced. Once the
be
ts
have
been
fitted, the pÜlyethylene washer
166 must
be
f
itled on the
spindle
(capstan) of
the f ywheei
164
Furthermore,
it
is advsable
to
press
the fast forward
or
reve[se
w
nd
key and clean the
capstan
and the
drive
belt
with
a
cloth
soaked in
methy
ated
sp
rit
6.
WOW
and
flutter
Measure
with
a
WOW
meter (e.g. Woelke
ME 101, ME 104 or Franc
EMT
42O
A)
and
WOW test
cassette
3150.
Setting
of the test instrument:
0.3 %
measurement range,
weighted.
ln
order
to avold
incorrect measurement caused
by
Jamming
tape
travel
we
recommend
that
the test
cassette be
rapidly wound
and
rewound occasionally.
Typical
values
for
the Dual
cassette
deck {playback}
):O.OB
- O.12
%
lndividual
higher deflections should not
be weighted
as
they
are
the
results of
band tape-head contact
caused
by
detr;tion,dust
or felt par-
ticles.
lf
necessary, check the
following points:
a)
Clean
the pinch roller
and
capstan
b)
Check
the pinch roller
for
free movement
c)
The take-up torque, which
is
adusted
at
the couplinq,
should
be
5.5
I
1
mN m
(55
+
10
pcm).
Slightly fluctuating
values clo
not
affect the
WOW.
At
the
same
time,
the
torque on
the non-driven
side
should
be
0.2
0.4
mN
m(2
-
4 pcm).
A
higher or carying
value suggests
that
the bearlng on the left winding gear
is
defective.
d)
Replace the
f
lat belt or
the
f
lywheel
Solenoids
When mounting
the two
solenoids
143
it
is
recommended. To
proceed
as
follows:
Bring
the
mechanical gear
in
the
upside
down
position.
With,
the
solenoids
in the operating posltion
move aTm
130
to
its
ower stop
and
mount
the solenoids.
Adjustment point
When
the right winding
gear 162
engages
the coüpling 158
make
sure
{or minimum play
for
theet.
To
compensate
unsuf{icient
play
of gear slightly
remove
the right
solenoid backwards.
To
compen
sate
excessive
play of
gear
slightly remove
the left pulling
back-
wards
Coupling
To
ensure sat;sfactory winding, the
take
up torque
of
the
coupling
must be correct. The
take-up torque should
be'5.5
t I
mN
m
(55
I
10
pcm) when
measuTed
with
a test cassette
(Dual
item
no.
232
197J
.
Readjustment
of
t he ant ire
unit
maV be
ca
rried out
as
f
ollows:
1)
lsolate
the unit from
the
mains
by
removing the power
cable.
2)
Remove
the housing
'1
3)
Rotate the
flywheel
164 until
one
of
the
two
adjustment
holes
becomes visible through the hole B ln the cover 108. Then,
using
the
special
adjustment spanner E
(Dual item
on.
230 933)
adjust
the
take
up
torque. Rotating
in
a
clockwise direction
will
increase
the
take up torque
whereas
rotatinq in
a
counterclockwise
direc
tion
willdecrease it.
Record/playback
head, erase head
When replacing
the
record/playback head 121
you
must
take
the
following
prel
iminary
adjustment measures:
Frx
the
record/playback head 121 together
wlth
the
tlat
spring
on
the
head assembiy and then secure
it
with
the
bushes
and
machine
screws
Z
in
such a
way that the tape guides
B
are
in
line
with
the tape
guides
on the head mounting
assembly
B
1 and the
erase head B
2.
The
section
ent
ilted
"electrical
al ign
ment"
descri
bes-the procedure
for fine
adjustment.
Cleaning/lubricat ion
Arwd\,\.ledn
the
Lrnil
wnen
rer\ici^g
or
repairing it
ln
order for the unit
to function properly, the record/playback
head
121, the erase head 120,
the pinch
rol
er 136 and the
capstan should
always
be
perfectly
clean. These
parts
aTe
best cleaned
usrng
a
rotton
cloth
or
soaked
ln
methyLated
spirit. On no
account
shou
d
you
use
rnetal objects
to
clean the
unlt.
Furthermore, the
surface
of
the
magnet
c
head
should
never be touched
wrth
bare fingers
A1
bearing and
slid
ing points on the unlt
are
adequately iubricated
at
the factory.
Felabrlcation
is formally not
necessary
tor
severa
years,
s
nce mosl important parts are provided
with
oi
retalners.
The motor
bearlngs
are provided
wrth lofg-lrfe
oil
relainers and ther
efore requ ere
no
ubrication.
l
:
I
7.
8.
9.
10.
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