Akai 1710W User manual
SERVIC
AKAI
TAPE
RECORDER
seiiadicrtinial
TABLE
OF
CONTENTS
I
Ill
IV
VI
Vil
VIII
IX
XI
LOCATION
CONTROLS
..........00.000
00]
DISMANTLING
OF
TAPE
TRANSPORT
UNIT
&
AMPLIFIERS
-
606
eccce
hee
ee
ewes
Oe
ed
ees
MECHANISM
ADJUSTMENT
..............-
AMPLIFIER
ADJUSTMENT...
we
ee
ee
eee
MAINTENANCE
PROCEDURES
.........2.-..-
REPLACEMENT
PARTS
TABLE
.........6.--
TROUBLE
SHOOTING
CHART
..............
SCHEMATIC
DIAGRAM
..
1...
2.
eee
ce
eee
:
I.
SPECIFICATIONS
STYLE
WEIGHT
DIMENSIONS
POWER
SUPPLY
RECORDING
SYSTEM
:
PLAY
BACK
SYSTEM
:
POWER
CONSUMPTION
TAPE
SPEED
TAPE
SPEED
DEVIATION
:
WOW
AND
FLUTTER
FREQUENCY
RESPONSE
:
SIGNAL
TO
NOISE
RATIO
DISTORTION
(Total
Harmonics)
CROSS-TALK
ERASE
RATIO
INSULATION
RESISTANCE
:
INSULATION
DURABILITY
:
LINE
OUTPUT
MAIN
OUTPUT
DIN
OUTPUT
LINE
INPUT
MIC,
INPUT
DIN
INPUT
FAST
FORWARD
AND
REWIND
TIME
MONITOR
SYSTEM
Portable
33
lbs.
(15
kg)
14H
x
13-1/2'W
x
7-1/2"D
(360H
x
345W
x
190D
mm)
AC
100
to
240
V,
50/60
Hz
In-line
4-track
stereo,
monaural
recording
In-line
4-track
stereo,
monaural
play
back
80
VA
3
speeds...
;
1-7/8",
3-3/4",
7-1/2"
(15"with
15’’
adaptor
kit)
Within
+
3%
at
all
tape
speeds.
Less than
0.18
%
R.M.S.
at
7-1/2”
Less
than
0.25
%
R.M.S,
at
3-3/4”
Less
than
0.35
%
R.M.S.
at
1-7/8”
40
to
15,000
Hz+
3
dB
at
7-1/2”
40
to
12,000
Hz
+
3
dB
at
3-3/4”
40
to
6,000
Hz+
3
dB
at
1-7/8”
Better
than
50 dB
Within
3
%
at
1,000
Hz
0
VU
recording
Less
than
—55
dB
(Monaural)
Less
than
—43
dB
(Stereo)
Less
than
—70
dB
More
than
50
M
ohms.
1,000
V.
AC
for
more
than
one
minute
duration.
2.5
V
at
volume
maximum
(250
Hz
0
VU
recorded
tape
used)
Impedance;
82
K.
ohms
4
W
at
music
power
per
each
channel,
total
8
W
Impedance;
8
ohms
2.5
V
at
Volume
maximum
Impedance;
82
K.
ohms
150
mV
Impedance...
130
K.
ohms
3
mV
Impedance...
30K.
ohms
20
mV
Impedance...
36
K.
ohms
150
seconds
for
1,200
ft.
tape
at
SO
Hz
120
seconds
for
1,200
ft.
tape
at
60
Hz
Can
be
monitored
the
program
being
recorded
by
using
a
stereo
headphone.
MOTOR
HEADS
REC/PLAY
HEAD
:
ERASE
HEAD
RECORD
LEVEL
INDICATOR
:
TRANSISTOR
USED
:
TUBE
USED
GERM
ANIUM
USED
:
REELS
USED
Condenser
starting
induction
two-speed
motor.
Horse
Power
....
1/100
HP
Power
Ratio
....
70%
Revolution
2,900
to
1,450
r.p.m.
at
50
Hz
3,480
to
1,740
r.p.m.
at
60
Hz
Inline
4-track
stereo/monaural
Gap....
4/1000
mm
Impedance...
.
3,600
ohms
at
1,000
Hz
Inline
4-track
stereo
Gap
....0.1mm
Impedance...
.
3,600
ohms
at
90
K.
Hz
Vertical
indication
model‘‘A’’
VU
meter
2SC650
x
2
2SC
-
458LG
(C,D)
x
2
12AT7x
1
6ARS
x
2
6CA4
x1
IN-34A
x
2
7",
5",
3"
reels
ll.
MEASURING
METHOD
TAPE
SPEED
DEVIATION
-{.
|
Method
involving
use
of
pre-recorded
tape
Playback
on
the
tape
recorder
to
be
tested
tape
pre-
recorded
at
1,000
Hz
+
0.1%
for
measuring
tape
speed
deviation.
Connect
the
appropriate
output
to
a
frequency
counter
meter
in
order
to
measure
the
tape
speed
deviation
from
the
resulting
deviation
of
the
measured
frequency.
2.
Method
involving
use
of
timing
tape
(designed
for
tape
speed
measurement)
This
method
utilizes
a
timing
tape
marked
at
intervals
of
7-1/2.
The
running
time
of
the
tape
over
60
marked
section
is
measured
in
order
to
calculate
the
deviation
of
the
tape
speed.
In
applying
this
method,
however,
it
should
be
born
in
mind
that
the
timing
tape
stretch
or
contract,
measurement
error
is
inevitable,
so
that
it
is
necessary
to
measure
the
total
length
of
the
tape
in
advance.
WOW
AND
FLUTTER
Playback
the
3,000
Hz
pre-recorded
tape
whose
wow
and
flutter
level
is
guaranteed
to
be
smaller
than
0.07%
for
measurement
by
means
of
a
wow
meter.
It
is
also
possible
for
a
3,000
Hz
sine
wave
to
be
recorded
and
played
for
measurement
by
means
of
the
wow
meter.
In
this
case,
however,
the
wow
meter
indicates
a
value
as
much
as
twice
the
value
given
in
the
specification
on
the
first
page.
SIGNAL
TO
NOISE
RATIO
1710W
ee
Set
the
Equalizer
Switch
on
“7.1/2
ips”
position
and
playback
a
tape
containing
a
1,000
Hz
sine
wave
record-
ed
at
“0”
VU
level
on
a
standard
recorder.
Connect
a
V.T.V.M.
to
the
line
output
jack
of
the
recorder
and
measure
its
output.
Then
remove
the
tape
and
measure
the
noise
level
under
the
same
condition.
Convert
each
of
the
measured
values
into
decibles.
TOTAL
HARMONIC
DISTORTION
FACTOR
1K
Hz
Audio
Distortion
Oscillator
meter
Connect
the
measuring
instrument
as
shown
above,
and
record
the
1,000
Hz
sine
wave
at
“0”
VU.
Playback
the
resultant
signal
and
measure
the
overall
distortion
factor.
Measure
the
noise
level
of
the
tape
recorder
with
the
tape
removed;
connect
the
audio
oscillator
directly
to
the
distortion
meter
for
measurement
of
the
distortion
factor
of
the
oscillator.
The
required
distortion
factor
may
be
obtained
from
the
results
of
the
above
measurement
by
the
following
formula.
dy
=
d—d,
—d,
where,
dy
=
Required
d
=
Overall
distortion
factor
d,
=
Noise
level
d,
=
Distortion
factor
of
the
oscillator
(Note:
New
tape
of
particularly
good
quality
should
be
used
for
measurment
of
the
distortion
factor).
POWER
OUTPUT
Palyback
a
tape
containing
a
sine
wave
of
1,000
Hz
recorded
at
0
VU
on
a
standard
recorder.
Connect
a
V.T.VM.
to
the
line
output
jack
of
the
re-
corder
and
measure
the
voltage
at
the
output
of
the
recorder
to
be
tested.
CROSS
TALK
(Cross
talk
between
the
tracks)
BRA
ACO
£52509
$5503
xX
Tape
direction
pee
As
shown
in
the
figure,
first
record
a
1,000
Hz
sine
wave
on
track
No.
3
at
+3
VU
level.
Next,
remove
the
1,000
Hz
input
signal
and
record
under
a
non-input
condition.
Then,
playback
the
tape
on
track
No.
3
and
No.
1
(reversed
condition
of
tape)
through
the
1,000
Hz
BP.F.
(Band
Pass
Filter,
Sensitivity
....
1
:
1)
and
obtain
a
ratio
between
the
two
from
the
following
formula.
C=20log___
Fo
__(db)
E,
-E,
C
=
Desired
cross
talk
ratio
(db)
E
=
1,000
Hz
signal
output
level
P|
E,=
1,000
Hz
cross
talk
output
level
E,=
Non-input
signal
record
level
RRR
FREQUENCY
RESPONSE
Audio
1710W
Frequency
—-4
Line
Line
Oscillator
Input
Output
Connect
the
measuring
instrument
as
in
the
above
dia-
gram,
and
measure
the
frequency
response
in
the
follow-
ing
sequence:
RECORD:
1)
Give
a
sine
wave
of
1,000
Hz
to
the
Line
Input
of
the
recorder
to
be
tested
through
an
attenuator
from
an
audio
frequency
generator.
2)
Set
the
Record/Playback
Knob
in
“Rec”
position
and
adjust
the
line
input
volume
so
that
the
VU
meter
needle
indicates
“O”
VU.
3)
Under
the
condition
described
in
(2),
lower
the
input
level
10
db
by
means
of
the
attenuator.
4)
Record
the
spot
frequency
in
the
range
of
30
Hz
to
25,000
Hz
from
the
audio
frequency
generator.
PLAYBACK:
5)
Set
the
Record/Playback
Knob
in
“Play”
position.
6)
Set
the
Equalizer
Switch
on
7-1/2"
or
3-3/4"
position.
7)
Connect
a
V.T.V.M.
to
the
Line
output.
8)
Playback
the
tape
previously
recorded.
9)
Adjust
the
output
level
to
“0”
dbm
at
1,000
Hz
as
indicated
on
the
V.T.V.M.
by
the
range
selector
of
a
V.T.V.M.
10)
Playback
the
recorded
spot
frequencies
with
the
conditions
in
(9);
make
a
memo
of
output
level
and
plot
the
value
on
a
graph.
Il.
LOCATION
OF
CONTROLS
a
———————
@
Supply
Reel
Shaft
(2)
Cycle
Conversion
Switch
(A)
@
Capstan
@)
Capstan
Storage
Post
®
Tape
Guide
©
Erase
Head
@
Tape
Cleaner
®
Record/Playback
Head
)
Reset
Button
Index
Counter
@)
Track
Selector
2
@
Microphone
Jack
(Left)
@
Microphone
Jack
(Right)
SOOQS@
22)
03)
4)
Volume
Control
(Left)
(94)
@
Tone
Control
(Left)
P
®)
@®6
Take-up
Reel
Shaft
arenes
‘
@
Pause
Lever
iam
BP
moe
26)
ae
:
cher
muavir
48
Speed
Change
Switch
Capstan
Shaft
@0
Pinch
Wheel
@
Automatic
Shut-off
Lever
@)
Fast
Forward/Rewind
Knob
@3
Record/Playback
Knob
@%
Record
Safety
Button
@)
Automatic
Shut-off
Switch
@6)
VU
Meter
(Left)
@
VU
Meter
(Right)
Stereo
Headphone
Jack
29
Power
Switch
80
Volume
Control
(Right)
@
Tone
Control
(Right)
®
Voltage
Sclector
Switch
83
Fuse
Post
84
Cycle
Conversion
Switch
(B)
85
Speaker
Switch
66
External
Speaker
Jack
(Left)
3
External
Speaker
Jack
(Right)
38
Line
Input
Jack
(Right)
69
Line
Output
Jack
(Right)
_
@
DIN
Jack
@
Line
Output
Jack
(Left)
@
Line
Input
Jack
(Left)
rere
AY
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BPPOOSEEVOOE@OOHO
CS8e8
IV.
DISMANTLING
OF
TAPE
TRANSPORT
UNIT
&
AMPLIFIERS
(1)
Loosen
the
RETAINING
SCREW
(a)
of
the
PINCH
WHEEL
(A)
using
a
philips-headed
screw
driver
and
re-
move
the
PINCH
WHEEL
by
hand.
(4)
Loosen
the
SCREWS
(marked
from
(a)
to
(d))
by
using
a
philips-headed
screw
driver.
,
(7)
Disconnect
the
PLUGS
(marked
(a)
to
(d))
carefully
by
hand.
(2)
Loosen
the
RETAINING
SCREWS
(a)
and
(b)
of
the
DECK
CONTROL
KNOBS
(A)
and
(B)
by
using
a
philips-headed
screw
driver
and
re-
move
the
KNOBS
by
hand.
(S)
Loosen
the
SCREWS
(marked
from
(a)
to
(d))
by
using
a
philips-headed
screw
driver.
EOS
ass
as
(8)
Loosen
the
SCREWS
(marked
from
(a)
to
(d))
of
the
DECK
FRAME
by
using
a
philips-headed
screw
driver.
(9)
Separate
the
TAPE
TRAISPORT
ines
riba
t
(3)
Loosen
the
SCREWS
(marked
from
(a)
to
(d))
by
using
a
philips-headed
screw
driver
and
remove
the
DECK
PANEL
(P)
by
hand.
(6)
Remove
the
TAPE
TRANSPORT
MECHANISM
ASSEMBLY
AND
AM-
PLIFIER
ASSEMBLY
(D)
ty
slowly
lifting
it
from
the
CASE
(C)
is
shown
in
picture.
MECHANISM
ASSEMBLY
(Wf)
from
the
AMPLIFIER
ASSEMEL“Y
(A)
carefully
by
hand.
[5]
V.
TRANSPORT
MECHANISM
Fig.
1
Fig.
2
DRIVING
OF
CAPSTAN
Figure
1.
(A)
Motor
(B)
Driving
Belt
(flat
belt)
(C)
Capstan
(D)
Flywheel
High-speed
rotation
of
Motor
(A)
is
reduced
by
Driving
Belt
(B)
and
transmitted
to
Capstan
(C),
which
is
con-
nected
of
flywheel
with
ample
inertia.
This
enables
the
rated
rotation
by
absorbing
minor
rotation
distortion
of
motor
itself.
Capstan
Rotation:
606
RPM.
at
7-1/2”
(19
cm)
per
sec.
303
R.P.M.
at
3-3/4”
(9.5
cm)
per
sec.
151.5
RPM.
at
1-7/8"
(4.75
cm)
per
sec.
Motor
Rotation:
3,000
to
1,500
R.P.M.
at
50
Hz
3,600
to
1,800
R-P.M.
at
60
Hz
DRIVING
OF
PINCH
WHEEL
Put
tape
between
rotating
capstan
and
pinch
wheel
and
push
pinch
wheel
against
capstan,
this
will
transport
the
tape
at
rated
speed.
The
appropriate
pressure
of
pinch
wheel
is
between
1,000
to
1,150
grams
at
the
tape
speed
of
7-1/2’
(19
cm)
per
second.
RECORDING
AND
PLAYBACK
Turn
the
RECORD/PLAYBACK
KNOB
(A)
to
“PLAY”
position,
and
pinch
wheel
presses
against
capstan
to
move
tape
at
the
rated
speed.
At
the
same
time,
Idler
(B)
moves
between
Motor
Bushing
(C)
and
the
Take-Up
Reel
Spindle
(D)
to
transmit
the
motor
rotation
to
(D)
so
that
the
tape
is
moved
and
wound
on
the
take-up
reel.
The
Take-up
Reel
Spindle
Base
is
made
up
of
two
plas-
tic
rollers
(1
and
2)
with
a
clutch
felt
in
between.
The
Idler
is
rotating
the
plastic
roller
(2)
underneath.
Therefore,
the
tape-winding
friction
is
adjusted
by
the
slipping
of
the
felt
to
maintain
rated
winding
of
the
tape.
On
the
other
hand,
the
Supply
Reel
Spindle
(H)
hasa
Brake
Roller
(E)
hung
on
the
Plastic
Roller
(4)
under-
neath,
which
provides
appropriate
back
tention
by
the
felt
clutch
slipping
to
the
rotation
of
the
Puelly
(3)
above.
To
prevent
accidental
erasure,
the
Record
Interlock
Button
(F)
must
be
depressed
before
the
RECORD
/
PLAYBACK
KNOB
can
be
moved
to
the
“REC”
posi-
tion.
The
Safety
device
(G)
is
depressed
to
operate
the
recording
mechanism.
(See
figure
2)
High-Speed
Rotation
5
2
5
°
ary
breh
Co)
Fi
iy
!
-t-7
Wheel
\.
Sx”
FAST-FORWARD
MECHANISM
Turn
the
FAST
FWD-REWIND
knob
(A)
in
“FAST
FWD”
position,
and
the
cam
(B)
under
the
knob
pushes
up
the
Lever
(C).
The
Idler
(D)
moves
into
the
space
between
the
Plastic
Roller
(F)
above
the
Take-up
Reel
Spindle
and
the
upper
part
of
the
rotating
motor
drive
bushing
to
transmit
the
motor
rotation
to
the
take-up
reel
spindle.
At
the
same
time,
Brake
Rollers
(H)
and
(1)
come
off
the
reel
spindle
to
free
the
Supply
Reel
Spindle
(G),
thereby
allowing
fast
winding
of
the
tape
onto
the
take-up
reel.
(See
figure
3)
REWIND
MECHANISM
Tur
the
FAST
FWD-REWIND
knob
(A)
in
‘““REWIND”
position,
and
the
cam
(B)
under
the
knob
pushes
the
Lever
(C)
up.
The
Idler
(D)
moves
into
the
sapce
bet-
ween
the
upper
part
of
the
rotating
Motor
drive
bushing
(E)
and
the
Intermediate
Pulley
(F)
to
transmit
the
high-
speed
rotation
of
the
motor
through
the
intermediate
pulley
to
the
Supply
Reel
Spindle
(G).
At
the
same
time,
Brake
Rollers
(H)
and
(I)
come
off
the
reel
spindle
to
free
the
take-up
reel
spindle
(J),
thereby
rewinding
the
tape
into
the
supply
reel
at
a
fast
speed.
(See
figure
4)
STOP
CONTROL
Turn
the
stop
lever
in
“STOP”
position,
Brake
R
ollers
(A)
and
(B)
depress
reel
spindles
to
stop
rotation
of
the
reel
spindles.
:
As
the
brake
rubber
depresses
the
plastic
rolles
under
the
reel
spindles,
no
friction
works
on
the
tape
ite
If.
(See
figure
5)
Se
one
ele
a
ee
SSS
SS
TT
4
Take-up
Rewind
|
Take-up
|
Supply
Modes
of
Operation
Pinch
|
Idler
Idler
side
side
Wheel
|
Wheel
Wheel
Brake
Brake
tt
+-
—-
1
—t
—_—_-—_—
(a)
STOP
P
x
Xx
x
1e)
fe)
=
|
}
|
+
1}
(b)
FAST-FORWARD|
=X
oO
x
x
x
-
iz
an
ae:
eee
(c)
REWIND
Xx
x
O
x
oO
kK
.
17
T
(a)
RECORDING
fe)
O
Xx
x
1
x
PLAYBACK
NOTE:
X-
marks
indicates
“open”
and
O-
marks
“engaged”
RECORD/PLAYBACK
CHANGING
MECH
ANISM
By
turning
the
RECORD/PLAYBACK
KNOB
(N)
to
the
recording
position,
the
CAM
(a)
pushes
the
RECORD-
ING
LEVER
(b),
as
illustrated
in
dotted
line.
Then
the
LEVER
(b)
pulls
the
RECORDING
LEVERS
(d)
and
(e),
which
are
joined
with
the
RECORD/PLAYBACK
CHANGING
SWITCH
(SW1)
to
be
turned
to
recording
position.
If
the
LEVERS
(b),
(d)
and
(e)
are
not
pulled
properly,
the
(SW1)
does
not
operate
properly,
so
abnormal
oscil-
lation
may
occur
and
also
recording
cannot
take
place.
The
LEVERS
must
be
adjusted
to
proper
position
by
loosing
the
SCREWS
(f)
and
(g).
VI.
MECHANISM
ADJUSTMENT
1.
ADJUSTMENT
OF
PINCH
WHEEL
It
is
important
that
the
pinch
wheel
shaft
is
kept
in
complete
alignment
with
the
capstan
shaft.
A
proper
pinch
wheel
pressure
is
between
1,000
and
1,150
grams
when
the
unit
is
operated
at
the
tape
speed
of
7-1/2
ips.
Any
deviation
from
this
specification
will
result
in
wow
and
flutter.
Check
pinch
wheel
pressure
by
a
spring
scale,
and
if
necessary,
adjust
the
pinch
wheel
load
spring.
2.
ADJUSTMENT
OF
TAKE-UP
IDLER
WHEEL
The
take-up
idler
wheel
must
be
kept
in
complete
align-
ment
with
the
take-up
reel
shaft.
When
the
unit
is
set
in
fast
forward
condition,
the
idler
wheel
will
contact
with
the
upper
knurled
wheel
of
the
take-up
reel
shaft
assembly,
and
it
will
contact
with
the
lower
knurled
wheel
during
record
or
play
operation.
Adjust
idler
wheel
load
spring
so
that
the
idler
wheel
pressure
is
kept
between
50
and
80
grams.
The
idler
wheel
rapidly
wears
if
the
pressure
is
excessive.
Slippage
occurs
if
the
pressure
is
smaller
than
the
specification.
(a)
Rewind
reel
shaft
assy.
(b)
Take-up
reel
shaft
assy.
|
reel
Sd
reel
table
|'___reel
stopper
reel
table
;
er
base
plate
drive
shaft
ring
rewind
pulley
conical
spring
"=>
‘aétal-
washer
=
felt
clutch
«mm=ss—~retainer
=a
take-up
EEE
ia
a
drive
wheel
xr
t
star-shaped
waa
:
woe
spring
=
oles
washer
——
=
>
metal
washer
ss
retainer
~—>==
nylon
washer
“==
oilite
metal
4+—
oilite
metal
mig.
plate
t
star-shaped
—
ohn
=
coil
spring
spring
for
==
paper
washer
:
brake
==
retainer
washer
=e
retainer
nto
fi
nylon
spring
$>——->—-
washer
set
s
as
leeve
-
34
Fig.
|
3.
ADJUSTMENT
OF
REWIND
IDLER
WHEEL
The
rewind
idler
wheel
must
be
kept
in
complete
align-
ment
with
the
rewind
reel
shaft.
The
amount
of
pressure
to
the
knurled
motor
bushing
should
be
maintained
about
50
grams
during
rewind
operation.
Adjust
both
the
idler
load
spring
and
rewind
roller.
4.
ADJUSTMENT
OF
INTERMEDIATE
WHEEL
The
intermediate
wheel
is
located
between
the
rewind
idler
wheel
and
the
rubber
ring
which
is
used
on
the
upper
part
of
the
supply
reel
shaft
assembly.
When
the
unit
is
set
in
rewind
condition,
it
will
contact
with
these
parts
simultaneously
transmitting
torque
of
motor.
An
adequate
pressure
is
50
grams.
Adjust
the
load
spring
of
the
intermediate
wheel
if
the
pressure
is
not
sufficient.
5.
ADJUSTMENT
OF
TAKE-UP
REEL
SHAFT
ASSEMBLY
A
felt
clutch
material
is
attached
to
the
bottom
side
of
the
reel
table
base
plate
so
that
recording
tape
will
not
be
stretched
during
fast
forwarding
operation
due
to
excessive
tension.
To
check
the
amount
of
friction
of
this
part,
place
a
5-inch
reel
with
recording
tape
wound
by
60
m/m
in
diameter,
and
gently
pull
the
end
of
tape
upward
using
a
spring
scale.
Adjust
the
conical
spring
so
that
the
amount
of
tension
at
this
part
will
be
kept
bet-
ween
400
to
500
grams.
Another
felt
clutch
material
is
attached
to
the
take-up
drive
wheel.
It
is
to
provide
proper
slipping
operation
during
record
or
play
mode.
The
procedure
for
checking
friction
of
this
part
is
same
as
the
foregoing,
and
between
150
and
200
grams
of
friction
will
provide
the
best
result.
Adjust
the
star-
shaped
spring
just
under
the
take-up
drive
wheel.
When
the
unit
is
set
to
rewind
operation,
the
amount
of
friction
of
this
part
will
be
greatly
reduced
and
will
become
15
to
20
grams.
Check
to
see
whether
this
is
satisfactory,
if
not,
readjust
the
star-shaped
spring
for
Brake,
and
spring
retainer
washer
accordingly.
(See
figure
1
(b)
at
left)
6.
ADJUSTMENT
OF
SUPPLY
REEL
SHAFT
ASSEMBLY
Felt
clutch
material
is
used
between
the
lower
side
of
the
reel
table
base
plate
and
the
rewind
rubberring
to
protect
recording
tape
from
excessive
tension
dui
ng
the
recording
operation.
To
check
the
amount
of
friction
of
this
part,
place
onto
the
supply
reel
table
a
5—imch
reel
with
a
tape
60
m/m
in
diameter,
and
gently
pull
the
end
of
tape
upward
by
a
spring
scale.
Adjust
the
conical
spring
so
that
the
amount
of
tension
is
kept
be
tween
400
and
500
grams.
Other
felt
clutch
matwial
is
attached
to
the
rewind
drive
wheel
to
provide
proper
slipping
operation
during
record
or
play
operation.
The
procedure
for
checking
friction
of
this
part
is
the
same
as
the
foregoing,
and
between
80
and
120
gnams
of
friction
will
give
the
best
result.
When
the
unit
4
set
to
fast
forward
operation,
the
amount
of
friction
will
be
greatly
reduced
and
will
become
15
—
20
grams.
Check
to
see
whether
this
is
correct.
If
not,
readji
st
coil
spring
and
spring
retainer
washer.
(See
figure
]
(a)
at
left)
[9]
(A)
(B)
(C)
ADJUSTMENT
OF
HEADS
Adjustment
of
Head
Height
(See
Fig-2
and
Fig-3)
.
Erase
Head
Adjust
the
height
of
the
Erase
Head
by
turning
the
height
control
screws
(a)
(a’)
as
the
upper
edge
of
the
tape
passes
through
until
it
is
just
0.125
—
0.15
mm
under
the
top
edge
of
the
CH-1
erase
head’s
core.
.
Playback
Head
Adjust
the
height
of
the
Playback
Head
by
turning
the
height
control
screws
(b)
(b’)
as
the
upper
edge
of
the
tape
passes
through
in
the
same
way
as
the
top
edge
of
the
CH-1
playback
head’s
core.
Adjustment
of
Vertical
Azimuth
of
the
Head
Adjust
the
vertical
azimuth
of
each
head
(erase
and
playback)
by
turning
the
height
control
screws
(a)
to
(b’)
until
the
tape
contacts
each
head
properly.
Adjustment
of
Head
Alignment
Playback
Head
Playback
an
Ampex
Alignment
tape
(8000
Hz)
at
7-1/2"
tape
speed
and
turn
the
alignment
control
screw
(c)
until
the
out-put
level
of
both
channels
reaches
the
maximum.
0.125~0.15mm
0.01~0.025mm
Vil.
AMPLIFIER
ADJUSTMENT
1.
ADJUSTMENT
OF
RECORDING
BIAS
FREQUENCY
(Fig.
1)
a.
Put
on
the
resistor
10
or
50
ohms
in
series
with
the
Bias
Head
and
connect
the
Vertical
Input
Terminal
of
the
Oscilloscope
to
points
(a)
and
(b).
b.
Feed
in
the
sine
wave
signal
from
an
Audio
Frequen-
cy
Oscillator
to
the
Horizontal
Input
of
the
Oscillo-
scope
and
tune
the
Dial
of
the
Audio
Frequency
Oscillator
until
the
Oscilloscope
displays
a
circular
or
linear
pattern.
c.
If
it
reads
60
K
Hz
+
5
K
Hz,
the
Recording
Bias
Frequency
is
correct.
d,
If
it
is
not
correct,
it
may
be
adjusted
by
inserting
.
another
condenser
(C-11)
value
560
PF.
REC/P.B
HEAD
OSCILLATOR
CIRCUIT
oS
OSCILLOSCOPE
AUDIO
FREQUENCY
OSCILLATOR
Fig.
1
2.
ADJUSTMENT
OF
RECORDING
BIAS
VOLTAGE
(Fig.
2)
a
.Connect
the
V.T.V.M.to
the
point
(A)
and
(B),
then
read
the
figure
on
the
meter
of
the
V.T.V.M.
b.
If
it
reads
AC
35
V
£5
V,
the
Recording
Bias
Voltage
is
correct.
c.
If
it
not
correct,
it
may
be
adjusted
by
inserting
another
resistor
(R-17,
18)
value
68
K
Ohms.
3.
ADJUSTMENT
OF
ERASING
BIAS
VOLTAGE
(Fig.
3)
a.
Connect
the
V.T.V.M.to
the
point
(A)
and
(B),
then
read
the
figure
on
the
meter
of
the
V.T.V.M.
b.
If
it
reads
AC
47
V
+
10
V,
the
Erasing
Bias
Voltage
is
correct.
c.
If
it
not
correct,
it
may
be
adjusted
by
inserting
ano-
ther
regulator
coil
(L2,
L3)
value
22
mH.
L2
22mH
Cl4@
250P
Ci2
|OOP
=
RI7
68K
t
AW
3100P
RI8
68K
es
Lt
68mH
Cl
RET
F
|
Vill.
MAINTENANCE
PROCEDURES
a
eee
1.
LUBRICATION
INSTRUCTION
For
maximum
service
life
and
optimum
performance,
lubricate
the
parts
identified
below
after
each
500
hours
of
operation.
Use
only
light
machine
oil
of
good
quality.
Motor
Flywheel
Assembly
Rewind
Idler
Wheel
and
Wind
Take-Up
Idler
1
drop
Intermediate
Ider
1
drop
Pinch
Wheel
1
drop
Also
apply
a
liberal
film
of
light
machine
grease
to
each
roller
surface
of
all
levers
and
cams.
CAUTION:
DO
NOT
OVER-LUBRICATE,
AND
WIPE
OFF
EXCESS
OIL
WITH
A
COTTON
SWAB
SOAKED
IN
ALCOHOL.
OTHERWISE,
EXCESS
LUBRICANT
MAY
BE
SCATTERED
DURING
OPE-
RATION.
AND
THE
RUBBER
COMPONENT
NENT
PARTS
WILL
DETERIORATE.
FLYWHEEL
2.
CLEANING
TAPE
HEADS
AND
OTHER
PARTS
Wipe
surface
of
tape
heads,
guide
roller
bearing,
capstan
bushing
and
pinch
wheel
periodically
with
a
soft
cloth
soaked
in
alcohol
or
carbon-tet.
MEMO
IX.
REPLACEMENT
PARTS
TABLE
600
900
100
100
200
300
400
500
600
700
800
900
400
200
500
300
700
800
HEAD
BLOCK
REEL
ASSEMBLY
BLOCK
SWITCH
BLOCK
MOTOR
BLOCK
FLY
WHEEL
BLOCK
MECHA.
FRAME
(front
&
rear)
PRE-AMPLIFIER
CARD
(1
&
2)
AMPLIFIER
(1,
2
and
3)
CASE
&
TOP
PANEL
BLOCK
3
:
HEAD
BLOCK
LCS-101
k
1
r
LCS-102
LCS-103
LCS-623
b
LCS-101]
LCS-101j
LCS-101h
LCS-101f
a
me
-—
LCS-101d
6
:
ct
—
|
4
LCS-101b
)
LCS-101r
H3
LCS-101s
LCS-101t
HEAD
Head
Assembly,
:
Complete
Erase
Head
Record/Play
back
Head
Table,
Lifter
Pin
(with
Lifter
Pin)
Screw
Flat
Mould
4x8
Prop
C,
Head
Cam
A,
Head
Lifter
Spoke,
for
Lifter
a
REEL
ASSEMBLY
BLOCK
LCS-201
Supply
Reel
Assembly
a
Screw,
without
Head
4x7
b
Pulley,
Reel
Shaft
Holder,
Reel
Shaft
(Star
Type
Spring)
g
Metal
Fitting
A,
;
Reel
Table
re)
Holder,
Reel
Shaft
(Star
Type
Spring)
Take-up
Roller,
C
Spring
G,
Left
Rewind
Pulley
Rubber
Ring
Table
C,
Reel
LCS-202
Plate,
Reel
Table
LCS-203
Screw
Flat
3x6
LCS-204
Take-up
Reel
Assembly
a
Nylon
Tube
b=
Screw,
without
Head
3x3
c
Set
Sleeve
f
Spring,
F3
i
Metal
Fitting
B,
Reel
Table
q
Hoider,
Reel
Shaft
LCS-205
LCS-202
LCS-204w
LCS-201lv
<fceu
BD
LCS-204y
\
LCS-201t
SS
LCS-201s
(Star
Type
Spring)
rt
Take-up
Roller,
B
_-1CS-2011
/u
Spring
G,
Right
=
vy
Take-up
Roller,
A
w
Reel
Shaft
A,
LCS-201p
Take-up
Reel
LCS-205
Plate,
Reel
Table
LCS-206
Screw
Flat
3x6
SUPPLY
REEL
TAKE-UP
REEL
SWITCH
BLOCK
LCS-301
Switch
Block
a
Switch
Table,
A
pes
aula
c
Lever,
I
LCS-301n
ao
Nak
:
f
Fast/Forward
LCS-301p
Rewind
Shaft
g
Plate,
Cam
LCS-301m
h_
Spring,
K
i
Cam,C
LCS-301r
k
Rotary
Switch
S-133-B
1
Switch
Table,
B-2
Pin
LCS-301j
LCS-3011
:
aches
LCS-301i
u_—s
Screw
Bind
3x5
LCS-302
Record/Piayback
Conversion
Pin
LCS-303
Cam
A-2
LCS-304
Cam
B
LCS-305
8
mm
Ball
Bearing
LCS-301h
LCS-301g
LCS-301f
LCS-301d
LCS-301c
SWITCH
C2
LCS-401j
LCS-401i
LCS-401
WD
py
i
LCS-401s
t
it
Hl
LCS-4011
6
|
=
|
ly
LCS-401d
LCS-401p
LCS-401g
LCS-401f
LCS-4010
LCS-401n
dm:
Lcs-4ole
LCS-401d
LCS-401¢
LCS-401b
LCS-401a
MOTOR
BLOCK
LCS-401
a
ru
SFrman
Motor,
Complete
Screw
Flat
Mould
3x15
Stepped
Pulley
Belt
Holder
Motor
Pulley
Motor
Holder
Hexagonal
Nut
Motor
Fan,
D
Screw,
without
Head
4xs
Prop
A,
Motor
(8x22.5)
Prop
B,
Motor
(8x21.5)
Holder,
Motor
Condenser
MP
Condenser
2
uf
(260V
AC)
Wire
Wound
Fixed
Power
Resistor
(450
2
20H)
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