Sony TC-640 User manual

Power Requirements:
Track System:
Reel Size:
Tape Speed:
Recording Time:
(with 1,800 ft. tape)
Frequency Response:
we
Signal-to-Noise Ratio:
SPECIFICATIONS
AC 100 V,110V,117V,
120 V, 125 V, 220 V, 240 V
50/60 Hz, 80 W (for General Export)
AC 117 V, 60 Hz, 80 W (for USA)
Four-track stereo and mono
7” (18 cm) maximum Inputs:
7% ips and 3% ips
(19 cm/s and 9.5 cm/s)
4-track 4-track
Tape speed stereo. mono
7% ips 1.5hrs 3hrs
(19 cm/s)
3%
ips
3hrs
6
hrs
Outputs:
(9.5
cm/s)
5
30 ~ 20,000 Hz at 7% ips
(19 cm/s)
30 ~ 15,000 Hz at 3% ips
(9.5 cm/s}
{with standard tape)
20 ~ 25,000 Hz at 7% ips
(19 cm/s)
30 ~ 18,000 Hz at 3% ips
(9.5 ¢m/s)
(with SONY SLH tape)
Weight:
52 dB (with standard tape)
55 dB (with SONY SLH tape)
Flutter and Wow:
Recording Bias Frequency:
Semiconductors:
Dimensions:
8 [ISO)
Set using 1SO screws
0.07 % (WRMS) at 7% ips
(19 cm/s)
0.11 % (WRMS) at 3% ips
(9.5 cm/s)
120 kHz
Two MICROPHONE inputs
Impedance; 600
Maximum sensitivity: 0.19 mV
(—72 dB)
Two LINE INPUTs
Impedance; 100 k{2
Maximum sensitivity; 60 mV
(—22 dB)
Two LINE OUTPUTs
Impedance; 100kQ2 ,
Output level; 0.775 V (0 dB)
HEADPHONE output
Impedance; 8
Output level; 38 mV (—26 dB)
with 8 92 load
22-transistors and 8-diodes
1417/32(w)
x
159/16(H)
x
919/32"
(D)
(369
x
395
x
243.5
mm)
33 Ib 2 0z (15 kg)
SON
Ye
SERVICE
MANUAL

Section Title
Specifications
1. GENERAL DESCRIPTION
1-1.
1-2.
Block Diagram
Major Parts Locations
2. DISASSEMBLY.............
3. FREQUENCY ADAPTATION
4. MAINTENANCE
4-1. Lubrication ..........
4-2. Cleaning eerie bea Bees
4-3. Demagnetizing.........
5. ADJUSTMENT PROCEDURES
5-1,
5-2.
Mechanical Adjustments. ...
Electrical Adjustments. ...
6. DIAGRAMS
6-1. Schematic Diagram .....
6-2. Mounting Diagram
6-2-1. REC BIAS Circuit Board . .
6-2-2. PB AMP Circuit Board... .
6-2-3. System Control
Circuit Board
TABLE OF CONTENTS
Page Section Title
: ] 6-2-4. REC MODE Circuit Board
6-2-5. SOS & ECHO Circuit Board
6-2-6. Resistor Terminal ......
3 6-3. Level Diagram. .......
4~5
7. SEMICONDUCTOR ELECTRODES...
. 6
8. ELECTRICAL PARTS LIST ....
: 6
9. EXPLODED VIEWS
9-1. Cabinet - topview-— ....
7 9-2. Amp Chassis
: 7 —topview(l)-.....
‘ 7 9-3. Head Deck —top view(1) ..
; 9-4. Head Deck —top view(2) ....
9-5. Printed Circuit Board
—topview-—.......
8~11 9-6. Chassis —topview~.....
12~24 9-7. Chassis —bottom view ~—. . .
9-8. Jack Panel .........
9-9, Packing 20 5 Se ee
5~28
é 10. HARDWARES ............
29~32 Hardware Nomenclature .......
33~36
37~38

“AjuO
japoyy
Ju0dx
gy
jessuad
40}
papinosd
Ss}
(gOEP)
40;9aUUCD
gg/D3H
BULL
as
t
na
&}
9
‘GOES
MS
.JGOW
22H
“B
ae
i
el
tkL
‘OLLO
980
SVId
:210N
zoes
MS
YOLINOW
oO
FOHNOS
ce
No
©
FdVL
LfdLNO
INIT
AGE
SNA
a.
—-
©
[
IN
2
O
oO
a
waLaW
AA
60Z0
8020
L0z0
9020
|
8010
£010
9010
21w)
solo
—
Q
dNV
JNOHIGVFH
dWV
INIT
dWV
OF
ad
|
dW
037
934
dw
XIW
dW
JIN
O
Lu x
”
oc
sos
£088
Lu
A
MS
a
{
oOHOF
8
SOS
Lu
VR-O
OHOI
re
yrs
40}28UU09
Gd/IFY
80er
JNOHdAV3H {_
ZOES
9
22¥NOS
2068S
°
1vWHON
@-
4
cy
en
MS
193738
=
5
Pidaas
5
LNdLNo
ANIT
Ts
uOLINOM
AW
ANdNI
INIT
nee
a
wehbe
be
es
a
ayuVOS
LINDYID
7
[eal
dW
&d
cc oO < a x
°o
-
|
YRLIW
NIA
eee
£020
HY
2010
£010
nin
2)
010
a
dNV
3NOHdGV3H
dNV
INIT
|
dWy
07
934
dW
XIW
dV
JIN
=
-

1-2, MAJOR PARTS LOCATIONS
Cabinet — Front View —
Y¥-20410-12-6S
counter, tape index
_ X-3 1440-08
3-144-042-10
cabinet
ass‘y,
wood
panel,
reel
3-140-864-01
3-140-864-01
reel
table
reel
table
1-514-692
switch, lever; MONITOR (S302)
3-144-058
3-144-050-20
cover, head knob, lever switch; REC
X-31408-07
x-
-3
1408-04
;
roller
ass’y,
guide
:
pinch
roller
ass’y
144-128
3-144-050-30
-
oe
tton
knob,
lever
switch;
rewind
1-514-769
(S305,
S306)
;
Spa
e
ee
er
3-144-050-40
knob, lever switch; stop
3-144-050-10
knob, lever switch; forward
3-144-050-30
knob, lever switch; fast forward
3-144-079
cover, pushbutton 8B
1-514-789
switch, slide; TAPE SPEED (S301)
X-3 1440-09
knob B ass‘y, PB VOL
X-3 1440-09
knob B ass‘'y, LINE VOL
switch, lever; REC MODE
1-507-28 1 (J301, J302)
jack, MICROPHONE
1-507-282 (J303)
jack, binaural: HEADPHONE
X-3 1440-11
knob C ass'y, VOL (ECHO/SOS)
1-514-324 (S303)
switch, slide; SOS & ECHO
X-31440-09
knob B ass'y, MIC VOL
1-513-347
switch, slide; TAPE SELECT (S307)
Cabinet — Back View —
3-456-002
grille, ventilation
1-509-341 (CNJ402)
socket, AC OUTLET
171-509-064
1-507-142
(J304,
305)
socket,
voltage
jack,
phono:
LINE
INPUT
selector
(J403)
LINE INPUT,
(for General Export}
171-509-029 (J308)
owen
SUPPLY
:
\
"
‘
connector,
REC/PB
171-509-062 (CNJ401) seoune 4 ! ~ : (for General Export}
socket, POWER SUPPLY ® 5 \ i :
f 1-507-142 (J306, 307}
jack, phono; LINE OUTPUT
X-380 12-04
terminal ass‘y, GROUND
171-532-100
fuse, 2A

Chassis — Front View —
1-514-324-11 (S407)
switch, slide; 50/60 Hz
(for General Export)
X-3 1428-30
brake (R) ass’y
3-144-037
be/t, counter
X-3 1428-29
brake
(L}
ass‘y
3-144-033
pulley, motor
1-454-080 (PM401)
solenoid, pinch roller
3-140-520
belt, capstan
1-454-079 (PM402}
solenoid, brake
1-524-077
meter, VU {(ME301, 302)
Chassis — Back View —
1-117-083 (C402)
capacitor, metalized paper 1-441-680 (T401)
transformer, power
(for USA)
1-441-694 (T401)
transformer, power
(for General Export}
1-54 1-033-21 (M402)
motor, reel (CM-71)}
8-83 1-634-13 (M401)
motor, capstan (HC-634D5)
1-117-083 (C403)
capacitor, metalized paper
1-54 1-033-21 (M403)
motor, reel (CM-71)

SE
CTION 2
DISASSEMBLY
A@RK 4x25
O@RK 4x 15
Fig. 2-1.
Cabinet Removal
Panel
SECTION 3
FREQUENCY ADAPTATION
Remove the front
four screws.
panel by loosening the
Set the frequency selector for the line fre-
quency of your local area.
Remove the motor pulley by the two set screws
and reinsert the motor pulley upside down,
then tighten the screws again.
cep
Remove the cabinet by removing the seven screws
marked with A in Fig. 2-1.
Removal
Remove the panel by removing the four screws
@RK 4 x 15) marked with o in Fig. 2-1.
4. Slightly loosen the four screws which tighten
the capstan motor to the chassis. Then, slide the
motor as illustrated and tighten the screws
again.
5. Replace the rubber belt on the motor pulley so
that the belt is threaded horizontally. Try to
turn the motor pulley several times to see
whether the belt is threaded securely.
6. Replace the front panel.
6OHz 50Hz
a
@( je
cP
ee
Fig. 3-1.
Frequency adaptation
es

SECTION 4
MAINTENANCE
4-1. LUBRICATION
Use
light
machine
oil
and
lubricate
the
pinch
roller
shaft
and
capstan
drive
motor
lubricating
hole.
It
will
cause
slippage
of
the
mechanism.
If
the
oil
spills
on
the
pinch
roller
or
the
rubber
belt,
wipe
it
off
immediately
with
denatured
alcohol.
To
lubricate
them,
proceed
as
follows:
Avoid excessive lubrication.
(1)
Remove
the
head
cover
and
the
screw
securing
pinch
roller
and
then
lubricate
the
pinch
roller
shaft
with
one
drop
of
light
machine
oil.
(2)
Remove
the
reel
panel
and
lubricate
the
motor
lubricating
hole
with
several
drops
of
light
machine
oil.
Note: Use the oil which is comparatively
viscous at the pinch roller shaft.
4-2. CLEANING
Dusts and dirts which were brought by tape
may stick to the core of the record, playback or
erase head, and they may deteriorate the perform-
ance of the record and the playback heads. So wipe
off the surface of the heads, with a clean and soft
cloth dampened with denatured alcohol. To ensure
proper operation, the heads should be cleaned at
least once during each ten hours of actual operation.
CAUTION
Do not use any other ‘solvent on the head as
some will damage the material which binds
the head laminations together. Also do not
use any metallic device which will scratch the
head.
At the same time, clean capstan, rubber belt,
pinch roller, tape guide, flutter filter roller and
tension arm.
4-3. DEMAGNETIZING
The record and playback heads may occasionally
acquire a degree of permanent magnetization, which
will result in an increase of noise level, distortion of
any recorded signal, and a gradual erasure of high
frequency on any recorded tape which passed over
them. These heads may be easily demagnetized
with a SONY head demagnetizer HE-2 (optional
accessory) or equivalent.
To demagnetize the heads, proceed as follows:
Steps:
(1) Remove the head cover.
(2) Make sure that power switch on the TC-640
is in the OFF position.
(3) Connect the demagnetizer to ac power source.
(4) Bring the tips of the demagnetizer in close
proximity to, but not in contact with, the
heads so that the tips straddle the gap in the
center of the head, run the tips up and down
the heads several times, and then slowly with-
draw the demagnetizer.
CAUTION
Do not bring magnet close to heads.

5-1.
5-1-1.
SECTION 5
ADJUSTMENT PROCEDURES
MECHANICAL ADJUSTMENTS
171-117-083 (C402)
capacitor, metalized paper
171-117-083 (C403)
capacitor, metalized paper
1-541-033-21 (M403)
motor, reel (CM-71) -
1-117-040 (C401)
capacitor, metalized paper
1-441-680 (T401)
transformer, power (for USA)
1-441-694 (T4017)
transformer, power (for General Export)
1-541-033-21 (M402)
motor, reel (CM-71)
8-83 1-634-13 (M401)
motor, capstan (HC-634D5}
Adjusting parts locations
Automatic Shut-off Switch Adjustment
Remove the head deck by taking off the two
screws, and put it upside down on a soft cloth.
Make sure that the shut-off lever does not touch
the head deck when pushing it by the hand.
See Fig. 5-1-1.
If necessary, adjust the position of the actuator
bracket by loosening the screws A.
Place the head . deck
See Fig. 5-1-1.
in a normal position.
Push the shut-off lever slowly by the hand, and
check to see that the microswitch turns on when
the lever comes the one-third position of the
slot as shown in Fig. 5-1-2.
If necessary, adjust the position of the micro-
switch by loosening the screws (B) and (C).
Release the shut-off lever, and make sure that
the microswitch turns off when the actuator
comes at one-fourth position of the slot (See
Fig. 5-1-2).
Make
sure
that
the
shut-off
lever
reaches
the
top
of
the
slot
when
pushing
the
lever
by
the
hand.
9. If it is not, readjust the position of the actuator
bracket.
actuator bracket
shut-off lever
Fig. 5-1-1. Automatic shut-off Switch adjustment (1)
shut-off lever ri *]
one _ U
% ia
Fig. 5-1-2, Automatic shut-off switch adjustment (2)

5-1-2.
Pinch
Roller
Pressure
Adjustment
1.
Place
the
unit
in
the
play
mode
to
energize
the
pinch
roller
solenoid,
and
turn
on
the
automatic
shut-off
switch.
Note: Hold the shut-off lever so that the shut-off
switch is activated (a rubber band or a piece
of masking tape will hold the shut-off lever
as though tape were threaded on the unit.)
2.
Adjust
the
adjusting
nut
(A)
for
1
mm
(3/64”
)
clearance
between
the
link
shaft
and
the
adjust-
ing
nut
(A).
See
Fig.
5-1-3.
:
3.
Attach
the
spring
scale
(5
kg)
to
the
pinch
roller
shaft
with
a
piece
of
string.
See
Fig.
5-1-4.
Pull
the
scale
horizontally
in
the
direction
shown
by
the
arrow.
The
capstan
shaft,
pinch
rolier
and
the
spring
scale
should
be
in
a
line.
Check
the
reading
just
when
the
pinch
roller
separates
from
the
capstan.
4, Adjust the adjusting nut (B) for 2.2 + 0.2 kg.
(4.4 to 5.3 1b)
5. Repeat steps 2 to 4 several times.
6. After adjustment, lock the adjusting nut (B) by
the lock nut (B).
7. Adjust the adjusting nut (A) for the clearance
of 0.1 to 0.2 mm between the lock nut (A) and
the link shaft.
8, Lock the adjusting nut (A) by the lock nut (A).
9, Check for the correct value again.
link shaft areal
lock nut (A)
adjusting
nut
(B)
adjusting
nut
(A)
Fig. 5-1-3. Pinch roller pressure adjustment (1)
Pull the spring scale aA
in the direction shown
by the arrow.
capstan
TS
pinch roller
Fig. 5-1-4. Pinch roller pressure adjustment (2)
5-1-3. Microswitch Position Adjustment
1. Check to see that the microswitch (for pinch
roller solenoid) is turned on when the pinch
roller touches the capstan. See Fig. 5-1-5.
2. If it is not, adjust the position of the micro-
switch by loosening the screws A.
to be contact
capstan
pinch roller
Fig. 5-1-5. Microswitch position adjustment
5-1-4. Reel Motor Torque Adjustment
Take-up Motor Torque Adjustment
1. Place the reel with string wound several turns
clockwise on the hub (44 mm dia) onto the
take-up reel table. Tie the string to the spring
scale.
2. Hold the shut-off lever so that the shut-off
switch is activated (a rubber band or a piece of
masking tape will hold the shut-off lever as
though tape were threaded on the unit).
3. Place the unit in the play mode. Pull the spring
scale and then allow to take up the string on the
reel while approaching the scale to the reel at
the same speed of tape running. Adjust RV401
for 330 to 350 g-cm (4.58 to 4.86 oz. inch) on
the spring scale. See Fig. 5-1-6.
Note: Read the scale while moving it.

5-1-5,
Back Tension Torque Adjustment
Place the empty hub with string wound several
turns counterclockwise on the hub (44 mm dia)
onto the supply reel table. Tie the string to
the spring scale.
Hold the shut-off lever so that the shut-off
switch is activated (a rubber band or a piece of
masking tape will hold the shut-off lever as
though tape were threaded on the unit.)
Place the unit in the play mode. Pull the spring
scale at the same speed of tape running. Adjust
RV402 for 240 to 260 g-cm (3.32 to 3.60 oz.
inch) on the spring scale. See Fig. 5-1-6.
Note: Read the scale while pulling it.
Fig. 5-1-6. Reel motor torque adjustment
Brake Torque Adjustment
This adjustment should be performed for both
supply and take-up sides.
Note: The instructions in [ ) are applied to the
’ supply brake torque adjustment.
Place the unit in the STOP mode.
Bend the portion A _ of the brake lever
with a pair of pliers so that the clearance
between the brake lever and the limiter is
approx. 2 mm (5/64").
Place an empty reel with string wound several
turns counterclockwise [clockwise] on the hub
onto the reel table.
Tie the spring to a spring scale.
—~10—
4. Pull the spring scale horizontally at a constant
speed, making sure that the string does not
touch either flange of the reel. The reel table
will rotate counterclockwise [ clockwise }.
Take a reading only when the reel table is in
steady motion.
5. Make sure that the brake torque is 350 to 450
g.cm (4.86 to 6.25 oz. inch).
6. Place an empty reel with string wound several
turns clockwise [counterclockwise] on the hub
onto the reel table.
Tie the spring to a spring scale.
ti Pull the scale horizontally at constant speed,
making sure that -the string does not touch
either flange of the reel. The reel table will
rotate clockwise { counterclockwise ].
Take a reading only when the reel table is in
steady motion.
8. Make sure that the brake torque is 1,000 to
1,300 g-cm (13.9 to 18.1 oz. inch).
9. If it is not, change the hooking position of the
spring for the specified brake torque.
10. Check to see that the center pole of the
solenoid should be pulled out from the
solenoid by approx. 3 mm(1/8") in STOP mode
as shown in Fig. 5-1-9.
If it is not, adjust the position of the brake arm
bracket A marked with x.
11. Make sure that the capstan belt does not rub
against the portion marked with a of the brake
lever in the play mode.
Specification:
Brake Torque of Supply Reel
in clockwise turning .. 350 - 450 g-cm
(4.86 - 6.25 oz. inch)
in counterclockwise turning
. 1,000 - 1,300 g-cm
(13.9 - 18.1 oz. inch)
Brake Torque of Take-up Reel
1,000 - 1,300 g-cm
(13.9 - 18.1 oz. inch)
in clockwise turning ..
in counterclockwise turning
.. 350-450 g-cm
(4.86 - 6.25 oz. inch)

brake lever 5-1-6. Reel Table Height Adjustment
1. Place the unit in the play mode.
2. See Fig. 5-1-11. Adjust the height of the take-
up reel table by loosening the set screws with
an allen wrench so that the tape is on the mid-
dle portion between the upper and lower
flanges of the reel.
3. Check for the supply reel table height in the
rewind mode.
reel table
a allen wrench
Fig. 5-1-10. Reel table height adjustment (1)
yr
LIED
brake arm {A} id 7 4 Upper and lower clearance should be equal
link red (B)
Fig. 5-1-9. Brake torque adjustment (3) Fig. 5-1-11. Reel table height adjustment (2)
oes ee

5-2.
ELECTRICAL
ADJUSTMENTS
Before
making
adjustments,
carefully
read
the
followings.
:
1.
Clean
the
record,
playback
and
erase
heads
with
asoft
cloth
dampened
with
denatured
alcohol.
2
Demagnetize
the
record
and
playback
heads
with
a
head
demagnetizer
(SONY
HE-2
or
equivalent).
3.
Set
the
switches
to
the
following
positions,
unless
otherwise
indicated.
MONITOR switch ......... TAPE
TAPE
SELECT
switch
......
NORMAL
ECHO & SOS VOL switch ... OFF
REC MODE switch......... OFF
TAPE SPEED switch ....... 19 cm/s
4. Input Connection
audio
oscillator
REC AMP
MIC jack
Fig. 5-2-1.
5.
Output
Connection
VTVM
PB AMP
MONITOR jack
Fig. 5-2-2.
6.
Input
and
output
levels
are
specified
as
follows,
unless otherwise indicated.
Normal input level
MICROPHONE LINE INPUT
Input
signal
level
—60
dB
(0.775
mV)
—10
dB(0.245
V)
Signal
source
:
600
22
100
kQ
impedance
Normal output level
LINE OUT HEADPHONE
0 dB (0.775 V) —28 dB(31 mV)
Load
sesistor
100
kQ
8
Outputlevel
7.
Set
the
VOL
controls
to
the
following
position,
unless otherwise indicated.
(1) MIC VOL (in using the MIC jack)
Set the LINE VOL controls extremely
counterclockwise and the MONITOR switch
to SOURCE. Deliver a 1 kHz signal (—60 dB)
to the MIC jack and adjust the MIC VOL
controls so that the LINE OUT level is
0 dB (0.775 V).
(2)
LINE
VOL
(In
using
the
LINE
INPUT
jack)
Set the MIC VOL controls extremely counter-
clockwise and the MONITOR switch to
SOURCE. Deliver a 1 kHz signal (—10 dB) to
the LINE INPUT jack and adjust the LINE
VOL controls so that the LINE OUT level
is 0 dB (0.775 V).
(3) PB VOL
Set the MONITOR switch to TAPE. Play the
Ist tone (400 Hz, 0 dB) of SONY alignment
tape and adjust the PB VOL controls so that
the LINE OUT level is 0 dB (0.775 V).
8. The adjustment should be performed for both
L-CH and R-CH.
9.
The
test
equipments
required
for
the
adjustment
are as follows:
Audio oscillator
Attenuator
Fixed
resistors
100
kQ2,
2.2
kQ
and
2.2
kQ
oscilloscope
VTVM
Standard tape (blank)
SONY SLH tape (blank)
Non-metallic screwdriver
SONY alignment tapes J-19-F2, J-9-F1,
distortion meter FAG
1 kHz bandpass filter
10.
A
blank
test
tape
should
be
a
new
tape
ora
well-demagnetized tape.
11. The following SONY alignment tapes are
required for the adjustments. They contain the
following information in the sequence indicated.
- 5 kHz] 400Hzj 400Hz| 5 kHz 3kHz) 160 Hz 80 Hz
-10 dB OdB} -10dB] -10dB{ -10dB}) -10dB] -10dB
J-19-F2 400 Hz| 400 Hz} 10 kHzji2.5 kHz 7kHz 80 Hz 40 Hz
OdB] -10dB} -!0dB] -10dB/ -10dB] -10 dB] -10dB
J-19-A2 12.5 kHz (-10 dB)

R213 19 cm/s
R214 9.5cmss
PB EQ adj
R254 9.5 cm/s
R253 19 cm/s
bias adj
dummy coil adj
R232 R272 R115 R155 L101
1. DC Power
Voltage Check
Specification: 21.5 +1Vdc
2. Automatic
Shut-off Switch
Operation
Check
3. Function Lever
Check
VU adj REC GAIN
adj
REC EQadj
Adjusting parts locations
system
control
circuit board
voltmeter
1OKe)
DC 50 V range
~13.—
Procedure
. Turn on the power switch.
. Check for the reading on the dc voltmeter
connected between the terminals 12 (+) and
7 (—) on the system control circuit board.
. Turn on the power switch.
. Depress the play lever with the shut-off lever
pushed by the hand.
. Make sure that the unit is set in the play mode.
. Release the shut-off lever. The play lever
should be released and the set should be
changed to the stop mode.
. Turn off the power switch.
. Thread the tape along the tape path.
. Push the play lever (or both play and record
levers) ;
- Turn on the power switch with ac 90 V power
source.
. Make sure that the tape starts to run in the play
(or record) mode.

4. PB Head Test Setup: 1. Play back the SONY alignment tape (J-19-A2).
Azimuth
: oscilloscope | 2. Adjust the adjusting screws for maximum playback
Adjustment
output at both channels.
. Make sure that the same phase is obtained at 2nd
tone (400 Hz) of the alignment tape (J-19-F 2).
. When touching the tape near the playback head
with a finger or a nonmetallic equipment, make
sure it does not cause a higher output level.
REC head azimuth
adjusting screws
PB head azimuth
adjusting screws
same phase 45° 90°
* Screw position: Angle where the maximum
output
level
is
obtained
Lissajous
figure
on
the
oscilloscope
* Phase difference between channels:
Same phase at 400 Hz
within 90 ° at 10 kHz
5. VU Meter Test Setup: . Place the unit in the vertical position.
Calibration
. Make sure that the pointer of the VU meter
VTVM
indicates —20 on the scale with no input signal in
PB AMP the play mode.
100 k8t
Op See . Play back the first tone (400 Hz) of the SONY
f \ alignment tape (J-19-F2).
ever PINE OUT [eck . Adjust the PB VOL control to obtain 0 dB
(0.775 V) on the VTVM.
. Adjust R232 (R272) to obtain 0 VU on the level
meter.
Notes:
1. Gain margin of PB VOL control should be 6 to
8 dB.
. Do not turn the PB VOL control after
the above step 4.
—14—

Test Setup: 1. Thread a blank tape along the tape path.
6. Azimuth
Adjustments
(Record Head)
blank tape
. Deliver a 10 kHz signal of —80 dB (77.5 UV) to the
MICROPHONE jack.
AF ose REC AMP
. Set the MONITOR switch to SOURCE.
MIC jack
eee tT . Adjust the azimuth adjusting screw for maximum
reading on the VTVM.
- Record the signal on the blank tape.
. Make sure that the playback output is not increased
when touching the tape near the record head with
LINE OUT jack
a finger or a nonmetallic rod.
Test Setup: . Place the unit in the record mode.
. Trap Coil
palusement _ Adjust C191 (C192) so that the VI'VM connected
ee pai REC AMP across the record head reads approximately 10 V.
eakage
3. Set the MIC VOL and LINE VOL controls
extremely counterclockwise.
Measurement
—> REC HEAD
check
100 kQQ
2 vTvM
Specification:
4. Adjust L195 and L196 for the minimum reading on
the VTVM connected to the check points.
. Measure the bias current leakage in the playback
output without the tape threaded.
Notes:
* Bias current
1. A shielded wire should not be used for the lead
of VT VM.
leakage: Less than —40 dB
. Use a nonmetallic screwdriver.
. The bias current leakage measurement is requir-
ed for both stereo and monaural record modes.
. Check points:
L-Ch : terminal (2)
R-Ch : terminal (42)
on the rec bias circuit board
—~15—

Procedure
1. Thread a blank tape along the tape path.
Items Remarks
8. Record Bias Test Setup:
Adjustment -
eae pus REG AME blank tape | 7 Set the MIC VOL and LINE VOL controls to the
specified position on page 12.
_
J . Turn the trimmer capacitorsC91 and C92 clockwise
to the full and turn them counterclockwise by
MIC jack ee OTM
three or four turns.
. Deliver a 1 kHz signal of —60 dB (0.775 mV) to the
MICROPHONE jack.
. Record the signal on the blank tape.
LINE OUT jack
6. Turn C91 (C92) clockwise slowly until the VTVM
reads a maximum.
. Turn C91 (C92) moreover until the VWITVM reads
0.5 dB below the maximum reading.
. After adjustment, apply lock paint to the capacitors.
—- bias current
9.
Record
Level
.
Thread
a
blank
tape
along
the
tape
path.
Adjustment
Test Setup:
blank tape . Set the MONITOR switch to SOURCE.
Reo REC AMP
3. Deliver a 1 kHz signal of —60 dB (0.775 mV) to
the MICROPHONE jack.
MIC jack - -- 4. Adjust the MIC VOL control to obtain 0 dB
ee (0.775 V) on the VTVM.
Note:
When changing the TAPE SELECT switch
to SPECIAL, make sure that the output de-
creases approximately 1 to 1.5 dB.
LINE OUT jack
. Change the MONITOR switch to TAPE.
. Record the signal on the blank tape.
. Adjust R115 (R155) to obtain 0 dB (0.775 V) on
the VTVM.
— 16 -—

10.
Playback
Test
Setup:
1.
Adjust
R213
(R253)
to
obtain
the
same
output
between
the 2nd
(400
Hz) and
3rd (10 kHz)
tones
VTVM
of the
alignment
tape
(J-19-F
2).
Response
Measurement PB_AMP Oe . Play the alignment tape (J-19-F 2) from the 2nd tone
19 cm/s Ze = to the 7th tone.
(7-1/2 ips)
. Measure the deviation of each frequency against the
LINE OUT jack 2nd tone.
Frequency
J-19-F2
. Make sure that the satisfied result is obtained.
Specification:
tape level deviation
tone against 2nd tone
oad O+154B
(10 kHz)
an 0.+ 1.5 dB
(12.5 kHz)
ou 0+1.5 dB
(7 kHz)
3
a + 1.0 + 2.0 dB
(80 Hz)
Tth
+ 1.0 +3.0dB
11. Playback Test Setup: . Adjust R214 (R254) to obtain the same output
Frequency between the 3rd (400 Hz) and 4th (5 kHz) tones of
Response VTVM the alignment tape (J-9-F 1).
Measurement .
9.5 cm/s PB AMP . Play the alignment tape (J-9-F1) from the 3rd
‘ f T 100 kl tone to the 7th tone.
(3-3/4 ips) sips z
. Measure the deviation of each frequency against
LINE OUT jack the 3rd tone.
J-9-F 1 <a F ;
: . Make sure that the satisfied result is obtained.
Specification:
tape level deviation
tone against 3rd tone
aa 0+1.5 dB
(5 kHz) was
au 0+1.5 dB
(3 kHz) oat
a 0+2dB
(160 Hz) 7
7th
(80 Hz) Denar
247.5

Test Setup: i. Set the TAPE SPEED switch to 19 cm/s (7-1/2 ips).
12. Playback
Signal-to-
2. Play the Ist tone (400 Hz) of the SONY alignment
tape (J-19-F2).
VTVM
NS
LINE OUT jack
Noise Ratio
. Adjust the PB VOL control so that the VT VM will
indicate 0 dB (0.775 V). ;
. Place the unit in the play mode without any tape.
J-19-F2
Note:
Hold the shut-off lever so that the shut-off
switch is activated (a rubber band or a piece of
Specification:
7/2 ips
(19 cm/s)
more than 80:48 masking tape will hold the shut-off lever as
though tape were threaded on the unit).
. Note the VTVM reading.
33/4 ips
(9.5 cm/s)
Seer are ree more than 48 dB
6. Make sure that the difference between the above
steps 2 and 4 is more than 50 dB.
. Set the TAPE SPEED switch to 9.5 cm/s (3-3/4 ips).
. Note the VI VM reading.
. Make sure that the difference between the above
steps 2 and 8 is more than 50 dB.
Test Setup:
13. Input Level
Variation
F REC AMP
Check a Sled 6002 mic
O-faT Fs
1 kHz 10 kX
= rN
O
LINE IN
ca
PB AMP LINE AMP
Specification: Level variation by MIC VOL Control
* MIC VOL............ Less than 0.5 dB . Set the LINE VOL control to the normal position.
2. Deliver a 1 kHz signal of -10 dB (0.245 V) the
LINE INPUT jack.
* LINE VOL............ Less than 0.5 dB
. Check for the level variation on the VTVM by
turning the MIC VOL control from MIN to MAX.
Level variation by LINE VOL Control
. Set the MIC VOL control to the normal position.
. Deliver a 1 kHz signal of —60 dB (0.775 mV) to the
MIC jack.
. Check forthe level variation on the VTVM by
turning the LINE VOL control from MIN to MAX.
—18—-—

14. Minimum Test Setup:
Input
Level
REC
AMP
Check ares 6002 MIC
© ad
1 kHz ‘|19 kQU
LINE IN
=
> TAPE
ps OUT jack
{0} O
Be]
PB AMP LINE AMP
Specification: . Set the MONITOR switch to SOURCE.
. Deliver a 1 kHz signal of —72 dB (0.2 mV) to the
MICROPHONE jack.
MIC jack
Less than —72 dB(0.2 mV)
. Set the LINE VOL control fully counterclockwise.
LINE INPUT jack
Less than —22 dB(61 mV)
. Make sure that the line output is more than 0 dB
on the VITVM when turning the MIC VOL control
fully clockwise.
. Deliver a 1 kHz signal of -22 dB (61 mV) to the
LINE INPUT jack.
. Set the MIC VOL control fully counterclockwise.
. Make sure that the line output is more than 0 dB
on the VT'VM when turning the LINE VOL control
fully clockwise.
Test Setup: . Set the MIC VOL and LINE VOL controls to the
normal position.
. Input and
Output Check
of REC/PB
Connector
(This check
is applied
blank tape
REC AMP
eee OS 2. Connect the audio oscillator to pin 1 (4) and 2
of the REC/PB connector.
3. Deliver a 1 kHz signal of —34 dB (15.5 mV) from
the audio oscillator.
for General
Export model
. Place the unit in the record mode.
only)
. Make sure that the VIT'VM reads 0 dB (0.775 V).
6. Disconnect the VTVM from the LINE OUT jack
and connect it to pin 3 (5) and 2 of the REC/PB
connector.
LINE OUT jack
Specification:
7. Play back the recorded tape.
0+2dB (0.62 — 0.97 V)
. Make sure that the VTVM reads 0 + 2 dB (0.62 —
0.97 V).
—~19—

16. Overall
Frequency
Test Setup:
AF osc REC AMP
_ Response
Adjustment
(NORMAL) MIC jack
Specification:
17. Overall
Frequency
Test Setup:
AP ose REC AMP
Response
Adjustment
(SPECIAL)
Specification:
blank tape
blank tape
LINE OUT jack
speed 7-1/2ips | 3-3/4 ips
(19 cm/s) (9.5 cm/s)
— 20 —
. Set the TAPE
. Thread a blank tape along the tape path.
. Set the TAPE SELECT switch to NORMAL.
. Set the MIC VOL and LINE VOL controls to the
specified position on page 12.
. Record the following frequency signals of —80 dB
(77.5 UV): 50 Hz, 100 Hz, 1 kHz, 5 kHz, 10 kHz,
1$ kHz and 18 kHz through the MICROPHONE
jack.
. Make sure that each deviation in the level for a
1 kHz signal is within the specification.
. If it is not, perform the record bias adjustment.
. Thread a blank tape (SONY SLH tape) along the
tape path.
SELECT switch to SPECIAL.
. Set the MIC VOL and LINE VOL controls to the
specified position on page 12.
. Record the following frequency signals of —80 dB
(77.5 LV): 50 Hz, 100 Hz, 1 kHz, 5 kHz, 10 kHz,
15 kHz and 18 kHz through the MICROPHONE
jack.
. Make sure that each deviation in the level for a
1 kHz signal is within the specification.
. If it is not, perform the record bias adjustment.