Sony CFM-20L Service Manual ▷ View online
6
CFM-20L
TAPE RECORDER SECTION
FUNOTION switch (S101)
: TAPE (RADIO OFF)
VOLUME (RV101)
: MIN
Standard Output Level
Output terminal
Earphone jack (J101)
load impedance
8
Ω
output signal level
0.25V (–10dB)
Test Tape
Type
Signal
Used for
WS-48A
3kHz, 0dB
Tape Speed Adjustment
P-4-A063
6.3kHz
Record/Playback Head
Azimuth Adjustment
Record/Playback Head Azimuth Adjustment
Procedure :
1.Playback Mode
Procedure :
1.Playback Mode
2.Rotate the screw to adjust level meter reading to the maximum.
Note :
Note :
Adjust to the maximum peak though there may be two or
three peakes
three peakes
3.After the adjustment, lock the adjustment screws with suitable
locking compound.
Adjustment Location :
SECTION 3
ADJUSTMENTS
3-1. MECHANICAL ADJUSTMENTS
PRECAUTION
1.Clean the following parts with a denatured-alcohol-moistened
swab :
record/playback head
pinch roller
erase head
rubber belts
capstan
2.Demagnetize the record/playback head with a head demagnetizer.
(Do not bring the head demagnetizer close to the erase head.)
3.Do not use a magnetized screwdriver for the adjustments.
4.After the adjustments, apply suitable locking compound to the
4.After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
Torque Measurement
Forward
CQ-102AS
Forward
CQ-102AS
Back Tension
Fast Forward
CQ-201WS
Rewind
CQ-201WS
Tape Tension Measurement
Torque Meter
Meter Reading
Torque
Torque Meter
Meter Reading
1.77 to 5.88 mN•m
(18 to 60 g•cm)
(0.25 to 0.83 oz•inch)
0.01 to 0.49 mN•m
(1 to 5 g•cm)
(0.014 to 0.069 oz•inch)
4.42 to 9.31 mN•m
(45 to 95 g•cm)
(0.63 to 1.31 oz•inch)
4.42 to 9.31 mN•m
(45 to 95 g•cm)
(0.63 to 1.31 oz•inch)
3-2. ELECTRICAL ADJUSTMENTS
CQ-405AS
more than 60g
(more than 2.12 oz)
(more than 2.12 oz)
0dB=0.775V
Head azimuth adjustment screw
set
test tape
P-4-A063J
(6.3kHz, -10dB)
P-4-A063J
(6.3kHz, -10dB)
8
Ω
level meter
J101 (Earphone jack)
+
7
CFM-20L
FM Section
Function switch (S101)
: FM
Volume
: MIN
Tape Speed Adjustment
Procedure :
Mode : Playback
Procedure :
Mode : Playback
Adjustment Value :3,000Hz
Standard Value
Standard Value
:2,960 to 3,040Hz
Frequency difference between the beginning and the end of the tape
should be within 1.0% (30Hz).
should be within 1.0% (30Hz).
Adjustment Location :
TUNER SECTION
LW Section
Function switch (S101)
: LW
Volume
: MIN
CT3, CT4
: mechanical center
0dB=1
µV
set
test tape
WS-48B
(3kHz, 0dB)
WS-48B
(3kHz, 0dB)
digital frequency
counter
counter
J101 (Earphone jack)
8
Ω
+
tape speed adjustment
control inside motor
control inside motor
AM RF signal
generator
generator
30% amplitude modulation by 400Hz
signal.
Output level : as low as possible
signal.
Output level : as low as possible
Put the lead-wire
antenna close to
the set.
antenna close to
the set.
set
+
level meter
J101 (Earphone jack)
8
Ω
set
+
level meter
J101 (Earphone jack)
8
Ω
FM RF signal
generator
generator
75kHz frequency deviation by
1kHz signal.
Output level : as low as possible
1kHz signal.
Output level : as low as possible
telescopic
antenna
terminal
antenna
terminal
0.01 F
µ
8
CFM-20L
• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
done by the trimmer capacitors.
LW IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T1
455kHz
LW FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L4
145kHz
CT6
300kHz
LW TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L3
160kHz
CT5
260kHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L2
87.00MHz
CT1
108.30MHz
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1
87.00MHz
CT2
108.30MHz
Adjustment Location : MAIN board
FM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
L5
10.7MHz
[MAIN BOARD]
(Conductor side)
(Conductor side)
CT3 : LW Frequency Coverage Adjustment
(Set to mechanical center)
(Set to mechanical center)
CT4 : LW Tracking Adjustment
(Set to mechanical center)
(Set to mechanical center)
CT2: FM Tracking Adjustment
CT1 : FM Frequency
Coverage Adjustment
Coverage Adjustment
[MAIN BOARD]
(Component side)
(Component side)
L5 : FM IF Adjustment
T1: LW IF Adjustment
L1: FM Tracking Adjustment
L3: LW Tracking Adjustment
L4 : LW Frequency
Coverage Adjustment
Coverage Adjustment
CT5 : LW Tracking Adjustment
CT6 : LW Frequency
Coverage Adjustment
Coverage Adjustment
L2: FM Frequency
Coverage Adjustment
Coverage Adjustment
9
9
CFM-20L
SECTION 4
DIAGRAMS
4-1. BLOCK DIAGRAMS
• Signal path.
F
: FM
f
: LW
E
: PB
a
: REC
N
: MIC
VOLUME
ANT1
CT2
CT1
CV1
CV2
CF1
CF2
ECM101
M101
SP101
J101
F901
HRP101
HE101
RV101
T1
L5
L1
L2
J901
CT4
CT3
CV3
CV4
D104
D101
D103
S501
L4
CT5
CT6
FM
TELESCOPIC
ANTENNA
SPRAKER
QUAD
FM RF OUT
BAND SEL
FM OSC
DET OUT
FM RF IN
MIX OUT
FM IF IN
IF AMP,DET,FM MPX
RADIO
+B
REEL/CAPSTAN
MOTOR
(TAPE POWER)
MIC
S102
PB/REC
REC/PB
HEAD
ERASE
HEAD
TRANSFORMER
POWER
T901
IN
MIC
IN
IN
PRE/POWER
AMP
POWER
ON/OFF
ON/OFF
AUX
TAPE
AUX
AUX
HEAD IN
(+)
(+)
HEAD IN
(-)
(-)
BTL1
BTL2
REC/PB
DRY BATTERY
SIZE"D"
(IEC DESIGNATION R20)
4PCS,6V
D901,902
RECT
+B
REG
+B
BIAS
BIAS
LINE
OUT
IN
POWER
IC1
IC101
AC IN
ANTENNA
L3
RADIO
+B
REG
Q101
RIPPLE
FILTER
FILTER
FERRITE-BAR
FM/LW FRONT-END
LW
LW IF IN
LW RF IN
LW OSC
OPR/BATT
+B
+B
RADIO +B
FUNCTION
TAPE/
RADIO OFF
FM
FUNCTION
TAPE/
RADIO OFF
FM
S101-1
S101-2
LW OSC
LW
LW
TRACKING
COVERAGE
FREQUENCY
FM
COVERAGE
FREQUENCY
TRACKING
FM
CT2,L1
CT1,L2
CT5,L3
LW
CT6,L4
LW
FM DET
LW IF
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