Adjustments; Mechanical Adjustments; Electrical Adjustments - Sony CFM-20 Service Manual

3-1. MECHANICAL ADJUSTMENTS

PRECAUTION
1.Clean the following parts with a denatured-alcohol-moistened
swab :
record/playback head
erase head
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
parts adjusted.
5. The adjustments should be performed with the rated power sup
ply voltage unless otherwise noted.
Torque Measurement
Torque Torque Meter
Forward CQ-102AS
Forward
CQ-102AS
Back Tension
Fast Forward CQ-201WS
Rewind CQ-201WS
Tape Tension Measurement
Torque Meter
CQ-405AS
SECTION 3

ADJUSTMENTS

pinch roller
rubber belts
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 )
Meter Reading
more than 60g
(more than 2.12 oz)

3-2. ELECTRICAL ADJUSTMENTS

TAPE RECORDER SECTION
FUNOTION switch (S101) : TAPE (RADIO OFF)
VOLUME (RV101)
Standard Output Level
Output terminal
load impedance
output signal level 0.25V (–10dB)
Test Tape
Type Signal
WS-48A 3kHz, 0dB
P-4-A063 6.3kHz
Record/Playback Head Azimuth Adjustment
Procedure :
1.Playback Mode
test tape
P-4-A063J
(6.3kHz, -10dB)
AEP, UK, CET, IT, AR, HK, SP model t
C&SA, MX, TW model t KH102 (Speaker output)
2.Rotate the screw to adjust level meter reading to the maximum.
Note :
Adjust to the maximum peak though there may be two or
three peakes
3.After the adjustment, lock the adjustment screws with suitable
locking compound.
• Abbreviation
SP : Singapore AR
HK : Hong Kong MX :Mexican
IT : Italian TW
C&SA : Central and South America
CET : East European & Russian
Adjustment Location :
Head azimuth adjustment screw
CFM-20
0dB=0.775V
: MIN
Earphone Speaker
8Ω 12Ω
0.775V (0dB)
Used for
Tape Speed Adjustment
Record/Playback Head
Azimuth Adjustment
level meter
Speaker output:12 Ω
Earphone jack:8 Ω
+
set
J101 (Earphone jack)
:Argentina
:Taiwan
7