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SECTION 3
MECHANICAL ADJUSTMENTS SECTION 4
ELECTRICAL ADJUSTMENTS
PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab:record/playback/earth head pinch roller
rubber belts capstan
idlers
2. Demagnetize the record/playback head with a head demagne-
tizer. (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
supply voltage unless otherwise noted.
Torque Measurement
PRECAUTION
1. The adjustment should be performed in the publication.
(Be sure to male playback adjustment at first.)
2. The adjustments and measurement should be performed for
both L-CH and R-CH.
•Switch position
DOLBY NR switch : OFF
DIRECTION switch : A
•Standard record position
Deliver the standard input signal level to input jack and set
the REC LEVEL (RV301) control to obtain the standard
output signal level as follows.
– Record Mode –
set
AF OSC
attenuator
600
Ω
10 k
Ω
LINE IN
+
–
LINE OUT
47 k
Ω
level meter
Standard Input Level
Input terminal LINE IN
source impedance 10 kΩ
input signal level 0.5 V (– 3.8 dB)
Standard Output Level
Output terminal LINE OUT (L-CH)
load impedance 47 kΩ
output signal level 0.5 V (– 3.8 dB)
TestTape
Type Signal Used for
P-4-A100 10 kHz, – 10 dB Azimuth Adjustment
P-4-L300 315 Hz, 0 dB PB Level Adjustment
WS-48B 3 kHz, 0 dB Tape Speed Adjustment
0 dB = 0.775 V
Mode Torque Meter Meter Reading
CQ-102C
30 – 65 g•cm
FWD (0.42 – 0.90 oz•inch)
FWD 1.5 – 6 g•cm
Back tension (0.021 – 0.083 oz•inch)
CQ-102RC
30 – 65 g•cm
REV (0.42 – 0.90 oz•inch)
REV 1.5 – 6 g•cm
Back tension (0.021 – 0.083 oz•inch)
70 – 130 g•cm
FF, REW CQ-201B (0.98 – 1.80 oz•inch)
Test Mode
With the POWER turned OFF, short the test point CN801 (2P) on
the SYSTEM CONTROL board (making IC801 pin !º “L”) and
turn the POWER ON. Thus, the TEST mode will be activated.
If a recording is done in the TEST mode, the REC MEMORY
mode becomes active where the tape is rewound by the amount of
recording when a rewinding is executed after recording.
After adjustment, make the CN801 (2P) open to release the TEST
mode.
