Sharp GF-9500H Serviceanleitung Seite 10

• RECORD/PLAYBACK
(See Figure 16-1 )
Insert the normal (non-recorded) tape into the unit
1.
Connect CR oscillator to the External Microphone
2.
socket J101A (or J101B), and apply signal (1kHz,
—60dB) to the unit.
3. Place the unit in Record
switch SW202 to manual position.
4. Adjust the record volume control VR103A
so that the 4th LED of the level meter will light up.
Reproduce the tape recorded in steps 3 and 4.
5.
Adjust the semi-variable resistor VR105 (or VRI 06) so
6.
that the 4th LED of the level meter will light up.
• RECORD AMPLIFIER
OSCILLATOR FREQUENCY
(See Figure 16-2)
1. Connect an Electronic Voltmeter between the test point
TPIOI (or TP102) and TP103.
2. Set the tape selector switch
Normal position and Beat Cancel switch SW105 to A
position.
3. Placethe unit in record mode,andadjust the biasoscilla-
tor frequency adjusting variable coil L 107 so that the
bias oscillator frequency, on the oscilloscope's Lissajou's
figure, is 85 kHz.
4. Adjust the step-up coil L 103 (or L104) so that the
Electronic Voltmeter's reading is 14V.
• RECORD AMPLIFIER
(See Figure 16-3)
1. Connect an Electronic Voltmeter to both ends of resistor
R324.
2. Placethe unit in record mode, and set the tape selector
switch SW203 and SW204 to normal position.
3. Check that the Electronic Voltmeter isreading60 mV.
PINCH ROLLER PRESSURE
(See Figure 16-4)
1. Set the unit in the playback mode.
2. Press the tensiongauge—which is graduatedfrom Oto 500g
onto part @ of the pinchrollerto let it leave the
capstan. Then return the tension gauge slowly and take its
reading when the pinch roller touchesthe capstanor begins
to rotate again. The reading should be 350 to 420 g.
3. If the readingis not within 350 to 420 g, adjustthe pinch
rol ler by bendingthe pinch roller pressing spring or replace
it.
PLAYBACK/FAST-FORWARD/REWIND
MEASUREMENT (See Table 16-1)
I. Load the unit with a torque measurement cassette.
2. The torque measurement for each mode should be as shown
in Table 16-1.
SENSITIVITY ADJUSTMENT
mode. Set the Record
(or V RI 03B)
BIAS CURRENT/BIAS
CHECK
SW203 and SW204 to
ERASE CURRENT CHECK
MECHANISM
ADJUSTMENT
TORQUE
Exernal Microphone
CR Oscillator
Socket JIOIA
Mode
o
I kHz. I V
8107
Record rncK3e
(or R
unit
...TPIOI (or TP102)
TP103
Record mode
un,t
ADJUSTMENT
Capstan
Pinch
o
roller
Mode
Playback
Fast-forward
Rewind
(or 3101
B) Record mode
Record/
Playback Head
A t a tor
unit
unit
Figure
16-1
Re cord
Oscilloscock
Playback Head
o
Figure
16-2
Erase Head
R 324
o
Figure 16-3
Tension gauge
Pinch roller pressing spring
Figure 164
Torque measurement
Measurement
cassette
TW-2111
35 — 60 g-cm
TW-2231 90 — 135 g-cm
90 — 135 g-cm
TW-2231
Table 16-1
T ape
A udi 0
Oscilloscope