Sharp GF-9090H User Manual

ELECTRICAL MEASUREMENT
* This unit operaters on DC 12 V. Check that the power * Refer to Figure 35.
supply is exactly 12 V before measurement.
* Set the FUNCTION switch (SW101G) to “TAPE”
position.
m RECORD OSCILLATOR BIAS CURRENT AND BIAS FREQUENCY ADJUSTMENT
(Refer to Figure 21)
1. Connect the V.T.V.M. across the 100 ohm resistor 5. As a result of the check in the step 5 above, if the
(R201, R202). reading is found outside the 53 + 1 kHz, adjust the
2. Place the unit in RECORD mode. bias oscillation coil (L601)
3. Adjust the semi-variable resistores (VR601, VR602) 6. After the step 5, again make sure of the bias current.
so that the V.T.V.M. reads 50 mV for the right
channel (R201) and left channel (R202) respectively.
4. Make sure the record oscillator bias frequency is
53 + 1 kHz.
POSITION
A
NORMAL
AC V.TV.M.
FREQUENCY
COUNTER
GROUND
Figure 21
m ERASE CURRENT CHECK
(Refer to Figure 22)
1. Connect the V.T.V.M. across the 1 ohm resistor
(R603).
2. Place the unit in RECORD mode.
3. Make sure the erase current is 90+ 20 mV.
SWITCH POSITION
BIAS (SW602) NORMAL
ERASE HEAD
AC V.TV.M,
RECORD mode
Figure 22
11
m RECORD AMPLIFIER SENSITIVITY CHECK
(Refer to Figure 23)
1. Connect the V.T.V.M. across the 100 ohm resistors 4. Place the unit in RECORD mode.
(R201,
R202).
5.
If
the
record
amplifier
sensitivity
is
normal,
the
2. Short circuit the primary coil of the oscillation reading on V.T.V.M. should be approximately
coil (L601) to stop bias oscillator. 1.75 mV.
3. Connect the signal generator to the EXT. MIC jacks
(J201, J202) and apply signals (1000 Hz, —78 dB)
MODE (SW303) STEREO
to the unit.
SWITCH POSITION VR CONTROL | POSITION
ALC/MANUAL (SW202) | MANUAL RECORD (VR201) |
EQ
Gw203)
NORMAL
RECORD
(VR202)
rarer
BIAS (SW602) NORMAL
R/P HEAD
AC V.T.V.M.
MIC JACK —-- RECORD mode
ceeea GENERATOR (J201,J202) - STOP BIAS OSC.
-78dB
ATTENUATER
(0 dB = IV)
Figure 23
m PLAYBACK AMPLIFIER SENSITIVITY CHECK
(Refer to Figure 24)
1. Connect load resistor (4 ohm) to the EXT. SP sockets
(SO301, SO302) and further connect the V.T.V.M.
3. Place the unit in PLAYBACK mode.
4. If the playback amplifier sensitivity is normal, the
thereto. reading on the V.T.V.M. should be approximately
2. Connect the signal generator across the REC/PB 0.5 V.
head and apply signals (1000 Hz, —80 dB) to the
unit.
SWITCH POSITION POSITION
EQ (SW203)
MODE (SW303) STEREO
Mechanical
TREBLE (VR302) ee
Center
BASS (VR303)
R/P HEAD
AC V.TV.M.
EXT. SP
* PLAYBACK mode (S030! ,302)
SIGNAL GENERATOR
lOOOHz
-80dB
ATTENUATER
O
GROUND GROUND
(OdB = IV)
Figure 24
12

Sharp GF-9090H Specifications

General

Brand	Sharp
Model	GF-9090H
Category	Stereo System
Language	English