As for “Description of APSS”, “Mechanical Adjustment”,
A
S
for all the items except “VU-Meter Adjustment”, refer to
“General Alignment Instruction” and “Electrical Measure- Service Manual of Model GF-9191X.
ment”, refer to Service Manual of Model GF-9191 X.
LEVEL AND SENSITIVITY ADJUSTMENT OF VU METER
1. Connect the V.T.V.M. across the
ohm resistors
15,
2. Short circuit the primary coil of the oscillation coil
to stop bias oscillation.
3. Connect the signal generator to the EXT.
jacks
A,
and apply signal
to the unit.
4. Place the unit in RECORD mode.
5. Connect DC voltmeter between TP51 and TP52 (ground)
and adjust left channel record level control
so that
DC voltmeter indicates
6. Adjust the semi-variable resistor
so that 5th LED
7. Next, change the voltage of TP51 to
by sliding the
record level control
and in this time, check the 5th
LED
of VU meter fails to light.
8. Adjust the record level controls (R147,
so that the
V.T.V.M. reads
9. Adjust the semi-variable resistors (R 187,
so that 4th
of VU meters begin to light.
Set the level of signal generator to
and this time,
check the 4th
(D908,
of VU meters fail to
light.
of VU meter begins to light.
SWITCH
POSITION
lower
01
tape
node
stereo
V
U
nixing
off
oudness
08)
off
normal
mode
manual
GENARATOR
R/P HEAD
JACK RECORD mode
DC
TEF
Figure 6
