JVC MF-47L - Tuner Alignment

| MF-47L/ML
2. While changing the bias switch, adjust so that the 5. Adjustment of Recording signal current
specified current will be obtained. The adjustment 1. For this adjustment, it is necessory that the swing
should be made from ‘“‘CHROME”. angle of the level meter and playback sensitivity are
correctly adjusted previously.
. Set the equalizer switch and bias switch to “NORMAL”.
3. In recording state, apply 1kHz signal of proper level
(0.5V approximately) to “AUX” input terminal, and
adjust the front Recording volume so that the level
meter will indicate 0 VU’
4. In this state, repeating the recording and playback,
adjust VR305 (L-ch) and VR306 (R-ch) until the
level meter indicates OVU.
NO
.
Bias
ae
Place
to
be
adjusted
Current
VR307
(L-ch)
550uA
CHROME
VR308
(R-ch)
(55mV/1002)
;
400uA
NORMAL
|
VR3O9(L,Rch)
|
aomVy/1002)
3. Regarding bias frequency, adjust T301 so that 57kHz
will be obtained when the front BEAT CUT Switch is
set to 1.
Tuner Alignment
AM IF & RF ALIGNMENT
@ IF Alignment x ~10KHz : 10KHz y,
Equipment required : 455kHz Sweep Generator with Oscilloscope ac Se te Es
Input terminal : Ain Fig. 18
Output terminal : Bin Fig. 18
@ RF Alignment
Equipment required : Standard Signal Generator (Modulation 1kHz, 30%)
AC Voltmeter, Oscilloscope b
Input terminal : Loop Antenna for LW and MW
Output terminal : Speaker terminal (4Q load) ae
ig.
|
Step
|
Band
|
Input
Frequency Alignment
point
Mw
455kHz
T101,102
(IF)
Adjust T101, 102 as Fig. 15
a
2
res
ieee as
Repeat the step 3 & 4 and adjust for no further improvement.
160kHz L101(LW side) 160kHz
350kHz
C103-2
350kHz
8
Repeat
the
step
6
&
7
and
adjust
for
no
further
improvement.
ieee]
| 10 |
ae Repeat the step 9 & 10.
iia
| 44 | Repeat the step 12 & 13 and adjust for no further improvement.
NOTE:
When
you
adjust
the
bar
antenna
coil
of
MW
or
LW,
check
the
tracking
error
for
each
band,
because
two
coils
interfere
to
each
other
though
slightly.
Always
use
an
insulated
screw
driver
for
adjustment.
—W1-