JVC UX-H300, Руководство по обслуживанию

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1-20 (No.MB215)
4.4 Cassette amplifier section
4.5 Tuner section
4.6 Location of adjusting parts
Item Measuring condition Check and adjustment procedure Standard value Adjusting part
Head azimuth
adjustment Test tape:VT703L
Signal output
terminal:PHONES
(with 32 ohm load) 1.Play back the test tape VT703L.
2.Adjust the head azimuth adjusting screw so that
the phase difference between the L and R
channels is minimized at an output level that is
/- 2 dB of the maxmum ooutput level.
After this adjustment, lock the kead azimuth
adjusting screw with screw sealant to cover more
than a half of the screw head.
When the head azimuth is maladjusted, correct it
with the head azimuth adjusting screw.
3.
Output level:
/-2 dB of
maximum output
level
Phase difference
L and R
channels:Minimum Head azimuth
adjusting
screw (to be
used only
after head
replacement)
Tape speed and
wow / flutter check
and adjustment Test tape:VT712
Signal output
terminal:PHONES
(with 32 ohm load) 1.Playback the test tape VT712 by the end position.
Connect a frequency counter and check that it
reads between 2940 and 3090 Hz. If not, adjust
the frequency with the motor semifixed resistor.
Check that the wow/flutter is within 0.38%
(unweighted)
2.
3.
2940 to 3090 Hz
within 0.38 %
(unweighted) Tape speed:
Motor semifixed
resistor
REC and PB
frequency response
adjustment Test tape:VT703L
Signal input FM 22.5
DEV 60dB with
Emphasis
Signal output
terminal:PHONES
(with 32 ohm load) At TUNER, set the BAND to the FM position, and
record the reference 1 kHz signal and 10kHz
signal alternately repeatedly. While playing back
the recorded signal differ from that of the 1 kHz
signal by within 0 ( +3 to -6) dB. Level difference
between REC and
PB:Within 0
(+3 to -6) dB.
Item Measuring condition Check and adjustment procedure Standard value Adjusting part
AM IF adjustment Signal input:
Loop antenna
Signal output:
IC101 pin (16) T103
AM tracking
adjustment Signal input:
Loop antenna
PHONES (with 32
ohm load)
1. Set the intermediate frequency sweep generator
to AM 450 kHz.
Adjust the T103 for maxmum and center output.
2.
1. Set the TUNER at 530 kHz adjust T102 until the
test pin of VD103 voltage at 1.5 V +/- 0.1 V.
Set the TUNER at 1710 kHz, check the pin of
VD103 voltage at 9.0V +/- 0.5V.
Set the TUNER and S/G at 600kHz, adjust T101
for maximum output.
Set the TUNER and S/G at 1400 kHz, adjust
VC101 for maximum output.
Repeat the above steps 3 and 4.
2.
3.
4.
5.
T102
T101
VD103
Main board assembly Cassette mechanism section
CASSETTE MOTOR
Tape Speed Adj.
+
-
BIAS FREQUENCY
L203
J201
R225
R226
IC202
L101
VD101
IC101
VC102
T103
T102
VC101
T101
VD103
VD102
www.freeservicemanuals.info 13/10/2016
Published in Heiloo Holland