JVC PC-W150 - Mechanism and Amplifier Section Adjustments

PC-W 150 B/E/G/GI
EB Main Adjustment: Mechanism and Amplifier Sections
Measuring Conditions and Main Adjustments
< Conditions >
1. Mode : PLAY
2. Test tape : VTT702 (8 kHz)
3. Measuring point : Speaker terminal ..... 32
Head azimuth
adjustment
< Adjustment >
1. Connect an electronic voltmeter to the speaker
terminal.
2. Playback the test tape VTT702.
3. Adjust the head azimuth with screw (A) (Fig. 8-3)
until the reading of the electronic voltmeter becomes
— 2 dB from the peak.
. Adjust to peak between FWD/REV within — 4 dB
from the peak.
< Conditions >
1. Mode : PLAY, Normal speed
2. Test tape : VTT712 at tape end
3. measuring point : Speaker terminal
Tape speed and
wow-flutter
adjustment
< Confirmation >
1. Connect a wow-flutter meter to speaker terminal.
2. Playback the test tape VTT712 at tape end.
3. Adjust Semifixed resistor in the motor so that is
obtained within 2950 ~ 3050 Hz at normal speed.
4. Check to see if reading of the meter is less than
0.35% (JIS RMS).
<Conditions >
Test tape : VTT736
Mode : PLAY
Measuring point : Speaker terminal
Playback
frequency
response
confirmation
< Confirmation >
Playback the test tape VTT736 difference
level against 1 kHz.
1 kHz/125 Hz : 143 dB
1 kHz/8 kHz : —1+3 dB
< Conditions >
Recording and
playback 1. Test tape : UR(TS8)
frequency 2. Signal input : MIC
response 3. Recording level : Reference — 20 dB
confirmation
Measuring point : Speaker terminal
<Confirmation >
1. Refference signal — 20 dB to be applied to MIC.
2. Difference level between 125 Hz and 8 kHz
against 1 kHz to be checked.
1 kHz/125 Hz: —1+4 dB
1 kHz/8 kHz : O +4 dB
Bias frequency <Conditions >
adjustment
1. Measuring point : Speaker terminal
2. Adjust L301 so that becomes is obtain standard
value.
1 (Normal)
2
3
14 (No. 1785)
Beat Cut Switch
Standard Value
Adjusting Point
— 2 dB from the
peak
Normal Speed
: 2950 ~ 3050 Hz
High speed
: 5100~ 5900 Hz
Wow-flutter
: less than 0.35%
(JIS RMS)
1 kHz/125 Hz
: 143 dB
1 kHz/8 kHz
: — 143 dB
Semifixed
resistor in the
motor
1 kHz/125 Hz
: —1+4 dB
1 kHz/8 kHz
: O44 dB
Bias frequency
72 kHz+3 kHz
70 kHz+3 kHz
68 kHz+3 kHz
L301