Sharp VL-WD650U Service Manual page 33

ADJUSTING THE MIC AMP CIRCUIT
(Wiring board diagram: Main Side B)
TL604
EE level check
Frequency character check
Super-directional microphone check
TL605
EE level check
Frequency character check
Super-directional microphone check
1. EE level check
Measuring instrument Valve voltmeter
Mode P-ON (CAM), Zoom Mic "OFF"
Test signal 1kHz -54dBs sine wave
Procedure 1) Input 1kHz, -54dBs sine wave into TL6605(INT MIC L) and TL6607(INT MIC R).
2) Make sure that the signal level of TL605 Audio-L out and TL604 Audio-R out is within the standard
Remark
2. Frequency character check
Measuring instrument Valve voltmeter
Mode P-ON (CAM)
Parameter; Zoom Mic "OFF"
Test signal 100Hz, 10kHz -54dBs sine wave
Procedure 1) Input 100Hz, -54dBs sine wave and then 10kHz, -54dBs sine wave into TL6605(INT MIC L) and
2) At this time make sure that the signal level of TL605 Audio-L out and TL604 Audio-R out is within the
Remark
3. Super-directional microphone check
Measuring instrument Valve voltmeter
Mode P-ON (CAM), Zoom MIC "TELE"
Test signal 1kHz -54dBs sine wave
Procedure 1) Input 1kHz, -54dBs sine wave into TL6602(TELE-MIC).
2) Make sure that the signal level of TL605 Audio-L out and TL604 Audio-R out is within the
Remark
SC5002
C6628
R6633
R6635
R6636
C6634 Q6603
C6639
R6637
R6644
C6640
C6632
C6641
R621
R6645
Q608 C6643
limits.
TL6604: GND
TL6607(INT MIC R).
standard limits (1kHz standard).
TL6604: GND
standard limits.
TL6604(GND)
EE level check
Frequency character check
P6602
P6601
C6621
R6628
R5801
C6604
R5800
R6602 L2800
C2800
L2801
C2801
C6611
R2804 R2803
R6615 R6616 R6619
R2808 R2806
R6617
R2807 R2805
C6618 R6621 R6620 R6624
C6619 C6617 R6622 C6616
R6658 C6615
C1801
R6657 R6623
R6627
C2804
R6651
R1802
C2803 C1810
C6647
D1800
C2802
C3473
Q6604 L6601
R3447
Test point
Adjustment rating
Test point
Adjustment rating
Test point
Adjustment rating
33
TL6602(TELE MIC)
Super-directional microphone check
TL6607(INT MIC R)
EE level check
Frequency character check
TL6605(INT MIC L)
EE level check
Frequency character check
R1803
TL605, TL604
-9dBs ± 3dB
TL605, TL604
(1kHz standard) 100Hz: -8dBs ± 3dB
10kHz: -5dBs ± 3dB
TL605, TL604
-10dBs ± 3dB
VL-WD650U