Service manual
33
VL-WD250U
VL-WD450U
2. Frequency character check
Measuring instrument Valve voltmeter Test point TL605, TL604
Mode P-ON (CAM) Adjustment rating
(1kHz standard)
100Hz: -8dBs ± 3dB
Parameter; Zoom Mic "OFF" 10kHz: -5dBs ± 3dB
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
TL6607(INT MIC R).
2) At this time make sure that the signal level of TL605 Audio-L out and TL604 Audio-R out is within the
standard limits (1kHz standard).
Remark TL6604: GND
3. Super-directional microphone check
Measuring instrument Valve voltmeter Test point TL605, TL604
Mode P-ON (CAM), Zoom MIC "TELE" Adjustment rating -10dBs ± 3dB
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
standard limits.
Remark
ADJUSTING THE MIC AMP CIRCUIT
(Wiring board diagram: Main Side B)
1. EE level check
Measuring instrument Valve voltmeter Test point TL605, TL604
Mode P-ON (CAM), Zoom Mic "OFF" Adjustment rating -9dBs ± 3dB
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
limits.
Remark TL6604: GND
0
4
5
1
TL1936
R3453
R1801
R1800
TL1800
C1800
C2802
D1800
R1803C1810
Q1800
C2803
R1819
R1802
TL3332
C2804
TL827
TL834
TL1801
TL3331
TL826
TL821
TL831
C1801
R1804
TL801
TL804TL806
SC801
TL810TL813TL814
TL815
TL819
TL824
TL832
TL820
TL818
TL833TL829
TL822
TL830
TL825
TL828
P6602
TL6602
TL816
TL6606
TL6605
TL6607
TL6601
TL817
R5801
C6604
R5800
TL823
L2800
TL812
C2800
R6612
TL811
L2801
C2801
TL809
TL808
C6605
C6611
TL807
R2803R2804
R6619R6616
TL805
R5804
R5803
R2806R2808
TL2800
TL2801
R2805R2807
TL803
R5802
R5805
TL2802
C6612
C6614
TL802
R6624R6620
TL703
C6616R6622
TL702
C6615
R6623
IC2800
R6656
R2800
R2801
R2802
C3473
R3439
R3447
R3438
R3457
L3405
C3459
R3469
R3471
R3444
Q
3403
4
68
4
79
3
4
01
6
1
C3432
R617
R3446
R603C616
L6601Q6604
C6642
R6647
C6644
R6650
C6647
C6620
C6648
R6646
R6648
R6649
R6625
R6626
R6651
Q6602
R6627
R6657
R6658
C6619
C6617
C6618
R6621
R6618
C6613
R6617
IC6601
R6615
R6613
C6610
R6614
C6608
C6609
C6607
C6603
C6602
R6602
C6606
R6607
C6601
R6609
R6606
R6610
R6608
R6605
TL6603
TL6604
R6629
R6628
C6622
C6621
TL5031
P6601
TL5032TL5034
SC5002
TL5033
TL5035
TL5036
TL5041
TL5037
TL5039
TL5042
C6630
C6628
TL5038
TL5043
C6624
C6623
C6626
R6630
C6629
R6631
C6627
R6632
R6633
C6631
R6635
R6634
R6638
C6637
C6636
R6640
R6639
R6641
R6642
C6638
R6636
Q6603
C6634
R6660
R6661
R6659
R6643
C6639
C6633
R6637
R6644
C6640
C6632
C6641
R621
R6645
TL603
R663
R6654
R6652
R6653
C6646
C6643
Q608
C6645
R609
Q602
R688
C603
R660
R687
R685
R686
R
610
L
572
C
636
TL605
Q601
TL604
C6635
TL5047TL5046TL5045TL5044
TL605
EE level check
Frequency character check
Super-directional microphone check
TL604
EE level check
Frequency character check
Super-directional microphone check
TL6605(INT MIC L)
EE level check
Frequency character check
TL6607(INT MIC R)
EE level check
Frequency character check
TL6604(GND)
EE level check
Frequency character check
TL6602(TELE-MIC)
Super-directional microphone check