3-21
DNW-A100/A50/A45
DNW-A100P/A50P/A45P
3-6-4. Analog Audio Offsets (CH3/4)
Adjustment (APR-13 Board)
n
For the VTR equipped with BKNW-105 (optional kit),
Section 3-6-4 is not needed.
Preparing tools
.
Oscilloscope:
TEKTRONIX 2465B or equivalent
.
Extension board: EX-556 (Part No. A-8277-212-A)
.
Shorting clip
Preparation
1. Check that the shorting plug settings on the
APR-13 board are the factory settings.
(Refer to “Shorting plugs setting” in Section 3-6-2.)
2. Extend the APR-13 board with an extension
board EX-556.
n
Wait more than 30 seconds after turning off the power,
then remove the APR-13 board.
3. Check the settings on the upper control panel.
PB (audio level) controls: CH3
8
PRESET
CH4
8
PRESET
4. Check the setting on the sub control panel.
EMPHASIS switch
8
OFF
5. Check that the equipment has warmed up.
Before starting the adjustment, warm up the VTR and
oscilloscope through the power for 20 minutes or more.
Offset Level Adjustment
1.
Set and connect the oscilloscope as follows:
Band width limit: ON
CH-1: TP700/APR-13(G-6), DC 5 V/DIV
CH-2: TP701/APR-13(G-5), DC 5 V/DIV
TIME: 2
µ
s/DIV
TRIG: CH-2,
_
slope
CH3 adjustment
2.
Short-circuit TP101(B-1) and E100(B-2) on the APR-
13 board with a shorting clip.
3.
Adjust so that audio CH3 part of the waveform at
TP700 makes the same waveform to the Figure 1 (left
side).
Adj. point:
1
RV103/APR-13(C-2)
4.
Remove the shorting clip on the APR-13 board.
CH4 adjustment
5.
Short-circuit TP201(F-1) and E200(E-2) on the APR-
13 board with a shorting clip.
6.
Change the oscilloscope’s trigger to the
+
slope.
7.
Adjust so that audio CH4 part of the waveform at
TP700 makes the same waveform to the Figure 1
(right side).
Adj. point:
1
RV203/APR-13(F-2)
8.
Remove the shorting clip on the APR-13 board.
Audio CH3
TP701
Oscilloscope
TP700
(OK)
16-Bit
4-Bit
Audio CH4
16-Bit
4-Bit
NG
Figure 1. Waveform of CH3/CH4 Offset Level Adjustment
APR-13 Board (Side A)
E100
RV100
TP801
COR101
16 18 20
COR100
0
–3
–20
+4
TP701
COR601
–20
–3
0
+4
1
2
3
4
5
6
A
A
B
C
D
E
F
G
A No.
LOTNO,
S NO,
APR–13
-133-
MADE IN JAPAN
RV102
RV101
TP101
TP100
RV103
E200
RV200
COR201
16 18 20
COR200
0
–3
–20
+4
RV202
RV201
TP201
TP200
RV203
TP802
TP803
TP804
E800
TP700
COR600
20 18 16
E600
RV600
TP600
COR501
COR500
20 18 16
E500
RV500
TP500
COR401
COR400
20 18 16
E400
RV400
TP400
COR301
COR300
20 18 16
E300
RV300
TP300
–20
–3
0
+4
–20
–3
0
+4
–20
–3
0
+4
3-6. Audio System Adjustment (APR-12/13 Boards)
3-6-4. Analog Audio Offsets (CH3/4) Adjustment (APR-13 Board)