Sony GV-A500 Service Manual ▷ View online
5-26
3. NTSC LP mode Switching Position Adjustment
(VC-197 board)
(VC-197 board)
If deviated in this case causes switching noise or jitter on the LP
mode played back screen.
mode played back screen.
Mode
Playback
Signal
Alignment tape:
For tracking adjustment (WR5-1NP)
For tracking adjustment (WR5-1NP)
Measurement Point
CH1: Pin
3 of CN207 (RF SWP)
CH2: Pin
6 of CN207 (PB RF)
Measuring Instrument
Oscilloscope
Adjustment Page
F
Adjustment Address
38, 39
Specified Value
t1 = 0 ± 10
µ
sec
Adjusting method:
1)
1)
Set page: 0, address: 01, data: 01.
2)
Set page: F, address: 29, data: 40 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
3)
Change the data of page: F, address: 39 and minimize “t1”,
and press the PAUSE button of the adjusting remote
commander. (Coarse adjustment)
and press the PAUSE button of the adjusting remote
commander. (Coarse adjustment)
4)
Change the data of page: F, address: 38, and adjust so that the
switching position (t1) becomes the specified value. (Fine
adjustment)
switching position (t1) becomes the specified value. (Fine
adjustment)
5)
Press the PAUSE button of the adjusting remote commander.
6)
Set page: F, address: 29, data: 00 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
7)
Set page: 0, address: 01, data: 00.
Fig. 5-3-8.
CH1
CH2
Enlargement
t1=0
±
10
µ
sec
CH1
CH2
3-4.
VIDEO SYSTEM ADJUSTMENTS
Video system adjustments must be performed in the following order.
[Adjusting Order]
1.
28 MHz origin oscillation adjustment
2.
Filter f0 adjustment
3.
Y OUT level adjustment
4.
C OUT level adjustment
5.
RP filter f0 adjustment
6.
AFC f0 adjustment
7.
NTSC Hi8 REC Y current adjustment
8.
PAL Hi8 REC Y current adjustment
9.
NTSC Hi8 REC C current adjustment
10. PAL Hi8 REC C current adjustment
11. REC C current adjustment
11. REC C current adjustment
1. 28 MHz Origin Oscillation Adjustment (VC-197 board)
Set the frequency of the clock for synchronization.
If deviated, the synchronization will be disrupted and the color will
become inconsistent.
If deviated, the synchronization will be disrupted and the color will
become inconsistent.
Note 1 :
If the x2 frequency is displayed, insert a 1 k
Ω
resistor
between the measuring point and probe.
Note 2 :
NTSC model : GV-A500
PAL model : GV-A500E
PAL model : GV-A500E
Mode
VTR stop
Subject
Arbitrary
Measurement Point
Pin
6 of IC206
Measuring Instrument
Frequency counter
Adjustment Page
F
Adjustment Address
3B
Specified Value
f = 14318181 ± 71 Hz (NTSC)
f = 14187500 ± 70 Hz (PAL)
f = 14187500 ± 70 Hz (PAL)
Adjusting method:
1)
1)
Set page: 0, address: 01, data: 01.
2)
Set page: 3, address: 01, data: 41 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
3)
Change the data of page: F, address: 3B, and set the oscillation
frequency (f) to the specified value.
frequency (f) to the specified value.
4)
Press the PAUSE button of the adjusting remote commander.
5)
Set page: 3, address: 01, data: 00 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
6)
Set page: 0, address: 01, data: 00.
5-27
2. Filter f0 Adjustment (VC-197 board)
Minimize the chroma signal residual components during composite
video signal input.
video signal input.
Note :
Do not insert a plug into the S video terminal.
Mode
VTR stop
Signal
Color bar (Video input)
Measurement Point
Pin
9 of CN207 (EZ I/O)
Measuring Instrument
Oscilloscope
Adjustment Page
F
Adjustment Address
5A
Specified Value
Minimum residual chroma signal
components
components
Adjusting method:
1)
1)
Set page: 0, address: 01, data: 01.
2)
Set page: 3, address: 01, data: 33 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
3)
Change the data of page: F, address: 5A, and minimize the
residual chroma signal components (A).
residual chroma signal components (A).
4)
Press the PAUSE button of the adjusting remote commander.
5)
Set page: 3, address: 01, data: 00 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
6)
Set page: 0, address: 01, data: 00.
Fig. 5-3-9.
Residual chroma component
H
H
Before
adjustment
adjustment
After
adjustment
adjustment
Residual chroma
component (A)
component (A)
3. Y OUT Level Adjustment (VC-197 board)
Set the Y signal output level.
Note :
Insert the plug into the S video terminal.
Mode
VTR stop
Subject
Arbitrary
Measurement Point
Y signal terminal of S VIDEO
terminal (75
terminal (75
Ω
terminated)
Measuring Instrument
Oscilloscope
Adjustment Page
F
Adjustment Address
56
Specified Value
A = 286 ± 5 mV (NTSC)
A = 300 ± 5 mV (PAL)
A = 300 ± 5 mV (PAL)
Adjusting method:
1)
1)
Set page: 0, address: 01, data: 01.
2)
Set page: 3, address: 01, data: 41 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
3)
Change the data of page: F, address: 56, and set the SYNC
level (A) to the specified value.
level (A) to the specified value.
4)
Press the PAUSE button of the adjusting remote commander.
5)
Set page: 3, address: 01, data: 00 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
6)
Set page: 0, address: 01, data: 00.
Fig. 5-3-10.
H
A
5-28
4. C OUT Level Adjustment (VC-197 board)
Set the chroma signal output level.
Note :
Insert the plug into the S video terminal.
Mode
VTR stop
Subject
Arbitrary
Measurement Point
Chroma signal terminal of
S VIDEO terminal (75
S VIDEO terminal (75
Ω
terminated)
Measuring Instrument
Oscilloscope
Adjustment Page
F
Adjustment Address
58
Specified Value
A = 286 ± 5 mV (NTSC)
A = 300 ± 5 mV (PAL)
A = 300 ± 5 mV (PAL)
Adjusting method:
1)
1)
Set page: 0, address: 01, data: 01.
2)
Set page: 3, address: 01, data: 41 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
3)
Change the data of page: F, address: 58, and set the burst level
(A) to the specified value.
(A) to the specified value.
4)
Press the PAUSE button of the adjusting remote commander.
5)
Set page: 3, address: 01, data: 00 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
6)
Set page: 0, address: 01, data: 00.
Fig. 5-3-11.
H
A
5. RP Filter f0 Adjustment (VC-197 board)
Adjust the LPF of the playback RF amplifier.
Mode
VTR stop
Subject
Arbitrary
Measurement Point
Pin
!∞ of CN207 (RF AGC OUT)
Measuring Instrument
Oscilloscope
Adjustment Page
F
Adjustment Address
5B
Specified Value
A = Below 10 mVp-p
Connection:
1)
1)
Input a 14.2 MHz, 400 mVp-p CW signal to Pin
7 of CN207
(RF AGC IN).
Transistor : General NPN transistor (2SC403, etc)
47 resistor :
47 resistor :
1-249-401-11
1k resistor :
1-249-417-11
15k resistor :
1-249-431-11
0.01µF capacitor : 1-101-004-00
Fig. 5-3-12.
Adjusting method:
1)
1)
Set page: 0, address: 01, data: 01.
2)
Set page: 3, address: 01, data: 35 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
3)
Change the data of page: F, address: 5B, and minimize the 14.2
MHz signal level (A).
MHz signal level (A).
4)
Press the PAUSE button of the adjusting remote commander.
5)
Set page: 3, address: 01, data: 00 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
6)
Set page: 0, address: 01, data: 00.
Fig. 5-3-13.
Signal
generator
generator
14.2MHz 400mVp-p
0.01
µ
F
47
Ω
15k
Ω
1k
Ω
Pin
!¡
of CN111
on VC-197 baord
(D 4.9V)
(D 4.9V)
Pin
7
of CN207
(RF AGC IN)
Pin
5
of CN207
(REG GND)
A
14.2MHz
5-29
6. AFC f0 Adjustment (VC-197 board)
Adjust the pull-in range of the A/D converted clock generator during
playback.
playback.
Note :
Do not insert the plug in the S video terminal.
Mode
VTR stop
Signal
Color bar (Video input)
Measurement Point
Pin
!§ of CN207 (AFC f0)
Measuring Instrument
Digital voltmeter
Adjustment Page
F
Adjustment Address
57
Specified Value
A = 2.2 ± 0.05 Vdc
Adjusting method:
1)
1)
Set page: 0, address: 01, data: 01.
2)
Set page: 3, address: 01, data: 31 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
3)
Change the data of page: F, address: 57, and set the DC voltage
(A) to the specified value.
(A) to the specified value.
4)
Press the PAUSE button of the adjusting remote commander.
5)
Set page: 3, address: 01, data: 00 and press the PAUSE button
of the adjusting remote commander.
of the adjusting remote commander.
6)
Set page: 0, address: 01, data: 00.
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