Ntsc Lp Mode Switching Position Adjustment; (Vc-197 Board); Video System Adjustments; 28 Mhz Origin Oscillation Adjustment - Sony GV-A500 Service Manual

3. NTSC LP mode Switching Position Adjustment

(VC-197 board)

If deviated in this case causes switching noise or jitter on the LP
mode played back screen.
Mode Playback
Signal Alignment tape:
For tracking adjustment (WR5-1NP)
CH1: Pin 3 of CN207 (RF SWP)
Measurement Point
CH2: Pin 6 of CN207 (PB RF)
Measuring Instrument Oscilloscope
Adjustment Page F
Adjustment Address 38, 39
t1 = 0 ± 10 µsec
Specified Value
Adjusting method:
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.
3) Change the data of page: F, address: 39 and minimize "t1",
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)
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.
7) Set page: 0, address: 01, data: 00.
CH1
CH2
Enlargement
CH1
CH2
Fig. 5-3-8.
t1=0 ± 10 µ sec
5-26
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
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.
Note 1 : If the x2 frequency is displayed, insert a 1 kΩ resistor
between the measuring point and probe.
Note 2 : NTSC model : GV-A500
PAL model : GV-A500E
Mode VTR stop
Subject Arbitrary
Pin 6 of IC206
Measurement Point
Measuring Instrument Frequency counter
Adjustment Page F
Adjustment Address 3B
Specified Value f = 14318181 ± 71 Hz (NTSC)
f = 14187500 ± 70 Hz (PAL)
Adjusting method:
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.
3) Change the data of page: F, address: 3B, and set the oscillation
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.
6) Set page: 0, address: 01, data: 00.