Sony GV-A500E, Service Manual

Page: 92 / 127

5-33
11. REC C Current Adjustment
(VC-197 board)
Set the recording current level of REC chroma signal. If it is lower
than its normal level, chroma signal noise in played back picture
will increase and white modulation noises will be produced.
Mode VTR recording (SP mode)
Signal No signal
Measurement point Pin
2
of CN207 (REC RF)
Measuring instrument Oscilloscope
(20 MHz BW LIMIT: OFF)
Adjustment page F
Adjustment address 72
Specified value A = 116 ± 6.4 mVp-p (NTSC)
A = 129 ± 7mVp-p (PAL)
Connection:
1)
Remove C1060 (0.01
µ
F, near Pin
5
of IC101).
Note : After completing “REC L Level Adjustment” and
“REC C Current Adjustment”, replace C1060 with new
parts (1-162-970-11 CERAMIC CHIP 0.01
µ
F 10%
25V).
2) Connect Pin
1
of IC101 and GND with a 0.01
µ
F capacitor.
0.01
µ
F capacitor: 1-101-004-00
3) Connect Pin
^£
of IC101 and GND with a 0.01
µ
F capacitor.
0.01
µ
F capacitor: 1-101-004-00
Adjusting method:
1)
Set page: 0, address: 01, data: 01.
2) Set to recording mode.
3) Note down the data of page: F, address: 29, set data: 01, and
press the PAUSE button of the adjusting remote commander.
4) Note down the data of page: D, address: 10, set data: 06, and
press the PAUSE button of the adjusting remote commander.
5) Set page: 2, address: 61, data: 30 and press the PAUSE button
of the adjusting remote commander.
6) Set page: 3, address: 01, data: 41 and press the PAUSE button
of the adjusting remote commander. (MP, SP mode)
7) Change the data of page: F, address: 72, and set the REC C
signal level (A) to the specified value.
8) Press the PAUSE button of the adjusting remote commander.
9) After setting data noted down at step 3) for page: F, address:
29, press the PAUSE button of the adjusting remote commander.
10) After setting data noted down at step 4) for page: D, address:
10, press the PAUSE button of the adjusting remote commander.
11) Set page: 2, address: 61, data: 10 and press the PAUSE button
of the adjusting remote commander.
12) Set page: 3, address: 01, data: 00 and press the PAUSE button
of the adjusting remote commander.
13) Set page: 0, address: 01, data: 00.
Fig. 5-3-18.
H
A