Audio System Adjustments; 5Mhz Deviation Adjustment (Vc-251 Board); Bpf Fo Adjustment (Vc-251 Board) - Sony CCD-TR618 Service Manual

3-6.

AUDIO SYSTEM ADJUSTMENTS

[Connecting the measuring instruments for the audio]
Connect the audio system measuring instruments in addition to the
video system measuring instruments as shown in Fig. 5-3-16.
Playback
Main unit
A/V OUT
Audio
(Black)
Fig. 5-3-16.
TV monitor
Video (Yellow)
Audio level meter
or Distortion meter
47k
47k (1-249-437-11)

1. 1.5MHz Deviation Adjustment (VC-251 board)

Adjust to the optimum 1.5MHz audio FM signal deviation.
If the adjustment is not correct, its playback level will differ from
that of other units.
Mode
Signal
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Specified Value
Adjusting method:
Order Page Address Data
1 0 01
2 F 7B
3 F 7B
4 0 01

2. BPF fo Adjustment (VC-251 board)

Sets the BPF passing frequency of IC760 so that the AFM signal
can separate from the playback RF signal properly. If deviated. the
mono/stereo mode will be differentiated incorrectly, and noises and
distortions will increase during high volume playback.
Mode
Signal
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Specified Value
Adjusting method:
Order Page Address Data
1 0 01
2 F 7D
3 F 7D
4 0 01
5-49
Playback
Alignment tape:
For checking operation
(WR5-5NSP (NTSC))
(WR5-5CSP (PAL))
Audio terminal of A/V OUT jack
Audio level meter
F
7B
–7.5 ± 2.0 dBs
Procedure
01 Set the data.
Change the data and set the
400Hz audio signal level to the
specified value.
Press PAUSE button.
00 Set the data.
Playback
Alignment tape:
For BPF adjustment
(WR5-11NS (NTSC)
(WR5-11CS (PAL))
Audio terminal of A/V OUT jack
Distortion meter
F
7D
The distortion rate should be minimum.
Procedure
01 Set the data.
Change the data and minimize
the distortion rate.
Press PAUSE button.
00 Set the data.