Hi8/Standard 8 Mm Afm 1.5 Mhz Deviation Adjustment (Vc-235 Board); Hi8/Standard 8 Mm Afm 1.7 Mhz Deviation Adjustment (Vc-235 Board); Digital8 Playback Level Check; Overall Level Characteristics Check - Sony DCR-TRV820 Service Manual

2. Hi8/standard 8 mm AFM 1.5 MHz Deviation
Adjustment (VC-235 board)
Adjust to the optimum 1.5 MHz audio FM signal deviation.
If the adjustment is not correct, its playback level will differ from
that of other units.
Mode Playback
Hi8/standard 8 mm alignment tape:
For checking AFM stereo operation
Monoscope section
Signal
(WR5-9NS (NTSC))
(WR5-9CS (PAL))
Audio left or right terminal of A/V
Measurement Point
jack
Measuring Instrument Audio level meter
Adjustment Page F
Adjustment Address 7B
Specified Value –7.5 ± 2.0 dBs
Adjusting method:
1) Select page: 0, address: 01, and set data: 01.
2) Set the Hi-Fi sound switch (menu display) to "1".
3) Select page: F, address: 7B, change the data and set the 400
Hz signal level to the specified value.
4) Press the PAUSE button.
5) Set the Hi-Fi sound switch (menu display) to "STEREO".
6) Select page: 0, address: 01, and set data: 00.
3. Hi8/standard 8 mm AFM 1.7 MHz Deviation
Adjustment (VC-235 board)
Adjust to the optimum 1.7 MHz audio FM signal deviation.
If improper, this causes deteriorated separation (with stereo sig-
nal).
Mode Playback
Signal Hi8/standard 8 mm alignment tape:
For checking AFM stereo operation
Monoscope section
(WR5-9NS (NTSC))
(WR5-9CS (PAL))
Measurement Point Audio left or right terminal of A/V
jack
Measuring Instrument Oscilloscope
Adjustment Page F
Adjustment Address 7C
Specified Value –7.5 ± 2.0 dBs
Adjusting method:
1) Select page: 0, address: 01, and set data: 01.
2) Set the Hi-Fi sound switch (menu display) to "2".
3) Select page: F, address: 7C, change the data and set the 1 kHz
signal level to the specified value.
4) Press the PAUSE button.
5) Set the Hi-Fi sound switch (menu display) to "STEREO".
6) Select page: 0, address: 01, and set data: 00.

4. Digital8 Playback Level Check

Mode
Signal
Measurement Point
Measuring Instrument
Specified Value
Checking Method:
1) Check that the playback signal level is the specified value.

5. Overall Level Characteristics Check

Mode
Signal
Measurement Point
Measuring Instrument
Specified Value
Checking Method:
1) Input the 400 Hz, –66 dBs signal in the MIC jack.
2) Record in the camera mode.
3) Playback the recorded section.
4) Check that the 400 Hz signal level is the specified value.

6. Overall Distortion Check

Mode
Signal
Measurement Point
Measuring Instrument
Specified Value
Checking Method:
1) Input the 400 Hz, –66 dBs signal in the MIC jack.
2) Record in the camera mode.
3) Playback the recorded section.
4) Check that the distortion is the specified value.
5-54
VTR playback
Digital8 alignment tape:
For audio operation check
(WR5-3ND (NTSC))
(WR5-3CD (PAL))
Audio left or right terminal of A/V
jack
Audio level meter and frequency
counter
32 kHz mode: 1 kHz, + 3.0 ± 2.0 dBs
48 kHz mode: 1 kHz, + 3.0 ± 2.0 dBs
44.1 kHz mode:
The 7.35 kHz signal level during EMP
OFF is +2.0 ± 2.0 dBs.
The 7.35 kHz signal level during EMP
ON is –6 ± 2 dB from the signal level
during EMP OFF.
Camera recording and playback
400 Hz, –66 dBs signal: MIC jack left
and right
Audio left or right terminal of A/V
jack
Audio level meter
–7.5 ± 3.0 dBs
Camera recording and playback
400 Hz, –66 dBs signal: MIC jack left
and right
Audio left or right terminal of A/V
jack
Audio distortion meter
Below 0.4%
(200 Hz to 6 kHz BPF ON)