Mhz Deviation Adjustment (Vc-195 Board) - Sony CCD-TRV15 Service Manual

1. 1.5 MHz Deviation Adjustment (VC-195 board)

Sets the spectrum of the L-ch ((L+R)/2 signal) level modulated
during recording. If deviated, the crosstalk signal of the audio signal
will occur and the audio level will drop during both playback and
recording.
Mode VTR recording
Signal Input the AFM DEV jig output signal to
the left and right audio input terminal
Measurement Point CH1: AFM DEV jig TP31
CH2: AFM DEV jig TP3
Measuring Instrument Oscilloscope
ADD mode
CH2 INV mode
Adjustment Page F
Adjustment Address 45
Specified Value The level difference between CH1 signal
and CH2 signal should be minimum.
Connection:
1) Connect TP24 and TP26 of the AFM DEV jig to CN910 of the
VC-195 board.
TP24(GND) ...................... Pin 8 of CN910
TP26(RF SWP) ................. Pin !¡ of CN910
2) Connect TP25 (REC AFM) of the AFM DEV jig to Pin @ª of
IC301 with a 0.01µF capacitor (1-101-004-00).
3) Connect the audio output terminal (J1 and J2) of the AFM DEV
jig to AUDIO terminal of the unit.
4) Connect TP28 (DC), TP27 (GND) of the AFM DEV jig to the
DC power supply (+7Vdc to +9Vdc).
5) Set the AFM DEV jig switches to the following positions.
S1 ............................... BIL Position
S2 ............................... NT Position
S3 ............................... SIN Position
Adjusting method :
1) Match the vertical ranges of CH1 and CH2 of the oscilloscope
to each other.
2) Set the oscilloscope to the ADD mode and CH2 to the INV
(invert) mode.
3) Select page: 0, address: 01, and set data: 01.
4) Select page: F, address: 45, change the data and minimize the
audio signal level difference (A).
5) Press the PAUSE button of the adjusting remote commander.
6) Select page: 0, address: 01, and set data: 00.
Approx. 2msec
Fig. 5-3-23.
2. 1.7 MHz Deviation Adjustment (VC-195 board)
Sets the spectrum of the R-ch ((L-R)/2 signal) level modulated during
recording. If deviated, the crosstalk signal of the audio signal will
occur and the audio level will drop during both playback and
recording.
Mode
Signal
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Specified Value
Connection:
1) Connect TP24 and TP26 of the AFM DEV jig to CN910 of the
VC-195 board.
TP24 (GND) ..................... Pin 8 of CN910
TP26 (RF SWP) ................ Pin !¡ of CN910
2) Connect TP25 (REC AFM) of the AFM DEV jig to Pin @ª of
IC301 with a 0.01µF capacitor (1-101-004-00).
3) Connect the audio output terminal (J1 and J2) of the AFM DEV
jig to AUDIO terminal of the unit.
4) Connect TP28 (DC), TP27 (GND) of the AFM DEV jig to the
DC power supply (+7Vdc to +9Vdc).
5) Set the AFM DEV jig switches to the following positions.
S1 ............................... BIL Position
S2 ............................... NT Position
S3 ............................... INV Position
Adjusting method :
1) Match the vertical ranges of CH1 and CH2 of the oscilloscope
to each other.
2) Set the oscilloscope to the ADD mode and CH2 to the normal
mode.
3) Select page: 0, address: 01, and set data: 01.
4) Select page: F, address: 46, change the data and minimize the
audio signal level difference (A).
5) Press the PAUSE button of the adjusting remote commander.
6) Select page: 0, address: 01, and set data: 00.
A
5-58
VTR recording
Input the AFM DEV jig output signal to
the left and right audio input terminal
CH1: AFM DEV jig TP32
CH2: AFM DEV jig TP2
Oscilloscope
ADD mode
CH2 normal mode
F
46
The level difference between CH1 signal
and CH2 signal should be minimum.
Approx. 2msec
Fig. 5-3-24.
A