Sony HCD-VX3A Service Manual page 15

REC Bias Adjustment
Procedure:
INTRODUCTION
When set to the test mode performed in Tape Speed Adjustment,
when the tape is rewound after recording, the "REC memory mode"
which rewinds only the recorded portion and playback is set.
This "REC memory mode" is convenient for performing this
adjustment. During recording, the input signal FUNCTION will
automatically switch to VIDEO.
(If do not operation of stopped from recording complete, and press
– 0 button then rewind to recording start position.)
1. Press FUNCTION button to select VIDEO. (This step is not
necessary if the above test mode has already been set.)
2. Insert a tape into deck B.
3. After press r REC button, press P button, then recording
start.
4. Mode: Record
AF OSC
5. Mode: Playback
6. Confirm playback the signal recorded in step 3 become
adjustable level as follows.
If these levels do not adjustable level, adjustment the RV341
(L-CH) and RV441 (R-CH) on the AUDIO board to repeat steps
4 and 5.
Adjustable level: Playback output of 315 Hz to playback output
Adjustment Location: AUDIO board
REC Level Adjustment
Procedure:
INTRODUCTION
When set to the test mode performed in Tape Speed Adjustment,
when the tape is rewound after recording, the "REC memory mode"
which rewinds only the recorded portion and playback is set.
This "REC memory mode" is convenient for performing this
adjustment. During recording, the input signal FUNCTION will
automatically switch to VIDEO.
(If do not operation of stopped from recording complete, and press
– 0 button then rewind to recording start position.)
1. Press [FUNCTION] button to select VIDEO. (This step is not
necessary if the above test mode has already been set.)
2. Insert a tape into deck B.
3. After press r REC button, press P button, then recording
start.
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DECK B
MD/VIDEO (AUDIO) IN

1) 315 Hz

50 mV (–23.8 dB)
2) 10 kHz

600 Ω
attenuator
set
recorded
level meter
portion
+
set
–
CN301 (Pin 3 : L-CH)
(Pin 1 : R-CH)
of 10 kHz: ±1.0 dB
DECK B
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4. Mode: Record
AF OSC
attenuator
5. Mode: Playback
recorded
portion
6. Confirm playback the signal recorded in step 3 become
adjustable level as follows.
If these levels do not adjustable level, adjustment the RV301
(L-CH) and RV351 (R-CH) on the MAIN board to repeat steps
blank tape
4 and 5.
CN-123
Adjustable level:
CN301 PB level: 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location: MAIN board
[MAIN BOARD] (Component Side)
[AUDIO BOARD] (Component Side)
RV441
RV401
RV301
R L
L R
PB LEVEL REC BIAS
– DECK B –
[LEAF SW BOARD] (Component Side)
TAPE SPEED
(NORMAL) (HIGH)
RV1002 RV1001
MD/VIDEO (AUDIO) IN
315 Hz, 50 mV (–23.8 dB)
600 Ω
set
level meter
+
set
–
CN301 (Pin 3 : L-CH)
(Pin 1 : R-CH)

1 3
RV301

CN301
L

REC LEVEL

CN303



RV351

R
CN304
IC602
CN601
RV311 RV411
RV341
L
PB LEVEL
– DECK A –
CN1001
blank tape
CS-123
R
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