Adjustment Location: Playback Head; Tape Speed Adjustment; Playback Level Adjustment - Sony HCD-V4800 Service Manual

3. Mode: Playback (FWD)
test tape
P-4-A100
MAIN board
(10 kHz, –10 dB)
CN207
pin 3 (L-CH)
pin 2 (GND)
set
pin 1 (R-CH)
waveform of oscilloscope
in phase 45 °
good
4. Repeat steps 1 to 3 in playback (REV) mode.
5. After the adjustments, apply suitable locking compound to the
parts adjusted.
Adjustment Location: Playback Head (Deck A)
Record/Playback Head (Deck B)
forward
oscilloscope
V H
90 ° 135 ° 180 °
wrong
reverse
Tape Speed Adjustment DECK A
Note: Start the Tape Speed adjustment as below after setting to the test
mode.
In the test mode, the tape speed is high during pressing the
H SPEED DUB button.
Procedure:
1. Turn the power switch on.
2. Press the GROOVE button, ENTER/NEXT button and
DISC 4 button simultaneously.
To exit from the test mode, press the POWER button.
Mode: Playback (FWD)
test tape
WS-48B
(3 kHz, 0 dB)
1. Insert the WS-48B into the deck A and the blank tape into the
deck B.
2. Press the r REC button and · button on the deck B. Then
the deck B is at recording mode.
3. Set the deck A to playback mode.
4. Keep pressing the H SPEED DUB button in playback mode.
Then at high speed mode.
5. Adjust RV652 on the AUDIO board so that frequency counter
reads 6,000 ± 90 Hz.
6. Take off the H SPEED DUB button.
Then at normal speed mode.
7. Adjust RV651 on the AUDIO board so that frequency counter
reads 3,000 ± 90 Hz.
8. Frequency difference between deck A and deck B the begin-
ning of the tape should be within ± 1.5 %.
Adjustment Location: AUDIO board (See page 20)
Sample Value of Wow and Flutter: 0.3% or less W.RMS
Playback level Adjustment DECK A
Procedure:
Mode: Playback (FWD)
test tape
P-4-L300
(315 Hz, 0 dB)
Deck A is RV311 (L-CH) and RV411 (R-CH), Deck B is RV301
(L-CH) and RV401 (R-CH) so that adjustment within adjustment
level as follows.
Adjustment Level:
CN207 PB level: 301.5 to 338.3 mV (– 8.2 to – 7.2 dB) level
difference between the channels: within ± 0.5 dB
Adjustment Location: AUDIO board (See page 20)
– 19 –
frequency counter
+
set
–
MAIN board
CN207 (pin 3 : L-CH)
(pin 1 :R-CH)
(WS-48B)
DECK B
level meter
+
set
–
MAIN board
CN207 (pin 3 : L-CH)
(pin 1 : R-CH)