Tape Speed Adjustment; Adjustment Location: Audio Board - Sony HST-471 Service Manual

2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1dB of peak.
within
L-CH
1dB
peak
output
level
R-CH
peak
Screw
position
3. Mode: Playback (FWD)
test tape
P-4-A100
(10kHz, –10dB)
rear panel
L
set
R
VIDEO1
AUDIO OUT connector
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
pats adjusted.
Adjustment Location: Record/Playback Head (Deck A and B)
and main board.
forward
within
1dB
Screw
position
L-CH
R-CH
peak peak
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.
Procedure:
Mode: Playback (FWD)
test tape
WS-48B
(3 kHz, 0 dB)
set
1. Insert the WS-48B into the deck A and the blank tape into the
deck B.
Press the REC button and · button on the deck B. Then
2.
the deck B is at recording mode.
3. Set the deck A to playback mode.
4. Press the DUBBING SPEED HIGH button in playback mode.
Then at HIGH speed mode.
5. Adjust RV652 on the AUDIO board do that frequency counter
reads 6,000 ± 90 Hz.
6. Press the DUBBING SPEED NORMAL button in playback
mode.
Then at NORMAL speed mode.
7. Adjust RV651 on the AUDIO board so that frequency counter
reads 3,000 ± 90Hz.
8. Frequency difference between deck A and deck B the beginning
of the tape should be within ± 1.5 %.

Adjustment Location: AUDIO board

Sample Value of Wow and flutter
W.RMS (JIS) within 0.3%
(test tape: WS-48B)
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:
VIDEO1 AUDIO OUT 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 and main boards
— 5 —
frequency counter
rear panel
+
–
VIDEO1
AUDIO OUT connector
(L: L-CH)
(R: R-CH)
DECK B
level meter
rear panel
+
set
–
VIDEO1
AUDIO OUT connector
(L: L-CH)
(R: R-CH)