Sony TC-WR990 - Playback and Speed Calibration; Playback Level Adjustment Process; Tape Speed Adjustment Process

_
3. Playback Mode
test tape
P-4-A100
(10kHz, - 10dB) :
oscilloscope
L-CH
LINE OUT
Screen pattern
in phase 45° 90° 135° 180°
good wrong
4,Change the reveres playback mode and repeat the steps
1 to 3.
5. After the adjustment, lock the adjustment screws with
suitable locking compound.
Adjustment Location: ~recordplayback head —
reverse side forward side
adjustment screws
Tape Speed Adjustment
Procedure:
— Forward Playback Mode —
test tape
WS-48B
(3kHz, 0dB)
LINE OUT
Perform high speed adjustment before normal speed
adjustment.
(high speed adjustment)
1.Connect @pin of IC801 to ground.
2.Set to FWD playback mode.
3.Keep on pressing the HIGH SPEED DUBBING switch.
4. Adjust RV72 so that the frequency counter reading
becomes 6,000 + 20Hz.
5. After adjustment, disconnect CN804 shorted in step 1.
(normal speed adjustment)
1.Set to FWD playback mode.
2. Adjust RV71 so that the frequency counter reading
becomes 3,000 + 10Hz.
Frequency difference between the beginning and the end of
the tape should be within 3%.
Frequency difference between deck A and deck B the
beginning of the tape should be within 1.5%.
Adjustment Location : AUDIO board
Playback Level Adjustment
Procedure:
— Forward Playback Mode ~—
test tape
P-4-L300
(315kHz, 0dB) VTVM
LINE OUT
Adjust deck A, B: RV11(L-CH) and RV21(R-CH) so the
VTVM reading becomes the adjustment limits below.
Adjustment Value :
LINE OUT level: —7.7+0.5dB (0.301 to 0.338V)
Level difference between channels: within 0.5dB
Confirm the LINE OUT level does not change in playback
mode while changing the mode from playback to stop
several times
Adjustment Location : AUDIO board