Technics SL-PJ27 - Page 14

SL-PJ27
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FOCUS OFFSET ADJUSTMENT
Note: Make sure that the servo gain adjuster’s gain switch
is set to position “2”.
Connect the oscilloscope’s CH. 1 probe across
(+) and (—) on the Servo P.C.B. and its CH. 2
probe (+) to VR104’s terminal.
Oscilloscope setting: VOLT.......... 100 mV (CH. 1)
100 mV (CH. 2)
SWEEP......... 0.2 ms.
Input coupling. .. AC (both CH. 1
and 2)
Trigger mode ... .NORM (trigger
CH. 1.)
. Switch the player power ON, and play track 9 on the
test disc (SZZP1057C).
Trigger the oscilloscope’s CH. 1 so that the following
waveforms are observed. Adjust VR105 until the dip in
the RF signal envelope on CH. 1 is smooth and the signal
amplitude on CH. 2 is minimized, i.e. when amplitude A
equals amplitude B.
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TRACKING OFFSET ADJUSTMENT
Note: Make sure that the servo gain adjuster’s gain switch
is set to position “2”.
. Connect the oscilloscope’s CH. 1 probe across BM RIth
(+) and {RH (—) on the Servo P.C.B., and its
CH. 2 probe (+) to VR102's terminal.
Oscilloscope setting: VOLT......... 100 mV (CH. 1)
100 mV (CH. 2)
SWEEP........ 0.2 ms.
Input coupling. . AC (both CH. 1
and 2)
Trigger mode. . pe (trigger
CH
. Switch the player power ON, and play tele 9 on the
test disc (SZZP1057C).
Trigger the oscilloscope’s CH. 1 so that the following
waveforms are observed. Adjust VR103 until the dip in
the RF signal envelope on CH. 1 is smooth and the
signal amplitude on CH. 2 is minimized, i.e. when
amplitude A equals amplitude B.
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Minimize the amplitude or make @=©.
Smooth
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TRACKING BALANCE ADJUSTMENT
. Make sure that the servo gain adjuster’s gain switch is
set to position “2”.
Set up the AF oscillator output for 1.1 kHz, 600 mVp-p,
and connect it across the OSC and GND terminals on the
servo gain adjuster.
Connect the oscilloscope’s CH. 1 probe across
(+) and SIRE (—) on the Servo P.C.B. and CH. 2 probe
(+) to the OSC terminal on the servo gain adjuster.
Oscilloscope setting: VOLT......... 100 mV (CH. 1)
200 mV (CH. 2)
SWEEP........ 0.1 ms.
Input coupling. .AC (both CH. 1
and 2)
Trigger mode .. .NORM (trigger
Switch the player power ON, and play the test disc
(SZZP1014F or SZZP1054C).
5. Set the servo gain adjuster’s gain switch to position
“4”, and adjust VR106 so that the wafveform of the
output section marked with > is balanced.
6. Disconnect the servo gain adjuster’s leads from the
player.
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XX This section of the waveform must be
balanced.