Adjustment; Auto Lead-In Timing Adjustment; End Timer Adjustment - Pioneer PL-L1000 Service Manual

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Preparation
1. Disconnect the panel according to the disas-
sembly nrethod outlined earlier.
2. Use extension leads to connect the panel to the
printed circuit board located in the base section.
3. Remount the turntable platter (but without
tightening the securing screws).
7 . 1
D . D . M O T O R O P E R A T I N G P O I N T
ADJUSTMENT
1. Connect the TP1 and TP2 terminals to the CH1
and CH2 inputs of a dual-trace oscilloscope.
2. Start the turntable platter turning by shifting
the tonearm over towards the center of the
record from the arm rest position.
3. Observe the waveforms in the oscilloscope, and
adjust the corresponding controls so that the
rising edge of the TP2 output waveform lies
within the TP1 output waveform.
4. VRl is the control to adjust for 4brpm speed,
while VR2 is the control for 33rpm adjustment.
Fis.7-2
7 . 2
A U T O L E A D - I N T I M I N G A D J U S T M E N T
1. Set the record size selector to the 30cm posi-
tion.
2. Press the START/STOP key to start the tonearm
lead-in movement.
3. When the tonearm is about 20mm away from
the outer edge of the record, an output pulse
signal will appear at TP3 (see Fig. 7-3). Adjust
VRB to obtain a time constant of 2.2 - 2.5 sec.
for this pulse signal.
7.3 END SENSOR SENSITIVITY ADJUST.
M E N T
1. Connect the oscilloscope to the TP4 terminal.
2. Set the arm elevator to the UP position, and
shift the tonearm across to near the lead-out
gloove.
3. Hold the tonearm carrier by hand, and move
the tonearm back and forth at a rate of 5 to
1Ocm/sec.
4. During this operation, adjust VR9 so that the
TP4 output saturates at H and L levels at about
'
50% duty.
Fis.7-4
7 . 4
E N D T I M E R A D J U S T M E N T
1. Connect the oscilloscope to the TP5 terminal.
2. Secure the tonearm to the arm rest. and remove
the turntable platter.
3. Insert a piece of paper (or any other light
shield) into the end sensor stage.
'4. As soon as the piece of paper (or light shield)
is removed, an output signal appears at Tpb.
Adjust the time constant of this output to
1.06 10.1 sec by means of VR4.
F i g . 7 - 5
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