Technics QUARTZ SP-15 - Page 9

mg ADJUSTMENTS
Adjustment Points of Electrical System
NOTE: Make the following adjustments after replacing parts such as IC’s, transistors, diodes, etc.
Adjustment oo Points
Adjustment
Point
Adjustment Method
Adjustment of
standard voltage
(VS)
DC voltmeter
or Oscilloscope
@ > TP18
‘S) > GROUND
With the start switch set at ON, adjust VR301 so that
the voltage is DC 2.10V +0.01 at 33 r.p.m.
Confirm that the voltage is 2.835V +0.05V at
45 r.p.m. and 4.9V +0.1V at 78 r.p.m.
4
|
Adjustment of
| Current source
(IR)
Tracking
adjustment
(TRACKING)
DC voltmeter
or Oscilloscope
> TP19
CO > TP21
Oscilloscope
(+) > TP18
© * GROUND
TP19 and TP21.
Turn start switch on to begin turntable rotation.
Adjust VR201 for 0 V potential difference of
TP18 waveform
—| To
Braking
adjustment
(BRAKE)
2SD636, 2SD639 |2SD592, 2SC828A| 2SC 1846 ,2SA886
2SB641 ,2SB643 |2SC1383
SVIUPC4558C
STOP SIGNAL
oa 1
270° 90°
@ TERMINAL GUIDE OF TRANSISTOR AND IC
2SD712A-C
2SC1847 2SC1826
With the start switch set
at ON, adjust VR101 so
that 8 [TO S8.5 msat
33 r.p.m.
Confirm that 5.8 =T0S
6.4ms at 45 r.p.m. and 3
<T0<4.5 ms at 78 r.p.m.
Adjust VR202 for complete
stop within 90° ~ 270°
after stop signal initiated.
(Turntable becomes free
a few seconds after stop.)
AN640G
Vip
Bot
SVIMSM4013
SVIM53217P