Akai AP-206

22 ±2msec
AROUND 7.5V
2V to 4V
OV
Fig. 21
Fig. 22
(
DOWNWARD)
PULSE
OV
2) Adjusting the Quartz-Locked Phase Angle (VRl)
a) Connect an oscilloscope to TP-2 and pin 5
(ground).
b) Release the Speed selector to the "33-1/3"
position.
c) Depress the Quartz Lock button in ON.
d) Move the tone arm to turn power on.
e) Adjust VRl until the width of the upward
pulse above 2 to 4V is 22 ±2 msec when the
Strobe markings is seen standing still, as Fig. 21.
(oscilloscope-DC Mode)
CAUTION: The upward pulse around +7.5V
shown above may change to
downward pulse (OV) below 2 to
4V with VRl turned as Fig. 22.
Be careful not to measure the
width of the downward pulse, It is
checked in a simple way that the
upward pulse will change to
downward pulse by loading on the
platter by hand.
20