JVC QL-5 User Manual

8.
Adjustment
Procedures
Servomotor Control Section
8-(1) Power Supply Voltage Check
1. Disconnect the motor socket from the circuit board.
Turn the power switch on. (Confirm that the rated
voltage is applied to the unit.) Set the speed select
switch to 33-1/3. Confirm that 23 + 0.5 V DC is present
at TP-5. If the voltage is deviate from that range, adjust
with the semi-fixed resistor VR803 (1 k&2).
2. Confirm that the voltage difference at TP-5 is less than
-1V_ when the speed select/on-off switch is set at
STOP.
8-(2) Lock Adjustment
1) With dual beam oscilloscope
1. Connect the motor socket to the circuit board. Connect
the dual beam oscilloscope to TP-3, TP-4. Obtain a
turntable speed of 45 rpm by setting the speed select
switch to 45, then adjust the semi-fixed resistor VR801
(100 kQ) until the following waveforms are obtained.
1
14.8ms
(20ms))
co...
! i
1 IL
oo ls
~at—
Adjust to get a difference of within + 1 msec from TP-4,
Fig. 10
2. Obtain a turntable speed fo 33-1/3 rpm by setting the
speed select switch to 33-1/3, then adjust the semi-
fixed resistor VR802 (47k) until the difference
between TP-3 and TP-4 is within + 1 msec.
QL-5
No. 2428
2) With single beam oscilloscope
Connect the single beam oscilloscope to TP-3, TP-4 as
shown in Fig. 11 below. Adjust until the waveforms shown
in Fig. 12 are obtained.
Connection diagram
TP-3)
ma
Ma
TR=4
Single beam oscilloscope
Fig. 11
Perfectly locked
|
|
Lock
adjustment
is
improper.
Out of lock in the direction
opposite to the diagrams above,
Out of lock
This
part
appears
to
flow.
Fig. 12

JVC QL-5 Specifications

General

Brand	JVC
Model	QL-5
Category	Turntable
Language	English