Adjustment - JVC MX-KB4 Service Manual

4.1 Measurement Instruments Required for Adjustment
(1) Low frequency oscillator
This oscillator should have a capacity to output 0dBs to
600 at an oscillation frequency of 50Hz-20kHz.
(2) Attenuator impedance : 600
(3) Electronic voltmeter
(4) Frequency counter
(5) Wow & flutter meter
(6) Test tape
VT712 : For Tape speed and wow flutter ( 3kHz)
VT703 : For Head angle (10kHz)
(7) Blank tape
TYPE l : AC-225
TYPE ll : AC-514
(8) Torque gauge
For play and back tension forward; TW2111A
Reverse; TW2121A
Fast Forward and Rewind; TW2231A
(9) Test disc
CTS-1000(12cm)
GRG-1211(8cm)
(10) Jitter meter
4.2 Measurement conditons
Power supply voltage AC 120V ~, 60Hz
Measurement Speaker out
output terminal TP101
(Measuring for TUNER/ DECK/CD)
Dummy load 6
4.2.1 Radio Input signal
AM modulation frequency
Modulation factor
FM modulation frequency
Frequency displacement
SECTION 4

ADJUSTMENT

400Hz
30%
1 kHz
22.5kHz
4.2.2 Standard measurement position of volume and
switch
Power
Sound Turbo,A,BASS EX
Sound mode
Main VOL.
Travers mecha set position Disc 1
Precautions for measurement
(1) Apply 30pF and 33k to the IF sweeper output side and
0.082 F and 100k in series to the sweeper input side.
(2) The IF sweeper output level should be made as low as
possible within the adjustable range.
(3) Since the IF sweeper is a fixed device, there is no need
to adjust this sweeper.
(4) Since a ceramic oscillator is used, there is no need to
perform any MIX adjustment.
(5) Since a fixed coil is used, there is no need to adjust the
FM tracking.
(6) The input and output earth systems are separated. In
case of simultaneously measuring the voltage in both of
the input and output systems with an electronic voltmeter
for two channels, therefore, the earth should be connect-
ed particularly carefully.
(7) In the case of BTL connection amp., the minus terminal
of speaker is not for earthing. Therefore, be sure not to
connect any other earth terminal to this terminal. This
system is of an BTL system.
(8) For connecting a dummy resistor when measuring the
output, use the wire with a greater code size.
(9) Whenever any mixed tape is used, use the band pass fil-
ter (DV-12).
Standby
(Light STANDBY Indicator)
OFF
OFF
0 Minimum
(No.MB196)1-19