JVC MX-KC4, Service Manual, Page: 25 / 61

(No.MB350)1-25
SECTION 4
ADJUSTMENT
4.1 Measurement Instruments Required for Adjustment
(1) Low frequency oscillator
This oscillator should have a capacity to output 0dBs to
600
Ω
at an oscillation frequency of 50Hz-20kHz.
(2) Attenuator impedance : 600
Ω
(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
4.3 Radio Input signal
4.4 Frequency Range
4.5 Standard measurement position of volume and switch
Precautions for measurement
(1) Apply 30pF and 33k
Ω
to the IF sweeper output side and
0.082
µ
F and 100k
Ω
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).
Power supply voltage AC 120V (60Hz)
Measurement
output terminal Speaker out
TP101
(Measuring for TUNER/ DECK/CD)
Dummy load 6
Ω
AM modulation frequency 400Hz
Modulation factor 30%
FM modulation frequency 1 kHz
Frequency displacement 22.5kHz
AM 530kHz - 1710kHz
FM 87.5MHz - 108MHz
Power Standby
(Light STANDBY Indicator)
Sound Turbo,A,BASS EX OFF
Sound mode OFF
Main VOL. 0 Minimum
Travers mecha set position Disc 1