Adjustment - JVC MX-GA9V Service Manual

4.1 Measurement instruments required for adjustment
(1) Low frequency oscillator,
This oscillator should have a capacity to output 0dBs to
600Ω at an oscillation frequency of 50Hz-20kHz.
(2) Attenuator impedance : 600Ω
(3) Electronic voltmeter
(4) Frequency counter
(5) Wow flutter meter
(6) Test tape
VT712 : For Tape speed and wow flutter ( 3kHz)
VT710 : Head azimuth
VT724 : For Reference level (1kHz)
(7) Blank tape
TAPE : AC-225
(8) Torque gauge : For play and back tension
Forward ; TW2111A, Reverse ; TW2121A
Fast Forward and Rewind ; TW2231A
(9) Test disc
Disc : CTS-1000(12cm), GRG-1211(8cm)
(10) Jitter meter
4.2 Measurement conditions
Power supply voltage
AC110V/127V/220V/230V~240V~, adjustable
Measurement output terminal
• Speaker out
• TP101(Mesuring for TUNER/DECK/CD)
• Dummy load 6Ω
1-36 (No.MB011)
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SECTION 4

ADJUSTMENT

4.2.1 Radio input signal
AM modulation frequency : 400Hz
Modulation factor : 30%
FM modulation frequency : 400Hz
Frequency displacement : 22.5kHz
4.2.2 Frequency Range
AM : 531kHz~1710kHz
FM : 87.5MHz~108MHz
4.2.3 Standard measurement positions of volume and switch
Power : Standby (Light STANDBY Indicator)
Sub woofer VOL. : Minimum
Sound mode : OFF
Main VOL. : 0 Minimum
Traverse mecha set position : Disc 1
Mic MIX VOL : MAX
ECHO : OFF
4.2.4 Precautions for measurement
(1) Apply 30pF and 33kΩ to the IF sweeper output side and
(2) The IF sweeper output level should be made as low as pos-
(3) Since the IF sweeper is a fixed device, there is no need to
(4) Since a ceramic oscillator is used, there is no need to per-
(5) Since a fixed coil is used, there is no need to adjust the FM
(6) The input and output earth systems are separated.
(7) In the case of BTL connection amplifier, the minus terminal
0.082 F and 100kΩ in series to the sweeper input side.
sible within the adjustable range.
adjust this sweeper.
form any MPX adjustment.
tracking.
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 connected
particularly.
of speaker is not for earthing. Therefore, be sure not to con-
nect any other earth terminal to this terminal. This system
is of an OTL system.