JVC MX-J30 - Page 48

MX-J30/MX-J330/MX-J35R
Adjustment method
Measurement Instruments Required
for Adjustment
1. Low frequency oscillator,
This oscillator should have a capacity to output OdBs
to 6000hm at an oscillation frequency of 50Hz-20kHz.
2. Attenuator impedance : 6(00ohm
3. Electronic voltmeter
4. Frequency counter
5. Wow flutter meter
6. Test tape
VTT712 : For Tape speed and wow flutter (3kHz)
V1TT724 : For Reference level (1kHz)
TMT7036 : For Head angle(10kHz),Play back frequency
characteristics(1kHz),and dubbing frequency
characteristics(63, 1,10kHz)
Because of frequency-mixed tape with 63,1k,10k and
14kHz(250nWb/m -24dB).
Use this tape together with a filter.
7. Blank tape
TAPE J: AC-225, TAPE IT: 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)
GMT-9900(CD-G),MMCD-VCD01(VIDEO-CD)
10. Jitter meter
Measurement Conditions
Power supply voltage
AC110/127/220/230-240V(50Hz) : Ver.U type other
AC220V(60Hz) : Ver.UP than UP
AC120V(60Hz) : Ver.J,C
AC240V(50Hz) : Ver.A
AC230V(50Hz) : Ver.B,E,EN,EE,EV
Measurement
output terminal : Speaker out
:TP101(Mesuring for TUNER/DECK/CD)
:Dummy load 6ohm
2-28
Radio input signal
AM modulation frequency : 400Hz
Modulation factor : 30%
FM modulation frequency : 400Hz
Frequency displacement : 22.5kHz
POLAR stereo(for Ver.EE) : 50kHz
Frequency Range
AM = 530kHz~1710kHz = Jy, C
531kHZ~1710kHz —__U type other than UX
531kHz~1602kHz — only UX
522kHz~1629kHz = A,B, E, EN, EV,EE
LW 144kHz~288kHz B,E,EN,EV,EE
FM 87.5MHz~108MHz except EE
65~74MHz / 87.5~108MHz only EE
Standard measurement positions of volume
and switch
Power : Standby (Light STANDBY Indicator)
A.H.BASS : OFF
Sound mode : OFF
Main VOL. : 0 Minimum
Travers mecha set position : Disc 1
Mic MIX VOL : MAX
KARAOKE/ECHO : OFF (only U type)
Precautions for Measurement
1. Apply 30pF and 33kohm to the IF sweeper output
side and 0.082 uF and 100kohm 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 MPX 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 connected particularly.
.
In
the
case
of
BTL
connection
amplifier,
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
OTL
system.
N