JVC HX-Z9, Service Manual

Page: 33 / 77

(No.22066)1-33
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) Distortion meter
(5) Frequency counter
(6) Wow & flutter meter
(7) Test tape
VT703L : Head azimuth
VT712 : Tape speed and running unevenness (3kHz)
VT724 : Reference level (1kHz)
(8) Blank tape
TYPE l : AC-225
TYPE ll : AC-514
(9) Torque gauge : For play and back tension
FWD(TW2111A), REV(TW2121a) and FF/REW(TW2231A)
(10) Test disc: CTS-1000
4.2 Measurement conditons
4.2.1 Radio Input signal
4.2.2 Tuner section
4.2.3 Standard measurement position of volume
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 110V/AC127V/AC220V
AC 230V·AC240V (adjustable with the
voltage selector), ~50Hz/60Hz
Reference output Speaker : 0.775V/6
Ω
Headphone : 0.077V/32
Ω
Reference frequency and input level 1kHz, AUX : -8dBs
Measurement output terminal at Speaker J3002
Load resistance 6
Ω
AM frequency 400Hz
AM modulation 30%
FM frequency 400Hz
FM frequency deviation 22.5kHz
Voltage applied to tuner +B : DC5.7V
VT : DC 12V
Reference measurement output 26.1mV(0.28V)/3
Ω
Input positions AM : Standard loop antenna
FM : TP1 (hot) and TP2 (GND)
Function switch to Tape
Beat cut switch to Cut
Super Bass/Active hyper Bass to OFF
Bass Treble to Center
Adjustment of main volume to reference output VOL : 0.775V