JVC AV-20F475 Service Manual page 25

4.8.6 MTS CIRCUIT
Measuring
Item
instrument
MTS INPUT Remote
control unit
LEVEL
TV audio
MTS
SEPARATION multiplex
signal
generator
Oscilloscope
Remote
control unit
L-Channel
signal waveform
1 cycle
Test point Adjustment part
[3.SOUND (A)]
A01: IN LEVEL
R OUT [3.SOUND (A)]
L OUT A02: LOW SEP.
[AUDIO OUT] A03: HI SEP.
R-Channel
crosstalk portion
Minimum
Description
(1) Receive any broadcast.
(2) Select the 3.SOUND (A) from the SERVICE MODE.
(3) Select the < A01 > (IN LEVEL).
(4) Set the initial setting value of the < A01 >.
Setting item
A01: IN LEVEL
(1) Input the stereo L signal (300Hz) from the TV audio
multiplex signal generator to the antenna terminal.
(2) Connect an oscilloscope to R OUT pin of the AUDIO
OUT, and display one cycle portion of the 300Hz
signal.
(3) Select the 3.SOUND (A) from the SERVICE MODE.
(4) Select the < A02 > (LOW SEP.).
(5) Set the initial setting value of the < A02 >.
(6) Adjust the < A02 > so that the stroke element of the
300Hz signal will become minimum.
(7) Change the connection of the oscilloscope to L OUT
pin of the AUDIO OUT, and enlarge the voltage axis.
(8) Change the signal to 3kHz, and similarly adjust
the < A03 > (HI SEP.).
Setting item
A02: LOW SEP
A03: HI SEP
Initial setting value
12
Initial setting value
39
16
(No.YA052)1-25