JVC AV-20320/S Service Manual page 22

AV-20320
AV-20321
Measuring
Item
instrument
MTS SAP Signal
VCO generator
adjustment
Frequency
counter
MTS FILTER
check
MTS TV audio
SEPARATION multiplex
adjustment signal
generator
Oscilloscope
L-Channel
signal waveform
1 cycle
22
Test point Adjustment part
No.8 5FH MON.
MPX
Connector
No.9 SAP VCO
4 pin SDA
3 pin GND
R OUT
[AUDIO OUT]
No.5 FILTER
L OUT No.6 LOW SEP.
R OUT
[AUDIO OUT] No.7 HI SEP.
R-Channel
crosstalk portion
Minimum
No. 51964
Description
1. Receive a RF signal (non modulated sound signal) from the
antenna terminal.
2. Connect between pin 4 of MPX connector and GND (Pin
3 of MPX connector) through 1M
3. Select the "No.8 5FH MON." of the SOUND MODE, and reset
the setting value from 0 to 1.
4. Connect the Frequency Counter to R out RCA pin of the
AUDIO OUT.
5. Select the "No.9 SAP VCO".
6. Set the initial setting value of "No.9 SAP VCO" with the
LEFT/RIGHT key of the menu.
7. Adjust the "No.9 SAP VCO" so that the Frequency Counter
will display 78.67kHz 0.5kHz.
8. Select the "No.8 5FH MON." of the SOUND MODE, and reset
the setting value from 1 to 0.
1. Select the "No.5 FILTER" of the SOUND MODE.
2. Verify that the "No.5 FILTER" is set at its initial setting value.
1. Input a stereo L signal (300Hz) from the TV audio multiplex
signal generator to the antenna terminal.
2. Connect an oscilloscope to L OUT RCA pin of the AUDIO
OUT, and display one cycle portion of the 300Hz signal.
3. Change the connection of the oscilloscope to R OUT RCA pin
of the AUDIO OUT, and enlarge the voltage axis.
4. Select the "No.6 LOW SEP." of the SOUND MODE.
5. Set the initial setting value of the "No.6 LOW SEP." with the
LEFT/RIGHT key of the menu.
6. Adjust the "No.6 LOW SEP." so that the stroke element of the
300Hz signal will become minimum.
7. Change the signal to 3kHz, and similarly adjust the "No.7 HI
SEP.".
Resistor.