Aiwa XR-EM50K Service Manual page 55

< CD SECTION >
CD C.B (PATTERN SIDE)
CD CHECK
Perform the adjustments after the main unit enters the test mode.
Place the CD mechanism on level ground.
Equipment and tools required
Measuring equipment
Digital multi-meter
Jitter meter (KIKUSUI 6235)
Test disc: TCD-782
ATD-001
1.RF WAVEFORM CHECK
1) Connect oscilloscope to the test point RF and Vref.
nd
2) Play back the 2
3) Check that the RF waveform has the maximum amplitude and the center
of the wedge waveform has the clear blank.
2.JITTER CHECK
1) While oscilloscope is kept connected in the same test point as in
step2. RF WAVEFORM CHECK, connect the output terminal of
an oscilloscope to the input terminal of the jitter meter.
2) Set the VOLT range selector of oscilloscope to 500mV range or
below.
nd
3) Play back 2 track of TCD-782.
4) Check that jitter meter indicates 28.0ns or less.
IC202
FE
JW102
track of TCD-782.
EYE PATTERN
must be CLEAR and MAX
R8A
RF
TE
Vref
4
11
JW103
IC101
Approx.
1.8 ±0.3Vp.p
VOLT / DIV: 500mV
TIME / DIV: 0.2µs
RF
Vref
– 55 –
⑤
Q1
①②③
①②
③
OSCILLOSCOPE
RF
Vref
OSCILLOSCOPE
OUTPUT
OUTPUT
JITTER METER
INPUT
ns