Sony TRINITRON KV-A2121D - Page 24

ears
SECTION 4
CIRCUIT ADJUSTMENTS
4-1. ABOARD ADJUSTMENTS
TUNER AGC ADJ
VIF101 ©
A BOARD (COMPONENT SIDE)
TUNER AGC ADJUSTMENT (AGC VR
1, Align with an appropriate signal between stations.
2. Adjust AGC VR so that snow noise and cross
modulation just disappear from the picture.
IFG5.5S SIF
@ ©
RVI
STEREO SEPARATION
RV2
IFG5.5S SIF -component side-
STEREO SEPALATION ADJUSTMENT (RV1
1. Input stereo signals. (L-CH 400Hz, R-CH 1KHz)
Check the stereo indicator.
Connect on oscilloscope to pin®@) (CH1) of CN1
through band pass filter of 1KHz
4. Adjust RV1 so that 1KHz voltage goes down to
the minmum.
1.
Input
a
PAL
COLOR
BAR
signal,
then
connect
a
jumper
between
pin@®
IC4
and
GND.
2.
Connect
a
frequency
counter
to
pin@
IFG5.5S
(HP)
of
CN1
through
a
probe
of
10:
1.
3.
Adjust
RV2
(H.FREQ)
15.625
+50Hz.
4. After adjustment, remove the jamper.
4-2. B1 BOARD ADJUSTMENTS
CT301 ane RV301
REF OSC R-VK@
CT302 = 8
L308
tin gq NESCTRAP
SECAM TRAP f=
L313
B1 BOARD (COMPONENT SIDE)
REFERENCE OSCILLATOR ADJUSTMENT
(CT302 8.8MHz)
1. Input a PAL color bar signal.
2. Ground pin @ of the IC304.
3. Adjust CT302 to obtain synchronization.
REFERENCE OSCILLATOR ADJUSTMENT
(CT301 7.16MHz)
. Input an NTSC color bar signal.
Ground pin @ of 1C304.
Adjust the CT301 to obtain synchronization.
Remove the jumper grounding pin @ of IC304.
Pe N o
BELL FILTER ADJUSTMENT (L313
Input a SECAM color bar signal.
Connect the oscilloscope to the emitter of Q344.
Adjust L313 so that the waveform is flat.
{HU >
<Before Adjustment >
Sin es
<After Adjustment >
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