ADJUSTMENT PROCEDURE
Item / Preparation
Adjustments
Sub Tuner AFT
1)
Set a signal generator with
-RF FREQUENCY = 38,9MHz
-RF OUTPUT LEVEL = 80±5dBuV.
2)
Connect a signal generator RF output to TP2 (TUNER IF
OUTPUT). Ensure there is no signal input to the
TUNER.
3)
Connect the DC voltage meter to TP3.
Adjust L201 (AFT COIL) for 2,2V ± 0,1V.
Main Tuner AGC
1)
Set a pattern generator with RF level 60 ± 2dBuV,
210,25MHz.
2)
Connect an oscilloscope to P101 (Tuner AGC Input).
Adjust using "AGC UP/DOWN" key until the voltage drops to
1,0Vdc ± 0.2Vdc below its maximum voltage.
Sub Tuner AGC
1)
Set a pattern generator with RF level 60 ± 2dBuV,
210,25MHz.
2)
Connect an oscilloscope to P101 (Tuner AGC Input).
Press the "SUB AGC" key in Service mode and monitor the
SUB TUNER picture whilst adjusting R202 (SUB AGC VR) to
1,0Vdc ±0.2Vdc below its maximum voltage.
Screen
1)
Apply a Colour Bar Pattern signal.
2)
Connect an oscilloscope to P906 (CRT Cathode RGB).
3)
Press the SCREEN key.
Adjust the screen volume on the FBT so that the highest
black level voltage is 130V ± 5Vdc {150V ± 5Vdc}.
Focus
1)
Apply a RETMA Pattern signal.
Adjust FOCUS VOLUME on the FBT for optimum setting.
White Balance
1)
Apply a Colour Bar Pattern signal.
Adjust the RGB UP/DOWN key to obtain optimum
WHITE BALANCE.
X-Position Adjustment, P2 and P3
1)
Play DP-2 Test tape (Colour bar, Audio 6KHz).
2)
Enter Service Mode using Service Remote and
deactivate Auto-Tracking by pressing ATK-OFF key.
3)
Set oscilloscope to CHOP mode and connect CH1 to
VIDEO HEAD SW (PYO4 pin 6). Connect CH2 to the
PB ENVE (PYO4 pin 4) and trigger CH1.
Adjust, with the corn screw, until both TRK MAX and
TRK MIN have the same size of envelope.
Adjust P2, P3 so that both the beginning and the end of the
envelope waveform are flat.
Azimuth Adjustment
1)
Connect an oscilloscope to the AUDIO OUTPUT
terminal (P601).
After test tape playback, adjust the output level, using the
outer screw of the A/C head to obtain maximum waveform.
(6KHz -3,8dBm +1dBm / -3dBm.)
Fix the azimuth screw with locking paint.
6
Summary of Contents for TX-21GV1
Page 34: ...cp421vbl sch 1 Wed May 19 17 22 44 1999 VIDEO BLOCK DIAGRAM ...
Page 35: ...cp421abl sch 1 Wed May 19 17 19 52 1999 AUDIO BLOCK DIAGRAM ...
Page 36: ...cp421pbl1 sch 1 Wed May 19 17 21 31 1999 POWER BLOCK DIAGRAM ...
Page 48: ...39 6 3 EXPLODED VIEW OF F L ASS Y 3 576 2 7 21 9 5 ...
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Page 51: ...SCHEMATIC DIAGRAMS FOR MODELS ZEICHENERKLÄRUNG FÜR MODELL TX 21GV1C TX 14GV1C ...
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