Table of Contents
Advertisement
PIF/AFT/AGC ADJUSTMENT
3. AFT ADJUSTMENT: T204(T104)
1. Receive the E-12CH (PAL colour bar) signal. If
this signal is not available, any signal above the
E-5CH band is acceptable.
•Field strength:
55~80 dBµV
Make sure the frequency is almost the same as
that of the received channel (± 30 kHz).
2. Using the channel setting control, make a fre-
quency of 224.25 MHz appear on the screen.
(AFT off)(If any other channel than E-12CH is
received, make its frequency on the screen.)
3. Turn T204 (T104) coil clockwise first to have 6V
reading and then counterclockwise to get 0.2 V
reading.
Within this range, adjust this coil to reach the volt-
age below.
4. Adjust T204 (T104) so that the DC voltage at the
pin (1) of IC201 (IC101) be 3.3 ± 0.2 V. (See Fig.
3 .)
Note: Operate PIP when you adjust T104.
4. RF AGC CUT-IN ADJUSTMENT: R226 (R116)
1. Receive the E-12CH "PAL COLOUR BAR" signal.
• Field strength: 57 ± 1 dBµV (75 ohms open)
2. Connect the oscilloscope to P201 (P101), as
shown in Fig. 4.
• Bias box: About 6.5V
3. Turn R226 (R116) to have the highest voltage.
4. Turn R226 (R116) slowly in the oppsite direction
untill the voltage goes down 0.1V below the high-
est level.
5. Adjust the signal level to 63-67 dBµV and make
sure there are no noise.
6. Now adjust the signal level to 90-95 dBµV and
make sure there is no chrominance modulation
beat.
Note: Operate PIP when you adjust R116.
Note: If a 50 ohm field strength meter is used with-
out a 50/75 impedance converter, set the field
strength to 55 ± 1dBµV. Pay attention to a loss
that would be cause with the converter.
5. VIDEO DETECTION LEVEL ADJUSTMENT: R224
1. Receive the "B/G SYSTEM PAL COLOUR BAR" signal (100% white colour bar). Set the S system to B/G.
2. Adjust R224 so that the video output at the AV OUT terminal be 1.0 ± 0.05 Vp-p with a 75-ohm termination.
DC voltage at TP201 [ Pin (1) of IC201]
TP101 [ Pin (1) of IC101]
6V
3.3V
DOWN
A
B'
B
B''
C
Fig. 3
* Turn the core counterclockwise for the UP di-
rection, and clockwise for the DOWN direc-
tion. Adjust the T204 core to point B (between
B' and B''). Point A and C are rejectable.
TV Set
Oscilloscope
P201
0.1V
(P101)
Bias box
+
-
Fig. 4
7-1
DIGITAL COMB FILTER Y LEVEL ADJUSTMENT
1. DIGITAL COMB FILTER Y LEVEL ADJUSTMENT: R5467
1. Input the PAL colour bar (100% white colour bar) signal to AV-IN terminal with a 75 ohm termination (input
level 1.0 Vp-p ± 0.05Vp-p).
2. Connect the oscilloscope to TP5462 (connector YA pin (7)).
3. Adjust R5467 so that the Y signal (100% white) at TP5462 be 2.0 ± 0.1Vp-p.
Note: Make sure that the signal is linearly amplified overall. (The 100% portion should be kept intact.)
<Reference> Note the voltage level for the adjustment with the E-12CH signal.
To be adjusted to 2.0 Vp-p at TP5462
* Make sure the above value is available after the adjustment No. 5. (See Page 12.)
UP
Input (YB) (2):
2.0 V ± 0.1 Vp-p
Output (YA) (7): 2.0 V ± 0.1 Vp-p
PIP (SUB-SCREEN) ADJUSTMENT
1. PIP Y LEVEL ADJUSTMENT:
R4938 (on P-in-P unit)
1. Receive E-12CH "PAL COLOUR BAR" signal for
the main and PIP.
2. Connect the oscilloscope to TP805(PI (16)) on
the main unit.
3. Adjust R4938 so that the 100% white portion in
the PIP and that in the main screen be at the
same level. (See Fig.5. )
• Adjustment error: 0 ± 0.02 V.
Note: The level difference between the pedestal and
that 100% white portion should be 0.7Vp-p or
so.
2. PIP SUB-COLOUR ADJUSTMENT:
R4952 (on P-in-P)
1. Receive E-12CH "PAL colour bar" signal for the
main and PIP.
2. Connect the oscilloscope to TP804 (PI(14)) on
the main unit.
3. Adjust R4952 so that the R-Y red portion in the
PIP and that in the main screen be at the same
level.(See Fig.6. )
Sub 100%
white
Main 100%
white
To be at the
W
same level
About
0.7Vp-p
P
Fig. 5
H: Horizontal sync
V: 0.1 V/div. (reading)
Sub R - Y red
Main R - Y red
To be at the
same level
Fig. 6
H: Horizontal sync
V: 0.1 V/div. (reading)
7-2
Advertisement
Table of Contents
