ADJUSTMENT
Adjusting point
Adjusting procedure/conditions
Waveform and others
1. Receive the
(monoscope pattern) signal.
adjustment:
2. Using the remote controller, call the P-NORM
mode.
3. Connect a beam ammeter between
and
Ammeter’s full-scale
: 3
range
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Ammeter’s positive
lead :
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Ammeter’s negative (-) lead :
4. Take the beam ammeter reading to make sure
that the beam current is between 600
and
800
and 1100
(21”).
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If not, readjust the
screen control to ob-
tain the beam current of 600-800
900-1100
(21”).
5. Connect a digital voltmeter to
6. Adjust
so that the digital voltmeter should
read 115
V.
CHECKING
Jo. Adjusting point
Adjusting procedure/conditions
Waveform and others
1 Tuner IF
1. Get the tuner ready to receive the
signal.
(preset):
but with no signal input. Adjust the
data.
IF-OUT
2. Connect the sweep generator’s output cable to
1
1
the tuner antenna. (RF sweep)
3. Adjust the sweep generator’s output level to 80
4. Connect the response lead (use a low-impedance
probe with wave detector; see Fig. to the
IF output terminal.
(This terminal must have the probe alone con-
nected.)
5. Set the RF
voltage to
V with no contact
with the waveform.
Fig.
6. Adjust the tuner IF coil to obtain the waveform as
shown in Fig. 2.
Note: Be sure to keep the tuner cover in
P
during this adjustment.
Fig. 2
6-1
ADJUSTMENT
lo. Adjusting point
Adjusting procedure/conditions
Waveform and others
1
1. Disconnect the antenna from the tuner antenna
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Warm up the unit for longer than
terminal.
10 minutes in advance.
2. Apply DC voltage to pin
of
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DC voltage: 6.0 V (allowable
V)
3. Using a digital voltmeter, measure the DC volt-
age at pin
of
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The digital voltmeter must be able to take read-
10
at about 0.007 V.
down to the third decimal place.
4. Relieve pin (4) of
of the DC voltage.
5. Reconnect the antenna in position and receive
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Position the
core in the
the
signal. (With the AFT off, adjust the
range in which the E-l
receiving frequency to 224.25 MHz.)
can be received.
6. Connect the DC digital voltmeter to pin (20) of
Adjust
so that the voltmeter should
read the same voltage as in Step 3.
Allowable error : 0.015 V (20
2 AFT
adjustment:
3
cut-in
adjustment:
1. Receive the
(PAL
bar) signal. If
this signal is not available, any signal above the
band is acceptable.
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Field strength : 55-80
DC voltage at
Make sure the frequency is almost the same as
that of the received channel
,
2. Using the channel setting control, make a
I
of 224.25 MHz appear on the screen (the
I
AFT turns off). If any other channel than
DOWN A B’ C UP
is received, make its frequency on the screen.
(The AFT turns off when the on-screen display
Fig. 3
turns yellow.)
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Turn the core
3. Turn
clockwise to have a
point, and
for the UP direction, and clock
counterclockwise to have a
point. Position
wise for the DOWN direction.
the coil at the center of these two points.
Adjust the
core to point E
4. Adjust
so that the DC voltage at pin (1) (AFT
(between and
(Points
OUT terminal) of
be 3.3
(See Fig.
and C are rejectable.)
Receive the
(PAL
bar) signal.
Note: If a
field
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Field strength : 57
(75 ohms open)
meter is used without a
2. Connect the oscilloscope to
as shown in
impedance converter, set
Fig. 4.
field strength to 55
Oscilloscope
TV Set
Pay attention to a loss
would be caused with the con
+
. . . . . .
Bias box
+
Fig.
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Bias box: About 6.5 V
3. Turn
to have the highest voltage.
4. Turn
slowly in the opposite direction until the
voltage goes down 0.1 V below the highest level.
5. Adjust thesignal level to 63-67
and make
sure there is no noise.
6. Now adjust the signal level to 90-95
and make
sure there is no chrominance modulation beat.
6-2
