Sharp 21N52-E1, Руководство по обслуживанию

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SERVICE ADJUSTMENT
ADJUSTMENT
TUNER COILS
The tuner has been factory preset (no
adjustment is needed).
Set voltage at in band.
Connect sweep generator’s output to the test
point of tuner, by using a
DC cut probe.
I
Connection Diagram of DC Cut
* NOTE:
The sweep generator’s probe should
be
grounded closely to the tuner test point.
Output level of sweep generator:
Connect response lead (low impedance probe
with detector)
to the collector of (in IF
unit).
To
To
1
t e s t
A A A
Connection Diagram of Low Impedance Probe
(with Detector).
Apply DC to pin of (in IF unit).
RF
Apply DC (about, to the tuner
terminal.
Connect ohm resistor between base of
and line.
Adjust the tuner IF coils to obtain the
waveform as shown figure below.
NOTE:
For the adjustment, keep the tuner covered
with its lid.
P = MHz
Adjust so that are at the same /eve/.
P-DETECTOR COIL:
This coil (in IF unit) has been factory
Adjust so that MHz signal is at
preset (no adjustment is needed).
maximum
Connect sweep generator’s output to pin
of
l
Probe in use: DC cut probe
l
Sweep output level:
PI F
Apply DC to pin of
Have AFT muted.
AFT is muted if pin of IF unit is grounded.
Connect response lead to
The response lead in use should be a direct
probe with a resistor of ohms included.
P MHz)
1
To
test point
* Adjust voltage so that the output
waveform is of 1
Direct Probe.
3