TUNER ADJUSTMENT
１．
１．
１．
１．
VT ADJUSTMENT (AM)
Requirement
Measuring equipment: Digital multi-meter
Test point: TP1(FFE801
④
pin),GND
Adjustment point: L773
(1) Adjust the reception frequency of the main unit to 1710KHz.
(2) Adjust L773 until the test point voltage (VT) is 9.0V
±
0.5V.
(3) Adjust the reception frequency of the main unit to 530KHz.
(4) Check that the test point (VT) voltage is about 1.3V.
２．
２．
２．
２．
VT CHECK (FM)
Requirement
Measuring equipment: Digital multi-meter
Test point: TP1(FFE801
④
pin),GND
(1) Adjust the reception frequency of the main unit to 108.0MHz.
(2) Check that the test point (VT) voltage is about 9.0V.
(3) Adjust the reception frequency of the main unit to 87.5MHz.
(4) Check that the test point (VT) voltage is about 2.5V.
３．
３．
３．
３．
DC BALANCE ADJUSTMENT
Requirement
Measuring equipment: Digital multi-meter
Test point: TP4, 5
Adjustment point: L771
(1) Adjust the reception frequency of the main unit to 98.0MHz.
(2) Adjust L771 until the test point voltage difference between TP4 and TP5 is
0mV
±
20mV.
＜
＜
＜
＜
AM ADJUSTMENT
＞
＞
＞
＞
For AM adjustment, do wiring and connection as in the following.
Measuring equipment: Oscilloscope or Millivoltmeter
Test point: TP7 (IC771 24pin), GND
Adjustment point: L772
(1) Adjust the setting of Standard Signal Generator (hereinafter S.S.G.) to 450KHz
of 30
％
variation.
(2) While looking at the waveform on the oscilloscope, reduce the output level all the
way.
(3) Adjust L802 until the waveform of the oscilloscope reaches the maximum.
V
DIGITAL MULTIMETER
TP1
GND
GND
OSCILLOSCOPE
CH1
CH2
Lch
Rch
GND
V
DIGITAL MULTIMETER
VT
GND
V
DIGITAL MULTIMETER
VT
GND
60cm
SET
TP
Lch
Rch
GND
measuring equipment
Connect to the respective
-24-
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