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<MW/LW Adjustment>
Make sure that the following settings are done before adjustment.
Preparation
*
Measuring instruments:
Standard Signal Generator (S.S.G.) / Loop antenna / Oscilloscope / Millivoltmeter / Dummy resistor (6
Ω
)
(1) Connect the measuring instruments as shown in the diagram below.
(2) Keep a distance of 60cm between the loop antenna of signal generator and the one connected to the unit.
DUMMY
SPOUT(L)
AC MILLIVOLTMETER
CH2
CH1
6
Ω
OUTPUT
OSCILLOSCOPE
CH2
CH1
LOAD
60cm
SET
Standerd Signal Genertaor
SPOUT(R)
5. IF Adjustment (MW)
Requirements
*
Test point: SP OUT (Lch, Rch)
Adjustment point: L802
(1) Adjust the S.S.G. setting to MW; carrier at 999 kHz with 30% modulation, and source at 1 kHz, position output at maximum.
(2) Adjust the unit to MW 999 kHz.
(3) While monitoring the 1 kHz waveform through oscilloscope, decrease the S.S.G. output level (till slight noises appear in the waveform).
(4) Adjust L802 so that the millivoltmeter indicates maximum.
6. Tracking Adjustment (MW)
Requirements: Same as Item 5.
* Adjustment point: L952 / L953
(1) Adjust the S.S.G. setting to AM; carrier at 999 kHz with 30% modulation, and source at 1 kHz, position output at maximum.
(2) Adjust the unit to MW 999 kHz.
(3) While monitoring the 1 kHz waveform through oscilloscope, decrease the S.S.G. output level (till slight noises appear in the waveform.)
(4) Adjust L952 so that the millivoltmeter indicates maximum.
(5) Adjust the S.S.G setting to AM; carrier at 603 kHz; distortion rate at 30 %, and source at 1 kHz.
(6) Adjust the unit to MW 603 kHz.
(7) Adjust L953 so that the millivoltmeter indicates maximum.
(8) Repeat above steps (1) to (7) two to three times.
* Adjustment point: TC942 / L941
(1) Adjust TC942 to the mechanical center.
(3) Adjust the unit to LW 144 kHz.
(5) Adjust L941 so that the millivoltmeter indicates the maximum level.
(7) Adjust the unit to LW 290 kHz.
(8) Adjust TC942 so that the millivoltmeter indicates the maximum level.
(9) Repeat the above steps (2) to (8) two to three times.
Standard Signal Generator
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