Sailor RE2100, Техническое руководство

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3 SERVICE RE2100
3.6.2.4 CHECK OF SELECTION CIRCUIT FOR PRE-FILTERS
The switching between the pre-filters is controlled from the microprocessor through the shift register J01-
2 and six operational amplifiers which are included in the two IC’s U02-2 and U03-2.
1. Key-in the receiver frequencies and control the DC-voltage at the output of U02-2 and U03-2 to be
in accordance with the table in point 2.
2.
3.6.2.5 CHECK OF LO1 SIGNAL AND BUFFER
In this test the level of the L01 signal at the output of the buffer is controlled.
The L01 signal is used in the mixing process from the receiver frequency f
RX
to the 1st IF at 70,000,640
MHz.
The frequency of the LO1 signal can be varied from 70 MHz to 100 MHz and is determined by the equation:
f
LO1
= f
RX
+ f
IF1
= f
RX
+ 70,000,640 MHz
where f
RX
is the receiver frequency.
1. Connect the voltmeter through the diode probe across the coil L41-2.
2. Turn the RE2100 on.
3. Key-in the receiver frequency 2182 kHz.
4. Control the measured DC voltage to be 7.5V +/-1V
3.6.3 MODULE PERFORMANCE CHECK OF SYNTHESIZER UNIT
This chapter contains the following sections:
3.6.3.1. Check of TCXO
3.6.3.2. Check of PLL1
3.6.3.3. Check of PLL2
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