Furuno FS-1570 Service Manual page 182

6.1 Self-test
RT test items
PLL
The PLL circuit on TX/RX board (05P0733) is tested. By changing the frequency, PLL
UN-LOCK-1 signal is monitored.
The test frequency includes 2300 kHz, 4500 kHz, 7700 kHz, 11500 kHz, 15500 kHz,
19000 kHz, 23500 kHz, and 27500 kHz. When the test detects an error, NG appears.
Fig.6.1.4 PLL test signal flow
RF
The output power from TX/RX board (05P0733) is measured. If it is normal, "OK"
appears. 2190 kHz (J2B) mark tone signal and the power data of 110 for FS-1570 and
FS-2570 are used.
If "NG", TX/RX board is defective.
Fig.6.1.5 RF test signal flow
PA 1
Ic and Vc of power amplifier on PA board (FS-1570T: 05P0735; FS-2570T: 05P0739)
are measured. If the value is within the rating, "OK" appears. The test signal is the same
as that of RF check.
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