Furuno RC-1800T - Chapter 6 Troubleshooting; Selftest; Fs-2550;1562

6.1 Selftest
6-1
6.1 Selftest
For detailed procedures of self-tests, refer to the operator’s manual of RC-1800T/F and
the service manual of each equipment. This chapter describes the selftest briefly.
6.1.1 FS-2550/1562
Selftest is carried out with the RF VR set to fully cw.
With FS-1562, switch on power while pressing [Tx] key. With FS-2550, switch on
power while pressing [CURSOR] key.
Rx: receiver, TE: TX exciter, TP: PA/antenna coupler are automatically tested.
Understood are test frequency and the circuit which the signal passes through.
Fig. 6.1.1 Detection of FS-1562 check signal
Rx Section:
13.5 MHz signal inputs into the Rx RF circuit on the Tx/Rx board in the TLX mode. S
value shows the test result. If RF VR is set to minimum, the test result becomes NG. If
the test result is NG, the Tx/Rx board (05P0526) is faulty.
TE Section:
The output power level from the Tx/Rx board is measured. Test is made in TLX mode
of 3 MHz with the PA circuit being turned off. If the test result is NG, the Tx/Rx board
(05P0526) is faulty.
TP Section:
If the TE section test is OK, then this TP section is tested. From the PA circuit to the
antenna coupler circuit is checked. The system transmits a 3-MHz signal in TLX mode
and tunes to the dummy load in the antenna coupler. If test result is NG, the PA, Tx FIL
board, or AT-1560 may be faulty.
Chapter 6 Troubleshooting
DET
EXC OUT
Ia
(Check TP)
CHK EXC
(Check TE)
CHK S
(Check RX)
PA
PA
PA
TX FIL
TX FIL
TX/RX
PA-2500(J)
AT-1560
ANT
250W
150W
FS-2550/1562
RF
DUMMY
Check TP
3MHz TLX mode
DUMMY ON
Check TE
3MHz TLX mode
PA OFF
Check RX
13.5MHz TLX mode
AGC ON
Rx RF AGC
13.5MHz
Rx ANT
CPU
(10 ohm+200pF)
(05P0526)
(05P0525) (05P0520)
(05P0520)
(05P0528)
(05P0525A)