Tx Board Self-Test Detection Circuit - Furuno FS-1575 Service Manual

PA-IF VS
T-CPU Power Data
Note)
Although the protection circuit has been designed to be activated first by the PA IC signal, the
over current protection (19A) of the SW REG board is actually activated first, resulting in a
drop in PA VC (42V).

5. TX board self-test detection circuit

When conducting a self-test, the test results are judged for each circuit and detected
signal levels are also displayed. For details, refer to information on pages 6-6 and 6-15.
1) IF CHECK
Detection signal of 36-kHz TX IF signal inputted to the TX board
2) RF CHECK
Detection signal of output signal from the TX board
3) UN-LOCK
PLL circuit "lock or unlock" detection signal. When it detects that the PLL
circuit is unlocked, transmission will be stopped and an error message saying
"WARNING: TX PLL UNLOCK!" will be outputted.
4) TX_HW_VER0, 1
TX board hardware information. This information will be displayed when
selecting [MENU] -> 9.SERVICE -> 5.TEST -> 1.VERSION.
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It is strictly prohibited to reproduce the document in whole or in part without prior written permission of FURUNO.
Displays numerical values when conducting a
self-check.
And for added the ALC circuit of the PA-IF board.
Note) Operates at an 18V or less voltage. The
low rvoltage lockout function is activated first.
Controls the ALC circuit of the TX board.
7-18
7.2 Transmission Circuit
Hardware
Software