Function Of Pcb - Furuno FS-1503 Service Manual

2. Function of PCB

Board Name
CPU
TX/RX
NB DET
REMOTE (A)
REMOTE (B)
CONTROL
PA/FIL
SW REG
COUP
DUMMY CONT
Note) TX/RX board is equipped with CONTROL board (option), REMOTE-(A) or -(B)
board (options), and NB-DET board. REMOTE-(A) or -(B) board is selected according
to the used remote-control specification, RS-232C or current-loop, respectively.
Table 2-1 Function of PCB
Type
FS-1503
Scans the key switches, outputs signals
05P0665 to the LCD-panel display, and controls
each circuit block (input/output control).
Comprises a modulator for microphone
and LINE input signals, a transmitting
05P0666 RF amplifier, a receiving RF amplifier,
low-frequency amplifiers, and a synthe-
sizer (DDS) circuit.
05P0466 Includes a noise blanking control circuit.
Equipped for remote control of DSC,
05P0457
RB-500, and NBDP.
05P0458 Equipped for remote control of RB-500.
Equipped when BK and MUTE signals
05P0459
are needed to interconnect receivers.
Comprises the power input relay section,
PA section, and TX-FIL section. The
relay section contains a power ON/OFF
circuit by a power input-line relay, and a
protection circuit against over-voltage
and over-current. The PA section in-
05P0667
cludes a transmitting high-frequency
power amplifier circuit and a tempera-
ture detecting circuit. The TX-FIL secti-
on contains
ALC/reflection detecting circuit, and a
transmitter/receiver switching circuit.
Equipped to change the grounding of the
05P0668 unit from negative ground to floating
ground.
AT-1503
The automatic tuning circuit in which
CPU controls L/C matching network by
detecting the phase, SWR, and frequency
of the RF input signal from the main
05P0669
unit. The input/output signals are TUNE,
BUSY, and THROU. The input imped-
ance is 50 Ω and the maximum input
power is 150 Wpep.
Controls ON/OFF of the dummy antenna
05P0670
of 10 Ω + 250 pF, 100 W.
Description
transmitting LPF,
2-3
Remarks
TLX FIL
(optional)
OPTION
(RS-232C)
OPTION
(Current Loop)
OPTION
BC BAND FIL
Setting
OPTION
Selftest function
with JP-1 set to
"SELF TEST"
OPTION