2-3
2. Function of PCB
Table 2-1 Function of PCB
Board Name Type Description Remarks
FS-1503
CPU 05P0665 Scans the key switches, outputs signals
to the LCD-panel display, and controls
each circuit block (input/output control).
TX/RX 05P0666
Comprises a modulator for microphone
and LINE input signals, a transmitting
RF amplifier, a receiving RF amplifier,
low-frequency amplifiers, and a synthe-
sizer (DDS) circuit.
TLX FIL
(optional)
NB DET 05P0466 Includes a noise blanking control circuit.
REMOTE (A) 05P0457 Equipped for remote control of DSC,
RB-500, and NBDP. OPTION
(RS-232C)
REMOTE (B) 05P0458 Equipped for remote control of RB-500. OPTION
(Current Loop)
CONTROL 05P0459 Equipped when BK and MUTE signals
are needed to interconnect receivers. OPTION
PA/FIL 05P0667
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-
cludes a transmitting high-frequency
power amplifier circuit and a tempera-
ture detecting circuit. The TX-FIL secti-
on contains transmitting LPF,
ALC/reflection detecting circuit, and a
transmitter/receiver switching circuit.
BC BAND FIL
Setting
SW REG 05P0668 Equipped to change the grounding of the
unit from negative ground to floating
ground. OPTION
AT-1503
COUP 05P0669
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
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.
Selftest function
with JP-1 set to
"SELF TEST"
DUMMY CONT 05P0670 Controls ON/OFF of the dummy antenna
of 10 Ω + 250 pF, 100 W. OPTION
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.