Furuno FS-1570 - Antenna Tuning

5.8 Antenna coupler, AT-1560
5-52
5.8.1 Antenna tuning
Start
Check input frequency.
TUNE ERROR
1.6 to 32 MHz?
Operating frequency is
used first time?
SWR< 1.5?
TUNE OK
Phase detection
Antenna is inductive (L) or
Frequency >
7.68 MHz
Antenna is capacitive (C) and
Frequency <
7.68 MHz
Pi matching
Try to tune only b
y
using coils.
First time?
YES
NO
YES
NO
YES
NO
(a) (b)
TUNE OK: “TUNE OK” signal is sent to the transceiver unit and relay on/off condition is
memorized onto EEPROM.
TUNE ERROR: “TUNE ERROR” signal is sent to the transceiver unit while the matching
circuit is bypassed.