Furuno FS-1570 Service Manual page 171

(c)
Short circuit the matching circuit.
(all capacitors: OFF, all coils: ON)
SWR< 2.0?
(3.36 MHz or less:
SWR<3.0)
NO
Retry pi matching
(Small change is made.)
SWR< 2.0?
(3.36 MHz or less:
SWR < 3.0)
NO
Frequency
< 3.36 MHz?
YES
Insert shortening capacitor
and then retry pi matching.
SWR< 2.0?
(3.36 MHz or less:
SWR<3.0)
YES
TUNE OK
YES
TUNE OK
YES
TUNE OK
NO
Change L and C and then retry pi
matching.
NO
TUNE
ERROR
5-54
5.8 Antenna coupler, AT-1560
NO
SWR< 2.0?
YES
TUNE OK
(d)