Furuno FS-1562 Manual page 362

On the handset, three vertical bars (short, medium, and long) right to the antenna
symbol indicate the C/N data or signal quality. The number of the bar versus C/N value
is;
CESH (HSD)
(Telex)
59 or more: 3 bars
more: 3 bars
56 or more: 2 bars
53 or more: 1 bar
52 or less: no bar
The following figures show the change of C/N when the azimuth and elevation angles
are changed from the antenna position where the strongest signal is detected.
C/N LEVEL
Indcation
60
40
NG
20
-20
-10
- Rx IF AGC Level (150 or more)
AGC level used in the receiver circuit on the RF CON board is detected and sent
to the SYS CPU. If it is 150 or more, the circuit is normal.
CESD/CESV (FIU/Data/Voice)
50 or more: 2 bars
47 or more: 1 bar
46 or less: no bar
NG
0 +10 +20
AZ Degree
Rx HSD Circuit
U3
Rx Non HSD Circuit
RF CON
53 or more: 3 bars
C/N LEVEL
Indcation
60
40
NG
20
-20
U8 U13
U16
U21 U21 U17
2/2 1/2
H3-33
NCSC
48 or
44 or more: 2 bars
40 or more: 1 bar
39 or less: no bar
-10
0 +10
EL Degree
Rx IF
U20
10.7MHz
(10.7MHz)
AGC ADJ
R33
AGC Level
FELCOM 82
NG
+20