Furuno MODEL CSH-73 - Manual (Page 26)

3-6
Inter-
ference
Figure 3-5 How CYCLE works
Note: When the sonar is used in shallow water with the range
set between 60 m and 200 m and Tx cycle at “9”, seabed reflec-
tions caused by the 2nd-to-the-last transmission may appear on
near ranges. Reduce the Tx cycle setting to “2” or “3” to sup-
press them.
Setting F-shift (data setting window: SONR•BEAM,
SONAR)
If interference cannot be suppressed by the interference rejector
(IR) or Tx cycle, change the setting of F-SHFT from 1 to 2.
Noise limiter (data setting window: SIGNAL, SIGNAL
PROCESS)
Weak, unwanted reflections, colored light-blue or green, appear
when the water is dirty, plankton layers exists, or due to ship’s
noise. The noise limiter (NL) can reduce the effects of these
unwanted reflections–raising the setting causes them to become
bluish to background color. Normally a setting of 3 or 4 is suffi-
cient.