Selecting Horizontal Beamwidth; Selecting Vertical Beamwidth - Furuno CSH-5 MARK-2 Operator's Manual

Selecting Horizontal Beamwidth

Selecting Vertical Beamwidth

Rejecting Noise with IR Control
This control is similar to the interference rejector on echo sounders
and radars. It is effective for rejecting random noise and sea surface
reflections in rough sea conditions. Set the IR control to positions
"1" thru "3" so that noise is just eliminated. Do not use an unneces-
sarily high setting since it may also reject small wanted echoes.
Rejecting Noise with NOISE LIM Control
Weak, unwanted reflections, colored light blue or green, are displayed
when water is contaminated or plankton layers exist or due to ship's
noise. These echoes gradually become bluish as the NOISE LIM con-
trol is turned clockwise. Usually position "3" to "4" is used.
Rejecting Interference with TX Cycle
When other sonars operate nearby at the same transmission interval
as that of own ship's sonar, interference ring caused by other sonars
are displayed. To erase the interference ring from the screen, reduce
the TX cycle setting on the scan menu screen. See page 8.
Note: When the sonar is used in a shallow water with the range set
between 100 m and 200 m and the TX cycle at "10", seabed
reflections caused by the transmission which is the last but
one on near range on screen. Reduce the figure of TX cycle to
"7" or "8" to reject them.
If you wish to have better bearing discrimination* for fish schools
and also wish to examine the contour of seabed, call up scan menu
and select "narrow horizontal beam width".
* Ability to distinguish two closely located targets at the same range
and different bearings.
When better detection range is required, call up scan menu and select
"narrow vertical beamwidth".
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Interference