Installation manual

Simrad SH80
The RCG will remove unwanted echoes from the sea surface and
the bottom. If you select a strong setting the bottom echoes will
disappear altogether if the bottom is flat, while schools of fish
close to the bottom will be easier to see.
Note that scattered fishmaybemoredifficult to spot if the RCG
function is active, as these can be misinterpreted as reverberation.
It is therefore important that you use the RCG with great care if
your are searching for scattered fish.
Default setting on the SH80 sonar is
7.
About tilt
The sonar beam can be tilted vertically in steps of 1 degree, and
the chosen tilt is shown on the sonar picture. At 0 degrees tilt
you will transmit the sonar beam in parallel with the sea surface,
while 90 degrees tilt will direct it straight down.
The maximum tilt on the SH80 sonar is 60 degrees.
Figure 31 Tilt
(CD015005D)
C
B
A
The challenge will always be to find a tilt that prevents the fish
echoes to be buried in reverberation and bottom echoes.
If you use a steep tilt (A) the fish will easily be disguised by
the bottom echoes, but a strong RCG setting will help. As the
distance from the bottom to the fish increases, the fish will
be easier to see w hen the RCG removes the bottom echoes.
However, this assumes that the fish echoes are considerably
stronger than the bottom echoes.
If you use a very small tilt (C) you will not be bothered by bottom
echoes. If the sea surface is gusty, you will however easily see
echoes from the waves. These echoes will normally be rather
weak, and will hardly move in relation to your vessel.
By means of a medium tilt angle (B) you will most likely be able
to pick up scattered fish or schools if these are located at some
distance above the bottom. The upper school in the illustration
will appear on the sonar picture before the bottom echo, while
the lower school will easily be disguised by the bottom echoes.
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