Installation manual

Simrad SH80
interference, noise and reverberation. In addition to giving
a clean and stable echo presentation, this will normally also
increases the sonar’s detection range.
Frequency selection (Option)
The optional multiple frequency selection can be used for
suppression of interference from other sonars.
However, the sound absorption in salt water increases with the
frequency, thus giving the lower frequencies a longer detection
range.
RCG (Reverberation Controlled Gain)
The R CG filter senses the noise level (reverberation, propeller
noise, etc.), and adjusts the gain individually for each of the 64
receiver beams in order to eliminate noise on the display. The
strength of the filter can be selected in the menu. With maximum
strenght is selected, the RCG will effectively reduce the bottom in
shallow water, while variations on the bottom will be displayed.
Note that scattered fish can be perceived as reverberation. The
RCG filter must therefore be used with care if scattered schools
are to be detected.
Ping-to-ping fi lter
Thee Simrad SH80 Fish finding sonar sonar is equipped with
a ping-to-ping filter (PP Filter) to provide a clean and steady
presentation by reducing the interference and noise. This filter
compares the echoes from a selected amount of transmissions
(pings), and an echo has to be present in the selected amount of
pings in order to be presented on the display.
Note that in rough seas, when the beam easily can miss the target
in several pings, the PP Filter must be used with care.
TVG(TimeVariableGain)
The TVG function controls the gain of the receiver so that
a school with a given size and density is presented with
approximately the same strength on the display, inside the
regulated TVG range. This can also be seen as a filter, because it
reduces the noise close to the vessel.
The regulated strength of the TVG can be selected in the menu.
Transmission
The transmitting is controlled by the signal processor in t he
Transceiver Unit. The parameters you have chosen are used.
There are 240 separate transmitters in the unit distributed on
eight transceiver circuit boards. Each transmitter is individually
addressed and controlled from the signal processor. The
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