Pp Filter; Pulse Form And Length; Gain - Simrad SH40 - MINI MANUAL REV A Manual

Simrad SH40
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PP Filter

PP Filter means "Ping-to-Ping Filter". When this function is
activated, the sonar will compare the echoes from one ping with
the echoes from the next pings. If an echo is present at the first
ping, but then disappears at the next, the sonar will interpret this
as noise and reverberation, and remove it.
If you choose setting
consecutive pings. If you choose settings
sonar will compare four and eight pings respectively.
Default setting on the SH40 sonar is

Pulse form and length

On the SH40 sonar, you can transmit sound modulated as FM
or CW.
FM means "frequency modulated", which means that the
frequency of the transmitted pulse is changed during the
transmission. In most cases this method will provide better echo
presentation and stability, and you will avoid excessive noise
and reverberation.
Default setting on the SH40 sonar is
transmission mode, the sonar will automatically choose from a
set of different frequencies depending on the current range.
CW means "continuous wave", which means that the
transmission frequency is fixed during the entire pulse. When
you use CW transmission you can choose the length of the
pulses. In a search phase under good conditions, you should try
setting . If the conditions worsen, try to shorten the pulse
Long
length. This will make it easier to distinguish the various echoes,
and the reverberation will be reduced.

Gain

You can adjust the gain in many different ways, but the most
important is the setting made by the
menus.
Vertical
If you have too much gain, you will see a sonar picture with too
many echoes. This is because the large amplification presents all
kind of noise and reverberation that the sonar picks up. If the
gain is smaller the noise and reverberation will disappear, but if
it is too small the fish echoes may disappear as well. In most
cases you should try with a medium value. On the SH40 sonar,
the default value is set to 30.
, the sonar will only compare two
Weak
Medium
Medium
FM Auto
on the
Gain
or the
Strong
.
. In this
and
Horizontal
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