Scanning Sonar Techniques - Wesmar HD825 Series Operation And Installation Manual

OFFSET
This setting enables the alignment of the image on
the screen with respect the bow in plus or minus
one degree steps. Adjust the screen offset if the
FWD mark on the soundome is not accurately
directly aligned with the forward direction.
TUNING
Pre-Set at Factory
This setting adjusts the frequency of the
transmitter. This should match the factory setting.
To reduce noise or interference, adjust the
frequency up or down for the best picture.
Tuning Adjustment:
160kHz, set to 159kHz: span 156kHz to 162kHz.
110kHz, set to 114kHz: span 108kHz to 117kHz.
60kHz, set to 60 kHz: span 57 to 62kHz.
TEST PAT
Sonar simulation mode. Will only work if sonar is
disconnected from transmit/receive board.
SCANNING SONAR
TECHNIQUES
In Deep Water
If the vessel is being operated in deep enough
waters so that the sonar receives no bottom
echoes when being operated at a 5 degree tilt, set
the sonar on medium or long range and adjust the
GAIN controls high enough to receive bottom
echoes from shallow water at long ranges and set
SECTOR SIZE for a 90 degree sector.
Use enough FAR GAIN and NEAR GAIN to
detect even a gently sloping mud seabed. When
properly adjusted, the sonar will display fish
schools, boat wakes and other major changes in
the water.
Although it is possible under ideal circumstances
to locate surface targets such as large logs and
boats, the sonar is not a reliable tool for detection
of these surface targets and should only be used
for locating underwater targets.
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WESMAR