Gain - NorthStar EXPLORER 443D Installation And Operation Manual

It is difficult to get fish arches in shallow water as the transducer sonar beam is very narrow near the
•
surface and fish do not stay within the beam long enough to display an arch. Several fish in shallow
water tend to display as randomly stacked blocks of pixels.
• Wave motion may result in distorted fish arches

4-4 Gain

Gain (sensitivity) controls the amount of
detail displayed on the Explorer 443d/443df.
Understanding how to set suitable Gain settings
is important for optimum performance.
The Northstar fishfinder has three gain modes,
Cruising, Fishing and Manual.
• Cruising Mode
Use this mode to show only the bottom and
large fish.
• Fishing Mode
Use this mode to show as much detail as
possible.
• Manual Mode
The gain can be adjusted by the user to
compensate for water depth and clarity.
High Gain settings may amplify the normal
background noise until it appears as random
pixels.
Changing between Cruising, Fishing
and Manual
To change between Cruising, Fishing
and Manual
1. From any Sonar display, press ENT.
2. Use the or cursor keys to highlight mode
option, then use the
desired option from list.
Adjusting Gain and Threshold settings
The gain settings and the threshold settings can
be adjusted independently for each frequency
(83kHz and 200 kHz).
Use threshold to eliminate colors in the sonar
display.
1. From any Sonar display, press ENT.
2. Use the or cursor keys to highlight the
desired setting, then use the
to change it.
22
cursor key then select
cursor key
Northstar Explorer 443d/443df Installation and Operation Manual
Note: The Gain mode automatically changes to
Manual Gain if the gain or threshold settings are
adjusted by the user.
Obtaining the best results
To obtain the best detection capability for both
fish and bottom we recommend the use of the
Sonar A-Scope display:
1. Set the threshold to 0%.
2. Adjust the gain until the threshold line is just
to the right of the unwanted noise.
Gain
Threshold line
Unwanted
signal
Gain line