1. OPERATIONAL OVERVIEW
1-9
1.3.7
Adjusting the gain
The [GAIN] control adjusts receiver sensitivity. It should be adjusted to see fish
echoes clearly with minimal noise on the screen. Too high a setting not only
causes excessive noise on the screen and makes it difficult to discriminate
wanted fish echoes but also causes bottom echoes to be painted in strong colors,
resulting that the echoes from bottom fish are masked by bottom reflections. A
setting between 3 and 7 is usually suitable. Each time the control is operated the
newly selected range appears in large characters for five seconds at the top of
the sonar display. The current range is always displayed at the top right corner of
the sonar display.
Gain too low
Gain proper
Gain too high
Examples of proper and improper gain
1.3.8
Retracting the transducer, turning off the power
1. Set speed under 16 knots and then press the [
↑
] switch to retract the
transducer. The lamp above the switch blinks while the transducer is being
retracted. Transmission is stopped automatically. If you press the [
↑
] switch
when the speed is over 16 knots and the speed warning is turned on in the
SYSTEM menu, the message “Max allowable speed for extended transducer
is 16 kt. Max allowable speed during raising lowering transducer is 16 kt.”
and the audio alarm sounds. Press the [R/B key to silence the audio alarm.
2. When the lamp above the [
↑
] switch lights, meaning the transducer is
completely retracted, press the [POWER] switch on the control unit to turn off
the power.
3. Turn off the monitor.
Note 1:
The transducer is automatically retracted into the tank whenever the
power switch is turned off. However, for safety purposes, make it a habit
to retract the transducer before turning off the power.
Note 2:
The equipment can be set to automatically retract the transducer when
the ship exceeds the operator-set speed. (Speed data required.) The
transducer may be retracted at a different speed than set if the speed
data is different from actual speed. In all cases, reduce the speed below
16 knots and then retract the transducer.
