show up on the display screen. The surface clutter filter will not change,
reduce or eliminate the signals from the bottom, noise or from fish (unless
the fish is located very close to - or in the surface clutter).
Noise Filter
Small bubbles deeper in the water, acoustic noise due to engine vibrations,
“transducer slap” at high boat speeds and other electrical noise can create
real or “ghost” signals that can often be reduced or eliminated altogether
by using the Noise Filter. The higher the setting, the more effective the
filtering is. Warning - too high a setting can affect the returns from fish.
Chart Speed
The rate at which the screen is updated with new information can be
controlled with the Chart Speed setting. The higher the setting, the faster
the data scrolls across the screen. In deep water the maximum chart
speed will be reduced automatically because it takes a minimum amount
of time for the sonar pulse to reach the bottom and return back to the
depth transducer. For example, at a bottom depth of 1000 feet it takes
about 1/2 second for the sonar pulse to travel to the bottom and back up to
the transducer so if you set the depth range at 1000 feet the maximum
chart speed is about two updates per second.
Transmitter Power
The PcFF80 PC Fishfinder contains a dual frequency sonar transmitter
whose output strength can be controlled by software in 256 steps to output
a signal from 0 watts to 2560 watts peak-to-peak (320 watts RMS). In
manual mode the Transmitter Power selection is used to set the transmitter
power. More power allows you to go deeper and see smaller fish better.
Using too much power can cause the depth algorithm to become confused,
however, so be forewarned that the digital number at the bottom left hand
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