Raymarine L750, Руководство по эксплуатации

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L750 Fishfinder: Installation and Operation Handbook
50
display. This is a “real time” display, so you can see the fish images
moving as the fish swim under the boat.
Bottom coverage
This shows the diameter of the beam of sound waves where it
meets the bottom. This dimension will be shown using the same
units as the rest of the display – feet (FT), fathoms (FA), or meters
(M). If the unit is set at 200kHz single frequency, the bottom
coverage display will reflect the narrow (16°) beam of the 200kHz
frequency setting. All other frequency selections (200kHz dual,
50kHz dual, and 50kHz single) use the wider (65°) beam for the
bottom coverage display.
You can use the A-Scope feature to modify the Downlook and Window
displays.
Other Control Buttons
The unit includes a number of other control buttons which we have not
detailed yet. Each of these is dedicated to one particular function.
Display
You can use the Display button to call up the three main “pages” or
displays. Figure 3-2 showed the Soft Keys which appear when you
press Display. We explained the choices earlier in this manual:
Downlook page Standard display Page 33
Window page Standard display with digital info. Page 40
Digital page Digital info. only Page 41
Note – If the optional Sidelooker feature is turned on, a fourth Soft Key
will allow you to choose the Sidelooker page.
Gain/ Sensitivity
The “Gain” or “Sensitivity” setting controls the ability of the unit to tell the
difference between echoes of different strengths. In general, the
sensitivity should be as high as possible, to detect the fish and show the
detail on the bottom. However, if the sensitivity is too high, the unit will
begin to see bubbles in the water, debris, and other “background noise.”
Use a higher sensitivity setting for deeper water, and a lower setting for
shallower water.