Lowrance electronic X-70A 3D manual Menu Surface Clarity, ASP Advanced Signal Processing

For example, press the key next to the "Depth" label two times to switch from feet to meters. This moves the check mark two times from the “Ft” to the “M”.

After setting the units of measure, press the CLR key.

MENU - PAGE 3

SURFACE CLARITY

The markings extending downward from the zero line on the 2D chart when the manual mode is on are called “surface clutter.” These mark- ings are caused by wave ac- tion, boat wakes, temperature inversion, and other natural causes.

The Surface Clarity Control (SCC) reduces or eliminates surface clutter signals from the display. SCC varies the sensitivity of the receiver, de- creasing it near the surface and gradually increasing it as the depth in- creases. The maximum depth that SCC will affect is 75% of the selected depth range. For example, on a 0-60 foot range with maximum SCC, sur- face clutter will be reduced down to about 45 feet.

There are three levels of SCC available on the X-70A 3D: low, medium, and high. When it’s turned on for the first time, the SCC level is low. To change it, press the MENU key three times, then press the key adjacent to the “SCC” label until the check mark is on the desired SCC level. Press the CLR key when you’re finished.

ASP (Advanced Signal Processing)

The ASP feature is a noise rejection system built into the X-70A 3D that constantly evaluates the effects of boat speed, water conditions, and in- terference. This automatic feature gives you the best display possible un- der most conditions.

The ASP feature is an effective tool in combating noise. In sonar terms, noise is any undesired signal. It is caused by electrical and mechanical sources such as bilge pumps, engine ignition systems and wiring, air bubbles passing over the face of the transducer, even vibration from the engine. In all cases, noise can produce unwanted marks on the display.

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