We cannot emphasize this strongly enough. Too much Gain will only clutter the display with unnecessary information, making it more difficult to interpret the return signals. Keeping the Gain at minimum levels will actually provide you with the most accurate and precise information.
Interference Rejection - The Signal Interference Rejection sys- tem is designed to knock out competing return signals from other sonar units being used within close proximity. When other sonar units are causing interference to the display of the LX-3, activate the SIR feature by depressing the IR key located on the face of the LX-3. A red LED light located next to the IR key will come on when the SIR has been activated.
There are six levels of interference rejection that can be used to knock out competing signals. Press the key to activate (red LED is on) and each consecutive actuation (depressing the key) will change the level of signal rejection. Each actuation will result in an audible beep informing you that a system command has been recognized. The correct level of SIR will be achieved when the display is clear of display clutter. In some extreme cases, clutter will be greatly reduced but not totally eliminated.
Zoom - The Zoom function can be activated by depressing the ZM key. An audible beep as well as a red LED will be lit indicat- ing that the Zoom function has been activated. The Zoom func- tion divides the circular display screen in half. The right half of the display, (12 to 6 o’clock on the dial) will become your entire surface-to-bottom display. This will be indicated by a red band of light at the top (zero) and a red band of light at the bottom (or 6 o’clock). If you are on the 20-foot depth Range, the 12 o’clock position will be the surface of the water and 6 o’clock will be the bottom of your chosen Range (20 feet on the 20-foot scale). When utilizing the Zoom function, you will be reading your depth markings by viewing the inner circle (yellow numeric) located in the center of the LX-3 display dial. If you select the 40-foot scale, the same applies, except you multiply the yellow numeric mark- ings by 2. The 80-foot Range setting is a multiple of 4, and the 160-foot Range setting is a multiple of 8.
Once you use the LX-3 a few times, your brain will automatically make the adjustment without any noticeable thought process. The backside of the display (6 o’clock moving clockwise to 12 o’clock) is the other half of your split-screen display. This half reads what you see on the right half, but in a magnified version. The normal view (right half) will show targets that are 2.15 inch- es apart (on the 20-foot depth Range) but the Zoom view (left half) will show targets 1 inch apart. This will greatly enhance the precision of your presentation and show that multiple smaller targets might exist on the left half (Zoom) where it appears that one larger target is showing on the right (normal display). You can determine the size of your Zoom window (the width or amount of water viewed within the water column) by depressing the ZM key. If you depress the key once (turning Zoom ON), the window is 5 feet on the 20- or 40-foot Range setting, if you press the ZM key again the Zoom window is expanded to 10 feet. Depress the Zoom key again and the Zoom feature is turned OFF. The 80-foot range allows you a 10-foot viewing window, or depress Zoom again and it will become a 20-foot Zoom window. The 160-foot range has a 20-foot window, or it becomes 40-foot when ZM is depressed again.
Up & Down Keys - The UP / DN keys are used to move your Zoom window up or down in the water column. When you first depress the DN key, two yellow blinking lights will appear on the LX-3 display. The yellow blinking LEDs will be 5 feet apart between the 1-foot and 6-foot markings on the yellow scale located on the inner circle of the display dial. If you remove your finger from the keypad, the blinking yellow indicator lights will disappear after 2 seconds. If you hold the DN key, the two blink- ing lights will remain on and move down the display (with audible beeping) until you locate them in the area that you desire. To increase the Zoom window to 10 feet, depress the ZM key (audi- ble beep) and then depress the DN key, then the blinking yellow lights will appear 10 feet apart on the inner yellow numeric scale in the center of the LX-3 display decal. You can then locate the Zoom window at the desired viewing depth. Even though your yellow indicator lights are no longer blinking, your Zoom window is still set and in position.
