Lowrance electronic X515C DF Benutzerhandbuch

4 

The transmitter emits an electrical impulse, which the transducer con-

verts into a sound wave and sends into the water. (The sound frequency 

can't be heard by humans or fish.) The sound wave strikes an object 

(fish, structure, bottom) and bounces back to the transducer, which 

converts the sound back into an electrical signal. 

The receiver amplifies this return signal, or echo, and sends it to the 

display, where an image of the object appears on the scrolling sonar 

chart. The sonar's microprocessor calculates the time lapse between the 

transmitted signal and echo return to determine the distance to the 

object. The whole process repeats itself several times each second. 

Many instructions are listed as numbered steps. The keypad and arrow 

"keystrokes" appear as boldface type. So, if you're in a real hurry (or 

just need a reminder), you can skim the instructions and pick out what 

menu command to use by finding the boldface command text. The fol-

lowing paragraphs explain how to interpret the text formatting for 

those commands and other instructions: 

Arrow Keys 
The arrow keys control a horizontal line depth cursor on the sonar 

screen. The arrow keys also help you move around the menus so you 

can execute different commands. They are represented by symbols like 

these, which denote the down arrow key, the up arrow, the left arrow 
and the right arrow: 

↓ ↑ ← →. 

Keyboard 
The other keys perform a variety of functions. When the text refers to a 

key to press, the key is shown  in bold, sans serif type. For example, the 

"Enter/Icons" key is shown as 

and the "Menu" key is shown as 

. 

Menu Commands 
A menu command or a menu option will appear in small capital letters, 

in a bold sans serif type like this: 

. These indicate that you 

are to select this command or option from a menu or take an action of 

some kind with the menu item. Text that you may need to enter or file 
names you need to select are show in italic type, such as data type. 
Instructions = Menu Sequences 
Most functions you perform with the sonar unit are described as a se-

quence of key strokes and selecting menu commands. We've written 

them in a condensed manner for quick and easy reading.