Installation manual

Parameters
159
850-164186 / Rev.D
TVG (Time Variable Gain)
The TVG button is located in the Horizontal, Vertical,
Echosounder and Trawl menus.
The TVG controls the gain in the signal amplifier. The gain is
weakest just after the ping, and increases in accordance with
time (and therefore range).
The TVG reaches the maximum gain at approximately 1500
meters. In addition to Off, the TVG can be selected with five
different curve slopes, each having different gain regulations.
The 20 log R line in the menu is marked with an asterisk to
indicate the theoretically correct setting.
With this setting, the gain is adjusted in such way that a school
of fish with a certain size and density will be presented with
approximately the same strength on the screen in any position
inside the regulated TVG range.