Menu description
97
850--164186 A
TVG (Time Variable Gain)
The TVG button is located in the following index menus:
• Horizontal
• Ve rt ical
• Echosounder
• Second Ping
• Trawl
Figure 80 -
TVG submenu
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.