Furuno 1834C-BB, GD-1920C-BB manual Sounding area and transmission frequency, Marker-zoom display

4. VIDEO SOUNDER OPERATION

HF picture

The higher the frequency of the ultrasonic pulse the better the resolution. Therefore, the high frequency is ideal for detailed observation of fish school.

low frequency

high frequency

Sounding area and transmission frequency

Marker-zoom display

The marker-zoom display expands a selected area of the normal sounder picture to full vertical size of the screen on the left-half window. You may specify the portion to expand by operating the VRM (Variable Range Marker), which you can shift with the ENTER knob. The area between the VRM and zoom marker is expanded. The length of the segment is equal to one division of the depth scale.

Note: The VRM is set independently from other displays in case of multiple displays.

Fish school

		-		0'20"0	-
		-	Fish
		-
	50	-	school		-	VRM
		-		42.0	-
		-			-
		-		50		This part
		-			-	is zoomed.
		-
	60	-			-
		-			-	Zoom marker
		-
		-			-
		-		100	-
80	70	-
		-	HF
					-

MARKER-ZOOM NORMAL

DISPLAYDISPLAY

Marker-zoom display plus normal sounder display

4-3