Navman FISH 4500/4600 User Manual

To show the Sonar 50/200 display, press DISP  
and select Sonar Tab, select Sonar 50/200 
and press ENT.

This shows a split display, with the 50 kHz sonar 
history on the left side and the 200 kHz sonar 
history on the right side. Gain settings can be 
set independently for each frequency. Range 
settings  apply to both sections of the display.
To change items, press MENU until the Op-

tions

 menu is shown. Gain is explained in 

section 4-4 Gain. 

Range

 is explained in section 4-5 Range.

A-scope

 is explained in section 5-5 Sonar A-

Scope display.

Data header

 is explained in section 5-1 Sonar 

display.

Split ratio

 is explained in section 5-2 Sonar 

Zoom display.

To show the Sonar Bottom display, press DISP  
and select Sonar Tab, select Sonar Bottom 
and press ENT.

This shows a split display, with the sonar history 
on the right side and the zoom section on the 
left. The bottom signal is shown as a flat trace 
in the centre of the zoom section.

Showing the bottom as a flat trace can make it 
easy to compare the echo strengths shown in the 
bottom signals. This can help to identify the type 
of bottom and objects close to the bottom. 
The zoom bar can only indicate the zoom range. 
It cannot indicate the zoom offset as this changes 
for each sounding displayed on the display. 

The zoom bar is fixed in the middle of the 
display.

See section 4-5 Range, for information about 
adjusting the Zoom Range and Zoom Offset.

To change items, press MENU until the Options 
menu is shown.

Gain

 is explained in section 4-4 Gain. 

Range

 is explained in section 4-5 Range.

A-scope

 is explained in section 5-5 Sonar 

A-Scope display.
Data header

 is explained in section 5-1 

Sonar display.
Bottom lock

 and Split ratio are explained 

in section 5-2 Sonar Zoom display. 

See section 4-4 Gain, for more information.
The strength of an echo at a particular depth 
is shown by the length of the horizontal line at 
that depth. A strong echo produces a long line 
whereas a weak echo produces a short line.
To change items, press MENU until the Options 
menu is shown. 
Gain

 is explained in section 4-4 Gain. 

Range

 is explained in section 4-5 Range.

Data header

 is explained in section 5-1 

Sonar display.
Split ratio

 is explained in section 5-2 Sonar 

Zoom display.

The echo strengths shown on the A-scope can 
be useful in recognising the type of fish. Different 
species of fish have different sizes and shapes 
of swim bladders. The air in the swim bladder 
reflects the ultrasonic pulse, so the strength of 
the echo varies between fish species according 
to the size and shape of the swim bladder. 

The user can define the level of the weakest and 
strongest echoes to be shown on the sonar dis-
plays, by using the Gain and Threshold settings. 

Divider line 
between sonar 
history and 
A-scope

Gain setting 
(strongest echo 
for display)

Gain threshold 
(weakest echo 
for display)

To show the Sonar A-Scope display, press DISP  
and select Sonar Tab, select Sonar A-Scope 
and press ENT.

Use this to analyse the sonar data in detail and 
optimize the Gain settings.

FISH 4500/4600 Installation and Operation Manual

24

NAVMAN