1-2 How the FISH 4432/4433 works

The FISH 4432/4433 has two parts:
- the transducer attached to the hull
- the display unit.
The transducer generates an ultrasoni c pulse
(sound that is above the hearing range of
the human ear), which travels down towards
the bottom at a speed of about 480 0 ft/sec
(1463 m/sec), spreading out into a cone shape.
When the pulse meets an object, su ch as a
fish or the bottom, it is partly ref lected back
up towards the boat as an echo. The depth
of the object or bottom is calculat ed by the
FISH 4432/4433 by measuring the time taken
between sending a pulse and recei ving the
echo. When an echo has been returned , the
next pulse is sent.
The FISH 4432/4433 converts each echo into
an electronic signal, displayed as a ver tical
line of pixels. The most recent echo app ears
on the extreme right of the display, with th e
older echoes being scrolled toward s the left,
eventually disappearing off the display.
The scroll speed depends upon the w ater
depth and scroll speed setting . See section 3-2
Setup > Sonar and section 4-1 Interpreti ng the
display, for more information.
The appearance of echoes displayed a re
affected by:
• the fishfinder settings (f requency selec ted,
range and gain settings)
• echoes (different fish typ es, different
bottom types, wrecks and se aweed)
• noise (water clarity and bubbles).
See section 4-1 Interpreting the displ ay, for
more information.
If a menu is not displayed then go to the sonar
ESC display. If a menu is d isplayed then cancel a ny
changes and return to the p revious menu.
DISP Shows the Display menu.
, Cursor keys move the selection high light and
, change settings.
MENU Press to show the Options m enu on a display; press
agai n to show the Setup menu.
ENT Confirms any changes or from a so nar display shows
the Gain controls.
+ Incre ases the Range.
— Decreases the Range.
AUTO Selec t fishing/cruis ing or manual operati ng mode
Powers On and Off; shows the Ba cklight control.
2 Basic Operation

Key Names

FISH 4432/4433 Installation and Operation Manual7NAVMAN