Teleflex TFX128, Operation Manual

Page: 11 / 26

9
In murky or muddy water, it is often helpful to reduce the gain. This
prevents the display from being cluttered with sonar returns from debris
or suspended particles. In very clear or very deep water, it may be helpful
to increase the gain since even the smallest sonar return may be of
interest to the user.
3. Adjust the B
ACKLIGHT
through three settings. With the 128 on, a second
short push of the G
AIN
will turn on the Backlight at full brightness,
another push will set the backlight at its dimmed setting. The third setting
of Backlight OFF is set with another push. The backlight is very effective
for low-light and nighttime operation. When the backlight is on, the
128
will consume more power than with the backlight off. This is important
when using the
128 in a portable configuration powered by a separate
battery, or when powering the unit from a trolling motor battery.
4. G
AIN
can also be used to go directly into S
IMULATOR
mode. To enter
simulator, with the unit powered off, press and hold G
AIN
until multiple
chirps are heard, indicating switching on in the S
IMULATOR
mode. (see page
3 for S
IMULATOR
operation.)
C
ONTROL
P
ANEL
. C
ONTROL
P
ANEL
displays a menu on-screen for adjustment.
In normal operation, pressing the C
ONTROL
P
ANEL
Knob brings up a menu
window with five items, Depth Range, Zoom, Depth Alarm, Chart Speed
and Filter. Turn the C
ONTROL
P
ANEL
Knob counter-clockwise to move down
through the selections, clockwise to move up. The selected menu is
framed with a thicker line and also indicates with an arrow the direction
or directions that the Range
±
knob can be turned to adjust selection
setting. An audible error beep sounds to indicate end of selection range.
USING THE 128 SERIES
CONTROL PANEL