Furuno GD-1700, Operator'S Manual

Page: 201 / 249

5. CUSTOMIZING YOUR UNIT
5-31
Sounder system setup menu description (con’t from previous page)
Item Description Settings
TVG
(LF, HF) TVG (Time Varied Gain) compensates for propagation
attenuation of the ultrasonic waves. It does this by equalizing
echo presentation so that fish schools of the same size appear
in the same density in both shallow and deep waters. In
addition, it reduces surface noise. Note that if the TVG level is
set too high short range echoes may not be displayed. 0-9
Echo Offset
(LF, HF) If the on-screen echo level appears to be too weak or too
strong and the level cannot be adjusted satisfactorily with the
gain control, adjust echo offset to compensate for too weak or
too strong echoes. The default setting for both 200 kHz and 50
kHz is zero. -50 - +50
Bottom Level
(LF, HF) If the depth indication is unstable in automatic operation or the
bottom echo cannot be displayed in reddish-brown by
adjusting the gain control in manual operation, you may adjust
the bottom echo level detection circuit, for both 50 kHz and
200 kHz, to stabilize the indication. Note that if the level is set
too low weak echoes may be missed and if set too high the
depth indication will not be displayed. -100 - +100
KP Pulse Selects source of keying pulse. Internal, External
(See installation
manual.)
Smoothing Smoothes echoes to present stable display. The higher the
setting the greater the smoothing. SM1-SM4, OFF
TLL Output Outputs current position to plotter where it is marked with TLL
mark. Use a soft key to output TLL. ON, OFF
STC (HF, LF)
(For ETR-30N
only) Adjusts STC level for the high and low frequencies, and is useful for
suppressing surface noise. The setting range is 0-10; the higher the setting
the greater the extent or suppression. Setting 10 suppresses noise up to
several meters. Turn off the STC when there is no noise on the screen,
otherwise weak echoes may be missed. -10 - +10
FREQ. ADJ. (HF,
LF) (For
ETR-30N only) Interference from other acoustic equipment operating nearby or other
electronic equipment on your boat may show itself on the display. You may
suppress these type of interference by adjusting frequency. Normal, Surface
TARGET ECHO
(For ETR-30N
only) Sets fishing objective. Normal for general fishing, Surface for detecting
surface. Pulse repetition rate is higher than Normal on the specified
transducer. See next section for
details.
SENSOR
SETUP
(soft key) Offsets speed, depth and water temperature indications and
speed of sound. See next section
for details.