Wesmar SS590 SERIES, Installation & Operation Manual

Page: 48 / 62

INSTALLATION AND OPERATION
Page III-10
WESMAR
7.0 LOW POWER
This option is related to the POWER control
setting on the front panel.
When the POWER control is set on HI, you have
100% of maximum transmit output power. When
the POWER Control is set on LO, you can choose.
75%, 50% or 25% of maximum transmit power
output selected in menu. This function is very
helpful for adjusting the sonar
to different
fisheries and conditions. A high transmit power
provides the longest scanning ranges possible. A
low transmit power output is useful at short
ranges and/or in shallow water because it
minimizes reflections that clutter the screen
display.
Selected Power Output appears in the lower
right corner of the display, between Speed and
Pulsewidth readouts.
8.0 TVG MILLISECONDS
The TVG Time (Time Variable Gain) is preset at
the factory according to frequency:
Frequency
160kHz
Milliseconds
400
You can raise or lower TVG Time here in Menu
1. As a soundwave travels through water, it loses
strength due
to attenuation. This makes distant
objects seem smaller than they really are. As you
approach them, they appear larger and larger. To
offset the effects of attenuation, the sonar
gradually increases sensitivity relative
to the
amount of time the soundwave travels
to
the
target. This increase in sensitivity is
automatically graduated by the gain circuitry.
However, this graduation (slope) stops
increasing at some time. The point at which
the slope stops can be selected in Menu 1.