Chapter 3: Using the Sounder Module 31
3. Use the rotary knob to adjust the value in the slider. This value takes immedi-
ate effect:
• GAIN MODE. This should be set high enough to see fish and bottom detail
but without too much background noise. Generally, a high gain is used in
deep and/or clear water; a low gain in shallow and/or murky water.
• COLOR GAIN. This sets the lower limit for the strongest echo color. All ech-
oes with a signal strength above this value are displayed in the strongest
color. Those with a weaker value are divided equally between the remain-
ing colors. Setting a low value produces a wide band for the weakest color,
but a small signal band for the other colors. Setting a high value gives a
wide band for the strongest color, but a small signal band for the other
colors.
• TVG. A low TVG value has little effect on gain in shallow water. A high
value decreases the gain in shallow water so that only the strongest ech-
oes are displayed.
4. Press CANCEL or ENTER twice to return to the default display.
Operating Frequency
The DSM provides four frequency modes:
•
AUTO mode. The system automatically selects the appropriate frequency
according to your depth. As the depth increases the DSM changes the fre-
quency from 200 kHz to 50 kHz and as the depth decreases it switches from
50 kHz to 200 kHz. This mode is useful for automatically searching for the bot-
tom. This is the default setting.
•
50 kHz only. The DSM25 scans a wide area and penetrates water well, so is
good for use in deep water.
•
200 kHz only. The DSM scans a narrower area, but produces a more detailed
view so is good for finding fish that are near the bottom or close together. It is
better for use in shallow water.
•
BOTH frequencies. This setting displays separate screens for both 50 and
200kHz. The scrolling bottom display is split vertically; the left half shows the
200 kHz detailed view and the right half shows the 50 kHz image.
To change the current frequency setting to AUTO mode:
1. Press FISHFINDER SETTINGS. A new set of soft keys appear.
2. Press FREQUENCY until AUTO is highlighted. The SELECTED FREQ soft key is
grayed out.
3. Press CANCEL or ENTER to return to the default display.
81254.book Page 31 Monday, March 6, 2006 2:29 PM
To Next Page
Loading...
