Furuno MFD12 - System-ETR-6;10 N Menu

13. How to Adjust Settings
13-19
echo in the bottom lock display, lower the bottom level to erase the vertical lines. If you
can not identify the fish near the bottom from the bottom echo, increase the bottom
level. For the DFF1, set both of these items to “-20”.
External KP: Turn on to sync with external keying pulse.
Stc HF (LF): Delete unnecessary echoes (plankton, air bubbles, etc.) near the surface
that hide the fish near the surface. The setting range is 0-10, and 0 is Off. “10” deletes
unnecessary echoes from the surface to approximately 16 ft. Make sure you do not
use more STC than necessary, because you can erase the small echoes near the sur-
face.
Frequency Adjust HF (LF): You can adjust the TX frequency of both the low- and
high-frequency transducers. Use this feature when your fish finder and another fish
finder operate on the same frequency, causing interference. Change the frequency of
your transducer by enough percentage points to remove the interference.
TX Pulse HF (LF): The pulse length is automatically set according to range and shift,
however it can also be adjusted manually. Use a short pulse for better resolution and
a long pulse when detection range is important. To improve resolution on zoom dis-
plays, use “Short 1” or “Short 2”. Short 1 improves the detection resolution, but the de-
tection range is shorter than with “Std” (pulse length is 1/4 of Std). Short 2 raises the
detection resolution, however detection range is shorter (pulse length is about 1/2 of
Std) than Std. Std is the standard pulse length, and is suitable for general use. “Long”
Increases the detection range but lowers the resolution (about 1/2 compared to the
Std pulse length). “Manual” enables manual setting of pulse length.
Manual Pulse Length HF (LF): This item is effective when TX Pulse is set for Manual.
The pulse length may be set between 0.05 msec and 5.0 msec. A short pulse length
gives better resolution, but decreases the detection range. A long pulse increases the
detection range, but lowers the resolution.
Rx Band HF (LF): The Rx bandwidth is automatically set according to pulse length.
To decrease noise, select “Narrow”. For better resolution, select “Wide”.
13.5.5 System-ETR-6/10N Menu
External KP: Turn on to sync with external keying pulse.
For [Transmission], [Gain Adjust] and [Bottom Level], see the descriptions in section
13.5.4.