Northstar
FISH 457/467
Installation and Operation Manual
59
b The transducer may be in turbulent water.
Air bubbles in the water disrupt the echoes
returned, interfering with the 457/467’s ability
to find the bottom or other targets. This often
happens when the boat is reversed. The
transducer must be mounted in a smooth
flow of water in order for the 457/467 to work
at all boat speeds.
c
Electrical noise from the boat’s motor
can interfere with the 457/467. Try some
suppression spark plugs.
3-5 There is a double bottom trace displayed:
a
The boat may be in an area that generates
shadows (see section 3-2).
b In shallow water, the echoes may bounce.
Reduce the gain setting (see section 3-6)
and/or reduce the sonar pulse power (see
section 8-2).
c Decrease
the
Range.
Appendix C - Glossary and navigation data
NavBus
- A way of connecting Northstar instruments together to share data (see section 9-8).
NMEA
- National Marine Electronics Association.
NMEA 0183
- A standard for interfacing marine electronic devices (see section 9-9).
SBN
II
- Signal enhancement Bottom recognition Noise rejection.
SmartCraft
- A feature of Mercury Marine engines for monitoring engine performance.
Glossary