Finding The Cause Of Noise; Specifications - Humminbird 383c Operation Manual

531450-1_A - 383c_Eng.qxd 11/18/2005

Finding the Cause of Noise

Electrical noise usually affects the display with many black dots at high speeds, and high
sensitivity readings. One or more of the following sources can cause noise or
interference:
Possible Source of Noise Isolation
Other electronic devices Turn off any nearby electronic devices to see if the
problem goes away, then turn them on one at a
time to see if the noise re-appears.
The boat's engine
To determine whether the boat's engine is the
source of the noise, increase the RPMs while the
boat is in neutral and stationary to see if the noise
increases proportionately; if noise appears when
you rev the engine, the problem could be the spark
plugs, alternator, or tachometer wiring. Replace the
spark plugs with resistor plugs, install an alternator
filter, or route the control head power and
transducer cables away from the engine wiring.
Cavitation from the boat's Turbulence created by the propeller can cause
propeller noise; make sure the transducer is mounted at least
15" (38 cm) from the propeller, and that the water
flows smoothly over the face of the transducer at all
times.
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Specifications

Depth Capability.......................................................................................... 1000 ft (330 m)
Power Output ........................................ 300 Watts (RMS), 2400 Watts (Peak to Peak)
Operating Frequency........................................ 200 kHz and 83 kHz DualBeam PLUS
Area of Coverage ............................................................................ 60° @ -10 dB in 83 kHz
Target Separation .......................................................................... 2 1/2 Inches (63.5 mm)
Power Requirement.............................................................................................. 10-20 VDC
LCD .................................................................................................................... 320 V x 240 H
Transducer.............................................................................................................. XHS-9-20-T
Transducer Cable Length .................................................................................... 20 ft (6 m)
Current Draw ......................................................................................................0.433 Amps
NOTE: Humminbird® verifies maximum stated depth in saltwater conditions, but actual
depth performance may vary due to transducer installation, water type, thermal layers,
bottom composition and slope.
NOTE: Product specifications and features are subject to change without notice.
90
TM
20° @ -10 dB in 200 kHz