Furuno CI-88 Installation Manual page 8

1. INSTALATION OVERVIEW
b) Mount the transducer at a location between one-third and one-half of the ship's full
length (measuring from the bow). Select a place where the transducer is free from the
effects of air bubbles. The transducer face should not be above the sea surface when
the ship is pitching or rolling.
c) In general, the air bubbles produced at the bow flow backward alongside the keel.
Therefore, separate the transducer by more than 1000 mm from the keel, or flush mount
the transducer inside the keel.
d) The surface of the transducer should project by 250 mm or more from the hull bottom.
For better performance, its surface should be even with the keel's lowest point or below
it.
e) The following is important for preventing interference between the CI-88 and other
equipment.
If the transducer of an echo sounder or scanning sonar whose harmonic is within the
frequency range of 236 kHz to 252 kHz (244 ±8 kHz) is mounted, interference may
occur. Even if the harmonic is out of the range, the risk of interference still exists if the
transducer of the CI-88 and other equipment are mounted near one another. For this
reason, separate the transducer of the CI-88 as far as practical from other equipment
which have high output power. If interference is unavoidable due to limited mounting
space, connect the interfering equipment to the built-in interference rejection circuit (two
inputs) in the transceiver unit. For connection to this circuit, you will need to run a
two-core cable between it and the interfering equipment.
f) Make the transducer cable as short as possible. The cable is generally installed in
grounded steel conduit run between the transducer and the junction box, to prevent
pick-up of noise. The transducer with the 20 m transducer cable can be used only when
it is passed inside conduit.
Do not transport the transducer by pulling the cable.
The internal wiring may be cut.
1-2
NOTE