Basic Transducer And Cable Information - Simrad EQ42 Manual

EQ42/50/52 Installation and service Chapter 9

9.7 Basic transducer and cable information

For optimum performance of the EQXX Echosounder, the Simrad combi
transducers C38/200 and C50/200 are recommended. These transducers also
include a water temperature sensor. A variety of alternative medium-range
transducers is available for vessels mainly operating in shallow waters and/or
where the size of the transducer is critical.
The installation should be carefully planned in advance, keeping in mind the
standard cable length of 10 meters (32 feet) which is connected to the transducer.
In the event where the standard cable is not long enough, up to an additional 10
meters (32 feet) may be connected without affecting the performance of the
system. The cable must be of the same type as the standard cable.
The EQXX must be turned off while connecting/disconnecting the transducer
cable.
The use of longer cable runs, while possible, always increases the likelihood of
increased interference and decreased performance. Care must be taken when
increasing the cable lengths to ensure that proper, adequate and consistent
shielding is maintained, that cable of adequate cross section is used, and that all
connections are properly made and protected from the effects of the marine
environment.
If possible, running the transducer cable through a grounded conduit will greatly
decrease the likelihood of interference. Likewise, the EQXX transducer cable
should be run as far as possible from other electrical cabling. If it is absolutely
necessary to pass close to other cabling, it is best to keep as much distance as
possible, and to make all crossings as close to a right angle as possible.
The 1kW output signal from the echosounder is automatically reduced due to the
difference of impedance in the transmitter, which is 75 ohms, and the transducer,
which is 185 to 425 ohms. See section 5.7 Echosounder setup for correct setting
for the transducer selected.
The EQXX's transmitter is designed to match Simrad 1kW 75 ohms high
performance transducers described in section 9.7.1 Transducers.
! Warning!
Transducers containing speed log sensor e.g. Airmar B744V must never be
connected to the port "ECHO2". To avoid accidental connection, "ECHO2" is
sealed with a small silicone plug, which of course is removable so e.g. a combi
transducer can be connected.
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