Instruction manual

Chapter 12-14 Installation and service
12.6 Basic transducer and cable information
For optimum performance of the Echosounder, the Simrad combi transduc-
ers 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 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 10.1 Echosounder setup for
correct setting for the transducer selected.
The EQXX’s transmitter is designed to match Simrad 1kW 75 ohms high per-
formance transducers described in section 12.6.1 Transducers.
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 trans-
ducer. In the event where the standard cable is not long enough, up to an addi-
tional 10 meters (32 feet) may be connected without a noticeable reduction of
the performance. The cable must be of the same type as the standard cable.
 The EQXX must be turned off while connecting/disconnecting the trans-
ducer 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 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.
! 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.