Advanced Marine Electrics and Electronics Troubleshooting A Manual for Boatowners and Marine Technicians

have gone mainstream on recreational boats
over the last decade. The need (or perhaps per-
ceivedneed) of boatowners to stay connected
in one way or another has driven this change.
As a result, boatowners today have a variety of
choices in satcom systems. The capabilities of
most of the common two-way satcom systems
are shown in Table 14-2 on page 146.

Satcom Installation

Most of the usual installation considerations
apply to satellite systems:

• Maintain the usual 3% maximum voltage
  drop to ensure peak performance, espe-
  cially since communications systems play
  such an important role in vessel safety.


• Use appropriately sized wire. Current
  draw is fairly low, ranging from about
  2.5 amps to about 5 amps, so wiring is
  not as much of a concern as with, for
  example, an SSB.


• Do not alter the length of the antenna
  cable (as with almost all coaxial cable
  installations) or you may seriously
  degrade performance.

Satellite domes are showing up on a lot of boats lately, due to our desire to stay connected.

phone handset

and cradle

single coax

cable design

DOMEANTENNA

transceiver

fax

auxiliary phone

ground out

data

A typical satellite-based telephone/data system using the Inmarsat

Mini-M satellite system.

installing communicationsand position-finding systems 145