3-38
SHIPBOARD COMMUNICATIONS SYSTEMS QUALITY MONITORING (QMCS)
In recent years the volume of shipboard communications has increased greatly. This expansion has
led to the shipboard installation of sophisticated equipment. Factors such as frequency accuracy and dc
signal distortion are critical to the operation of communications systems. These systems demand precise
initial lineup and monitoring to ensure satisfactory operations are maintained. System degradation is often
caused by many small contributing factors. When these factors are added together, the system becomes
unusable.
Scheduled Maintenance
When you perform scheduled, logical checks that ensure continuous, optimum performance of
shipboard communications systems, you are doing SCHEDULED MAINTENANCE. In many cases this
maintenance prevents outages before they occur. Some of the scheduled checks will include the
following:
Transmitter/receiver frequency
Transmitter power out
Receiver sensitivity/bandwidth
Primary power (voltage, current, cycles)
Electromagnetic Interference (emi)
Many complex electronic systems are installed aboard Navy ships. In modern ships, complex
systems with higher power and greater sensitivity are being crowded into a restricted and corrosive area.
Figure 3-34 is a Spruance class destroyer with its crowded (compact) communications environment. The
ability of these systems to perform their individual functions without interference is known as
ELECTROMAGNETIC COMPATIBILITY (emc). Emc is concerned with the structure of the ship and
its electrical and electronic system. Compact environment is a major limitation to the effectiveness of a
total ship system concept.
Figure 3-34.—Total ship.
