Motorola GM1200E, Руководство по установке

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Noise Sources
2-2 Reducing Noise Interference in Mobile Two-Way Radio Installations
It is impractical to prevent all arcing in the standard vehicle electrical system. In an 8-cylinder engine
running at 2,000 RPM, arcing occurs across the spark plugs at a rate of 8,000 sparks per minute or
133 sparks per second. Electrical motors and generators also produce arcs.
Figure 2-1 Noise Sources.
2.2 Conducted Noise
Conducted noise enters the radio through the points where the radio is attached to the vehicle’s
electrical system such as battery cables, ignition switch, chassis ground etc. It can be generated by
electrical transients, electrical motors, poor grounding points, or inadequate electrical system
filtering (from alternators, generators, voltage regulators, or weak batteries). Conducted noise can
degrade both transmit and receive performance of a mobile radio.
2.3 Induced Noise
Induced noise enters the radio through the proximity of radio wiring to other wiring in the vehicle.
Electrical currents through the standard vehicular wiring can induce undesirable noise signals into
the radio cabling (and degrade communication) simply because the wiring provides a transformer-
type coupling action without any actual physical connection. Induced noise can degrade both
transmit and receive performance of a mobile radio.
Idle Stop Solenoid
Spark Plugs
Spark Plug Wires
Ignition Coil
Distributor
Voltage
Alternator or
Generator
Regulator
Wheel Static
Power Seat Motor
Hood Static
Electric Window Motors
Heater Air Conditioner Blower
Windshield
Wiper Motor
Inadequate Terminal
or Fuse Block Filtering
Electric Fuel Pump
Antenna Ground
or Location
Radiated Noise Pick-up