GE MLSH041, Maintenance Manual

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MAINTENANCE
LBI-38438A 5
3 MAINTENANCE
3.1 PREVENTIVE MAINTENANCE
To insure high operating efficiency and to prevent mechanical and electrical failures from
interrupting system operations, routine checks should be made of all mechanical and
electrical parts at regular intervals. Preventive maintenance should include checks
detailed in the following sections.
3.1.1 Connections
Ground connections to the voltage source should be periodically checked for tightness.
Loose or poor connections to the power source will cause excessive voltage drops and
faulty operation. When ground connections are not made directly to the battery, the
connection from the battery to vehicle chassis must be checked for low impedance. A
high impedance may cause excessive voltage drops and alternator noise problems.
3.1.2 Electrical System
Check the voltage regulator and alternator or generator periodically to keep the electrical
system within safe and economical operating limits. Over-voltage is indicated when the
battery loses water rapidly. Usage of 1 or 2 ounces of water per cell per week is
acceptable for batteries in continuous operation. A weak battery will often cause
excessive noise or faulty operation.
3.1.3 Mechanical Inspection
Since mobile units are subject to constant shock and vibration, check for loose plugs,
nuts, screws and parts to make sure that nothing is working loose.
3.1.4 Antenna
The antenna, antenna base and all contacts should be kept clean and free from dirt or
corrosion. If the antenna or its base should become coated or poorly grounded, loss of
radiation and a weak signal will result.
3.1.5 Alignment
The transmitter and receiver meter readings should be checked periodically, and the
alignment “touched up” when necessary. Refer to applicable Alignment Procedure and
Troubleshooting sheet for typical voltage readings.
3.1.6 Frequency Check
Check transmitter frequency and deviation. Normally, these checks are made when the
unit is first put into operation, after the first six months and once a year thereafter.
3.1.7 Disassembly
To gain access to the transmitter, receiver, and the system control/synthesizer boards for
servicing, loosen the four screws securing the cover at the rear of the radio. Then pull the
cover out from under the edge of the front panel and lift the cover off.