Nautel NV3.5, Troubleshooting Manual

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NV5/NV3.5 Troubleshooting Manual Responding to alarms
Issue 3.2 2014-12-10 Page 1-3
Electrostatic protection
The transmitter's assemblies contain semiconductor devices that are susceptible to damage from
electrostatic discharge. The following precautions must be observed when handling an assembly
which contains these devices.
Electrical discharging of personnel
Personnel should be electrically discharged by a suitable grounding system (e.g., anti-static mats,
grounding straps) when removing an assembly from the transmitter, and while handling the assembly
for maintenance procedures.
Handling/Storage
An assembly should be placed in an anti-static bag when it is not installed in a host transmitter, or
when it is not undergoing maintenance. Electronic components should be stored in anti-static
materials.
Tools/Test equipment
Testing and maintenance equipment – including soldering and unsoldering tools – should be suitable
(i.e., grounded tip) for contact with static sensitive semiconductor devices.
Stress current protection
Every precaution should be taken to ensure the static sensitive semiconductor devices are protected
from unnecessary stress current. This is achieved by ensuring that current is not flowing when an
electrical connection is broken, and that voltages are not present on external control/monitoring
circuits when they are connected.
NOTE:
Reduce the RF output level to a minimal value when troubleshooting faults in the power
amplifier stage while the transmitter’s RF output is connected to the antenna system.
CAUTION:
Electrostatic energy is produced when two insulating materials are rubbed
together. A person wearing rubber-soled shoes, walking across a nylon carpet or a
waxed floor, can generate an extremely large electrostatic charge. This effect is
magnified during periods of low humidity. Semiconductor devices such as
integrated circuits, field-effect transistors, thyristors and Schottky diodes may be
damaged by this high voltage unless adequate precautions are taken.