Nautel NG1000, Troubleshooting Manual

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NG1000 Troubleshooting Manual Responding to alarms
Issue 0.4 2010-10-12 Page 1-11
TXA (or TXB) Ext
Interlock TRANSMITTER A
TRANSMITTER B This alarm occurs when the external interlock circuit
for the associated transmitter is not closed, inhibiting
the transmitter’s output. Check the interlock
connection between J4-1 and J4-2 on the exciter/
control PWB. If the interlock is intact, check all
external interlock switches. Otherwise, suspect a
problem with the interlock circuitry on the exciter/
control PWB.
TXA (or TXB) External
Mute TRANSMITTER A
TRANSMITTER B This alarm occurs when the external mute input from
the system controller is asserted, inhibiting the
associated transmitter’s output.
TXA (or TXB) Fan
1 - 5 Fail TRANSMITTER A
TRANSMITTER B This alarm occurs when the associated cooling fan’s
tachometer reading is less than 3000 RPM. Typical
fan speed is between 6400 and 7000 RPM.
TXA (or TXB)
Firmware Upgrd TRANSMITTER A
TRANSMITTER B This alarm occurs when an exciter firmware upgrade is
in progress. The associate transmitter cannot produce
RF.
TXA (or TXB) Insuff
Fans On TRANSMITTER A
TRANSMITTER B This alarm occurs when two or more cooling fans fail,
which results in insufficient cooling. The associated
transmitter’s output is inhibited.
TXA (or TXB) Intake
Over Temp TRANSMITTER A
TRANSMITTER B This alarm occurs when the temperature of the intake
air for the associated transmitter exceeds the design
limit for safe operation (55°C or 131°F). The
associated transmitter’s RF output will be inhibited
until the intake air cools to a temperature that is within
design specifications.
TXA (or TXB) IPA
Bias Fail TRANSMITTER A
TRANSMITTER B This alarm occurs when the associated transmitter’s
IPA is unable to reach the desired bias current
(450 mA) for a gate bias voltage range between 2 V
and 3 V during a bias routine.
TXA (or TXB) IPA
Output High TRANSMITTER A
TRANSMITTER B This alarm occurs when the associated transmitter’s
IPA output power is greater than 130% of the set point
level (set point = 150 W; alarm threshold = 195 W. The
alarm clears when the IPA output power decreases to
a level that is less than 110% of the set point.
Alarm (with Prefix) Alarm/Status LED Description and Troubleshooting Action