Comtech EF Data XTRT-400C Operation And Installation Manual page 83

TWT Over-temperature – During operation the TWT achieves a temperature unsafe for
continued operation. The over-temperature fault will turn off high voltage which will
consequentially allow the TWT to cool. When the TWT has cooled to a safe operating
temperature the high voltage will be restored.
Note: An over-temperature fault should be cause for immediate maintenance action as it may indicate
fan failure or blocked air passage(s).
RF related faults are generated in the RF chain. These faults are designed to protect the TWT and the
rest of the RF chain from damage.
VSWR Fault – When the amplifier senses excessive reflected RF. Check waveguide
tightness and input VSWR of the RF load on the amplifier.
W/G Arc Fault – When an internal detector senses an arc in the waveguide. This fault
will inhibit the RF then turn off the high voltage to the TWT. In most cases this fault will
require service as waveguide arcs will usually tend to deposit carbon traces on the
internal surfaces of the waveguide.
WARNING - Resetting these faults excessively could cause damage to the TWT.
Overdrive Fault – When the amplifier senses a RF overdrive condition.
This fault is only present in amplifiers with peak power TWT's.
Up-converter Fault – This fault occurs when an integrated up-converter looses lock
signal. This is usually an indication of a loss of the reference oscillator signal. Some
Xicom XTRT series amplifiers have integrated 10 MHz oscillators while others are
configured to use an external source. If an external oscillator is required check integrity
of the signal at the input of the amplifier.
This fault is only present in amplifiers with integrated up-converters.
Interlock faults are generated by a contact closure (or lack thereof) in internal or external circuitry.
Cover Interlock Fault – Indicates an internal cover switch is open.
External Interlock Fault – Indicates the external interlock pins 11-13 connection on the
auxiliary interface connector on the rear panel is open.
MNC-0400-071
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Operation
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