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SECTION 7.0
MAINTENANCE AND SERVICING
7.1 PERIODIC MAINTENANCE
The only periodic maintenance required on the TWT amplifier system is insuring that the cooling
vents are not obstructed in such a manner that the airflow is restricted. Periodic cleaning of the vents
may be required depending on the degree of dust in the atmosphere.
7.2. SERVICING THE AMPLIFIER
Servicing of the amplifier by the operator is not recommended. Most of the internal circuitry requires
special and unique test instruments to trouble shoot, align and calibrate the circuits. Should servicing
be required, refer to Paragraph 7.3.
7.2.1
TROUBLESHOOTING
PROBLEM
CAUSE
SOLUTION
COMMENTS
TOUCHSCREEN display
blank
No service voltages
Check line power.
Check service voltages,
+12VDC, -12VDC, 5VDC
Connect AC line to
specified Prime power
source.
Refer to S/N tag on unit
Amp will not go to Operate
mode
Door interlock open,
High VSWR
Check that door interlock BNC
connector is terminated with
either 50 Ohms or short.
Check RF output termination
connection.
When operating any RF
amplifier proper
termination must be
connected to the RF output
connector.
Helix supply fault after
warm-up time
Helix Power supply faulty
Check Helix voltage output
without TWT connected
Check on the
TOUCHSCREEN display
for the fault description.
Danger High Voltages
Helix Supply fault when
turning amplifier to OPRT
mode.
HV arcing (Overcurrent
fault).
TWT gassy
Disconnect TWT and operate
amplifier. Check for arcing if
fault consist.
Degas TWT by leaving Amp in
STBY mode for few hours.
TWTA must be turned ON
at least once a month, so to
eliminate TWT gassing up.
Collector supply fault
Collector supply faulty
Check Collector voltage output
without TWT connected
Check on the
TOUCHSCREEN display
for the fault description.
Danger High Voltages
Air Flow fault
No sufficient Air-inlet
Move any obstructions from air
inlet sections
Thermal fault
Over-heating
Make sure airflow is adequate
and ambient temperature within
the limit.
