3-4
Operation
Series XT-50, XT-80, and XT-100 Amplifiers
2
A TWT Temperature fault may be caused by: (1) air intake filter
clogged, (2) cooling fins clogged, (3) fan failure, or (4) fan power
supply failure.
•
High Voltage ON
. Indicates amplifier's high voltage system status. Status
line goes low when high voltage is ON.
•
Fan ON
. Indicates that the amplifier's main cooling fan is on. The main
cooling fan is controlled by the temperature of the TWT. The fan will cycle on
and off in cooler ambient conditions. The fan is typically operated below its
nominal voltage design in order to maximize fan life. Status line goes low
when the fan is on.
•
High Voltage Fault
. Indicates there is a high voltage fault within the amplifier.
Status line goes low when fault occurs. A high voltage fault is typically an
indication of a serious power supply failure.
•
Fan ON High
. Indicates that the TWT has heated up to the point that the fan
must run at its nominal rated voltage. Status line goes low for this condition.
This is not a fault condition. The fan is expected to operate on high during
elevated ambient temperature conditions.
•
Summary Fault
. Indicates there is a fault within the amplifier. Status line
goes low when fault occurs.
•
Fan Lock
. Indicates that the fan is locked. A fan lock signal is caused by either
a fan failure or some object interfering with the rotation of the fan. Status line
goes low when fault occurs.
Status, Analog
•
RF Output Power
. This is an amplifier option. The output power of the
amplifier may be determined by monitoring this voltage and referring to the
chart in Figure 2-7.
•
Helix Current
. The TWT's helix current may be determined by monitoring this
voltage. There is 2 mA of helix current for each
volt measured.
•
High Voltage Monitor
. The high voltage applied to the TWT may be
determined by monitoring this voltage. The high voltage is divided down so
that one volt output equals 1,000 volts.
•
TWT Temperature
. The TWT's collector temperature may be determined by
monitoring this voltage and referring to the chart in Figure 2-8.
Initial Turn-On
The check list below should be followed to ensure proper operation of the amplifier
and to avoid permanent damage to the amplifier.
