AR 10037990, Operating And Service Manual, Page: 45 / 54

Rev A 25
4. MAINTENANCE
The TWTA does not require routine scheduled maintenance. The only moving parts are the elements of switches,
relays and blowers. Preventive maintenance is recommended in Section 4.3.
The TWTA is basically a factory repairable unit. However, since limited logic schematics and partial parts
information is supplied in this manual (Section 5) some user service organizations may choose to perform their
own corrective maintenance. Warnings and Cautions should be observed.
4.1 SAFETY WARNING
WARNING:
Service work must be performed only by technicians thoroughly familiar
with the high voltages present in microwave tube amplifiers in general,
and with this equipment in particular.
Never handle the TWT leads or the high-voltage connectors unless it has
been positively established that the high-voltage filter capacitors have
been discharged to a known safe level.
CAUTION:
A malfunctioning power supply can cause damage to the TWT. If you are
troubleshooting the TWTA, remove the TWT and substitute suitable
loads to prevent damage to the TWT.
4.2 UNAUTHORIZED REPAIRS
CAUTION:
Unauthorized repairs or modification of this product during the warranty
period may void the warranty. In the event that the TWTA malfunctions
while it is still under warranty, always contact an authorized service
representative.
4.3 PREVENTIVE MAINTENANCE
The RF characteristics and power supply voltages and currents of the TWTA should be logged on a regular basis.
Maintenance should be performed if significant deviations from the logged values appear. If the unit is under
warranty, contact an authorized service representative if impaired performance is suspected.
If there is accumulated dust on the air intake grill, clean it with dry compressed air.
If significant dust has been noted on the air intake filters, it may be desirable to vacuum the dust and debris from
inside the enclosure. Perform this procedure to only one power supply at a time:
1. Remove the amplifier from the cabinet or rack as follows:
NOTE: Due to the weight of the unit, the removal of some of the amplifier’s units from the cabinet is a
two person operation.