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6.4.2
Checking A3 LEDs and Display
At least once a month, run the CHPA's built-in test to verify proper operation of all indicators.
To run this test, press the Menu key repeatedly until LAMP TEST appears in the display. Press
Enter.
6.4.3
Collector Air System Maintenance
The TWT collector airflow system must be checked to ensure that it is properly transferring the
heat into the airstream and away from the TWT. This means that the measurement of air flow
and temperature and the inspection and elimination of any contaminants restricting the air flow
must be performed periodically. The recommended cycle is three months, but inspection may
be required more often if local air pollution warrants it.
Follow these steps to verify the cooling:
1. Put the CHPA in Standby and allow the TWT to cool before switching off the front panel
circuit breaker. Switch off the main breaker. The control panel display should be dark.
2. Inspect the exhaust screen and collector radiator for blockage with a flashlight. All collector
radiator fins should be free of material. If not, remove the TWT and the cover on the
collector to blow out the material. Clean the air exhaust screen as required.
3. If the radiator is clean, power up the amplifier.
4. Put the amplifier in Transmit and check the collector air temperature rise by measuring the
intake air temperature and the exhaust air temperature. After 5 minutes of operation, the
exhaust air temperature rise should be no more than 65
and Troubleshooting" chapter of the CHPA Service Manual.
6.4.4
Checking B1 Collector Blower
The collector blower is a rotating component subject to wear. Inspect it every six months.
Follow these steps to check operation of the collector blower:
1. With the CHPA in Standby state, open the top cover.
2. Listen for whining, rattling, or other unusual noises from the collector blower that might
indicate worn bearings or other malfunctions. If a mechanical stethoscope is available, listen
for motor-bearing rumble. If such noises are present, replace the blower.
6.4.5
Miscellaneous Cleaning
You must perform the following cleaning procedures on the HPA every three months or more
frequently in unusually dirty environments.
•
Clean all transformers, inductors, and coils, using a small vacuum cleaner, a compressed-air
blower at low pressure, or a lint-free cloth.
•
Clean the front panel using a dry, clean cloth or a soft-bristled brush.
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ERIES
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