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6-1
6
Chapter 6
Preventative Maintenance
6.1 Overview
This chapter provides instructions for routine maintenance and performance testing of the
compact high power Traveling Wave Tube Amplifier. It covers procedures and test equipment
for scheduled maintenance tasks, electrical calibration, and performance testing. It also explains
how to diagnose and repair common problems to the circuit-card assembly level (PCB).
Note: Improper maintenance of the CHPA may void the warranty. For
details, see Appendix A, “Warranty and Support Information.”
WARNING! ANY PERSON PERFORMING EQUIPMENT MAINTENANCE
MUST HAVE TRAINING AND KNOWLEDGE OF BOTH THE PRODUCT AND
RELATED SAFETY HAZARDS. READ AND PRACTICE THE SAFETY
GUIDELINES IN THE SAFETY SECTION AT THE FRONT OF THIS MANUAL.
WARNING! SOME CASES MAY REQUIRE WORK ON THE EQUIPMENT
WITH EXPOSED LIVE VOLTAGES EXCEEDING 50V. ACCESS TO THE
CIRCUITRY WITH LIVE VOLTAGES EXCEEDING 50V IS RESTRICTED TO
AUTHORIZED PERSONNEL. AUTHORIZED PERSONNEL ARE BOTH
SKILLED AND KNOWLEDGEABLE IN RF AMPLIFIERS AND HIGH-VOLTAGE
EQUIPMENT. ANYONE EXPOSED TO LIVE VOLTAGES MUST BE
OBSERVED BY AT LEAST ONE OTHER PERSON WHOM IS ABLE TO
SWITCH OFF EQUIPMENT WITHOUT DELAY. THE OBSERVER SHALL BE
TRAINED IN FIRST AID CPR AND HAVE IMMEDIATE ACCESS TO THE
“EMERGENCY OFF” BUTTON. ALWAYS WORK SAFELY!
6.2 Scheduled Preventive Maintenance
To function safely and effectively, the CHPA requires periodic maintenance. This consists of
inspecting, cleaning, testing, and calibrating the HPA’s subsystems at one- to six-month
intervals. In addition, a daily log should be kept of all the CHPA meter readings, including
heater and beam hours of operation and any other trends. This can be helpful in identifying
emerging or continuing problems.
