8-47F: Equipment Faults 4 Flashcards
Installation, Maintenance, and Repair (2 cards)
8-47F2
Targets displayed on the RADAR display are not on the same bearing as their visual bearing. What should you first suspect?
A. A bad reed relay in the antenna pedestal.
B. A sweep length misadjustment.
C. One phase of the yoke assembly is open.
D. Incorrect antenna position information.
ANSWER D
Descrepancies between antenna and display position are usually the result of either the antenna or the display device becoming loose in its mouting and rotation. In the case of a geared synchro system with large descrepancies, the synchro microswitch in the antenna or display should be checked.
8-47F3
Loss of distant targets during and immediately after wet weather indicates:
A. A leak in waveguide or rotary joint.
B. High atmospheric absorption.
C. Dirt or soot on the rotary joint.
D. High humidity in the transmitter causing power supply loading.
ANSWER A
Moisture can accumulate and leak into the rotary waveguide joint feeding the antenna. Moisture inside a waveguide can severely attenuate the RADAR signals.
