OPERATING MANUAL
C-20
21833-3.4
NORMARC 7013
INSTRUMENT LANDING SYSTEM
Maintenance Procedures ©1999 Navia Aviation AS
6. Attenuate upper antenna alarm.
(a) Insert the capture-effect test kit attenuator into the upper antenna feedline. This attenua-
tor should have been previously checked with a vector voltmeter to ensure that the total inser-
tion phase delay equals 360° ±5°. Also, the accuracy of the dial calibration of the attenuator
should be verified. Refer to paragraph 5-155 for this procedure.
(b) Adjust the test attenuator until the path monitor alarms. (c) Record the attenuation value
in the upper antenna attenuation column on Navia Aviation Form “CEGS Monitor Reference
Data”. Confirm that the attenuation is less than, or equal to, the established reference value.
If not within tolerance, corrective action is required.
(d) Remove the test attenuator from the upper antenna feedline.
7. Attenuate middle antenna alarm.
(a) Insert the capture-effect test kit attenuator into the middle antenna feedline.
(b) Adjust the test attenuator until the width monitor alarms.
(c) Record the attenuation value in the middle antenna attenuation column on Navia Aviation
Form “CEGS Monitor Reference Data”. Confirm that the attenuation is less than, or equal to,
the established reference value. If not within tolerance, corrective action is required.
(d) Remove the test attenuator from the middle antenna feedline.
8. Modulation level alarms.
(a) Reduce the carrier power until the monitor is in rf low-level alarm. This is accomplished
from the PMDT: Open the TX Adjustments window. Select COURSE RF Power (for active
transmitter to antenna). Note the 3-digits value.
(b) Then reduce the value of the 3-digits number followed by Update until the monitor chan-
nel CL is in alarm. Measure and record the COU CSB dc voltage at the transmitter test con-
nector.
(c) Measure the carrier power using the BIRD wattmeter connecting to the course CSB feed-
line inside the facility.
(d) Restore the carrier rf power to normal (original 3-digit value).Measure and record the car-
rier power still connecting the BIRD wattmeter to the course CSB feedline inside the facility.
(e) Determine if the carrier power reduction corresponding to alarm is within the operating
tolerance in chapter 3.
(f) Remove the wattmeter from the carrier feedline.
9. Rf level alarms.
(a) Reduce the carrier power until the monitor is in rf low-level alarm. This is accomplished
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