Thales 421, Operation And Maintenance, Page: 105 / 256

LLZ 421
Operation and Maintenance Alignment Procedure LLZ−1F (Dip./Refl.)
ILS 420
4−15
Ed. 01.10 SOAC
4.4.4 Calibration and Normalization of Standby Monitors
NOTE: Before performing this procedure it is recommended to check alarm limits acc. 4.4.5.
a) Switch TX2 on.
4.4.4.1 COURSE POSITION STANDBY Monitor
a) RF−level of the corresponding path on the SOAC (Fig. 4−2, 4−3) is set to amplitude of 3.6 Vpp
as described in 4.4.2.
b) Open dialog ’Monitor1−Nominal Values’ and open dialog ’Monitor2−Nominal Values’. Enter the
values for ’Stby CRS Position DDM’ and ’Stby CRS Position SDM’.
c) Open dialog ’Transmitter2−Waveform Data#1’. Note down the value of ’CRS SBO Amplitude’ of
Standby TX (TX2). Set it to 0.
d) Send to Monitor1/2 the command ’Calibration, Standby CRS Position Detector’.
e) Restore TX2 SBO setting of 4.4.4.1 c) back to normal.
f) Send to Monitor1/2 the command ’Normalization, Standby CRS Position Detector’.
4.4.4.2 COURSE WIDTH STANDBY Monitor
a) RF−level of the corresponding path on the SOAC (Fig. 4−2, 4−3) is set to amplitude of 3.6 Vpp
as described in 4.4.2.
b) Open dialog ’Monitor1−Nominal Values’ and open dialog ’Monitor2−Nominal Values’. Enter the
value for ’Stby CRS WIDTH DDM’.
c) Open dialog ’Transmitter2−Waveform Data#1’. Note down the value of ’CRS SBO Amplitude’ of
Standby TX (TX2). Set it to 0.
d) Send to Monitor1/2 the command ’Calibration, Standby CRS Width detector’.
e) Restore TX2 SBO setting of 4.4.4.2 c) back to normal.
f) Send to Monitor1/2 the command ’Normalization, Standby CRS Width detector’.
g) Set ’Ident keying’ of both transmitters to ’keyed’ again.
NOTE: If it is not set, the monitor indicates green, but the TX may perform a shutdown after about 10 s.