Thales 421 - Calibration and Normalization of Standby Monitors

LLZ 421
Operation and Maintenance Alignment Procedure LLZ−1F (LPD)
ILS 420
7−15Ed. 07.08
SOAC
d) Open dialog ’Transmitter1−Waveform Data#1’. Note down the values of ’CRS SBO Amplitude’.
Set it to 0.
e) Send to Monitor1/2 the command ’Calibration, Executive Nearfield Pos. detector’ (or ’Executive
Ch. 4 Width detector’).
f) Restore TX1 SBO settings of 7.4.3.3 d) back to normal.
g) Send to Monitor1/2 the command ’Normalization, Executive Nearfield Pos. detector’ (or ’Executive
Ch. 4 Width detector’).
7.4.4 Calibration and Normalization of Standby Monitors
NOTE: Before performing this procedure it is recommended to check alarm limits acc. 7.4.5.
a) Switch TX 2 on.
7.4.4.1 COURSE POSITION STANDBY Monitor
a) RF−level of the corresponding path on the SOAC (Fig. 7−2, 7−3) is set to amplitude of 3.6 Vpp
as described in 7.4.2.
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 values 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 settings of 7.4.4.1 c) back to normal.
f) Send to Monitor1/2 the command ’Normalization, Standby CRS Position Detector.
7.4.4.2 COURSE WIDTH STANDBY Monitor
a) RF−level of the corresponding path on the SOAC (Fig. 7−2, 7−3) is set to amplitude of 3.6 Vpp
as described in 7.4.2.
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 values 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 CSB and SBO settings of 7.4.4.2 c) back to normal.
f) Check and set DDM indication to 15.5 % with R25.
g) Send to Monitor1/2 the command ’Normalization, Standby CRS Width detector’.
h) 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.