During Calibration:
1. Instruction to check coverage
• Change power value in DBm from “Modulators Power Settings “ for each
Tx as per instruction.
Steps:
1. Select “Tools” from top Menu
2. Select “Modulator Power Settings” from the options
3. Change the power from the scale given in the window
4. Update and Save the changes.
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2. Instruction to adjust Sector Width ( Asymeterical UHSW & LHSW)
NB-DDM
LOWER-A1
-10.4 (X)
MIDDLE-A2
-42..0 (4X)
UPPER-A3
+0.052 (|X|/200) – RF Level 90
-0.052 (|X|/200) – RF Level 150
0.46(UHSW)
Glide Angle , 2.95
0..44(LHSW)
Ex:
Sector Width = 0.44+0.46 = 0.90 (Measured)
Sector Width= 0.36 + 0.36° =0.72 (Required)
Sector Width x DDM = Constant
DDM Required = Sector Width Measured x DDM old/ Sector Width Required
DDMrequired = 0.90 x -10.3 /0.72 = -12.9
Therefore ,
Lower = -12.9
Middle= -12.9 x 4 = -51.2
Upper = 12.9 / 200 = +/- 0.064
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Value for Upper Antenna
to be entered here
Value for Lower and Middle
Antennas to be entered here
## For Symmetrical Sector Width ( UHSW=LHSW) , only Value of
NB-DDM( A1) needs to be changed as per the relation above.
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3. Instruction to give Sector Width alarm
Parameter
CAT-I
DDM
8.75 ± 25% (20% for CAT-II)
UHSW
0.07θ - 0.14θ
HSW
0.14θ -0.28θ
HSW for θ =3°
0.42° – 0.84°
## Sector Width x DDM = Constant
(A1)DDM Required = Sector Width Measured x (A1) DDM old/ Sector Width Required
Wide Alarm
Sector Width Required = 0.84
Narrow Alarm
Sector Width Required = 0.42
• Corresponding changes to be made in A2 DDM (4X) and A3(|X|/200)
DDM.
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Value for Upper Antenna
to be entered here
Value for Lower and Middle
Antennas to be entered here
4. Instruction to give Clearance alarm
• Increase or decrease WB-DDM as per FIU instruction.
# Alarm given at nominal value of 22%.
# Minimum 190 uA fly-up current required for CLR Alarm
Value for WB-DDM to be entered here
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5. Instruction to give Position Alarm
• Increase NB-DDM (A1)(MKA or %) for adding 150 dominance….High
Angle ALM
• Decrease NB-DDM (A1)(MKA or %) for adding 90 dominance……Low
Angle ALM
# Alarm to be given at ± 0.075θ (θ =3°) ~ ± 5% DDM
Increase/Decrease value
of NB-DDM for Antenna 1
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6. Instruction to adjust Glide Angle
• Increase or decrease NB-DDM (A1) (MkA or %) as per instruction of FIU
Ex: 2.96 → 3.00
0.36° → 8.75% → 75uA
0.04° → 8.75/9 = 8.3 %
NB-DDM (%)= NB DDMold ± 8.3
(adding 150 dominance → Glide Angle pushed Upwards) + sign
(adding 90 dominance → Glide Angle pushed Downwards) - sign
7. Instruction to give equipment on Stand-By Power
• FIU checks if the same Coverage (10 Nm) is achieved if GP eqpt. runs on
battery.
• Switch off AC power (PS1 MCB for Kit-1, PS2 MCB for Kit-2) in Input
Panel. Eqpt. now operates on Battery.
• Normalise after confirmation from FIU.
C) Post Flight check
● Both MONs (MD1/MD2) offsetting required synchronising MON values
with those in Air.
● Record all the post-flight calibration readings (Modulator settings,
Modulator data and MON executive parameters).
● New values of the modulator settings should be saved along with the
date.
● Backup of GP data to be taken for saving post calibration values and
results.
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