©1999 Navia Aviation AS 21833-3.4 Periodic maintenance CAT I and II
OPERATING MANUALNORMARC 7013
INSTRUMENT LANDING SYSTEM
6-7
Switch on Tx1.
• Connect the Field Test Set to the CSB Cou test connector on the Change Over Section
through a 20 or 30 dB attenuator.
• From the local panel/display or from the RMM program set Cou Ident modulation to CON-
TINUOUS.
• Use a double shielded 50 ohm coaxial test cable. On the Field Test Set read IDENT MOD.
The nominal reading should be 10% MOD, alternatively the same value as previous
recording. (If voice modulation is applied the Ident modulation shall be 5% modulation
depth.)
6.4.3.7 Voice modulation check. (If voice ident is used)
Switch on Tx1.
• Connect the Oscilloscope to CSB test connector on Course Tx1 Section via 50 ohm test
cable.
• From the local panel/display connect the audible transducer by command “Set ident
speaker”.
• Listen to the voice message and check that the waveform has a peak amplitude approxi-
mately six times the Ident waveform peak amplitude seen on the oscilloscope.
6.4.4 CSB output power.
a) Course Tx CSB. Switch off the transmitters. Select Tx1 as Main Tx.
• Insert the power meter into the Course CSB output path of the Cabinet. Switch on Tx1.
Read and record the Tx1 power in Table 6-14.
• Change over to Tx2. Read and record the Tx2 power in Table 6-14.
b) Clearance Tx CSB. Switch off the transmitters. Select Tx1 as Main Tx.
• Insert the power meter into the Clearance CSB output path of the Cabinet. Switch on Tx1.
Read and record the Tx1 power in Table 6-14.
• Change over to Tx2. Read and record the Tx2 power in Table 6-14.
6.4.5 Monitor Alarm Limit checks.
After completion and recording of the alarm parameters into Table 6-15, compare and check
that the values are the same as in the previous records.
External RF Signal Generator applied as signal source.
Set the
AUTOMATIC/MANUAL switch to MANUAL, the REMOTE/LOCAL to LOCAL and MAIN
SELECT
to Tx1.
Switch on Course Tx1 and Clearance Tx1.
Check Monitor 1 first.
6.4.5.1 CL DDM ALARM
Apply a test signal from the RF Signal Generator to the CL input connector in the back of the
cabinet.(Disconnect first the signal cable from the Monitor network). Adjust the signal to the
same RF level and frequency as the normal signal applied to the monitor.
Modulation shall be: 0.0% DDM, 40.0% SDM.
Verify modulation setting (DDM, SDM) by checking the test signal with the Field Test Set.
To Next Page
Loading...