©1999 Navia Aviation AS 21833-3.4 Corrective maintenance
OPERATING MANUALNORMARC 7013
INSTRUMENT LANDING SYSTEM
7-3
• Make sure you are wearing an ESD chain that is connected to either the ILS cabinet or
some other grounded point.
• Replace the faulty module.
• Power up the system.
• Perform necessary adjustments for the unit in question; please refer to ch. 7.3.2-7.3.10.
• Check the Monitor and Maintenance parameters, make a new printout and compare with
the printed report made when the system was operating normally.
• If any anomalies are discovered, follow the procedure described in chapters and to locate
the specific error.
The manufacturer don’t recommend repairing faulty units. The ILS cabinet is modularly built
up to make it possible to change smaller parts of the system at a relatively low cost.
7.3.2 MF1211/MF1219 replacement
PREPARATIONS:
Power down system. Remove old unit and place the new unit on an extender board.
ADJUSTMENT (DS-CHANNEL):
Pre-check Check that all monitor inputs from MCU are correct. (Use field measurement
instrument NM3710). Make a note of the values.
RF-level Set R338 in middle position. Set strap fields S++ on connector P2 and adjust
R338 until TP23 reads 240mV. Adjust RF potentiometer R342 on front of
MF1211 card until DS RF level reads exactly 3,0 volts.
AGC Time Adjust AGC timing pot R49 until DC value measured at TP1 are the same with
transmitters on and off.
SDM Adjust SDM pot R48 until the DS SDM reading is the same as the value mea-
sured with the 3710.
DDM Check that the DS DDM reading is the same as with 3710 (Nominal Value may
be set in RMM program to give a DDM screen readout of 0%).
ADJUSTMENT (CLR-CHANNEL):
Pre-check Check that all monitor inputs from MCU are correct. (Use field measurement
instrument NM3710). Make a note of the values.
RF-level Set R1338 in middle position. Set strap fields S++ on connector P1002 and
adjust R1338 until TP1023 reads 240mV. Adjust RF potentiometer R1342 on
front of MF12119 card until CLR RF level reads exactly 3,0 volts.AGC.
AGC Time Adjust AGC timing pot R1049 until DC value measured at TP 2 is the same with
transmitters on and off.
SDM Adjust SDM pot R48++ until the CLR SDM reading is the same as the values
measured with the 3710.
DDM Check that the CLR DDM readings are the same as with 3710 (Nominal Value
may be set in RMM program to give a DDM screen readout of 0%).
ADJUSTMENT (CL CHANNEL):
Pre-check Check that all monitor inputs from MCU are correct. (Use field measurement
instrument NM3710). Make a note of the values.
RF-level Set R2338 in middle position. Set strap fields S++ on connector P2002 and
adjust R2338 until TP2023 reads 240mV. Adjust RF potentiometer R2342 on
front of MF1211 card until RF level reads exactly 3,0 volts.
AGC Time Adjust AGC timing pot R2049 until DC values measured at TP 3 is the same
with transmitters on and off.
SDM Adjust SDM pot R2048 until the CL SDM readings is the same as the value
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