Thales DVOR 432, Техническое руководство

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DVOR 432
Operation and Maintenance Maintenance
5-1
Ed. 01.04
CHAPTER 5
MAINTENANCE
5.1 GENERAL
There are two basic types of maintenance, namely periodic maintenance and normal maintenance.
It is essential to ensure that the radiated signals remain within the fixed tolerances at all times after
the navigation systemhas been handed over for service to air traffic. With this aimin mind, ICAO recĆ
ommends verifying the most important signal parameters of the ground station within the framework
of periodic maintenance. In Navaids 400, all the main parameters are maintained at the preset values
throughout the entire life of the system by means of a microprocessor controlled transmitter, so that
drift as a result of ageing should not normally occur. In addition, the radiated signals are checked by
two high-precision microprocessor controlled monitors. These prevent fault signals from being
emitted by either switching over to the standby transmitter or shutting down the system completely.
Since, moreover, no parts which are subject to mechanical wear and tear are used, the periodic mainĆ
tenance intervals can be made longer than usual and the number of measurements restricted to a
minimum. Due to the measurement facilities which are integrated in the system, only a few external
instruments are required. In addition to the periodic maintenance tasks, there are a few activities of
normal maintenance which should be performed as and when necessary.
5.2 PERIODIC MAINTENANCE
NOTE: The items marked with an asterisk (*) are normally performed continuously via a conĆ
nected RMMC.
Compare also measuring values with those of recorded data (refer to section 5.2.4)
Handling with subassemblies regard instructions in section 5.2.1.
We recommend performing the maintenance activities listed in the table below once every month or
six months. The following measuring instruments are required for this:
- Personal Computer (Laptop or standard PC; used for maintenance on site)
- Headphones (600 ohms, 3.5 mm plug; for station identification)
- Portable field dipole
- RF terminating resistor (50 ohms, 1 W)
- Multimeter
- Battery maintenance equipment (acidimeter, acid syringe, areometer, thermometer, funnel).
No. Monthly maintenance
1
2
3
4
5
7
8
9
10
6
11
12
13
14
15
Check systemstatus/visual inspection (refer to 5.2.2)
Check station frequency of former master transmitter*
Check station identification of former master transmitter*
Check settings of both transmitters and monitors*
Check measured values of former master transmitter and monitors*
Check switch over function by simulating monitor alarm and changing master transmitter*
Check station frequency of new master transmitter*
Check station identification of new master transmitter*
Check measured values of new master transmitter and monitors*
Additional six-monthly maintenance
Check ground error curve of former master transmitter
Check ground error curve of new master transmitter
Check remote control system (line loss)*
Check lead batteries/visual inspection (refer also to section
5.3.2
and
5.4
, if need be)
Check battery function by simulating a power failure*
Clean all equipment thoroughly (refer to 5.2.3)