User's Manual

Model 1150A DVOR
Rev. - November, 2008
This document contains proprietary information and such information may not be disclosed
to others for any purposes without written permission from SELEX Sistemi Integrati Inc.
7-1
7 C
ORRECTIVE MAINTENANCE
7.1
INTRODUCTION
This section contains instructions required for on-site corrective maintenance and offsite repair of the DVOR
system. Required test equipment is defined and packing instructions are included in this section.
7.2
TEST EQUIPMENT REQUIRED
Portable Maintenance Data Terminal with current SELEX Sistemi Integrati PMDT software. In addition hand tools
such as straight and Phillips screwdrivers are required for the removal and replacement of modules.
7.3
ON-SITE CORRECTIVE MAINTENANCE
The maintenance on-site is limited to identifying a faulty module and replacement with a spare module. Repair of
modules on-site is not recommended due to the complex nature of the circuitry and the specialized tools necessary to
remove and solder parts on to the circuit cards.
The PMDT software includes a Fault Isolation routine that is used to identify faulty modules. In addition RMM
system within the DVOR provides extensive measurements and special tests to aid in any further trouble shooting so
that in general the maintenance technician does not require special tools and test equipment.
7.3.1
General Troubleshooting Information
a. Perform fault isolation test.
b. Replace the module identified by the Fault Isolation Routine.
c. Turn on the DVOR and verify that the equipment restores to the normal state.
d. Make any adjustments to either Transmitters>>Configuration or Monitors>>Configuration in order to
normalize DVOR performance.
7.3.2
Test Point Waveform References
NOTE
Unless otherwise indicated, Carrier output power is 100 watts and Sideband output power is 2.5
watts. Scope probe is 10:1, trigger source is Channel 1, input is DC coupled (zero ground
reference point is indicated by the arrow(s) on the left side of each figure).
All oscilloscope presentations are typical; however, variations are possible due to site-specific operating
requirements.
NOTE
The following waveforms vary in shape due to the difference in amplitude of the near and
far antennas on the counterpoise. This creates a 60 Hz modulation which varies in phase
relative to the 30 Hz modulation and is dependent upon the azimuth location of the field
monitor antenna.