___________________________________________________________
Page 4-50
GNS 400W Series Maintenance Manual
Rev. A
190-00356-05
Localizer Course Deviation Sensitivity
The magnitude of the course deviation output must not be less than 60% (54 millivolts) of the
nominal output (90 millivolts) measured at the NAV +LEFT J6-5 and NAV +RIGHT (NAV
COMMON) J6-6 outputs with a Standard Localizer Deviation Signal at 108.10 mHz.
VOR
The VOR Course Deviation Flag must be flagged when measured through the VLOC SERIAL
OUTJ10-10:
•
In the absence of an RF signal.
•
In the absence of the 9960 Hz modulation on an otherwise Standard VOR Test Signal of
-93 to -27 dBm.
•
In the absence of either one of the two 30 Hz modulations on an otherwise Standard VOR
Test Signal of -93 to -27 dBm.
•
When a -67 dBm VOR carrier at the selected frequency is modulated 30% only by an
audio signal at 350 Hz, 1000 Hz, or 2500 Hz.
•
When the RF level of a Standard VOR Test Signal is such that the deviation sensitivity is
1/2 that with a -73 dBm signal. Verify that the bearing error is less than 3 degrees at a
RF level just above the flagged level. Note: there is 3 dB of hysterisis on the VOR flag
output.
•
The VOR Course Deviation Flag must not be flagged when measured through the VLOC
SERIAL OUT J10-10:
•
When the RF level of a standard VOR test signal is varied over the range of at least -93 to
-27 dBm. Use only -93 dBm for this test since it will flag before the -27 dBm signal will.
Localizer (Optional Test)
The Localizer Course Deviation Flag must be flagged when measured through the VLOC
SERIAL OUT J10-10:
•
In the absence of an RF signal.
•
When either the 90 Hz or 150 Hz modulating signals is removed and the other is
maintained at its normal 20%.
•
In the absence of both 90 and 150 Hz modulation.
•
When the level of a standard localizer deviation test signal produces 50% (0.0465 ddm)
or less of standard deflection of the deviation indicator. Note: there is 2 dB of hysterisis
on the LOC flag output.
