OPTION 006 Avionics
Annex-A-3
General description
This option provides internal generation of waveforms suitable for testing Instrument Landing
Systems (ILS) and VHF Omnidirectional Radio Range (VOR) systems. Option 006 requires
Option 001 (Second Modulation Oscillator) to be fitted.
ILS mode
In ILS mode the SDM (Sum of Depth of Modulation) of the 90 Hz and 150 Hz tones is entered to
a resolution of 0.1% AM depth. The DDM (Difference in Depth of Modulation) is entered to a
resolution of 0.01% depth for a DDM up to 20% and 0.1% for higher DDM settings. A choice of
which tone is dominant is available to the user. DDM is also displayed in
μ
A, to a resolution of
0.01
μ
A.
The 30 Hz repetition frequency of the ILS waveform can be adjusted in 0.1 Hz steps. For 0%
DDM additional modulation signals can be added to the ILS waveform.
Marker beacon mode
In marker beacon mode the outer, middle and inner beacons can be tested by simple key selection.
VOR mode
In VOR mode the AM depth of the sub-carrier and 30 Hz tone can be independently set and the
relative phase of the 30 Hz tone and the modulation tone on the sub-carrier is set by directly
entering the bearing information in degrees. The VOR rate repetition rate of 30 Hz can be
adjusted in 0.1 Hz steps. For a fixed bearing additional modulation can be applied to simulate
voice/identity signal. A
[To/From]
beacon key provides a rapid means of reversing a bearing
entry and accounting for different bearing conventions.
ADF mode
The ADF mode provides a simple method of testing automatic direction finding receivers
operating on carriers with amplitude modulation.
SEL-CAL mode
In SEL-CAL mode the signal generator enables selective calling tones to be generated as
amplitude modulation. This facility can be used to test the aircraft operator's communication
system on commercial aircraft.