Keysight EXG and MXG X-Series Signal Generators User’s Guide
137
Avionics VOR/ILS (Option 302)
Using ILS Localizer Softkeys
4.
Enter a value that is within the range of the current SDM value.
Typically the SDM default value provides sufficient range for most
applications.
If SDM is set to 99%, then the full range (–958.1 to 958.1
μ
A) of DDM uA is
available. The following demonstrates the limits of DDM uA’s range:
((–SDM/100)*(150/.155)) to ((SDM/100)*(150/.155))
As SDM’s value increases or decrease, so does the range.
The DDM uA default value is 0.0 uA.
To set the ILS Localizer DDM value as a percentage (%)
This process sets a value for the difference in depth of modulation (DDM)
in %. DDM can be expressed either in terms of percentage (%) or as a
modulation index. A DDM of 1% is equivalent to 0.01 DDM.
1.
Press Aux Fctn > Avionics > ILS Localizer
2.
Press DDM/SDM
3.
Press DDM%
(Default value is 0.00%.)
4.
Enter a value within the range of the current SDM value.
Typically the SDM default value provides sufficient range (–40% to 40%)
for most applications.
If SDM is set to 99%, then the full range (-99% to 99%) of DDM is
available. The following demonstrates the limits of DDM’s range:
(-SDM) to (SDM)
As SDM’s value increases or decrease, so does DDM’s range.
To set the ILS Localizer SDM value
This process sets the sum of depth of modulation (SDM):
1.
Press Aux Fctn > Avionics > ILS Localizer
2.
Press DDM/SDM
3.
Press SDM
(Default value is 40.00%.)
4.
Select a value from 0 to 99% and press Enter.
The SDM range is defined by the following equation:
SDM = [AM(90 Hz) + AM(150 Hz)] / 100:
