OPERATION
3-14
Single
In the single mode, only one modulation can be active at any one time. Selecting another
modulation mode cancels the first.
Dual
In the dual mode, a common carrier wave is modulated by two different types of modulation, e.g.
one AM and one FM. Each type of modulation can carry separate information.
Composite
This mode consists of two modulating channels of the same type of modulation (e.g. FM1 + FM2)
with the effective modulation being the sum of the two waveforms.
Dual composite
This mode is similar to the composite mode of operation but with the two modulating channels
being the sum of two sources, e.g. FM1 + FM2 and AM1 + AM2.
Modulation mode selection
In order to select a different modulation mode:
(1) Press [UTIL].
Utilities Selection Menu 1
will appear on the display.
(2) Press the
[Mod’n Mode]
key. This calls up the
Modulation Mode Selection Menu
shown in
Fig. 3-6. The six possible modulation modes are shown. Press the required soft key.
Single
LOCAL
Dual
Comp
Dual
Comp
Single Modulation
Only
Dual (Eg. AM & FM)
Composite
(Eg. FM1 & FM2)
Dual Comp. (Eg. AM1
& AM2 + FM1 & FM2)
C3138
Digital
Vector
Advanced
Digital
Modulation Mode Selection Menu
Internal IQ
External IQ
Internal IQ, low
Adj. Channel Power
Fig. 3-6 Modulation mode selection menu
If the Avionics option (Option 006) is fitted an additional soft key [Avionics Modes] will be
displayed. See Annex A for avionics modes selection.
(3) Press [SIG GEN] to return to the
Sig Gen
menu where the modulation mode and individual
source parameters (where applicable) will be shown. For composite mode selection a menu
similar to Fig. 3-7 will be displayed.