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To open the "Amplitude Modulation" dialog, select "Modulation > Configure > Amplitude Modulation" or use the MENU key under "Modulation".
In the upper section of the dialog, the modulation source is selected and the modulation switched on. The modulation source can be selected independently for the different modulation types and the LF output.
The configuration of the selected external and/or internal modulation source is performed in the lower section of the dialog or in the "LF Output" dialog (internal source only).
These settings affect all modulations which use the same modulation source.
For a fully equipped instrument two LF generators and a noise generator are available as internal sources.
![]() | If an avionic modulation (VOR/ILS) is activated this modulation is deactivated and an error message indicated in the info line. |
Activates amplitude modulation.
Remote command:Selects the source for the AM modulation signal.
The source can be selected independently for the different modulation types and the LF output. The configuration of the selected external and/or internal modulation source is performed in the lower section of the dialog or in the "Mod Gen" block (internal source only).
For a fully equipped instrument two LF generators and a noise generator are available as internal sources.
"Internal" | Uses the internal LF generator as modulation signal source for AM. |
"External" | Uses an externally applied modulation signal. The external signal is input via the AM EXT connector. |
"Intern + Extern" | Uses both, the internal and externally applied modulation signal, for example to perform two-tone AM. |
Sets the modulation depth in percent.
Note: With two-tone modulation, observe that the set modulation depth applies to both signals and the sum modulation depth is determined by doubling the set modulation depth. This results in overmodulation if the maximal value for modulation depth is exceeded (see data sheet).
Source Internal only
Selects which internal modulation source is used. The available selection depends on the options fitted.
"None" | Switches off all internal modulation sources. |
"LFGen1 / LFGen2" | Selects one of the internal LF generators as the source for AM modulation. |
"LFGen1+2" | Selects both internal LF generators as the source for AM modulation. LF frequency and modulation depth can be set separately. The added modulation depths of the two modulation generators must not exceed the overall modulation depth. This selection enables two-tone AM modulation. |
"Noise" | Selects noise signal. The modulation signal is white noise either with Gaussian distribution or equal distribution. This setting affects all analog modulations which use the noise generator as the internal modulation source. See also "Noise Settings". |
"LFGen1+Noise / LFGen2+Noise" | Selects one LF generator as the source for AM modulation and the noise signal. In addition to the AM modulation signal, white noise is used as modulation signal. |
Source Internal, LFGen1+2 only
Selects the modulation depth for the two LF generators. The sum of the two values must not exceed the overall modulation depth set in the upper part of the dialog.
Remote command:Source Internal, LFGen1+2 only
Sets the frequency of the two LF generators.
Remote command:Source Internal, LFGen2 only
Selects the shape of the second LF generator signal. In case of selection Trapeze, additional settings concerning the duration of the single trapeze elements can be made (see "LF Output Dialog").
Remote command:Displays the input sensitivity of the externally applied modulation signal at the AM EXT input in %/V.
The modulation depth entered under "AM Depth" is achieved with 1 Volt modulation of the input.
Remote command:Selects the coupling mode (AC or DC) for external feed.
Note: Coupling for external feed via input AM EXT can be set independently for all modulations using the external modulation signal.
"AC" | Disconnects the DC voltage component and uses only the AC component of the modulation signal. |
"DC" | Uses the modulation signal with both components, AC and DC. |
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