PeakTech 4105 Bedienungsanleitung Seite 101

5.4.2 Modulation Depth
Press 〖Depth〗softkey then set desired depth using knob or numeric keypad. The modulation depth
is expressed as a percentage and represents the extent of the amplitude variation. If the maximum
amplitude of modulating carrier is expressed as Amax, the minimum amplitude Amin, setting value of
amplitude as A and modulation depth as M, the relationship among the four factors are expressed as
following:
Amax＝(1+M)×A/2.2 Amin＝(1-M)×A/2.2
Therefore,
M＝（Amax－Amin）×1.1/A
If modulation depth at 120%, then Amax=A and Amin= -0.09A. If modulation depth at 100%, then
Amax=0.909A and Amin=0. If modulation depth at 50%, then Amax=0.682A and Amin=0.227A. If
modulation depth at 0%, then Amax=0.455A and Amin=0.455A. This is to say, when the modulation
depth is at 0, carrier amplitude is a half of amplitude setting.
5.4.3 Modulating Waveform Frequency
Press 〖AM Freq〗softkey to set the value of AM frequency. Generally speaking, the modulating
frequency is always lower than carrier frequency.
5.4.4 Modulating Waveform Shape
Press 〖Shape〗 softkey then select 'Shape' to enter the desired wave. Press 【Waveform】 key, then
select one of most waveforms in above as modulating waveform. Finally, return to FM menu.
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