User Manual

2) External Source

When modulation source is external, parameter list will hide the modulation wave option

and modulation frequency option, and carrier waveform will be modulated by an external

waveform. AM modulation depth is controlled by ±5V signal level of external modulation

input terminal Modulation In connector). For example, if modulation depth value is set to

100%, AM output amplitude is the maximum when external modulation signal is +5V , AM

output amplitude is the minimum when external modulation signal is -5V.

Set Modulation Wave Frequency

When modulation source is internal, frequency can be reset. Default of modulation wave

frequency is 100Hz. Press Param→ ModF req to change. Modulation frequency range: 2

MHz~1MHz. When modulation source is external, parameter list will hide the modulation

wave option and modulation frequency option, and carrier waveform will be modulated by

an external waveform. The range of external signal frequency is 0Hz~ 20 kHz.

Set Modulation Depth

Modulation depth indicates the extent of amplitude variation which is expressed as

percentage. Settable range of AM modulation depth is 0% ~ 120%, and the default is

100%. When modulation depth is set to 0%, the constant amplitude (half of the carrier

wave amplitude)is output. Output amplitude changes as modulation waveform changes

when modulation depth is set to 100%. The instrument output a peak-peak voltage less

than ±5V (50Ω terminal) when modulation depth is more than 100%.

If need to change, press Param → Depth in amplitude function interface. When modulation

source is external, output amplitude of the instrument is controlled by ±5V signal level of

external modulation input terminal (Modulation In connector) in rear panel. For example,

if modulation depth value in parameter list has been set to 100%, AM output amplitude is

the maximum when external modulation signal is +5V, AM output amplitude is the minimum

when external modulation signal is -5V.

Comprehensive Example

Set a sine wave with 200Hz from the internal of the instrument as a modulation signal and

a square wave: frequency =10 kHz, amplitude of 200mVpp and duty ratio of 45% as a

carrier wave signal. Finally, set modulation depth to 80%. Specific steps are seen as

following:

1) Enable Amplitude Modulation (AM) Function

Press Menu → Mod → Type → AM in turn.