Modulation EN is 100Hz. Note: This menu will be grayed out and disabled when other modulation sources except the internal modulation source are selected. 8.2.6 Modulation Depth The modulation depth represents the degree of amplitude variation, expressed as a percentage. The modulation depth of DSB-AM can be set from 0% to 120%. ⚫ Press [Mod] > Depth softkey to set DSB-AM modulation depth. ⚫ Modulation depth range: 0% to 120%. The default is 100%. ⚫ At 0% modulation, no signal is output. ⚫ At 50% depth, the DSB-AM amplitude is 1/4 of the carrier waveform amplitude. ⚫ At 100% depth, the DSB-AM amplitude is half of the carrier waveform amplitude.
⚫ In >100% modulation, the DSB-AM amplitude of the instrument would not exceed 10Vpp (50Ω load). When external modulation source is select, the output amplitude of the instrument is also controlled by the ±4V signal level on the [FSK/Trig/Sync/Extmod] connector on the rear panel. For example, set the modulation depth to 100%, the output amplitude is the maximum when the modulating signal is +4V or -4V, and the output amplitude is the minimum when the modulating signal is 0V. 8.3 FM Modulation A modulated waveform consists of a carrier waveform and a modulating waveform. In FM, the carrier frequency is varied by the voltage level of the modulating waveform.
8.3.1 Select FM Modulation Press [Mod] > Type > FM softkey to enable FM function. ⚫ When Mod is enabled, Sweep or Burst will be disabled automatically. ⚫ After FM is enabled, the instrument will generate FM waveform with the currently specified carrier and modulating waveforms. To avoid multiple waveform changes, enable modulation after configuring the other modulation parameters. 8.3.2 Carrier Waveform Shape FM carrier shape: Sine (default), Square, Ramp, Pulse, Arbitrary (except DC) or Harmonic waveform . ⚫ Press [Wave] button on the front panel to select the desired carrier waveform. Copyright © Qingdao Hantek Electronics Co., LTD HDG3000B User manual 39