Hello
I have a sine with an amplitude of 1.4Vpp. Now I want to add 140 mVrms Noise to it. How do I make the adjustmentss? Since with the SUM function I can not say I want 140 mVrms noise, but can only define a percental fraction of the carrier. But the carrier is defined in Vpp whereas the noise is defined in mVrms. So how do I resolve the issue?
Thank you
I have a sine with an amplitude of 1.4Vpp. Now I want to add 140 mVrms Noise to it. How do I make the adjustmentss? Since with the SUM function I can not say I want 140 mVrms noise, but can only define a percental fraction of the carrier. But the carrier is defined in Vpp whereas the noise is defined in mVrms. So how do I resolve the issue?
Thank you
The problem is that the noise amplitude depends upon the setting of the carrier amplitude,
and is added as a %, and will vary as amplitude with the signal, and not remain fixed at xxx Vrms or yyy Vpp,
(as soon as the user knobs the main amplitude the “voltage” of the SUM signal changes in proportion).
Now to fix your problem. First set your amplitude to 1.4VPP, now press the units button on the front panel, at the bottom of the screen there is some soft keys, the third one from the left says "Ampl as". Press the blue softkey and change it from VPP to VRMS. The amplitude should now be converted to VRMS and should show 495 mVRMS.
You want to add 140mVRMS of noise: 140mVRMS/495mVRMS = 28.28%, so when you go into the modulate menu set the Sum Amplitude to 28.28%