I am using latest version of WaveForms and it looks like the signal has a 60 HZ wave, how do I filter it out?

[silverdiamond]

I am using BNC adapter with probes on AnalogDiscover3 and latest version of WaveForms and it looks like there is a heavy 60 HZ noise, how do I setup the filter to filter it out?  Here is the image, for 10 waves it is 6 Hz, which means it is 60 Hz that needs to be filtered out.

Edited August 23, 2023 by silverdiamond
Added image

[JColvin]

Hi @silverdiamond,

The 60 Hz is almost certainly from the ambient environment via the power grid; on my own AD3 with a BNC adapter and probe, I see this most notably when I am holding the probe tip without any load connected, though the amplitude on mine is much smaller (11 mV peak to peak vs your 46 mV and only around 55 dBV). When I am no longer holding the probe (still floating), the 60 Hz portion disappears from the plot view and the magnitude from the FFT drops to ~-70 dBV.

(me holding the probe at the tip)

(probe lying on my desk)

If you wanted to remove this source (presuming you're seeing the frequency when you are holding the probe), I would recommend making sure that your device under test and yourself are properly grounded. The device under test can have a shared ground line through one of the MTE cables, you can ground yourself either by touching one of the ground pins or BNC shields on the BNC adapter, or use a grounding strap to help keep this noise to a minimum.

The FIR filter on the Analog Discovery 3 can be used to filter out certain frequencies, although it's frequency range you can use is between 500 kHz and 30 MHz.
Alternatively, you would use the FIR Windowing to eliminate noise and high frequency components from a signal (this would be used in case your system was sensitive to overshoot or ringing). From my testing, this works up to around 2 MHz before you start to experience signal attenuation that can occur with FIR filters. The pink and green traces in the splash screen for the oscilloscope section of the reference manual offer a visual of smoothing out a signal: https://digilent.com/reference/test-and-measurement/analog-discovery-3/reference-manual#oscilloscope.

Let me know if you have any questions.

Thanks,
JColvin

[silverdiamond]

If there is no way to remove the 60Hz noise electrically, in the scope on the right +Channel => Filter => Chebyshev filter can be used to remove the low frequency noise.  This seemed to work reasonably well.