Benedito wrote:In reality the Math Channel Averager are a powerfull COMB FILTER

Hi Nedi,

When I read your message first I wondered what made you think of a comb filter.

Normally these are used to separate equally spaced channels, so how should they do the desired averaging.

But investigating how comb filters are implemented and how the Picoscope averaging actually works made things clear, and you are right.

Picoscope averaging adds up buffered samples of the signal. So this can be seen as a time delay. The triggering makes sure that the starting point of the repetitive signal is the same for all samples. Therefore the resulting comb fillter will have its pass bands at the harmonics of the repetitive signal and erase the frequencies in between, thus clearing the signal from distortions.

This explanation requires good understanding of signal and filter theory.

One could also explain the signal improvement simply by looking at the properties of a noise signal.

While the noise amplitude randomly changes at equally spaced points, summing up a number of such samples eqals to almost zero, while the underlying repetitive signal amplitude will be the same at these times and therefore multiplied by the number of sample sets.(Needs to be divided afterwards to get the correct amplitude.)

So the signal will be restored while the noise is averaged away. However both ways require proper triggering.

Kind regards

Eilert