filters for 50/60Hz and harmonics

[tester]

Are there any specific filters, that would work well with removing 50/60Hz traffic with harmonics, but without content in-between? I'm working on a multimodal differential amplifier for very weak signals, that would be used in regular environment.

[martinvicanek]

That would be a comb notch filter. I have done some experiments in this regard, however I was not happy with the results. Attenuation is good, but you get artifacts like fast ecos.

[tester]

It's possible that this would be better than loud buzzing hum/noise (captured from electrical network around) that covers everything else. What I expect to get are signals (including low frequency radio signals) that may be even burried within the selfnoise of such differential amplifier. For what I will try to do, maybe some profiled noise for masking will help.

Could you post some of your results?

[martinvicanek]

Here you go. Turning the knob to the right will give you sharper nothches but also more artifacts. Try it,maybe there is a sweet spot for your aplication.

[tester]

Thanks, I will let you know. I'm curious as well how it will behave.