Re: 60Hz Notch filter at 25kHz sampling rate?



abradley1984 wrote:

Hello,

I have an ENG signal, sampled at 25kHz that has high mains interference
that I want to remove. The problem is I need the surrounding frequencies,
maybe not 50-70, but I can't afford to sacrifice much more than this. The
filter designs I've been looking at don't seem to be able to do this at
such a high sampling rate.

Any suggestions? Would downsampling help?

As mentioned by many, it is not a big deal to build the narrowband notch at power frequency with or without downsampling. However if you are dealing with the recorded signal (as opposed to the processing in the real time) the better approach would be to estimate the parameters of the interference and then subtract it from the signal. Assuming the interference is stationary or slowly varying, this will allow canceling it without making damage to the useful data.

Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com
.