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

On Thu, 28 Aug 2008 17:20:45 -0500, SteveSmith 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?

Thank you in advance for your help

Allison




Hi Allison,
Here's a simple IIR notch filter that you can try. Feel free to e-mail
me with questions.
Steve

http://www.dspguide.com/ch19/3.htm

Your expression for R may be correct when the fractional bandwidth is <<
1, but it doesn't look at all right for BW = 1/2.

Little matter in this case.
.