On Tue, 7 Mar 2000, David VanHorn wrote:

> No, it's a problem of receiving a waveform that's synchronus to what I'm
> doing,
> but the waveshape is essentially random.
> It may have any population of harmonics, but I'm only interested in the
> fundamental, and whatever processing I do to it has to preserve the phase over
> frequency. It can introduce an absolute shift, as long as it's constant.
> (hence
> the boxcar filter),

?

What's your application? I don't understand the concept of 'constant phase
over frequency', when there's only one frequency involved. If there's a
frequency band then it does make some sense (but I tend to think in terms
of group delays [and bessel filters]). Are you building a tone decoder?
What's the bandwidth and center Frequency? Or are you building a PLL?

Scott