Hi David & Glen, On 18/09/15 16:13, glen english wrote: > If we were to sample at 8kHz, our nyquist frequency is 4kHz of course. > Any spectral information above the nyquist rate will be aliased bay into > the baseband, IE below the nyquist rate. > > IF we assume we don't care about aliases between 3.4 and 4kHz, then this > allows for signals up to 4.0 - 3.4 = 0.6, and 0.6+Fyquist(4kHz) = > 4.6kHz. (as a 4.5kHz signal will get aliased to 3.5 kHz.)
Fair enough. I just wondered, seemed that we could save some CPU processing power if we used a lower rate, but good point on the analogue filtering, I wasn't thinking of that side of things. Definitely we want to avoid nasty aliasing, and having a higher rate does make the filter cutoff less critical. -- Stuart Longland (aka Redhatter, VK4MSL) I haven't lost my mind... ...it's backed up on a tape somewhere.
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