Recent content by virtualetters

If I have a signal that I'd like to filter very precisely (say, a few Hz bandwidth), I feel like the "best" one can possibly do is to take a time sample long enough to get a discrete transform frequency resolution of the same width, erase all but the frequency component of interest, and then...

Reells, the device's frequency cannot be the same as any electric potential. The units don't match. I seem to remember that the Earth's electromagnetic field resonates at 7.83 Hz (among other frequencies). I am not sure exactly what causes, this, however. Anyone?