>  I'm not sure about the implementation, but what about a switched capacitor
> filter for the bandpass (just a suggestion, since I#ve never worked with
> either analog multipliers or switched cap filters) ? Of course this will
> (like the multiplier setup) only be feasible if your input signal is
> constant during the time needed to sweep the filter.

Good point about the signal being constant.  Since I'll be looking at the
signal from an accelerometer on an engine, I'm sure the signal will not
be constant.

Yours,
--
Derrick Early
early@finite.nrl.navy.mil