> Such a filter can be implemented with a FET-input op-amp and moderately
> sized capacitors in the 1-10 uF range.

Where can I see this implemented.. It sounds too simple, and I think I
have the wrong picture in my head.

> If you need pure wideband modulation and a fast lock time that's the way
> to go.  But it is a can of worms.
>

I think I'll leave the can-opener on the shelf for now :)