455KHz resonators are commonly used in remote controls. Have not tried
building a lattice or a ladder filter with them yet. But, what if
it just might be succesful-- that's why experimenting is fun.
Collins mechanical filters do have very good rejection just as Pete has
stated, in fact, at 455KHz it might as well have better
selectivity/rejection/low distortion/phase linearity than any other
filter type. I believe R-2000 is a triple conversion receiver, has
anybody ever try changing out the first (roofing) filter.Just for the
sake of experimenting.