"Michael Black" wrote in message
...
....
when
the stage kicks into oscillation, that isn't necessarily the best
place for amplification (I've heard conflicting views about this,
and some have said it's merely that one isn't controlling the stage
properly and good gain and selectivity can be had while the stage
is oscillating).

The general fact is that a stage has maximum useable amplification and
selectivity just *before* the point of oscillation