I got a better copy of the schematic. It appears all is digital in the
adjustment of this control.

Perhaps I am missing something.

When using 2.7 or 1.8 kHz filters in CW mode, I still have to turn
I.F.VBT way to the right to get full strength cw signals.

When I add 500Hz filter, it MUST be within one or two clicks to hear
anything...just what I would expect.

Anyone have any ideas or insight as to what my brain is not
comprehending here?

All is appreciated.

Mark