Evan and Jack,
Thank you both for your reply. The links from Evan provided interesting reading. The first one included contained a post from Ashhar regarding his reason for providing CW1 and CW2, to facilitate adding a narrow bandwidth filter (at about 1.8 Mhz) in parrallel with the existing 11 Mhz filter. Filter election would be accomplished by software changing clock frequencies as appropriate. The other posts, in the thread Evan mentioned, highlight the problems involved in implementing an additional crystal filter.
I have been considering the Hi-per-mite audio filter. It seems to have very positive reviews.
