You may try some of the Ham Radio sources for filters.  MFJ  Enterprises has 
a few.  
 
this one  
_Click  here: Tunable SSB/Morse Code / CW Audio Filter Electronic Kit_ 
(http://www.vectronics.com/products.php?prodid=VEC-841K)  
 
is about 35.00
 
They also have a super duper wopper chopper at about 250.00 with all the  
bells and whilses ioncluding DSP
 
Building your own ?   just do a search for the filters and get  ready to play 
with some op amps
 
Eddie Turner, kc4awz

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist