> Why not a slide potentiometer?

It really does need to be 200mm (8") long, possibly even 250mm
if more options are added. IME slide pots can turn out to be noisiest
pots of all, and this will get plenty of use. I have thought of using the
element from a bar heater. From memory I think they're about 70
ohms. Perhaps even resistance wire

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