> From: patchell <patchell at teletrac.com> > I know this is not much of an answer. But finding LM13600 is going to be > difficult from here on out because they have been discontinued. Mouser does > have a replacement part :513-njm13600d. You can find them at > http://www.mouser.com. Ouch, the new PAiA VCF uses 3 of the 13600s I think. Larry H