For VERY short lengths "plastic" fishing line has been used. MAY just work at 20m depending on coms speed required. Probably not, but easily tried. RM > What kind of source need to use to communicate two pics using a 20 mts. > optic fiber cable ? -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu