On Sat, 13 Mar 2004 15:44:10 GMT, Dave Dilatush wrote: > Andrea wrote... >> For the receiver I'm thinking about using a small telescope, pointing >> it to the transmitter (hopefully 1+ Km away.. ehm). Will the lens be >> transparent for the incoming 875nM or 950nM light? Surely at that sort of range you would be better going with an RF solution no? At those sort of distances atmospheric scattering, dust, fog & heat lens effects will be tremendously problematic. If you are really determined you would be much better going with a powerful IR laser such as one salvaged from a CD burner (808nm i think), but be careful of your eyes, only work on it using a video camera so you can see what you are doing. Regards Alex Rice -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics