One might take a peek at Allan Coleman's web site, in relation to the topic of opto-electronics, where he uses a small Radio Shack incandescent bulb and acouple small photodiodes in his VBB horizontal seismometer. This looks alot more feasible to myself as a non-high-tech amateur. http://hometown.aol.com/acole65464/OS_2000.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>