ToneJack RS-11 audio generator. Sine and square wave. I bought one some years ago. Nice little device. http://search.yahoo.com/search;_ylt=A0geu6Bupt5IqusAMvJXNyoA?p=tonejack+audio+generator&y=Search&fr=yfp-t-501&ei=UTF-8 Rich __________________________________________________________ Public Seismic Network Mailing List (PSN-L)