Sean Thomas I agree with what you have said(I think). As I remember it, (it happened with the first lvdt I constructed), The output was considerably reduced with my configuration. As a consequence all the later versions I constructed with isolated cores. Since the isolated core worked I left it at that. I make lvdts with acrylic tubing. They have ~ 1/16 space around the core. My thought was if the secondary coils were attached to ground at one end that providing a ground(core) near the coils would drag the output down. Bwt now that I think of it, how can the secondary coils be induced by the primary if the field is grounded by the core? I have another one on the bench. I'll try a calibration both ways. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>