Sean Thomas I responded because my designs frequently change and I thought maybe you had improvements. I do have your posting, and in fact I bought the magnet as well. Small is where I'm going. I currently have a 10" leaf spring vertical. It however is using a 6" speaker coil and homemade lvdt. It still records teleseismic events well but has a poor response to events closer than ~200k. My full size smt8 style sensor responds better to local events as I anticipated. I have a homemade calibrated vrdt which I made. Combined with a homemade feedback coil which you have described, I am hopeing to put everything in a sealed insulated ammo box for field use. Thanks again for all your help over time. Regards Barry __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>