{{ /2dmch2/experimental_non-standard_epstein_frame.jpg?500 }} A photograph of experimental (non-standard) Epstein frame for investigation of effective magnetic path length. The component on the left is the air-cored mutual inductor. experimental_non-standard_epstein_frame.jpg {{page>insert/file-sz-cc}} {{tag>Files 2DM_book 2017 Epstein_frame}}