A well logging apparatus is disclosed which employs slot antennas having a plurality of conductive probes traversing the slot. Also disclosed are a logging apparatus having electrically isolated antenna probes and a logging apparatus with an improved circuit for generating and applying a reference signal...http://www.google.se/patents/US4766384?utm_source=gb-gplus-sharePatent US4766384 - Well logging apparatus for determining dip, azimuth, and invaded zone conductivity
