Vintage SENTINEL models 285P and 1U-285P Superheterodyne 6 tube AM radio receiver. Original old Sams Photofact manual includes schematic, layout, alignment instructions, voltage & resistance test charts, repair parts list and description. Dated 1946. 4 pages. Sentinel Radio Corp., of Evanston, IL. This manual would make a sensational accompaniment to your classic retro radio equipment.