Vintage Radio Service Manual - SENTINEL model 305-I 305-I-3 305-W & 305-W3 6-tube multi-band -Superheterodyne AM SW radio receiver. Manufactured by Sentinel Radio Corp., of Evanston, IL. Dated 1948. 4 pages. Original old Sams Photofact manual includes schematic, layout, alignment instructions, voltage & resistance test chart, repair parts list and description. This manual would make a sensational accompaniment to your retro audio equipment.