Vintage Radio Service Manual - AIR CHIEF model 4-A-42 (Code 117-7-4A42) 10-tube. Superheterodyne AM FM radio receiver with phonograph record changer combination. Manufactured by Firestone Tire & Rubber Company, of Akron, OH. Dated 1947. 10 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 phono equipment.