Vintage Radio Service Manual - MECK model CM-500 (5D7-W18) 4-tube (battery-line operated) Superheterodyne AM radio receiver. Manufactured by John Meck Industries, Inc., of Plymouth, IN. 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.