Lincoln Radio Corp. 31 Get a print! $8.00 Add to Cart Product Information: Model:31 Manufacturer:Lincoln Radio Corp. Schematic Pages Page 1 Schematics Content Page 1: LINCOLN 8-80 ONE SPOT SUPER. Model 31 Superheterodyne. Please note: we carry a wide range of products which will fulfill the specifications above. Please use our search function or browse our products to find what you need!