International Correspondence School Voucher For Supreme Instruments In 1932 the International Correspondence School offered a 15% discount voucher for purchasing Supreme test equipment for it's students in the I.C.S. Radio Course. Enclosed with the voucher was a 1932 Supreme Sales flyer. Supreme Catalogs, Advertisements, and Flyers Home Page Supreme History Tube Testers Radio Diagnometers Multimeters Radio Analyzers Advertising Supreme Parts Manuals & Schematics Items Wanted Copyright © 1995-2025 Steve Johnson, Elbridge NY, All rights reserved.