This is a vintage antique Booklet. 1938 National Radio Institute Est. 1914. Washington, D.C. How Practical Requirements changed receiver circuits (Crystals to Supers). 18 FR-2. 29 pages plus Hand written test graded with an A! and a model answers form #18FR-2. Book in very good shape for age. See all photos to confirm fine condition. I will ship upon receipt of funds. Thanks for viewing my store.