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.