Air Publication 1938, 1st Edition, (some 6/44 print dates inside). P/b, 15 x 24.5cm. 100+ pages. Loose-leaf format. Issued for the assistance of airmen under training as Air Mechanics. It covers radio valves, receiver and transmitter principles and has information on the R.1082, T1083, R1084, T1131, R1132, R1132A, T1154 & R1155 (as used in many bombers including the Lancaster), also the T.R.9 used in the Spitfire. Illustrated with diagrams and charts. With amendments and additions. Worn and dog-eared throughout but it remains perfectly legible. Stock code P20573.