00654nam a2200205Ia 4500 CTU_186734 210402s9999 xx 000 0 und d 621.3841 O.75 Orr, William I. Radio handbook : Twenty-first edition William I. Orr ndianapolis Editors and Engineers 1978 Contents: Introduction to amateur radio communications; Direct current circuits; Alternating current, impedance and resonant circuits... Radio,Radio Giang Trung tâm Học liệu Trường Đại học Cần Thơ