Amateur radio : how and why of wireless with complete instructions on operation of receiving outfits (1922)
Grainger, Maurice J · New York : James A. McCann · leaf 36
3 B Fig. 4 … N Fig. 5 16 AMATEUR RADIO In direct current (D.C.) the electricityflows in one direction, and the lines of forcemove in one direction. In alternating cur-rent (A.C.) or in current that changes its di-rection a certain number of times a second,the lines of force change their direction twiceas often…
Radio · Amateur radio stations
Internet Archive · University of Connecticut Library · Public Domain Mark 1.0. Free to use for anything.
