Robison's Manual of radio telegraphy and telephony for the use of naval electricians (1918)
Robison, S. S. (Samuel Shelburne), b. 1867, United States Naval Institute, Todd, David Wooster, Hooper, Stanford Caldwell · Annapolis, Md. : The United States Naval Institute · leaf 218
oscillations of single frequency are emitted from aradio transmitting station much more selective receiving apparatus maybe employed with advantage at receiving stations, permitting sharp tuningwith consequent minimizing of interference caused by stations other thanthose with which communication is… … Fig. 117c. order that a series of decaying trains of waves may approach as near aspossible to the condition of persistent oscillations. A wave train having a
