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 140
are mounted in suchmanner in the wave-changer that by a simple movement of one handlethe inductance of both couple coils and loading coils is varied properly togive any one of several wave lengths for which the apparatus is adjusted.The wave changer is the invention of Mr. Guy Hill and G. H. Clark,… … I ^
