See page 14 - Roosevelt’s Special Relationship With Radio
http://books.google.com/books?id=12dk9bizqIAC&printsec=frontcover&dq=manipulating+the+ether&source=bl&ots=KG5qBaPKsc&sig=CwS_jfTL2tLBcVRAB3_hzPdgM4Y&hl=en&ei=Ha4UTeG-MYPGlQfh3u2eDA&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBYQ6AEwAA#v=onepage&q&f=false
The book is: Manipulating The Ether: The Power Of Broadcast Radio In Thirties America By Robert J. Brown
VERY interesting!