There's a substantial account of the use of Radio Range, and other navigation aids of the period, in the book "The Golden Years of Flying", by Tex Searle, published 1998 and still in print, which is an account by various pilots of times at Frontier Airlines, Denver, principally from the 1950s in DC3s, but stretching back through their WW2 experiences to pre-war days. Well worth a read if you have an interest in this priod.