Greetings : We have put up on you tube a Video of the 1928 to 1970's
Four Course Radio Range The radio range was the backbone navigation
system until replaced by the VOR system. We built an actual four
course Radio Range and put it on the air. Please visit you tube, In
the search bar enter : Four Course Radio Range..... you will see a
picture with the caption navigation in the 1940's Please give it a
view.... our video has actual flying with audio of what a four
Course Radio range sounded like to pilots Please feel free to make
comments on the you tube comment section

Thanks and ENJOY the step back into Aviation history!