Hoar had a thing about radio. If you take a look at his bibliography it's quite obvious (see below) His first book The Radio Man had radio as a key plot device. (pun unintentional) He and science fiction had a small Renaissance in the late 1940s and his early serial works came into back print. That brief window is what elevated him above the rest of the pulp magazine writers and among peers like Robert Bloch, Gordon Dickson and Olaf Stapledon. It's not exactly H.G. Wells, or Bradbury but we must be realistic.
The Radio Man, 1924 - Fantasy PublishingSo about that radio fixation. You have to remember that Hoar was born in 1887, so he was a teenager in the early years of experimental radio; when it seemed like the realm of mad scientists come to life. He wrote his first book the same year KDKA was licensed. So to him radio was as sci-fi as flying saucers. Critic Den Valdron, author of the sci-fi mag ERBzine noticed his radio obsession as well.
The Radio Beasts, 1925 - Ace Books
The Radio Planet, 1926 - Ace Books
The Radio Flyers, 1929 - Rialto
The Radio Gun-Runners - 1930 - Rialto
The Radio Menace, 1930- Rialto
The Radio War, 1932 - Rialto
The Radio man Returns, 1939 - Argosy
The Radio Minds of Mars, 1954 - Spaceway
"A few brief comments are worth making over Farley's obsessions with Radio, and it is damned near an obsession. In the Radio Man, a radio engineer manages to accidentally teleport himself with a radio broadcaster to another planet where the beings all use radio instead of sound. He manages to communicate with them, with his own radio device. In the Radio Planet, he winds up on another continent and is so obsessed with radio that he builds an entire technological infrastructure in order to construct a radio to talk to his wife... Radio appears in several more titles. So Farley's signature was 'Radio'... But why?"After and the republishing hoopla, Ralph Milne Farley wrote a new book, his last one The Radio Minds of Mars, which was published in 1954. He died in 1963 before the rest of his bibliography was re-issued. He hadn't written any non-fiction since 1934.