Philco's new 1939 model line was dramatically different from its previous offerings. New, streamlined cabinets housed very different chassis; only a few table models bore any resemblance to 1938 models.
This was the year Philco introduced the industry's first wireless remote control. Philco dubbed it Mystery Control and tried to keep the technical aspects of its operation a secret, even going so far as to claim in its advertising that it was "not a radio beam," when in fact it was! The remote unit sent a pulse modulated signal which was set at a frequency between 350 and 400 kc to the main receiver, which received the signal, processed the information and performed the desired operation by either switching to one of eight preset AM stations, turning the volume up or down, or turning the set off. It should be noted that you could not turn the set on with the remote.