[Arran]

It's funny that people say that Philco sets went downhill from 1939-42 but I submit that isn't really a fair assessment. While it's true that Philco quit making the 690 series after 1938 you also have to take into account that by 1938 the radio market had largely matured by that point. Around 1938 everyone who could afford a radio already had a main one in their living room, so the original market was limited mostly to replacing older sets. So the smart radio manufacturers turned their attention towards marketing a secondary radio for the bedroom, kitchen, picnics, etc., there was a slogan at the time along the lines of "A radio in every room".
Some like Philco and RCA were also anticipating new markets opening up for television and F.M receivers, so they focused much of their engineering research into those. Some early 40s Philcos were excellent receivers, some with an FM band. They often also incorporated a Beam of Light phonograph which was years ahead of the competition.
Regards
Arran