[Arran]

Ron;
  I looked up the infamous Mr. David Grimes last night because of this thread, and because I remember that he used to run a radio manufacturing firm back in the early to mid 1920s. One of his more famous contributions was a series of sets using his "inverse duplex" circuit, without studying it further it was a sort of hybrid between a TRF and a regenerative circuit with his own spin, where they would use three or four tubes to do the job of five. It sounds interesting but for a 1920s radio they were rather complex, even compared to an early superhet, the man clearly did not adhere to the KISS principle, which was likely why his company failed around 1927-28, why pay more for a finicky set when you could buy an A.K model 20, or a Freshman Masterpiece, for much less that's easy to operate? Here I thought that a Sparton Equasonne (Lester Jones Technidyne) circuit was convoluted, but those have nothing on some of Grimes stuff. After what I read here I think I will stop collecting big Philcos at the model 116 or 3116, unless I happen by a 37 or 38-116 cheap, or luck into a model 380 somehow.
 An interesting twist to the David Grimes story is that the Canadian branch of his company was partnered with, and later owned, by the Pollock-Welker/Phonola phonograph company, called the "Grimes Radio Corporation of Canada, LTD". They did not continue with the Grimes inverse duplex designs after the U.S company went bust, or selling sets under the David Grimes name, they went into the AC radio market, and at first built some Well Gardner sets under license, then made some sort of arrangement with U.S Radio and Television manufacturing (or assembling) chassis under license for a time. They carried on manufacturing under the Grimes Radio Corp. name until about 1936, primarily making private label sets for Eatons, Simpsons, etc., as well as under the Phonola brand, then changed their name to "Dominion Electrohome Industries", however they never sold any sets under the Electrohome name until after the war.
Regards
Arran