sentences:  The original call letters were WFLM, but the station was purchased in December 1946 by George W. Trendle and H. Allen Campbell, who changed the call letters to WTCB and made the station into Flint's NBC Radio Network affiliate.The calls changed to WTAC October 13, 1948, still under Trendle and Campbell's ownership.WTAC popularly stood for "WE THE AUTO CITY", referring to Chevrolet and Buick plants formerly located in Flint, but it actually stood for Trendle and Campbell.