sentences:  In mid-1929 the call letters were changed to WJAC, which would be used for 70 years.On July 14, 1939 WJAC moved to 1370 kHz, which allowed it to resume unlimited hours of operation.In March 1941, under the provisions of the North American Regional Broadcasting Agreement, most stations on 1370 kHz, including WJAC, were reassigned to 1400 kHz.