KRTH (101.1 FM, 'K-Earth 101') is a U.S. oldies radio station located in Los Angeles, California, broadcasting to the Greater Los Angeles Area. Its signal covers an extremely large area, due in part to height upon Mt. Wilson, and sometimes can be heard as far south as San Diego and Tijuana, as far east as Moreno Valley, as far west as Santa Barbara and as far north as Baker, California. KRTH first signed on August 11, 1941 with the call letters K45LA, broadcasting on 44.5 FM. After World War II, when the FCC mandated the 88-108A_MHz range, the station was moved to 99.7 FM, and the call letters were changed to KHJ-FM, after its then-sister AM station KHJ. In 1948, KHJ-FM moved yet again to its current broadcast frequency of 101.1 FM.
Contributions by 184.108.40.206, Transent, and 220.127.116.11.