KHJ, even to this day, is 5 kw.
Correct. KHJ started out being owned by the Los Angeles Times and in the mid-twenties was sold to Don Lee, one time bicycle shop owner turned auto dealer (initially Buick, then Cadillac and for a time Oldsmobile) as a protoge of Earle C Anthony (Packard/KFI). Lee also owned stations KDB in Santa Barbara, KGB in San Diego and KFRC in San Francisco. These outlets plus other affiliates he cobbled into the Don Lee broadcasting system which was for a time the Pacific Coast affiliate of the Columbia Brioadcasting System until CBS bought KNX. Lee by then had died and his son Thomas was running things. Thomas Lee kept the Don Lee name and helped start Mutual.
The reason for the 5000 watt limitation was because of the class of the station. 50,000 watt clear channel stations were intended to give radio reception to the remotest villages and farms and had exclusive use of their assigned frequencies. Lesser stations were intended to serve metropolitan areas and shared their assigned frequency with others. This sharing necessitated lower power to avoid interferance. When network broadcasting started the NBC Red network quickly captured most of the 50,000 watt stations. NBC also had a Blue network (later to become ABC) made up principally of lower power stations. The NBC Gold and Orange networks were Pacific Coast only subsets of the Red and Blue which emulated Don Lee's relationship with Columbia. Columbia and Mutual tended to have lower power outlets for the same reason as NBC Blue - although Columbia gradually acquired several clear channel powerholuises.
Earle C Anthony and Don Lee were friendly competitors, a relationship that continued after Don's death with his son Thomas Lee until the unfortuante incapacitation and eventual suicide of the latter around 1950. Along with Klaus Landsburg and Paramount Anthony and Lee were also pioneers of television in Los Angeles (KTLA, KSEE/KFI-TV, KTSL).
All of this cosy relationship ended when the Thomas Lee estate sold KTSL channel 2 to CBS, which renamed it KNXT - now KCBS. The Don Lee radio network was sold with the aforenamed O&O stations to the General Teleradio affiliate of General Tire, controlled at the time by the O'Neill family. General Teleradio already owned WOR New York and a regional network plus stations in New England. Acquisition of Don Lee made them owners of most of Mutual. General Teleradio had acquired RKO pictures and with it their film library, enabling them to bring the "Million Dollar Movie" series to the living rooms at a time when Hollywood studios were embargoing showing of their films on tv.
CBS dumped its affiliation agreement with LA Times owned KTTV; and General Teleradio also bought Anthony's KFI-TV, which was tied up in a strike over union juristictional issues. KFI-TV was rebranded KHJ-TV and is now KCAL, channel 9, co-owned with channel 2 by CBS. This left Anthony with KFI radio as the glory days of radio network broadcasting began to fade. By the end of the decade the baton would be passing to color tv.