Regarding Jon's comment, there were no radio stations in Avalon/Catalina Island in the 1930s sand '40s, until KBIG-740 went on the air in 1952.
I believe he's thinking of the short-lived KFWO (Katalina For Wonderful Outings) which was on the air from July of 1925 until sometime in 1928, when the owner, Lawrence Mott, got married and moved to the Hollywood Hills. KFWO was first on 1420 kilocyles in the AM band, not 1430. In June of 1927, the FRC moved the station's frequency from 1420 to 1370 and again later in 1927 to 1000 kilocycles, until it went dark. The station was to move to 1500-AM and share time with KWTC-1500 in Santa Ana in November of 1928, but Major Mott decided to take KFWO off the air for good without selling the station, and the license was turned into the FRC and deleted.
The other comment was correct, Earle C. Anthony had purchased his second radio station in L.A. in November of 1929, KPLA-1000. The calls were changed to KECA for his initials and KECA was moved to 1430-AM as of 11-15-1929. When Anthony bought KEHE-780 from Hearst Radio in 1939, KECA moved from 1430 to 780 in the summer of 1939 and again to 790 on March 29, 1941.
Anthony was forced by duoply rules at the time to sell KECA in 1943. It became KABC in 1954.
KWKW went on the air first in 1942 at 1430-AM as at 1,000 watt daytimer in Pasadena. Andrew G. Haley's KAGH went on the air on 1300-AM in 1948, also in Pasadena. In 1950, the stations swapped frequencies, with KWKW moving from 1430 to 1300; KAGH moved to 1430 and changed calls to KALI, and city of license became San Gabriel.
Jim