KLS was a pioneering Bay Area station launched by brothers Stafford and Eugene Warner. The Warners were amateur radio operators who ran a small grocery store at 22nd and Telegraph in Oakland. They originally sold radio parts in one corner of the store, but the interest in radio sales grew until they finally discontinued grocery sales completely and turned their store into a wireless shop about 1918. They operated their amateur station 6XAM from the shop, and it eventually evolved into a broadcast station.
In 1921, the Warners were airing regular programs consisting of phonograph records and occasional piano music. On March 6, 1922, 6XAM was licensed as KLS, and the little station continued to broadcast through the twenties, mostly with programs of recorded music. Its sole function was to serve as a publicity agent for the Warners’ Oakland radio shop, as well as their two later San Francisco stores. Its most prominent early program was the Radio Church of America.
Like many stations in radio’s early years, KLS saw its frequency shifted about the dial several times. It settled at 1280 kHz in the mid-’30s and would make a final shift to 1310 kHz during the nationwide frequency reallocation of 1941.
The Warner brothers moved KLS to their newly-built “Warner Brothers Radio Village” on 21st Street, near Lake Merritt. The newly-built studios were surrounded by shops in what the Warners saw as a radio-themed commercial development. The station’s 250-watt signal was boosted to 1,000 watts at the new location.
KLS changed its call letters to KWBR (for Warner Brothers Radio) on September 10, 1945.
