You might call KPO the “mother” of one storied set of San Francisco call letters (KNBC) and the “grandmother” of another (KNBR).
KPO came to life on April 17, 1922, broadcasting from the Hale Brothers department store. The arrangement was typical in the early years of radio broadcasting: a retail business saw radio as a way to broaden its reach and enhance its image.
KPO was on the air just one hour daily during its first year, sharing a single broadcast frequency of 360 meters (833 KHz) with other San Francisco stations. Programs were usually from recordings and consisted mainly of classical music or opera. Frequent live concerts featured local singers and pianists.
Less than a year later, Hale Brothers saw the value of an enhanced license, known as a Class “B” license. This allowed the station to boost its power to 500 watts, but required all programming to be originated live–no more phonograph records.
Also in 1923, KPO completed a remote connection to the Fairmont Hotel, allowing its to broadcast speeches and musical performances form the Fairmont.
In May of 1923, the Department of Commerce shuffled radio frequencies. KPO, as a Class “B” station, was given the preferred frequency of 710 KHz. The following year, KPO was moved to 700, and then back to 710 in 1926. Finally, in 1927, KPO moved to its permanent home at 680 on the AM dial.
On March 4, 1925, it was announced that the San Francisco Chronicle, whose new building was just around the corner from Hales, would join with the store in the operation of KPO. On that date, the station began announcing what was to become a trademark: “This is KPO — Hale Brothers and the Chronicle.” Also on that date, KPO became a part of the first coast-to-coast network broadcast: the inauguration of President Calvin Coolidge.
KPO was the home of many local personalities who later went on to become big names across the nation in the 1930s. One such person was Hugh Barrett Dobbs, known as “Dobbsie.” His physical fitness program on KPO morphed into the Ship Of Joy, which attracted sponsorship from Shell Oil Company.
There were other KPO personalities well-known to the local radio audience: Jolly Bennie Walker and his Women’s Magazine of the Air began on KPO and later moved to NBC. And, there was the well-known “Big Brother,” host of a popular KPO children’s program.
By the late 1920s, KPO’s facilities had been enlarged, while still hosted on Hale Brothers premises.
KPO continued to hold its reputation as one of the West Coast’s most important stations through 1932. At that time, the station was leased to NBC, which later purchased it outright. The existing KPO operation was absorbed into the vast NBC-San Francisco complex, and the great station that was KPO became only a local relay for NBC programs, with few local shows and no staff of its own. This was KPO’s role throughout the 1930s and into the 1940s.
On November 23, 1947 the KPO call letters vanished from the airwaves, with NBC changing the call letters to KNBC.
RELATED EXHIBITS:
“Hail and Farewell” Broadcast (KPO becomes KNBC)
