Tuesday, November 19, 2019

CBS on Shortwave in California: The Voice of America Delano

At the time when the United States entered the Pacific War on December 7, 1941, there was only one shortwave broadcasting station on the air on the continental west coast, and that was the well known two year old 50 kW General Electric station KGEI in San Francisco.  There was obviously a desperate need for the United States to establish additional shortwave broadcasting stations in California as quickly as possible.

The Office of War Information (OWI) was established by an Executive Order from President Franklin Delano Roosevelt on June 13, 1942, and one of their top priorities was to establish two shortwave stations in California just as soon as possible.  These two shortwave stations were soon established at Delano (CBS South Station) and Dixon (NBC North Station).  In our program today, we look at the story of the Voice of America Relay Station that was built near Delano and operated by CBS, the Columbia Broadcasting System. In order to be effective, the newly appointed Chief of Communication Facilities Bureau at OWI, James Weldon, set up a list of preferred criteria which would include the following:
At least three miles from the coast
        No mountains more than 3 degrees above horizon
        Large property 1 mile E-W & ½ mile N-S
                Aviation approval for towers 150 ft tall
        Land not more than $400 per acre
Also electricity in quantity available (50 or 60 cycle)

At the time, Lester Bowman was the Western Engineer for CBS at their Columbia Square office in Hollywood and he was tasked with establishing the new South Station for the Voice of America.  Initially Bowman gave consideration to procuring additional land near the KNX mediumwave transmitter site in Torrance in the South Bay area of Los Angeles.  Upon this additional site, a transmitter building could be constructed, together with the installation of a few rhombic antennas pointed out across the Pacific. 

However, a Torrance location for this VOA South station proved to be inadequate, and consideration was given ultimately to some forty different sites in California, including Barstow on the edge of the Mojave Desert.  Finally, an 81 acre tract of almost desert land due west of Delano was chosen and OWI approval for this location was granted on February 15, 1943. Subsequently, additional adjacent land was acquired, making the CBS-VOA property near Delano a complete square mile.  The surrounding farm areas are now mainly almond and orange orchards, due to the availability of irrigation water. 

A Ground Breaking Ceremony was conducted on this property at 11015 Melcher Road a little over a year later, in May 1944.  The main transmitter building was then constructed and the first two transmitters were installed; two 50 kW RCA units Model No M17331-8. 
Due to wartime shortages, the two RCA 50 kW transmitters employed a common high-level modulator, though there were two separate radio frequency sections.  In this way, the same programming was carried in parallel on two separate shortwave channels under the dual callsigns KCBA and KCBF. 

The first broadcasts from this RCA double unit KCBA-KCBF became airborne in November 1944, and the first monitoring observations are shown in the Australian magazine Radio & Hobbies in February of the next year 1945.  The famous red, white and blue OWI QSL cards verifying the broadcasts from the Delano 50 kW double unit showed both callsigns, KCBA-KCBF linked together on the same card.

At the same time as the double 50 kW RCA transmitters were installed, a 200 kW Federal transmitter was also installed at Delano and this unit, together with a third 50 kW RCA transmitter as the driver, was activated on June 15, 1945 under another CBS callsign KCBR.  A separate red, white and blue QSL card was available for verification of this specific transmitter.

Now at the same time as the three transmitter units at Delano were under installation, expansion of the total facility was also underway.  Two new wings were added to the main transmitter building, North and South, and a 100 kW General Electric transmitter Model No. G100C was installed in each of those wings.  In addition, two 50 kW Continentals Model 617A were also installed. 

Back at that time, there were no harmonic filters attached to the output of these shortwave transmitters, and on Monday July 16, 1945, a harmonic signal from VOA KCBA Delano in California invaded the communication system at the Manhattan Project in the desert areas of New Mexico, one thousand miles away.  The countdown was underway for the test explosion of the world’s first atomic bomb, when suddenly the sign on with the military version of the Star Spangled Banner heralded the opening of the VOA daily programming to Latin America.  Although the countdown was interrupted with the unexpected and undesired incursion from the programming of the Voice of America, yet the atomic detonation was carried out successfully. 

During the half a dozen years from 1945 to 1951, there is no indication anywhere that the four additional transmitters that were installed at Delano in 1945 (2 @ 50 kW and 2 @ 100 kW) were accorded any additional callsigns.  Monitoring observations as listed in the Australian Radio & Hobbies magazine during this early postwar period would suggest that when these newly installed transmitters were on the air, they were listed generically under the callsign KCBA.
(AWR Wavescan/NWS 559)