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"Wavescan" is a weekly program for long distance radio hobbyists produced by Dr. Adrian M. Peterson, Coordinator of International Relations for Adventist World Radio. AWR carries the program over many of its stations (including shortwave). Adrian Peterson is a highly regarded DXer and radio historian, and often includes features on radio history in his program. We are reproducing those features below, with Dr. Peterson's permission and assistance.


Wavescan N556, October 20, 2019

Mediumwave KNX-CBS in Los Angeles on Shortwave

In our program last week we presented the story of the well-known California mediumwave station KNX in Los Angeles, which is currently celebrating its 99th anniversary. This powerful mediumwave station on the continental west coast operates on the standard 10 kHz spaced frequency of 1070 kHz with 50 kW, the maximum power level permitted in the United States.

However, not quite so well-known is the fact that this same mediumwave station KNX has been associated with the international shortwave spectrum on at least four separate and distinct occasions. We go back to the year 1925.

Back in the era between the two World Wars, mediumwave stations in the United States were proliferating anywhere and everywhere. One of the pressing needs at the time was a suitable procedure for obtaining live off-site reports from events and activities at a distance from the studios of the various radio stations.

Suitable telephone lines were not always available for use as a remote feed back to the studio, and in any case, the audio quality was seldom satisfactory. Thus it was that small, low power portable shortwave transmitters began to fulfill that purpose.

The Radio Service Bulletin for September 1, 1925 shows an entry for a Special Land Station that was licensed to the Los Angeles Evening Express newspaper under the callsign 6XA. At the time, this newspaper also owned the mediumwave broadcast station KNX. The portable station 6XA was used when needed for the gathering of news for the newspaper, and also for the live relay on shortwave of remote broadcasts back to KNX.

In the early winter of 1927, the owner of Catalina Island out from Los Angeles, William Wrigley of chewing gum fame, organized a long distance swim from Catalina Island to the California mainland, a distance of some twenty two miles. The Wrigley Ocean Marathon, as it was called, covered a distance one mile greater than the swim across the English Channel between England and France, and it attracted 102 participants. This marathon swimming race began at midday on Saturday, January 15 (1927) and it ended at 3:00 am next morning, with only one successful contender, a 17 year old Canadian by the name of George Young.

In order to provide extensive radio coverage of the entire 15-3/4 hour swim event, mediumwave station KNX in Hollywood placed its low power remote shortwave transmitter 6XA on board the SS "Avalon", a popular tourist boat in service between Catalina Island and Los Angeles. The event commentator was the popular comedian Harry Langdon.

The continuous live coverage from shortwave 6XA was received off air on Catalina Island and it was rebroadcast by mediumwave KFWO in Avalon. In turn, KNX in Hollywood, California took a live off-air relay of the swim commentary from KFWO on Catalina Island, and this programming was then fed by telephone wire to many of the major mediumwave stations throughout the United States, including, for example: KGO in Spokane, Washington, KOA in Denver, Colorado, and KMOX in St. Louis, Missouri.

Although not known these days, we would presume that the low powered portable shortwave station 6XA that was owned by Los Angeles Evening Express newspaper and CBS-KNX was used on many other occasions to provide a live remote feed back to the on-air studios at KNX in Hollywood.

As the next occasion for the KNX involvement with shortwave radio coverage, we come to the year 1938. At that time, CBS-KNX moved from its older studios at Beverly Boulevard and Fairfax Avenue in West Hollywood into the newly-built Columbia Square Building at 6121 Sunset Boulevard in Hollywood, right at the corner with Vine Street.

The official opening day, Saturday, April 30, 1938, was a full day of special broadcasts culminating in the star-studded evening special, "A Salute to Columbia Square". Many CBS officials and well-known radio and music stars of the day participated in the lengthy sequence of special broadcasts that honored the official opening of the five story Columbia Square Building.

All of this special programming was produced and coordinated in the new studios of mediumwave KNX for local broadcast, and also for coast to coast coverage in the United States by the mediumwave stations in the CBS Network. In Canada, much of the days programming in Hollywood was broadcast live for coast to coast coverage via the government CBC network.

Shortwave coverage to Europe and elsewhere was provided by the 10 kW CBS shortwave station W2XE in Wayne, New Jersey on several consecutive channels throughout the day, and from the other 10 kW CBS shortwave station, W3XAU, in Philadelphia, Pennsylvania on 6060 kHz.

Now in addition to the international shortwave coverage that KNX achieved for the official opening in 1938 of their Columbia Square Building, arrangements were made for additional regular shortwave coverage across the Pacific. One of the program lines out of the Master Control Room on the second floor of the Columbia Square Building carried programming to a shortwave station for broadcast over the Pacific to Hawaii.

The only shortwave station capable of carrying a regular program relay to Hawaii was the RCA station at Bolinas in California. Their shortwave capability allowed for both transmission and reception across the Pacific between Hawaii and California.

Interestingly, just a few weeks before mediumwave KNX began the relay on shortwave of CBS programming from California to KGMB in Hawaii, Hawaii revived the broadcast of their very popular Hawaii Calls program to the United States. The revived Hawaii Calls program returned to the air via the RCA shortwave station at Kahuku, Oahu on Sunday, February 27, 1938 via KKH, 7520 kHz, and KIO, 11680 kHz.

Comes the year 1943: The United States is at war in the Pacific and in Europe, and the United States is in desperate need of shortwave capability on the west coast. CBS is charged with the construction of a large new shortwave station in California.

Their initial concept was to procure additional land adjoining their mediumwave KNX transmitter at Torrance in the South Bay area, install a new shortwave transmitter or two, plus a few rhombic antennas pointed out over the ocean. However, upon mature examination, the KNX site for a new CBS shortwave station proved to be unsuitable, and so wider investigation was made.

A total of forty or more sites around Los Angeles were investigated, including out in the Mojave Desert, near Barstow. Finally, a site near Delano was chosen, and that's where we plan to pick up this CBS shortwave story next time.