General Order 32

Radio transmissions in the United States were originally regulated by the Department of Commerce, as authorized by the Radio Act of 1912. The first formal regulations governing broadcasts intended for the general public were adopted effective December 1, 1921. This initially established just two transmitting wavelengths — 360 meters (833 kHz) for "entertainment" broadcasts, and 485 meters (619 kHz) for "market news and weather reports".^[1] The number of broadcasting stations grew dramatically in 1922, reaching over 500 by the end of the year, and the government began making available additional frequencies. By November 1924 a band of frequencies, from 550 to 1500 kHz, had been established, with higher-powered stations, known as "Class B", assigned to the frequencies from 550 to 1070, while lower-powered "Class A" stations were assigned to 1080 to 1500.^[2]

In 1926, the government's regulatory authority under the 1912 Radio Act was successfully challenged, and, for a chaotic period that lasted until early 1927, radio stations were free to use any frequency and power they chose, while the number of stations increased to 732. To rectify the matter, Congress passed the Radio Act of 1927, which was signed into law by President Calvin Coolidge on February 23, 1927. The Act adopted a standard that radio stations had to be shown to be "in the public interest, convenience, or necessity".^[3] The FRC started reducing the number of stations, beginning with eliminating "portable" stations.^[4][5]

Two technical issues limited the number of stations that could operate without interfering with each other. These issues were especially important at night, when a change in the ionosphere meant that radio signals traveled much greater distances. Most transmitters at this time were unable to precisely control their output frequencies, thus, signals from two stations operating on the same nominal frequency would combine to make a high-pitched "heterodyne" tone that interfered with the reception of both stations.^[6] Secondly, directional antennas would not be developed until the first installation at WFLA-WSUN in Tampa, Florida in early 1932, so there was no effective method for limiting signals in a given direction.^[7]

An additional requirement was that the station assignments meet the standards of the Davis Amendment, a provision attached to the March 28, 1928 reauthorization of the Radio Act of 1927, which mandated an "equality of radio broadcasting service" within the United States. It specified an "equitable allocation" among five regional zones, in addition to assignments proportional to population among the states within each zone.^[8]

Following the establishment of the Federal Radio Commission, existing stations were initially issued a series of temporary authorizations, starting on May 3, 1927.^[9] The FRC conducted a review and census of the existing stations, then notified them that if they wished to remain on the air they had to file a formal license application by January 15, 1928, as the first step in determining whether they met the new "public interest, convenience, or necessity" standard.^[10]

General Order 32^[11] was used to notify 164 stations that they had been identified as questionable in meeting this new standard. The following, dated May 25, 1928, was sent to these stations:

Dear Sir: Please note copy of attached Order No. 32 in which the commission has extended your present license for a period of 60 days. From an examination of your application for future license it does not find that public interest, convenience, or necessity would be served by granting it. The commission has fixed the date for hearing on this application on July 9, at 10 o'clock a.m. in its offices at Washington, D. C.
    At this hearing, unless you can make an affirmative showing that public interest, convenience, or necessity will be served by the granting of your application, it will be finally denied.^[12]

The table below reviews the stations included in the General Order 32 notifications. The focus was on the most congested regions, especially around the Chicago and New York City areas. No stations from the sparsely populated Zone 3 were included. On the table, the Elimination Notes column records cases where stations were ultimately eliminated, either through deletion, by surrendering their licenses, or by consolidation with other stations.^[12] Stations with a blank Elimination Notes entry were found to meet the new "convenience, interest, and necessity" standard, and were relicensed.

• North American Regional Broadcasting Agreement
• Federal Radio Commission