The Federal Radio Commission's (FRC) General Order 32, dated May 25, 1928, notified 164 of the over 600 existing U.S. radio stations that their applications for continued operation would be denied unless they showed that they met the FRC's "public interest, convenience, or necessity" standard. The result was the elimination of more than 60 stations, plus numerous power reductions, that somewhat reduced the congestion of the broadcast band, in preparation for implementation of the General Order 40 reallocation later that year.
Background 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"."Amendments to Regulations", Radio Service Bulletin, January 3, 1922, page 10. 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."Subcommittee No. 2: Allocation of Frequencies or Wave Lengths to Broadcasting Stations", Recommendations for Regulation of Radio adopted by the Third National Radio Conference, October 6–10, 1924, pages 16-17. 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".Radio Act of 1927 (Public Law 69-632), February 23, 1927, pages 186-200. The FRC started reducing the number of stations, beginning with eliminating "portable" stations."Portable stations no longer licensed" (General Order No. 30, May 10, 1928), Radio Service Bulletin, May 31, 1928, page 8."Extension of portable broadcasting stations licenses" (General Order No. 34, May 25, 1928), Radio Service Bulletin, May 31, 1928, page 9.
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."Appendix E (9): Suggestions of Louis B. F. Raycroft", Second Annual Report of the Federal Radio Commission (year ending June 30, 1928), April 3, 1928, page 142: "7. Of the 90 American channels, after the twenty-eight-odd cleared channels have been deducted, there remain approximately 60, subject to further reduction as time goes on. These 60 channels are for the lower-powered nonexclusive services, which in the present state of the art can not be strictly heterodyne free, except in their local service areas." 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."History of the Directional Antenna in the Standard Broadcast Band for Purpose of Protecting Service Area of Distant Stations" by Raymond M. Wilmotte, IRE Transactions on Broadcast Transmission Systems, (Volume: PGBTS-7, Issue: 1), February 1957, pages 51-55.
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."General Order No. 40" (August 30, 1928), Radio Service Bulletin, August 31, 1928, pages 9-10. The Davis Amendment was repealed in 1936.
General Order 32 provisions
Following the establishment of the Federal Radio Commission, existing stations were initially issued a series of temporary authorizations, starting on May 3, 1927."List of broadcasting stations issued temporary permits", Radio Service Bulletin, April 30, 1927, pages 6-14. 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."Extension of Broadcasting Station Licenses", Radio Service Bulletin, December 31, 1927, page 7.
General Order 32"Hearings set for applicants for certain broadcast licenses which have not satisfied the commission" (General Order No. 32, May 25, 1928), Radio Service Bulletin, May 31, 1928, pages 8-9. 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."Letter to and list of stations included in General Order No. 32, issued May 25, 1928", Second Annual Report of the Federal Radio Commission (year ending June 30, 1928), pages 147-150.
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. Stations with a blank Elimination Notes entry were found to meet the new "convenience, interest, and necessity" standard, and were relicensed.