This is the General History Section of
The Broadcast Archive

Maintained by:
Barry Mishkind - The Eclectic Engineer

Superpowers Crank It Up
by Mark Durenberger
Minneapolis, Minnesota

This is the second in a series of 6 articles about the history of clear-channel AM radio stations.

We discussed last time how early regulatory agencies tried, more or less unsuccessfully, to respond to the explosive demand for AM broadcast frequencies, and how the Chaos of 1926 led to the formation of the Federal Radio Commission.  The FRC’s first major proclamation came in 1928 as General Order 40. By its structure, this order finally demonstrated some regulatory consistency, and it would send a signal to broadcasters that they could commit to improving their facilities.

Road to high power

In 1930 the FRC authorized 50-kilowatt operation on 20 of the 40 channels previously reserved for wide-area coverage. Two years later, it officially recognized the term “clear channel,” and in 1933 authorized full power on all 40 of the wide-area frequencies.

Broadcasters immediately began to improve their facilities.  By the mid-1930s many stations were cranking out 50 kW and building solid transmitter plants, many of which are still in operation.  But even with 50 kW, the coverage of medium-wave stations had its limit, and the need for solid nighttime service to the “white areas” remained a front-burner industry issue.  Proposed solutions included more stations and/or higher power.

The idea of massive transmitter plants certainly had sex appeal. Power levels “several dB above 50 kW” were the usual suggestions. And Radio News combined high power with the use of the Long-Wave band.  In a well-researched proposal in its April 1931 issue, the publication suggested that seven geographically dispersed, one megawatt stations, operating at low frequency (200 kHz), that would cover the entire country with fade-free reception.  These stations would be connected by landline. They called it “Direct National Coverage”. The devil, of course, would be in the details.

The Federal Radio Commission was not interested in licensing LW operation, or in solving the coverage problem by other means, until it had optimized the use of the existing MW spectrum.

The ‘clear-channel case’

In the next few years, two events occurred that would affect the battle to define nighttime MW service.  First, through a series of court actions and rule makings, 10 of the 40 protected channels were duplicated. (Some channels were actually constricted with the consent of the Licensees, not always for valid technical reasons but sometimes as a quid pro quo for regulatory relief).  These “I-B” duplications would set a precedent for future shared use of the clear channels.

The second development occurred on May 2, 1934, when WLW in Cincinnati began what was to be a five-year experiment, broadcasting under Special Temporary Authority at a “super-power” of 500,000 watts on 700 kcs.  WLW went super-power at the same time serious opposition to the broadcast giants was beginning to materialize. One of the reasons the opposition to clear-channel operation was so intense was that WLW’s 500 kilowatt signal raised the specter of “domination by the few”.

FDR years

In the Franklin D. Roosevelt years, Congress, in response to pressure for new radio regulation, enacted the Communications Act of 1934, creating a Federal Communications Commission.  One of the early tasks facing the new FCC was the resolution of the legal and political attacks on the clear-channel stations by competitors and “have-nots.” As large targets, the clears were challenged from all sides, from Petitions To Deny to cross-filing on license renewals. In two such cases, John Shephard III applied in 1934 for full-time operation on 640 and 830 kHz, and forced the operators on those channels through long and expensive hearings until his challenges finally were denied in 1936.

But the FCC had more to do than think about clear channels, and its reputation as a “body deliberate and informed” often was in question. As an act of protection, in 1934 a number of large stations united behind Edwin Craig of WSM to form the Clear Channel Group, later known as the Clear Channel Broadcasting Service.  CCBS operated as a cooperative, typically including about 16 of the largest stations, and was the primary advocate for the protection of the clear channels.  The CCBS was careful to limit membership to those operators who demonstrated a clear commitment to the preservation of clear-channel service.  Because of concerns that some of the networks had “dealt away” some of their 1-A protection in deals with the FCC, the by-laws initially denied membership to “network owned-and-operated” stations.

White areas remain

By the end of the 1930s, all of the clear-channel stations were operating at 50 kW.  While the stations on some duplicated I-B channels had to directionalize, the others operated full-time, non-directional, as the only domestic nighttime assignment on their frequency. Their combined sky-wave service covered a good part of the United States, but there remained a large under-served nighttime white area, primarily in the West.

The FCC wanted to solve the white-area problem, but it had other matters before it in the mid-1930s. It was focused on preparing the U.S. position for the upcoming North American Regional Broadcasting Agreement.  That NARBA would bring about a major frequency reshuffle in 1941, to accommodate the needs of neighboring countries.  In developing its proposed station-inventory list in the 1930’s, the FCC engineering staff evaluated the overall health of the AM broadcast band and asked for proposals to better utilize the spectrum.

In a 1937 report, FCC Engineers Ted Craven and Andy Ring outlined a comprehensive proposal to make better use of the MW band.  They proposed across-the-board power increases and suggested six channel classes, to be defined by service area, from 100 watt “locals,” to wide-area “A” channels of 50 kW-plus.  While they recommended continued protection of 25 A channels for single-station operation, they also suggested that co-channel duplication on those clears might be a better use of spectrum, but only if the stations were separated by at least 2,500 miles.

These 1937 suggestions by the FCC engineers are of interest to us.  They would be cited by both sides in the coming battle to dispose of the clears.

First try for super-power gold

Ring and Craven stopped short of recommending super-power, but in positioning for the upcoming NARBA, the FCC said publicly it might authorize power in excess of 50 kW on the 25 U.S. I-A channels. In response to this notice, several stations immediately applied for increased power. The accompanying box lists those applications, on their original, (pre-NARBA) frequencies (many of these stations would be assigned a new dial position in 1941).  Two radio stations applied for 500 kW on 540, but had their requests turned down, probably because the United States was negotiating with Mexico to reserve 540 as a Mexican clear.

These super-power applications were tendered while WLW had its STA for 500 kW.  Other stations may have been doing high-power experimenting as well.  According to Radio News of April 1932, “Anticipating the continuing and increasing rapid growth of broadcasting service, KDKA has recently built a new 400,000-watt transmitter at Saxonburg, Pa. The new station has been operating experimentally between 1 a.m. and 6 a.m.”

All of these super-power applications subsequently were withdrawn or dismissed.  The applicants would file again, but that’s getting ahead of our story.

Was WLW successful?

WLW’s operation demonstrated the real-world impact of expanded power levels on adjacent-channel interference and on the economics of advertising sales.  It also caught the attention of Congress. In 1938 the Senate passed a resolution “against powers in excess of 50 kilowatts.” The FCC politely declined to be ordered about by such resolutions.  But super-power had a lot of broadcasters concerned, and politicians have always been responsive to the broadcasters in their home states.

WLW’s Special Test Authority lasted five years, kept afloat by repeated requests for additional time. The reasons the FCC finally stopped the operation are no longer clear. It’s probable that interference was a major issue. (Early on, WLW had to directionalize at night, to protect a Canadian adjacent-channel station some 350 miles away.)  It’s also likely the FCC staff would have weighed in at some point with an “energy-consumption” edict.  Radio veterans recall a World War II mandate to drop power by two or three dB, to conserve energy (that power restriction was lifted for daytime operation on Sept. 1, 1945, and fully lifted in October of that year).

One might speculate that the tangible returns to WLW didn’t justify the cost of high-power operation, but the record does show that WLW tried to keep its super-power authorization. On June 19, 1941, it applied for 500 kW, directional night. It then modified that request to 500 kW day, 50 kW night.  WLW finally withdrew its application on April 7, 1943 (for the “war effort”?).

But that wouldn’t be the last of the super-power action, as we’ll see.

Copyright 2000 by Mark Durenberger

What Might Have Been:
Super-Power Applications


Oct. 21:  KNX applies for 500 kW on 1050 kHz

April 11: WJZ (now WABC) applies for 500 kW on 760
April 27: WHAS applies for 500 kW, then for 750 kW, on 820
June 1: WJR applies for 500 kW on 750
June 5: KDKA applies for 500 kW on 980
June 15: KFI applies for 500 kW directional on 640
June 24: WSM applies for 500 kW on 650
July 2: WOAI applies for 500 kW on 1190
July 2: WOR applies for 500 kW on 710
Sept. 24: WGY applies for 500 kW on 790
Oct. 1: KSL applies for 500 kW on 1130

Jan. 25: WBZ applies for 500 kW on 990

July 1: WHO applies for test authority at 500 kW on 1000