Clear-channel station explained

A clear-channel station is a North American AM radio station that has the highest level of protection from interference from other stations, particularly from nighttime skywave signals. This classification exists to ensure the viability of cross-country or cross-continent radio service enforced through a series of treaties and statutory laws. Known as Class A stations since the 1983 adoption of the Regional Agreement for the Medium Frequency Broadcasting Service in Region 2 (Rio Agreement), they are occasionally still referred to by their former classifications of Class I-A (the highest classification), Class I-B (the next highest class), or Class I-N (for stations in Alaska too far away to cause interference to the primary clear-channel stations in the lower 48 states). The term "clear-channel" is used most often in the context of North America and the Caribbean, where the concept originated.

Since 1941, these stations have been required to maintain a transmitter power output of at least 10,000 watts to retain their status. Nearly all such stations in the United States, Canada and The Bahamas broadcast with 50,000 watts, with several clear-channel stations in Mexico going as high as 150,000 watts, and XEW in Mexico City having formerly operated with 250,000 watts for over 80 years before moving the transmitter and reducing to 100,000 watts in 2016. Cuba was originally included in the plan and had several stations given clear-channel status, but stopped participating after the Cuban Revolution of 1959.

Description

Sixty medium wave frequencies were set aside in 1941 under the North American Regional Broadcasting Agreement (NARBA) for use by usually only one, although in some cases two or three, AM stations, covering a wide nighttime area via skywave propagation. These frequencies were known as the "clear channels", and the stations on them are thus clear-channel stations. NARBA set aside 37 Class I-A frequencies and 27 Class I-B frequencies. The Class I-N stations in Alaska shared those same frequencies. Where only one station was assigned to a clear channel, the treaty provides that it must operate with a nominal power of 50 kilowatts or more. These were for the most part Class I-A. Stations on the other clear channels, with two or more stations, must use between 10 kW and 50 kW, and most often use a directional antenna so as not to interfere with each other. In addition to the frequencies, the treaty also specified the specific locations where stations on Class I-B channels could be built.

Some of the original NARBA signatories, including the United States, Canada and Mexico, have implemented bilateral agreements that supersede NARBA's terms, eliminating among other things the distinction between the two kinds of clear channel: the original "I-A" and "I-B" classes, and the newer, U.S.-only "I-N" class, which are now all included in class A. Classes "I-A" and "I-B" still mandate a minimum efficiency of 362.10 mV/m/kW at 1 km, whereas Class "I-N" is permitted to use the lower Class B minimum efficiency of 281.63 mV/m/kW at 1 km. There exist exceptions, where a former Class B station was elevated to Class A, yet it maintained its previous antenna system, or made only minor changes thereto.

Clear-channel stations, unlike other AM stations in North America, have protection from interference to their nighttime skywave secondary service area. Other stations are entitled, at most, to protection from nighttime interference in their primary service area—that which is covered by their groundwave signal.

Many stations beyond those listed in the treaty have been assigned to operate on a clear channel (and some had been long before NARBA came into effect in 1941). In most cases, those stations operate during the daytime only, so as not to interfere with the primary stations on those channels. Since the early 1980s, many such stations have been permitted to operate at night with such low power as to be deemed not to interfere; these stations are still considered "daytimers" and are not entitled to any protection from interference with their nighttime signals. Another group of stations, formerly known as class II stations, were licensed to operate on the former "I-B" clear channels with significant power at night, provided that they use directional antenna systems to minimize radiation towards the primary stations.

Daytimers

Daytimers (also known as daytime-only stations) are AM radio stations that are limited to broadcasting during the daytime only, as their signals would interfere with clear-channel and other radio stations at night, when solar radiation is reduced, and medium wave radio signals can propagate much farther. Such stations are allowed three manners of operation after sunset; to sign off the air completely until sunrise, reduce power (sometimes dramatically, to only a few watts), or switch to a nighttime-only frequency (such as the Detroit area's WNZK, which broadcasts on 690 during the day, and on 680 at night). Their broadcast class is Class D. A great number of these stations use FM translators to continue their broadcasts overnight, and some also broadcast on the internet and have separate streams that air when the station's over-the-air signal has signed off.

Daytime-only stations first originated in the late 1920s shortly after General Order 40 was imposed. One of the first to do so was WKEN in Kenmore, New York (now WUFO). WKEN proposed the concept to avoid the then-common practice of having to share one frequency between multiple stations; under General Order 40, WKEN would have had to share its frequency with WKBW, and the daytime-only proposal allowed both stations their own frequency.^[1] WUFO remains a daytime-only station to the present day, albeit with a 24/7 FM translator introduced in mid-2017.

As of 2013, daytimers exist only in the United States and Mexico. The last Canadian daytime station, CKOT, signed off on February 17 of that year after converting to the FM band. There were 61 daytimers in Mexico in 2015.

List of clear-channel stations

The following two tables show all of the class-A stations in North America.

First is the Canada, Mexico, and contiguous United States table, for the former class I-A and class I-B stations. General Order 40 allocations are in bold.

Second is the Alaska table, for the former class I-N stations.

Under the most recent treaty, Mexican Class A stations that previously operated with 50 kW or less (but a minimum of 10 kW nights) may increase power to 100 kW days while retaining their 10 kW night operation. This created some anomalies where stations licensed for 10 kW during all hours could increase power to 100 kW days and 10 kW nights, unless a directional antenna system was installed for nights, in which case the maximum night power was 50 kW. Additionally, one Class B station that had been operating non-directionally with 100 kW days and 50 kW nights was required to reduce power to 50 kW during all hours.

Class A (former I-A/I-B) stations! kHz! Call
sign! City of license! State / province! Coun-
try! kW^[2] ! Transmitter coordinates

align=right	540	CBK	Watrous	Saskatchewan		50
align=right	540	XEWA	San Luis Potosí	San Luis Potosí		150
align=right	640	CBN	St. John's	Newfoundland and Labrador		10
align=right	640	KFI	Los Angeles	California		50
align=right	650	WSM	Nashville	Tennessee		50
align=right	660	WFAN	New York City	New York		50
align=right	670	WSCR	Chicago	Illinois		50
align=right	680	KNBR	San Francisco	California		50
align=right	690	CKGM^[3]	Montreal	Quebec		50
align=right	690	XEWW	Tijuana	Baja California		77.5 / 50
align=right	700	WLW	Cincinnati	Ohio		50
align=right	710	KIRO	Seattle	Washington		50
align=right	710	WOR	New York City	New York		50
align=right	720	WGN	Chicago	Illinois		50
align=right	730	CKAC	Montreal	Quebec		50
align=right	730	XEX	Mexico City	Mexico City		60 / 100
align=right	740	CFZM^[4]	Toronto	Ontario		50
align=right	750	WSB	Atlanta	Georgia		50
align=right	760	WJR	Detroit	Michigan		50
align=right	770	WABC	New York City	New York		50
align=right	780	WBBM	Chicago	Illinois		35 / 42
align=right	800	XEROK	Ciudad Juárez	Chihuahua		50
align=right	810	KGO	San Francisco	California		50
align=right	810	WGY	Schenectady	New York		50
align=right	820	WBAP	Fort Worth	Texas		50
align=right	830	WCCO	Minneapolis	Minnesota		50
align=right	840	WHAS	Louisville	Kentucky		50
align=right	850	KOA	Denver	Colorado		50
align=right	860	CJBC	Toronto	Ontario		50
align=right	870	WWL	New Orleans	Louisiana		50
align=right	880	WCBS	New York City	New York		50
align=right	890	WLS	Chicago	Illinois		50
align=right	900	CKBI	Prince Albert	Saskatchewan		10
align=right	900	XEW	Mexico City	Mexico City		100
align=right	940	CFNV^[5]	Montreal	Quebec		50
align=right	940	XEQ	Mexico City	Mexico City		30
align=right	990	CBW	Winnipeg	Manitoba		50 / 46
align=right	990	CBY	Corner Brook	Newfoundland and Labrador		10
align=right	1000	KNWN	Seattle	Washington		50
align=right	1000	WMVP	Chicago	Illinois		50
align=right	1000	XEOY	Mexico City	Mexico City		50 / 10
align=right	1010	CBR	Calgary	Alberta		50
align=right	1010	CFRB	Toronto	Ontario		50
align=right	1020	KDKA	Pittsburgh	Pennsylvania		50
align=right	1030	WBZ	Boston	Massachusetts		50
align=right	1040	WHO	Des Moines	Iowa		50
align=right	1050	XEG	Monterrey	Nuevo León		150
align=right	1060	KYW	Philadelphia	Pennsylvania		50
align=right	1060	XECPAE	Mexico City	Mexico City		100 / 20
align=right	1070	KNX	Los Angeles	California		50
align=right	1080	KRLD	Dallas	Texas		50
align=right	1080	WTIC	Hartford	Connecticut		50
align=right	1090	KAAY	Little Rock	Arkansas		50
align=right	1090	WBAL	Baltimore	Maryland		50
align=right	1090	XEPRS	Rancho del Mar, Rosarito	Baja California		50
align=right	1100	WTAM	Cleveland	Ohio		50
align=right	1110	KFAB	Omaha	Nebraska		50
align=right	1110	WBT	Charlotte	North Carolina		50
align=right	1120	KMOX	St. Louis	Missouri		50
align=right	1130	CKWX	Vancouver	British Columbia		50
align=right	1130	KWKH	Shreveport	Louisiana		50
align=right	1130	WBBR	New York City	New York		50
align=right	1140	WRVA	Richmond	Virginia		50
align=right	1140	XEMR	Monterrey	Nuevo León		50
align=right	1160	KSL	Salt Lake City	Utah		50
align=right	1170	KOTV	Tulsa	Oklahoma		50
align=right	1170	WWVA	Wheeling	West Virginia		50
align=right	1180	WHAM	Rochester	New York		50
align=right	1190	KEX	Portland	Oregon		50
align=right	1190	XEWK	Guadalajara	Jalisco		50 / 10
align=right	1200	WOAI	San Antonio	Texas		50
align=right	1210	WPHT	Philadelphia	Pennsylvania		50
align=right	1220	XEB	Mexico City	Mexico City		100
align=right	1500	KSTP	Saint Paul	Minnesota		50	^[6]
align=right	1500	WFED	Washington, D.C.	Washington, D.C.		50
align=right	1510	WLAC	Nashville	Tennessee		50
align=right	1520	KOKC	Oklahoma City	Oklahoma		50
align=right	1520	WWKB	Buffalo	New York		50
align=right	1530	KFBK	Sacramento	California		50
align=right	1530	WCKY	Cincinnati	Ohio		50
align=right	1540	KXEL	Waterloo	Iowa		50
align=right	1540	ZNS-1	Nassau	New Providence		50
align=right	1550	CBEF^[7]	Windsor	Ontario		10
align=right	1560	KNZR^[8]	Bakersfield	California		25 / 10
align=right	1560	WFME^[9]	New York City	New York		50
align=right	1570	XERF	Ciudad Acuña	Coahuila		100
align=right	1580	CKDO^[10]	Oshawa	Ontario		10

Alaskan class A (former class I-N) stations! kHz! Call
sign! City of license! Nat-
ion! kW! Transmitter coordinates

align=right	640	KYUK	Bethel		10
align=right	650	KENI	Anchorage		50
align=right	660	KFAR	Fairbanks		10
align=right	670	KDLG	Dillingham		10
align=right	680	KBRW	Barrow		10
align=right	700	KBYR	Anchorage		10
align=right	720	KOTZ	Kotzebue		10
align=right	750	KFQD	Anchorage		50
align=right	770	KCHU	Valdez		9.7
align=right	780	KNOM	Nome		25 / 14
align=right	820	KCBF	Fairbanks		10
align=right	850	KICY	Nome		50
align=right	890	KBBI	Homer		10
align=right	1020	KVNT	Eagle River		10
align=right	1080	KOAN	Anchorage		10
align=right	1170	KJNP	North Pole		50 / 21

Notes

List of former clear-channel stations

Freq. (kHz)	Call sign	City of license	State / province	Country	Fate
540	CBT	Grand Falls-Windsor	Newfoundland		Moved to FM on December 31, 2022.
850	XETQ-AM	Ixhuatlancillo	Veracruz		Migrated to FM as XHTQ-FM in 2013. At its height XETQ was authorized for 100 kW day/50 kW night. In the 1990s it lowered its power to 10 kW day/1 kW night.
1070	CBA	Moncton	New Brunswick		Moved to FM in April 2008. Canada has not withdrawn the international notification for CBA.
1190	WOWO	Fort Wayne	Indiana		Downgraded to class B in 1998 by reducing night power to 9.8 kilowatts with a three tower directional antenna; Inner City Broadcasting purchased WOWO so that its station in New York, WLIB, could remain on air 24 hours a day. WOWO was later purchased by Pathfinder Communications, the current owners.
1510	KGA	Spokane	Washington		Downgraded to class B in 2011 to make room for co-channel sister station KSFN, Piedmont, California, reducing night power to 15 kW^[11]
1550	XERUV-AM	Xalapa	Veracruz		A bad permit renewal, made in 2005, required this station to shut down in June 2016. When the university applied to resume operation on AM, it was denied, and the station moved to FM and launched XHRUV-FM on a frequency of 90.5 MHz on June 1, 2016.

History

In the early days of radio, regulators had difficulty reducing interference between stations. There were two major limitations: a lack of good frequency control during the 1920s, resulting in heterodyne tones that were encountered far beyond the range of understandable audio, and no directional antennas or skywave-suppressing vertical antennas until the early 1930s. The problem was much more severe at night, when skywave signals expanded station signal coverage to hundreds of kilometers. However, with most stations located at urban locations, quality skywave service was considered to be important for providing nighttime reception to the extensive rural regions.

For the U.S., a form of clear channels first appeared in 1923 when the Commerce Department started moving stations which had previously shared three^[12] (initially two)^[13] frequencies (two for entertainment stations, one for "weather and crop reports") onto a band of frequencies from 550 to 1350 kHz,^[14] which was later extended to 1500 kHz, with 550 to 1070 kHz reserved for higher powered "Class B" stations. Many of the Class B frequencies were assigned to a single station, although a few were used on both the East and West coasts, which were considered far enough apart to limit interference.^[15] Class B stations with transmitters located in population centers were limited to 1,000 watts,^[16] although stations that operated transmitters at remote sites were permitted to use up to 5,000 watts.

Problems intensified in the summer of 1926, when a successful challenge was made to the government's authority, under the Radio Act of 1912, to assign station transmitting frequencies and powers.^[17] This led to unrestricted expansion of the number of stations to 732, and increased the number of stations operating on same frequency. Moreover, previously stations had been assigned to transmitting frequencies of multiples of 10 kHz, which largely eliminated heterodynes from adjacent frequencies. However, during the lapse in regulation, some stations relocated to non-standard "split frequencies", increasing heterodyne interference.^[18]

The Federal Radio Commission (FRC) was formed in March 1927, and one of its key tasks was to reorganize the chaotic broadcast band. A May 1927 reallocation began the process, in part by eliminating "split frequency" operations.^[19] A December 1, 1927 report on the FRC's ongoing work reviewed operations on 600 to 1000 kHz, which divided these frequencies into ones that were considered "clear" and "unclear".^[20] Its 1928 implementation of General Order 32 was only partially successful in reducing the number of stations. On November 11, 1928, the FRC implemented General Order 40, which classified AM band frequencies as Local, Regional or Clear. Under restrictions imposed by the Davis Amendment, eight clear channels were assigned to each of five U.S. regions. This classification also reserved a small number of frequencies for use by Canada. The maximum power for clear channel stations was gradually increased to 50,000 watts: additionally there were some short-lived experiments with 250–500 kilowatt "super-power" operations, most prominently by WLW in Cincinnati, Ohio

The Federal Radio Commission was replaced by the Federal Communications Commission (FCC) in 1934. There was debate in Washington, D.C., and in the U.S. broadcasting industry, over whether continuation of the clear-channel system was justifiable. The licensees of clear-channel stations argued that, without their special status, many rural areas would receive no radio service at all. Rural broadcasters pointed out that most of the clear-channel stations were licensed to serve large cities on the two coasts, which made little sense for a service that was meant to provide radio to the vast rural areas in the middle of the country. On June 13, 1938, the U.S. Senate adopted resolution 294, sponsored by Burton K. Wheeler (D-Montana), which stated that it was the "sense of the Senate... that the Federal Communications Commission should not adopt or promulgate rules to permit or otherwise allow any station operating on a frequency in the standard broadcast band (550 to 1600 kilocycles) to operate on a regular or other basis with power in excess of 50 kilowatts".^[21] However, the clear-channel licensees argued that a 50,000 watt limit in the U.S. should be lifted. They pointed to successful experiments made by WLW in Cincinnati before World War II, and in later years successful implementation by state broadcasters in Europe and the Middle East, as evidence that this would work and improve the service received by most Americans. Other broadcasters, particularly in the western states, argued to the contrary; that if the special status of the clear-channel stations was eliminated, they would be able to build facilities to provide local service to those rural "dark areas".

The clear channel standards were continued by the March 1941 adoption of the North American Regional Broadcasting Agreement, during which most stations shifted frequencies, in order to increase the number of Canadian clear channel assignments, as well as provide clear channels to Mexico and the Bahamas. Because FM and TV stations did not yet exist, the FCC's main intent for the clear-channel assignments was to provide reliable radio service to the thousands of Americans who lived in the vast rural areas of the United States.^[22] As a result, these stations usually reached large portions of North America at night. Radio fans (and staff at those stations) often affectionately call such stations "flamethrowers" or "blowtorches" because of their high power, and boast about their reach by a combined state and provincial count of their coverage area. One of the most outspoken of the small-town broadcasters, Ed Craney of KGIR in Butte, Montana, went so far as to apply to move his station, then on the 1370 kHz regional channel, to a class I-A signal on 660 kHz, asking the FCC to downgrade the NBC New York flagship, WEAF, to make way for the Butte station.^[23] The FCC denied Craney's petition.

After 1941, several clear-channel stations applied for power increases to between 500 and 750 kW;^{[24] [25]} with dissemination of national defense information cited as one reason this would be in the public interest. In October 1941 the FCC's engineering department presented a report on a complete reorganization of the clear-channel service; the report considered the possibility of "some 25 superpower stations of 500,000 watts or more, strategically located to provide maximum service" (as Broadcasting described it), and suggested that stations would have to be relocated away from the east and west coasts in such a scenario, as coastal stations waste energy over the oceans. One complication the FCC considered was the 1938 Wheeler resolution suggestion that stations be limited to 50 kW.^[26]

One station, KOB in Albuquerque, New Mexico, fought a long legal battle against the FCC and New York's WABC for the right to move from a regional channel to a clear channel, 770 kHz, arguing that the New York signal was so weak in the mountain west that it served no one there. KOB eventually won the argument in the late 1960s; it and several other western stations were allowed to move to eastern clear channels. (Western clear channels, such as 680 in San Francisco, had been "duplicated" in the eastern states for many years.) These new Class II-A assignments (in places like Boise, Idaho; Las Vegas and Reno, Nevada; Lexington, Nebraska; Casper, Wyoming; Kalispell, Montana; and others) began what would later be called "the breakdown of the clear channels". The class I-A station owners' proposal to increase power fifteen-fold was not immediately quashed, but the new II-A stations would make it effectively impossible for stations on the duplicated channels to do so, and the owners eventually lost interest. That proposal was finally taken off the FCC's docket in the late 1970s.

On May 29, 1980, the FCC voted to limit the protection for all clear-channel stations to a 750-mile (1,207 km) radius around the transmitter. Stations on those frequencies outside the area of protection were no longer required to sign off or power down after sundown.^[27]

In 1987 the FCC changed its rules to prohibit applications for new "class-D" stations. (Class-D stations have night power between zero and 250 watts, and frequently operate on clear channels.) However, any existing station could voluntarily relinquish nighttime authority, thereby becoming a class-D, and several have done so since the rule change.

See also

• Regulation of radio broadcast in the United States
• Clear Channel Communications
• MW DX

External links

• AM Station Classes - Clear, Regional, and Local Channels (FCC Website)
• Big USA, Mexico, and Canadian AM radio stations

Notes and References

1. News: Remembering Buffalo's BBC. Scott. Fybush. February 26, 2010. Tower Site of the Week. March 13, 2018.
2. When two figures are listed, the first is daytime power, the second is nighttime.
3. 690 kHz at Montreal was originally assigned under NARBA to CBF (that station migrated to FM in 1998), and was later reused by CINF; after CINF closed in January 2010, CKGM applied for and was granted the frequency, and moved from 990 kHz to 690 kHz in September 2012.
4. 740 kHz was used by CBC Radio One's CBL in Toronto until 2000 when the station moved to 99.1 FM. CFZM, known at the time as CHWO, acquired 740 in 2001.
5. 940 kHz at Montreal was originally assigned under NARBA to CBM (that station migrated to FM in 1998), and was later reused by CINW, which ceased operations in 2010. Despite leaving the air, it remained notified to the U.S. as a class-A allotment. A new license has since been granted to Tietolman-Tétrault-Pancholy Media (TTP) to broadcast a French news-talk format at 940 AM by the CRTC. After numerous delays, the station began broadcasting a series of test tones intermittently on October 26, 2016. Official testing began on November 16, 2016, with music and recorded announcements with a phone number to report signal interference. Although the station was given a deadline of November 21, 2016, by the CRTC to launch its French news-talk format, the station has yet to do so.
6. Nighttime site.
7. 1550 kHz was originally CBE (AM), which shut down the AM station after moving to 97.5 CBEW-FM in 2011. On November 1, 2012, CBEF, traditionally on 540 kHz, also started broadcasting on the same AM transmitter and frequency that CBE had used.
8. [KNZR (AM)|KNZR]
9. [WFME (AM)|WFME]
10. 1580 kHz was originally used by CBJ in Chicoutimi, Quebec. After that station moved to FM in 1999, CHUC applied for and was granted 1580 kHz in Cobourg, Ontario, with 10 kW, but chose instead to move to FM itself (despite being notified to the U.S. as an existing station on 1580). CKDO moved from 1350 to 1580 kHz on August 13, 2006, and became that day a class A station using 10 kW. U.S. FCC record is at http://www.fcc.gov/fcc-bin/amq?state=&call=CKDO&freq=530&fre2=1700&type=0&list=0&size=9
11. FCC license BL-20100527AGH
12. https://babel.hathitrust.org/cgi/pt?id=umn.319510008420257&view=1up&seq=462 "Amendments to Regulations: Regulation 57"
13. https://babel.hathitrust.org/cgi/pt?id=osu.32435066705633&view=1up&seq=200 "Amendments to Regulations"
14. https://archive.org/details/radioage12unse/page/n362/mode/1up/ "Radio Conference Recommendations: New Wave Lengths"
15. https://babel.hathitrust.org/cgi/pt?id=uiug.30112106763060&view=1up&seq=60 "Broadcasting stations of the United States by wave lengths"
16. https://chroniclingamerica.loc.gov/lccn/sn83045462/1924-10-20/ed-1/seq-18/ "U.S. Radio Power Scale Announced"
17. https://babel.hathitrust.org/cgi/pt?id=mdp.39015051148388&view=1up&seq=182 "Federal Regulation of Radio Broadcasting"
18. https://babel.hathitrust.org/cgi/pt?id=uiug.30112106763060&view=1up&seq=451 "Broadcasting stations, alphabetically by call signals"
19. https://babel.hathitrust.org/cgi/pt?id=uiug.30112106763078&view=1up&seq=60 "List of broadcasting stations issued temporary permits"
20. https://babel.hathitrust.org/cgi/pt?id=mdp.39015018399975&view=1up&seq=16 "Broadcasting stations by frequency, showing clear channels (600 to 1,000 kilocycles band), effective December 1, 1927, and subsequently" and "Broadcasting stations, by frequencies, showing uncleared channels (600 to 1,000 kilocycles), effective December 1 and subsequently"
21. https://babel.hathitrust.org/cgi/pt?id=mdp.39015087659424&view=1up&seq=511 "Limitation of Power of Radio Broadcast Stations"
22. Rural Radio Magazine, Vol. 1 No. 1, Clear Channel Group (November 1938), p. 2
23. KGIR, Butte, Requests 50 kw. On WEAF Clear Channel . September 1, 1941 . Broadcasting and Broadcast Advertising . Washington, D.C. . Broadcasting Publications, Inc. . 21 . 9 . 16.
24. . WHAS Superpower . October 27, 1941 . 52 . 21 . 17 . Broadcasting Publications, Inc. . Washington, D.C. . A half-dozen other applications ranging from 500,000 to 750,000 watts now are pending.
25. . WSB Revives Its 500-kw. Application, Seventh Stations Seeking Superpower . November 3, 1941 . 57 . 21 . 18 . Already pending before the Commission were the applications of WLW, Cincinnati, for 650,000 watts, WOAI, San Antonio, seeking 750,000 watts, KSL, Salt Lake City, for 500,000 watts, and WSM, Nashville asking 500,000-watt operation. Similarly the application of WHO, Des Moines, for an increase to 500,000 watts is reported to be about ready for filing..
26. . Superpower, Clear Channels Slated for Early FCC Probe . October 20, 1941 . 21 . 16 . 12.
27. Facts on File 1980 Yearbook, p. 519