Talk:Clear-channel station

Nation Icons
I added flag icons to the table of stations to show which are American, Canadian, etc. A user keeps reverting them as unnecessary. I disagree. I will revert it once again to include the flag icons, please discuss here if you agree or not. Please do not remove again until a consensus is achieved. — Preceding unsigned comment added by N9jig (talk • contribs) 19:10, 26 September 2022 (UTC)

Old errors
This article gets a bunch of things wrong. For starters, a "clear channel" is by definition a station which does not share its channel with any other. The old I-Bs were never "clear channel" stations, nor were the I-Ns, and this status was completely eliminated by the "Rio accord". The long list of stations ought to be labeled something like "List of stations in North America which are called out as being of class A under the ITU Region II Mediumwave Coordination Agreement of 1981" or some such.

There are important differences between class A stations and class B stations, even though the clear channels as such no longer exist. Specifically:
 * Class A stations must operate with at least 10 kW, and are restricted to specific locations and frequencies set out under Rio and previous international agreements. CBE and CBN are the last 10-kW class-A's.
 * Class A stations, unlike all others, have a protected nighttime skywave ("secondary") service area.
 * Class A stations, unlike all others, are entitled to protection from daytime skywave interference to their groundwave ("primary") service area (mostly a factor on the high end of the band, 1500 to 1560 kHz).
 * Class A stations must meet a higher minimum antenna-system efficiency than class B stations.
 * Once a station has lost class A status, it can never regain it. By contrast, a class B station may relinquish nighttime authority (thereby becoming a class D) and then later be returned to class B upon grant of an application to resume night operation.  This has happened, in the case of WOWO, which was demoted from A to B in order that WLIB might be promoted from D to B.  (With WOWO protected as an A, WLIB could not operate at night; as a B, WOWO no longer has a protected secondary service area, so WLIB need only protect WOWO's groundwave.)
 * Class A stations have generally not been subject to the "ratcheting" rules which require modifications to AM station facilities to reduce interference by at least 10%.

Class A includes all of the stations formerly designated as class I-A, I-B, or I-N. Class B includes the former classes II (secondary assignments on I-B channels) and III (regional channels, limited to 5 kW nominal power), except II-D and III-D which became class D. Class C is the former class IV (graveyard channels).

The breakdown of the clear channels began in the 1960s, when the FCC began assigning class II-B stations in the West on Eastern class I-A channels; in one case (KOB Albuquerque versus WABC on 770) the matter went all the way to the Supreme Court (and was decided in the FCC's and KOB's favor). In a last-gasp attempt to preserve their relevance, several of the I-A stations asked the FCC to increase the power limit from 50 kW to 750 kW. This was eventually turned down when even many of the I-A stations came out against it.

Protection of foreign class-A stations is still much stronger than protection of domestic class-A stations, in all three countries. This is an artifact of the requirement in NARBA that all stations on another country's I-A channel protect the entire border of the assigned country.

Oh, and nearly all of the callsigns in that big long list are wrong as well. Tain't no such thing as "-AM".
 * 18.26.0.18 05:45, 25 Jan 2005 (UTC)

Data source
The data in the updated version of the table comes from the FCC's Consolidated Database System (CDBS). The following SQL query was used to extract the relevant information from the public CDBS dumps:

select distinct fac_callsign as "Call", fac_frequency as "Freq.", comm_city as "City", station_class as "Cl.", region_2_class as "R2", old_station_class as "Old" from facility join am_eng_data using (facility_id) where station_class = 'A' and fac_country in ('US', 'CA', 'MX') order by fac_frequency, fac_callsign

I then filtered the data for known errors and silent stations, and added ZNS1 back in (since The Bahamas counts as "North American"). 121a0012 19:04, May 30, 2005 (UTC)

CKLW
Weird question, the CKLW page lists it as a Class A, but it's not on the list. Any thoughts?--RAult 08:52, 26 September 2007 (UTC)


 * I believe the CKLW page is wrong. 800 was/is a Mexican clear channel; all of the Canadian allocations on that frequency are old-class-IIs (modern class-Bs).  The FCC database, while not authoritative for Canadian or Mexican stations, agrees -- and since the FCC records determine the protection offered by U.S. stations to those stations, I would expect the authorities to correct errors of that sort very quickly.  It shows 31 class-Bs in the U.S. (and the rest are all class-Ds, which are treated like class-Bs for international purposes); 10 class-Bs in Canada; 7 class-Bs in Mexico; and one class-A in Mexico.


 * Under the ITU Region 2 Mediumwave agreement, AM stations are notified to national authorities throughout the Western Hemisphere. The FCC database shows class-A assignments on 800 in Brazil (2), Colombia, Cuba, Mexico, Venezuela, and the Netherlands Antilles.  None in Canada.  121a0012 03:09, 27 September 2007 (UTC)


 * I'm not sure what class CKLW (AM) used to be in the 1970s or before, but I'm certain it's currently a Class B (normal 50kW station) sitting on a Mexican clear channel, not a Class A (clear channel station) sitting on a Canadian clear channel. Here's a rundown of the stuff I found:
 * Official sources:
 * (U.S. government records) says CKLW is notified to the U.S. as a class B. It also is notified as having a multi-antenna directional pattern, which would probably not be as important for a clear channel in the middle of the continent.
 * Industry Canada's dBase III files (linked from - it's hiding in AMSTATIO.DBF if you care) show CKLW as a class B.
 * Wikipedia articles:
 * Border blaster says (unreferenced): "While licensed as a normal Class I-B station, its 50,000 watt directional signal blanketed Michigan and northern Ohio east to Cleveland. American-owned until 1970, it functioned as a Detroit-market station during the 1960s and 1970s." Old Class I-B is now Class A; I suspect that's supposed to say "normal Class B", not "normal Class I-B".
 * CKLW (AM) says Class A in the infobox but says in the text: "Even more impressive is the fact that this is not known to be a a clear channel station."
 * External sites:
 * http://www.thirteen.org/blogs/index.php?itemid=99 says: "Clear channel stations, once designated as Class I-A and I-B stations, are now designated as Class A AM stations. (There are other 50,000 watt stations but they are not clear channel stations, and are not protected from interference and have no recognized wide area coverage at night. Examples include WRKO 680 Boston, WEEI 850 Boston, WINS 1010 and WEPN 1050 New York, CKLW Windsor, Ontario, KTRH 740 Houston, and KCBS 740 San Francisco, among many others.)"
 * Robert Meuser in says: "CKLW is not an A and is not Omni (they are DA-2)"
 * Neil S. Adams in http://www.dobe.com/wts/funk/clears.txt on 1997-02-03 lists 800 kHz as "Mexican clear" (not "Canadian/Mexican Clear" like 940). He shows some Canadian I-B stations on Mexican clears in this chart, but not for 800 kHz &mdash; CKLW is shown as Class II (now called Class B):
 * {| class="wikitable"


 * + 800 (Mexican Clear)
 * XEROK || Ciudad Juarez, Mexico || 150kW || I-A || ND
 * CKLW || Windsor, ON           || 50kW  || II  || DA-2
 * CHRC || Quebec City           || 50kW  || II  || DA-1
 * }
 * I'll try and change the articles on Wikipedia to reflect this. --Closeapple 22:22, 29 September 2007 (UTC)
 * }
 * I'll try and change the articles on Wikipedia to reflect this. --Closeapple 22:22, 29 September 2007 (UTC)

KTWO 1.030 MHz in Casper, WY is not class A?
Excuse me, I once edited this page, edit was removed, but as far as I know, KTWO Casper, is class A, and both WBZ Boston, and KTWO must use directional antennas at night to keep down co-interference. KTWO is also one of only 10 Primary Emergency Alert System AM Stations in the USA (Source: FEMA Manual 1550.2 Page D-3 (http://www.vdem.state.va.us/library/handbooks/nawasmanual2001.pdf)). I seriously doubt this responsibility would be given to less than a true clear channel station with wide service area. Also please note WBZ Boston, a clear channel on the same frequency, is on that list. Please check your sources, and I re-submit KTWO for inclusion in the list. —Preceding unsigned comment added by 69.145.40.116 (talk) 06:10, 30 November 2007 (UTC)
 * You are incorrect. KTWO is a class B station, and has been since the system of lettered classes was introduced.  Prior to that, it was a class II-A station.  (There are 36 Primary Entry Point stations in the Emergency Alert System according to references more recent than your 2001 FEMA document, but the class of station is not relevant to this status.  It's hard to find a list of which stations are currently participating as PEPs or NPs, although I have seen the equipment at most of them.)  121a0012 (talk) 06:34, 30 November 2007 (UTC)

I agree, I was incorrect, doubly so for excluding the AM qualifier. I wish to change my post to read...

Perhaps this list is a little too tight only allowing class A stations. KTWO, in Casper Wyoming, is known very far and wide as a Clear Channel AM station (Not to be confused with it's owners, Clear Channel Communications) But is listed as clear channel in other federal documents, and is of national importance. KTWO is one of only 10 Primary Emergency Alert System AM Stations in the USA (Source: FEMA Manual 1550.2 Page D-3 (http://www.vdem.state.va.us/library/handbooks/nawasmanual2001.pdf)). I seriously doubt this responsibility would be given to less than a true clear channel station with wide service area. Also please note WBZ Boston, a clear channel on the same frequency, is on that list. I submit that a Class B 50KW Day/50KW Night list also be included in this article. (As a note of trivia, KTWO has sent QSL cards to every continent, including Amundsen-Scott South Pole Station in Antartica)

( I had only edited this page 20 minutes before your reply, give me some time for recheck. :) zaphodb777(at)gmail.com ) —Preceding unsigned comment added by 69.145.40.116 (talk) 06:44, 30 November 2007 (UTC)
 * Actually, it is known far and wide as one of the stations that contributed to the breakdown of the clear channels (although of course KFMB and KKOB take pride of place). The history in the article goes into this in some detail.  Only stations of the former classes I (I-A, I-B, and I-N) were ever considered to be "clear channel stations".  Now, it is true that a number of stations with secondary assignments on the clear channels called themselves "clear channel" -- but of course it was someone else's clear channel they were assigned to (most were daytimers).  Since "clear channel" was a distinction made by the FCC for regulatory purposes, we follow their usage.  (I live in a market where there are four 50 kW-U stations, all DA-2, which don't even cover the entire market never mind a significant region of the country as the II-As were intended to.)  It may be worth having a list of the II-A stations since they were the result of the "breakdown" which is an important topic treated in this article.  121a0012 01:21, 1 December 2007 (UTC)

KSTP clear-channel status
Is KSTP actually a clear channel station? The KSTP (AM) page gives conflicting information; There was also another comment on Talk:KSTP (AM) about it, too. The FCC query page indicates that while it maintains 50kW at night, it uses a directional antenna (but it's not directional during the day.) Does it therefore still count as a clear channel station, as long as it maintains 50kW? Mystic Pixel (talk) 07:10, 4 April 2008 (UTC)


 * Operating with 50 kW is neither necessary nor sufficient. This article treats as "clear channel stations" all stations in the United States, Canada, Mexico, and the Bahamas which are considered to be "class A" under the Region 2 Mediumwave Agreement ("Rio").  In the U.S., such stations must operate with at least 10 kW full-time (thus the significance of WOWO being downgraded to 9.8 kW nights)  and must have a minimum antenna-system efficiency of 282 mV/m/kW at 1 km .  See also the list at fcc.gov/mb/audio/amclasses.html, which identifies stations having specific class and frequency assignments by international agreement or FCC rule; KSTP is on that list, as a class-A station.  (So is KNZR in Bakersfield, which operates with 25 kW-D, 10 kW-N, DA-N.)  121a0012 (talk) 01:40, 5 April 2008 (UTC)


 * Ahh, ok - I didn't think 50kW was the critical condition, but I was wondering about the directional thing. Thanks for the links and info. Mystic Pixel (talk) 22:01, 6 April 2008 (UTC)

Breakdown of the clear channels
So in 2008 are there any North merican stations remaining which can still be meaningfully described as "clear channel" ? 213.40.129.129 (talk) 15:29, 22 November 2008 (UTC)


 * Yes and no. They are certainly not "clear" in the communications sense (only one transmitter at a time), but that hasn't been true since before the War.  The status still exists in international treaties and in domestic regulations of the relevant countries: the clear-channel stations are those which have a "secondary service area" as described in the article.  The vast majority of stations do not.  (The stations listed in the article are the only such stations as can ever exist, absent a major -- and unlikely -- change in regulation across North America.)  121a0012 (talk) 07:03, 24 November 2008 (UTC)

I think we also need a list of class B stations. I was listening last night to CFFR 660 from Calgary on my car radio in Oregon. I never had a list before, so I looked here for one, and was surprised to see that 660 Calgary is not on the list. It seems that it is class B. What I would like is a list of stations that I might expect to receive at night ( with an ordinary radio), and it seems that should include class B stations. Even more, I would like a list that I can print on one page and keep in the car. Gah4 (talk) 21:40, 3 August 2009 (UTC)
 * There are 1,717 class-B AM stations in the United States alone. Are you sure you want to undertake that effort?  Here is a current count for all four station clases:
 * {|class="wikitable" border="1"


 * Class
 * Count
 * A
 * 75
 * B
 * 1,717
 * C
 * 1,006
 * D
 * 2,008
 * }
 * 121a0012 (talk) 01:53, 4 August 2009 (UTC)
 * D
 * 2,008
 * }
 * 121a0012 (talk) 01:53, 4 August 2009 (UTC)
 * 121a0012 (talk) 01:53, 4 August 2009 (UTC)

Well, what do they need to be to effectively be clear channels? I received CFFR 660 from Calgary from about 900 miles away on a car radio. I will guess that there could be about 400 stations where one could be 900 miles away from the nearest class B on that frequency. (How many 900mi radius circles can you draw centered within the continental US and not overlapping?) Gah4 (talk) 04:20, 7 August 2009 (UTC)
 * I've heard 891 from Algeria from 2,000 miles away on a car radio; that doesn't mean that such stations form a meaningful, verifiable category. This page lists the stations that have a secondary service area.  Any nighttime skywave service you get from any other station is just gravy: it's not protected by law or treaty, just an unintentional result of the physics of mediumwave propagation from a station that was never intended to serve a wide area (former class II-A excepted). 121a0012 (talk) 04:08, 8 August 2009 (UTC)

Missing Mexican Class A stations
While I was looking at the FCC database (looking for daytimers) I found 3 Mexican stations not listed in this article or Template:Clear-channel AM but somehow notified (or at least in the database) as Class A: Is there a reason those 3 are not in the article? Were they the subject of later NARBA updates (there were some), notified under the 1981 Rio agreement, or addressed by the 1986 bilaterial U.S.-Mexico agreement one way or the other? Are they protected in the same way as the traditional clear-channel allocation, or in a different way? (On a related subject: there appear to be 70 full-power Mexican daytimers and 45 low-power Mexican daytimers notified in the FCC database also.) --Closeapple (talk) 00:02, 29 May 2010 (UTC)
 * 1000 XEOY-AM, in the FCC database as 50kW day 10kW night at Iztacalco, D.F.; shown in the official domestic INFRA_AM.pdf (as of 2009-12-31) as 50kW day 20kW night at Ciudad Mexico
 * 1090 XEPRS-AM, in the FCC database as 50kW day & night in three places just for good measure: "Rosarito", Baja California (coded as "BN"); "Rancho del Mar", Baja California (coded as "BC"), apparently some subdivision of Rosarito; and "Rancho Los Tres Herm.", Baja California (coded as "BC"), which appears to be "Tres Hermanos", a name vaguely common in Tijuana; in INFRA_AM.pdf as 50kW day & night at Rancho del Mar; used to be the border blaster known as XERB before 1972
 * 850 XETQ-AM, in the FCC database as 100kW day then once as 50kW night and once as 10kW night, at Orizaba, Veracruz; in INFRA_AM.pdf as 10kW day and 1kW night at Ixhuatlancillo, Veracruz
 * Good question. See, above, for the SQL query from which this list originally came.  Perhaps I got it wrong, or the data in CDBS is wrong (very likely -- the actual facilities of Mexican stations are often at variance from what is notified to the U.S.).  Here's what I can tell you from the most recent CDBS:
 * XEOY has one record, with domestic and region 2 class both 'A'.
 * XEPRS has five records; one for Rancho Del Mar (2006-06-02), class A/A; two more for Rancho Del Mar (2009-10-08), one class A/A and one class NULL/NULL; one for Rosarito (last_change_date NULL) for class A/A; and another for Rosarito (2009-10-08) class NULL/NULL. The Mexicans can't seem to decide whether to notify stations by their community of license or by the transmitter location; 1090's transmitter is in Rancho Del Mar if I remember correctly (it's been a few years since I was there); it's still a "border blaster", programmed for the San Diego market.
 * XETQ has two records, both class A/A. (The duplication is probably day vs. night facilities, which you can't tell from the am_eng_data table.)
 * So yes, it appears that these stations should have been included in the lists. 121a0012 (talk) 06:31, 29 May 2010 (UTC)
 * And I just reran the query shown above and the three stations you mention were all in the list, so I don't know how they got deleted. Here's a slightly revised version of the query that avoids some (but not all) of the errors by ignoring records that are marked as "archived" in the am_ant_sys table:

select distinct fac_callsign as "Call", fac_frequency as "Freq.", comm_city || ', ' || comm_state as "City", station_class as "Cl.", region_2_class as "R2", old_station_class as "Old" from facility join am_eng_data using (facility_id) join am_ant_sys using (application_id) where station_class = 'A' and eng_record_type <> 'A' and fac_country in ('US', 'CA', 'MX') order by fac_frequency, fac_callsign
 * 121a0012 (talk) 06:51, 29 May 2010 (UTC)

Here are those records with the day/night/pattern-type records for you (but not the dates). For what it's worth, I get my data by doing the web-based FCC AM Query, because I usually do my thing by piping it through scripts so I'm too lazy (as yet) to try to pull in from two inputs/tables at once. I dumped AMQ for all class A (351,163 bytes) at 01:20 Eastern on 2010-05-31 then did this:

And a little wiki formatting:

In the AMQ output, all these have A for domestic and international classes instead of null/dash, for what it's worth. I'm going to add them to the article, but I'm also trying to clean up North American Radio Broadcasting Agreement and this one slowly, and possibly make a Rio agreement article also, so I'd love to know how these stations got their status, which involves knowing the history of 850 and 1000 down south, and/or whether were ever relevant to the U.S. (they're closer to Florida than Denver, but over the Gulf) or were a factor for Cuba, which was where NARBA was negotiated. --Closeapple (talk) 07:07, 31 May 2010 (UTC)


 * To close the book on XETQ, it was indeed once 100/50; it went 10/1 in the 90s or early 2000s. The resource that made this information available, the IFT Public Concessions Registry, was not available until early 2014 — it is a gem of a source for writing Mexican radio and television history articles, and it really shines with the old AM concessions it has available. The station also migrated to FM (it's now XHTQ-FM), so it is now silent on AM. Raymie (t • c) 08:20, 1 July 2015 (UTC)

CFRN (AM)
I was looking on the revision history for this article, and there seems to be a dispute over CFRN's class A status. User "121a0012" undid the revision stating that this station is not a Clear Channel station. Well, according to a REC Broadcast Query of CFRN, http://cdbs.recnet.net:8080/fmq.php?canam=CFRN it is classified as a 50KW Class A station. I don't seem to be connecting the dots here. Are Canadian clear-channel stations classified differently? I thought Class A meant Clear-Channel status? Joski1624 (talk) 05:46, 27 October 2011 (UTC)

FCC records also indicate that CFRN is a Class A station. Joski1624 (talk) 05:59, 27 October 2011 (UTC)

The Lead Section
The lead section seems to talk around the subject, listing truisms etc, without ever getting to the meat, the concept, the why and the how. It also makes assumptions that the average guy does not have. ...for example it says: "A clear-channel station is an AM band radio station in North America that has the highest protection from interference...." Protection?? ...like lead shielding or a giant condom? Or could it mean government protection, and (wild-assed-guess) that a clear channel station is actually first a legal term within a government regulation while a brick and mortar clear channel station is a station that abides by those rules and designations to receive special regulatory entitlements and government protection?? ...not that anything like that is suggested in the Lead....nor contrary to that....

consider: First sentence http://en.wikipedia.org/wiki/Wikipedia:MOSINTRO#First_sentence "The article should begin with a declarative sentence telling the nonspecialist reader what (or who) is the subject. "...If its subject is amenable to definition, then the first sentence should give a concise definition: where possible, one that puts the article in context for the nonspecialist. Similarly, if the title is a specialised term, provide the context as early as possible"....etc

Also: Manual of Style (lead section) Quotes: "The lead serves both as an introduction to the article and as a summary of its most important aspects. The lead should be able to stand alone as a concise overview of the article. It should define the topic, establish context, explain why the subject is interesting or notable, and summarize the most important points—including any prominent controversies. ...and the notability of the article's subject should usually be established in the first few sentences."

And why do they exist? What is their alleged purpose, now and historically?

After the lead: And since the once-public airwaves (owned by the people for the common good) have been largely privatized (owned largely by quasi-monopolistic (anti-Market) corporations for private profits) by Reagan and Clinton, are the government subsidies (like entitlement, protection via treaty etc) still "paid for" with costly obligations and responsibilities to the common good? Or are they like so much today, government subsidy free-lunch give-aways of another We-the-People's Natural Monopoly, —welfare for the rich, to keep the Big Boys on top and everybody else as also-rans?? Is all this controversy really so unworthy as as to deserve zero mention? --68.127.87.79 (talk) 04:05, 14 August 2013 (UTC)Doug Bashford
 * In a word, yes. At least so far as I can understand your rant above. If you'd care to come back with some reliable third-party sources, perhaps we can have a proper discussion, rather than a political diatribe.  121a0012 (talk) 05:42, 16 August 2013 (UTC)

Cycles?
Every mention of "cycles" (with or without prefixes) should be changed to "Hertz", along with the attendant abbreviations. Peppering Wikipedia articles with archaic scientific terms helps nobody. HuntClubJoe (talk) 20:59, 13 November 2015 (UTC)


 * So fix it then. Proper usage currently (no pun!) is kHz, MHz. Complaining isn't particularly productive either. :) -- dsprc   [talk]  17:51, 30 November 2015 (UTC)