Mystique of the Three-Letter Callsigns

Thomas H. White -- January 1, 2025

Three-letter calls in the United States are an emotional topic for many -- the "passing" of one leads to mourning and oratory on the need to protect these historic creatures from extinction. However, some misconceptions do exist. This is a review of the origin and history of these unique calls, plus information on some equally interesting four-letter calls.
Sections

Background

By today's standards, the continued emphasis in the United States on call letters for radio, an entertainment and information service, is something of an anachronism -- most other countries have switched to slogans or network IDs for establishing public identity. One can imagine the cries of outrage which would result if a stuffy bureaucrat were to try to force, say, the New York newspapers to deal with the public through their "newspaper signs" of "WNYT" or "WPST". What kind of circulation would magazines entitled "WTME", "WMS", and "KGQ" garner? Still, with a century of tradition, call letters are fixed upon the American psyche. Besides, they make bookkeeping at the Federal Communications Commission easier.

Original Regulations

The use of identifying radio callsigns dates actually had its origins in wire telegraphy, where each station and operator along a telegraph line was assigned a short "call" or "signal". Because all early radio work was also done in telegraphic code, spelling out an operator's full name or location would have been cumbersome, so, following the landline telegraph practice, radio transmitter calls were assigned, usually from one to three characters and often based on geographic location or personal or ship names. Thus, stations "calling" each other were able to link up with a minimum of sorting out identities. Unfortunately, during this self-assigned era there were few standards, which resulted in problems when, say, two or more ships chose the same call. Unique identifiers, organized by national origin, were needed in order to keep track of exactly which vessel was in danger of visiting Davy Jones' locker.

With the adoption by the United States, in 1912, of an act to regulate radio stations, call letter assignments became formalized under federal authority. Under international agreement unique initial letters were allotted among the various nations. The July 1, 1914 edition of Radio Stations of the United States records the contemporary practices for allocating calls for sea and commercial land stations, which at this time were few enough so that all could be given three-letter calls:

The call letters assigned to the United States are all combinations (676) beginning with the letter N and all (676) beginning with the letter W, and all combinations (598) from KDA to KZZ, inclusive. [NOTE: KAA-KCZ was allocated to Germany at this time, and was not assigned to the United States until 1929.] The total number of international calls is thus 1,950, and these are reserved for Government stations and stations open to public and limited commercial service. All combinations beginning with the letter N are reserved for Government stations and in addition the combinations from WUA to WVZ and WXA to WZZ are reserved for the stations of the Army of the United States.

The combinations KDA to KZZ, with a few exceptions, are reserved for ship stations on the Atlantic and the Gulf of Mexico and for land stations on the Pacific coast. The combinations beginning with W (except WUA to WVZ and WXA to WZZ as already indicated) are reserved, with a few exceptions, for ship stations on the Pacific and Great Lakes and for land stations on the Atlantic and Gulf coasts and in the Great Lakes region.
Notice the policy was that calls for ocean-going ship stations started with a different letter than the land stations they communicated with: in the West ships received W-- calls and land stations were assigned K--, while the reverse was true in the East, with K-- ship calls and W-- land calls. (NOTE: The assignment of W and K to the United States appears to have been completely arbitrary--the letters have no particular significance. N, however, had been commonly used by the U.S. Navy since November, 1909).

Amateur and Special Land stations fell into a separate callsign scheme. In fact, they did not qualify for "international" calls, and the International Bureau at Berne was not notified of their existence. The United States was divided into nine Radio Inspection Districts and these stations received calls consisting of their district number followed by a pair of letters. Regular amateurs received calls whose first letter was from A through W, for example, 8MK. (The 1914 Radio Stations of the United States noted that "The three items-a given figure first, followed by two letters of the alphabet-thus may be combined in 598 different calls, which will probably suffice for the amateur sending stations in most districts for some time to come".) Among the three licence classes known collectively as Special Land Stations, X was reserved as the first letter for stations holding Experimental licences (e.g. 1XE), Y designated stations holding a Technical or Training School licence (e.g. 9YY), and Z went to stations operating with Special Amateur licences (e.g. 8ZZ). More letters and numbers were added as the number of amateurs grew. Also, as the range of amateur signals increased it became necessary to internationalize their calls, so beginning October 1, 1928 W and K prefixes were added.

Refinements

The Bureau of Navigation, a division of the Department of Commerce, regulated United States radio until the 1927 formation of the Federal Radio Commission. In 1934 the Federal Communications Commission succeeded the FRC. Understandably, the various agencies occasionally found it necessary to refine callsign practices.

In the early teens most non-amateur land stations engaged in ship-to-shore communication, and were found clustered along the coasts. As other services were developed stations crept inland, and a dividing line between the western K's and eastern W's was needed. As noted earlier, coastal land stations in states along the Atlantic and Gulf coasts, including Texas, received W calls. Thus, using the Texas-New Mexico border as a starting point and heading north, the original boundary ran along the eastern borders of New Mexico, Colorado, Wyoming, and Montana.

K/W MAP Click here for a detailed map showing the boundary change It was only in late January of 1923 that the Mississippi River, the current standard, was adopted as the dividing line. This meant new call grants in North and South Dakota, Nebraska, Kansas, Oklahoma, Texas, Iowa, Missouri, Arkansas, and western Minnesota and Louisiana became K's rather than W's. However, existing stations west of the Mississippi were permitted to keep their now non-standard W calls. Thus, pioneer broadcasters such as WKY Oklahoma City, Oklahoma, WOI Ames, Iowa, and WHB Kansas City, Kansas remain as monuments to the period before the boundary change.

World War I also had a disruptive effect. German submarines did much to popularize radio among American ships as wireless, formerly an expensive option, became a life-or-death necessity for making the Atlantic run. Unfortunately, there weren't enough three-letter calls to go around. The obvious solution was more letters, and four letter KE-- signs became the predominate issue for the rapidly expanding ship service, generally issued on a first come, first served basis in alphabetical order. The department, apparently noting the existence of the Panama Canal meant ships might show up on either coast, no longer tried to give ship calls that differentiated between the east and west coasts.

The less numerous land stations continued to receive three-letter calls, as turnover provided a reserve pool. Actually "turnover" is in some cases a euphemism. In the July, 1928 Radio Broadcast magazine, Broadcast Station Calls With a Past by William Fenwick reviewed a few land stations, including broadcasters WSB Atlanta and KLZ Denver, which received calls that became available with the demise of the ships that had used them. Because superstitious seafarers objected to being issued the calls "used by that ship which went down with all hands last month", these "tainted" calls were quietly issued to unsinkable land stations.

Showing partiality to vowels, the next major blocks drawn upon for ship stations were four letter KI--, KO--, and KU-- calls. After exhausting the vowels, and with KA-- to KC-- not yet assigned to the United States, the first available consonant, KD--, was drafted for ships beginning June 1920. At this point an anomaly occurred. The Bureau, perhaps caught up in a burst of egalitarianism, began assigning the last of the KU--, and the new KD-- calls to most stations, whether land or sea. The result, on October 27, 1920, was that a new Westinghouse station in East Pittsburgh, Pennsylvania, KDKA, was sandwiched between the ships Montgomery City (KDJZ) and Eastern Sword (KDKB). The "KD-- for everyone" policy continued until April, 1921, when the original three-letter land station policy was reinstated. This meant that, in May, 1921, when the second Westinghouse broadcast station, WJZ in Newark, New Jersey (now WABC, New York City) was authorized, the original call policy had been restored. Much speculation has been made about the unique status of KDKA's call, but this uniqueness actually is just a fluke, due to the fact that no other surviving broadcaster was licenced during this short anomaly. Had KDKA been licenced a few months earlier or later it most likely would have gotten a three-letter W call like everyone else.

[NOTE: two other land stations licenced during this anomaly, KDPM Cleveland, Ohio, and KDPT San Diego, California, both originally non-broadcasting service stations, later transferred to the broadcast service but were eventually deleted.]

Dawn of the Four Letter Calls

The flood of broadcasting service authorizations that began in earnest in December of 1921 served to overload the recycling three-letter land station calls. Before the crunch the Bureau was able to assign three-letter callsigns to about 200 broadcasters.

It was the more saturated East that was the first to feel the pinch. On April 4, 1922 an application from the Times-Picayune of New Orleans broke new ground with the assignment of WAAB (now WJBO, Baton Rouge) as its call. [NOTE: WAAA was skipped as no sign was permitted with the same letter three times in a row.] The progression continued in alphabetical order, with "A" fixed as the third letter, i.e. WAAB, WAAC, WAAD... WBAB, WBAC... etc. This explains why so many pioneers such as WBAP Fort Worth, Texas, WCAU Philadelphia (now WPHT), WEAF New York City (now WFAN), WHAS Louisville, Kentucky, WKAR, East Lansing, Michigan, WMAQ Chicago (now WSCR), WOAI San Antonio, and WTAM Cleveland share this same middle letter. In later years it became the norm for broadcasters to ask for distinctive calls. However, if they had no preference they were assigned calls from blocks used for a variety of radio services. Starting April of 1923 calls centering on "B" were issued, including WBBM Chicago, WCBM Baltimore, Maryland, WLBL Stevens Point, Wisconsin (now Auburndale - the station had requested "WLOL", but was told it had to accept a conforming W-B- call) and WMBD Peoria, Illinois. In mid-1928 there was a jump to the middle of the W-D- block, which yielded WHDH Boston (now WEEI) and WRDW Augusta, Georgia. W-E- calls followed beginning in early 1931, including WDEV Waterbury, Vermont, WEEU Reading, Pennsylvania, and WFEA Manchester, New Hampshire. In 1934, W-F- calls started to be assigned, including WMFJ in Daytona Beach, Florida.

The West held out until May 8, 1922, when western broadcasters started sharing the four-letter ship blocks. KDYL in Salt Lake City was both the first authorization and last survivor of this group. When it became KCPX (now KNIT) December 21, 1959 all thirty-three KD-- authorizations from this switchover had either expired or changed calls. The KF-- block, begun June 1922, boasts a few more noteworthies, including KFBK Sacramento, California, Doc. Brinkley's infamous KFKB, KFNF Shenandoah, Iowa (now KYFR), KFQD Anchorage, Alaska, and KFYR Bismarck, North Dakota. The KG-- group was tapped July 1926: KGEZ Kalispell, Montana and KGFX Pierre, South Dakota are two that survive to this day. (A ship station was not as fortunate. KGOV was assigned to the Morro Castle, which went on to burn spectacularly off the New Jersey coast in 1934. However, surprisingly KGOV is currently unavailable for use by broadcasting stations, since it is technically still assigned to the ship, according to the FCC's online Call Sign Search page). KH-- calls were reserved, beginning in 1927, for a new service category: Commercial Aircraft Stations. Surprisingly this group included a short-lived broadcast authorization, KHAC, issued in late 1927 to Flying Broadcasters, Inc. in San Francisco, for "Airplane (unnamed)". The KI-- block was drafted in early 1932, which resulted in KIEV Glendale, California (now KRLA), followed over the next few years by such stations as KIUL Garden City, Kansas, KIUN Pecos, Texas, and KIUP Durango, Colorado.

[NOTE: Calls in the early twenties were assigned at the time an application, usually a "Form 761", was received in Washington, DC, not with the issuance of the first licence, which usually took place a number of days after the application was received. Thus, you must list these pioneers by call assignment rather than first licence date for the four-letter calls to line up alphabetically. For more information see the Call Assignment Date entries in the station list included in U.S. Pioneer Broadcast Service Stations: Actions Through June, 1922. Also, there is an anomaly in the assignment of W calls which may mean that WAAB was actually the second four-letter W call issued. Purdue University's application for a station in West Lafayette, Indiana was assigned WBAA on the same day, April 4th, that WAAB was assigned. No other WBA- calls were issued until two weeks later, after the WAA- calls had been exhausted. It is possible that the original plan was to start with WBA- calls, but after WBAA was issued the situation was reconsidered and the procession pulled back to start with the WAA- calls.]

Three-letter Calls After 1922

All broadcast station activity in three-letter calls did not cease following the 1922 switchover to four-letter calls, as about half of today's holders of three-letter calls trace their first assignment to later than 1922. In many cases these post-1922 calls were not the station's first, but were ones they changed to some years later. Some calls were claimed when a previously authorized broadcaster or other station expired. And many of these calls were specially requested to tie-in with a slogan or licencee name: "World's Largest Store" (Sears); "World's Greatest Harbor" (Norfolk, Virginia); "World's Greatest Newspaper" (Chicago Tribune); "Woodman Of the World"; "We Shield Millions" (National Life), etc. The last new three-letter call assignment, excluding reassignments of previously used calls or FM and TV sister stations, was WIS (now WVOC), "Wonderful Iodine State" in Columbia, South Carolina on January 23, 1930.

As noted by the 1914 edition of Radio Stations of the United States, the standard practice was to separate K and W calls, "with a few exceptions". Various exemptions over the years, combined with the 1923 boundary shift, mean that in some areas K and W calls have become intermingled. Some exceptions do not have an obvious cause. For example, there does not seem to be any particular reason why KQV Pittsburgh, KYW--originally in Chicago and now in Philadelphia--or KSD in Saint Louis (now KTRS) should have gotten K rather than W calls. It may be that a harried bureaucrat either momentarily forgot the policy or on which side of the boundary the station was located. One exception, however, apparently was made to have a little fun--short-lived KOP was licenced to the Detroit Police Department. [For more information on K/W call letter policy, check out K/W Call Letters In The United States.]

The June 30, 1931 edition of Commercial and Government Radio Stations of the United States listed 93 three-letter broadcasters out of a total of 631, about 15% of the stations. It was only in the post-World War II boom, when stations came to be counted in the thousands, that these calls have faded into relative obscurity, although their absolute numbers have not declined as much.

Actually new three-letter calls are still being assigned, although not for broadcast services. Their use is currently reserved for a service which dates back to the original 1912 assignments, Coastal Land Stations. However, even this group has threatened to exhaust the small allotment. Previously "Class 2" coastal stations were allowed to draw on the block. But an impending shortage forced the FCC to restrict these calls to only new stations of the "Class 1 (excluding Alaska)" classification, where the matter stands today.

Additional (Non-Broadcasting Service) Stations

There were also a handful of stations assigned three-letter calls which, although their activities included broadcasts, were never formally recognized by the U.S. government as being broadcasting stations. These include:
FM and TV Sister Stations

FM and TV were developed in the 1940s and 1950s, and obviously the new services needed callsigns. After a short period of requiring FM and TV stations to have unique calls, the FCC decided to allow stations in the same market to have the same call as sister AM stations, provided they added an "-FM" or "-TV" suffix. (These suffixed calls were technically five- and six- letters, counting the two letter suffix.) All FM and TV stations trace their three-letter calls back to an original AM station.

Until 1957, wherever you found an FM or TV station with a three-letter call, the original three-letter AM was still around. The first exception occurred as a result of the American Broadcasting Company's 1953 decision to change the calls of its New York City stations from WJZ (AM, FM, and TV) to WABC. This proved very traumatic to the Westinghouse Corporation, which had founded WJZ thirty-two years earlier in Newark, New Jersey. (In 1923 the station was moved to New York City and transferred to RCA, where it became the flagship for the NBC-Blue, later ABC, network.) Although FCC rules prohibited new three-letter calls, they didn't restrict new five-letter ones, so, four and one-half years after WJZ disappeared the FCC gave Westinghouse permission to rename its Baltimore, Maryland TV outlet "WJZ-TV". With this precedent a new chapter of callsign practice began. This was the first time permission was given by the FCC to reclaim a previously abandoned three-letter call. In addition, this was also the first case of an "independent" three-letter call, i.e. one that did not appear concurrently on any AM station. (WJZ eventually returned to the AM and FM bands in 2008, as sister stations in Baltimore to WJZ-TV). A year after the appearance of WJZ-TV the second "independent" appeared, when the University of Texas was granted permission for a new Educational FM station in Austin, Texas. The calls KUT-FM were assigned (another five-letter call), in honor of the original KUT, which the college had sold three decades previously, and which became KNOW (now KJFK) in 1932. Since then "independence" has become more common, for in addition to the total of 53 active AM three-letter calls as of January 1, 2025 there are 14 independents, for a total of 67 different three-letter calls on all bands.

NOTES: Some of these FM and TV stations, because there is no longer an AM station using the three-letter call, have gotten permission to drop their -FM and -TV suffixes, and been assigned true three-letter calls. In 1987 the rules were relaxed a little, and stations no longer have to be in the same market to use the same "base" (or "common") call. Although four-letter calls can now be shared by stations that do not have a common owner, three-letter calls are still limited to only being shared by stations with common owners. Calls are still restricted to just one station per band, with -FM and -TV suffixes added as needed. Finally, occasionally a confused person will claim that AM stations can get -AM suffixes. This is false. AM stations only get three- and four-letter calls--no AM station has ever been assigned an -AM suffixed call, although in informal usage people will sometimes include one.

Later Developments

Beginning in 1995, the FCC began allowing analog Low Power TV stations to have callsigns with "-LP" suffixes, and in 2001 Low Power FM stations were also allowed to request calls with the -LP suffix. In 2000 a new classification of "Class A" analog Low Power TV stations was added, and these stations could receive callsigns with a "-CA" suffix. Later, digital Low Power TV stations became eligible for an "-LD" suffix, with digital Class A TV stations allowed "-CD" suffixes. But so far all the basic calls for these stations have been four letters, so it doesn't appear that there will be any three-letter Low Power stations.

In 2009, all full-power analog TV stations were converted to Digital TV. During a transition period, the Digital TV stations were identified using -DT suffixed calls, with the base call staying the same as the one assigned to the analog sister station, e.g., WRC-DT was paired with WRC-TV, etc. With the termination of the analog stations in June, 2009, most digital TV stations inherited the calls formally used by their analog counterparts. However, the FCC announced that these stations could optionally request a change to a -DT suffix, and two three-letter broadcasters took the FCC up on its offer, resulting in WHO-DT and WOI-DT.

Conclusions

Some people, seeing the disappearance of three-letter calls from the AM band, have accused owners of not being historically minded. The opposite is true. When AM holdings are disposed, the very historically minded owners often keep the three-letter calls for their FM and TV stations. And the good news about this development is that there have only been three cases (KWK, KYA and WOW) where a three-letter call, saved as an independent, subsequently disappeared from the airwaves. So, what does the future hold? Well, if you like your three-letter calls on the original stations, it's bound to be bad. AM radio doesn't have the financial glamour it once did, and more AMs will be unloaded, with callsign custody often passing to the more prosperous FMs and TVs. Some missing calls might return -- the FCC has had a soft spot at times for prodigal sons. Below are the occasions when three-letter calls which had completely disappeared from the AM, FM and TV bands were allowed to return:

CallCall Completely
Disappeared		 Call
Reappeared		 Lapse Notes
KUT1/26/1932 8/21/195826½ years Returned to FM only
WHN9/15/1948 2/28/1962 13½ years Became WFAN 7/1/1987 (now WEPN)
WJZ3/1/1953 8/5/1957 4½ yearsReturned to TV only -- AM+FM added 11/3/2008
KYA6/29/1960 7/13/1960 2 weeks Became KOIT 12/13/1983 (now KSFB)
KRE4/29/1963 6/11/19729 years Became KBLX 8/13/1986 (now KVTO)
KDB10/12/1969 10/22/1969 10 days Became KSPE 9/8/1990 (now KOSJ)
WGH9/1/1983 12/10/1984 15 months  
KHJ12/2/1989 3/15/2000 11 years  


Unfortunately, the overall trend is for fewer three-letter calls, which is a shame. Below is a review of the number of three-letter calls in existence on various dates from January 1, 1922 through January 1, 2025, which chronicles a rapid rise, peaking at 185 active three-letter stations on May 10, 1922 (almost all broadcast stations at this date had three-letter calls), then a decline through 1926, caused by high station mortality and the switch to mostly four-letter calls, followed by a small rally through 1930 due to specially requested calls, closing with a slow attrition over the remaining decades, as the government no longer issued new three-letter call to broadcast stations:

DateAM Band DateAM BandOnly on
FM or TV		 Total Unique
on All Bands
1/1/1922 281/1/1950 80 0 80
5/10/19221851/1/1960 77 2 79
1/1/1923 1601/1/1970 77 2 79
1/1/1924 981/1/1980 75 3 78
1/1/1925 891/1/1990 60 11 71
1/1/1926 771/1/1995 57 12 69
8/1/1926 731/1/2000 55 14 69
1/1/1927 811/1/2005 55 14 69
1/1/1928 851/1/2010 57 12 69
1/1/1929 921/1/2015 54 14 68
1/1/1930 941/1/2020 54 14 68
1/1/1940 861/1/2025 53 14 67



Current Three-letter Calls

The map below all 67 unique three-letter calls in use as of January 1, 2025. The 53 calls in black are still held by the original or a related AM station (some of these calls are also used by related FM and TV stations), while the 14 calls in red have disappeared from the AM band, but continue to be used by related FM or TV stations--KUT (FM), WRR (FM), WRC-TV, KHQ-TV, WJW (TV), KOB-TV, WIS (TV), KDB (FM), KGW (TV), KSD (FM), WIL-FM, KXL-FM, WIP-FM, KLO-FM and KGO-TV.

CURRENT THREE-LETTER MAP
67 Current Three-Letter Calls in the United States as of January 1, 2025

Three-letter Callsigns as of January 1, 2025

The following list includes all 101 three-letter calls in use as of January 1, 2025. The first three columns list information on AM-band stations, which in all cases were the original holders of the three-letter call, athough WJZ and KGB were originally held by other AM stations. The "Call" column lists the current call of the original station, with stations that have dropped their three-letter call listed in parentheses and in lowercase. The "first" column notes the first date that the station used the three-letter call for a broadcasting service authorization. (An "*" marks stations where this three-letter call was a call change for an existing station, and thus was not the first call the station had.) An entry in the "last" column notes change-over dates in cases where the AM station no longer holds the three-letter call. (In the case of WIL, the AM station that originally held this call sign was deleted, as KZQZ, on March 20, 2020).

The "FM" and "TV" columns list stations in these services which currently hold three- (or five-) letter calls. 

AM (Original Call Holder)
=============================
Call   First       Last        FM       TV       CITY
=====  ==========  ==========  =======  =======  =================
(kosj) 01/09/1929* 09/08/1990  KDB      --       Santa Barbara, CA
KEX    12/23/1926              --       --       Portland, OR
KFH    12/--/1925*             --       --       Wichita, KS
KFI    03/31/1922              --       --       Los Angeles, CA
KGA    02/04/1927              --       --       Spokane, WA
KGB    07/04/2020*             KGB-FM   --       San Diego, CA
(ksfo) 01/22/1924  01/01/2025  --       KGO-TV   San Francisco, CA
KGU    03/14/1922              KGU-FM   --       Honolulu, HI
(kpoj) 03/21/1922  03/01/1993  --       KGW      Portland, OR
KHJ    03/18/1922              --       --       Los Angeles, CA
(kqnt) 02/28/1922  01/07/1985  --       KHQ-TV   Spokane, WA
KIT    03/22/1929*             --       --       Yakima, WA
KJR    03/09/1922              KJR-FM   --       Seattle, WA
(kmes) 04/11/1929* 11/03/2020  KLO-FM   --       Ogden, UT
KLZ    03/10/1922              --       --       Denver, CO
KMA    08/12/1925              KMA-FM   --       Shenandoah, IA
KMJ    03/23/1922              KMJ-FM   --       Fresno, CA
KNX    05/04/1922*             KNX-FM   --       Los Angeles, CA
KOA    12/13/1924              --       --       Denver, CO
(kkob) 04/05/1922  10/28/1986  --       KOB      Albuquerque, NM
KOY    02/08/1929*             --       --       Phoenix, AZ
KPQ    05/02/1928*             KPQ-FM   --       Wenatchee, WA
KQV    01/09/1922              --       --       Pittsburgh, PA
(ktrs) 03/14/1922  03/10/1997  KSD      --       Saint Louis, MO
KSL    03/24/1925*             KSL-FM   KSL-TV   Salt Lake City, UT
KUJ    12/--/1926*             KUJ-FM   --       Walla Walla, WA
(kjfk) 10/30/1925* 01/26/1932  KUT      --       Austin, TX
KVI    11/24/1926              --       --       Seattle, WA
KWG    12/07/1921              --       --       Stockton, CA
(kxtg) 11/27/1926  06/01/2011  KXL-FM   --       Portland, OR
KXO    11/11/1928*             KXO-FM   --       El Centro, CA
KYW    11/15/1921              --       KYW-TV   Philadelphia, PA
WBT    03/18/1922              WBT-FM   --       Charlotte, NC
WBZ    09/15/1921              WBZ-FM   WBZ-TV   Boston, MA
WDZ    04/05/1922              --       --       Decatur, IL
WEW    03/23/1922              --       --       Saint Louis, MO
WGH    11/20/1928*             WGH-FM   --       Newport News, VA
WGL    11/11/1928*             --       --       Fort Wayne, IN
WGN    03/28/1924*             --       WGN-TV   Chicago, IL
WGR    03/14/1922              --       --       Buffalo, NY
WGY    02/04/1922              WGY-FM   --       Schenectady, NY
WHA    01/13/1922              --       WHA-TV   Madison, WI
WHB    05/10/1922              --       --       Kansas City, MO
WHK    02/21/1922              --       --       Cleveland, OH
WHO    04/15/1924              --       WHO-DT   Des Moines, IA
WHP    03/16/1929*             --       WHP-TV   Harrisburg, PA
(kzqz) 01/--/1925* 03/05/2008  WIL-FM   --       Saint Louis, MO
(wtel) 03/20/1922  12/01/2014  WIP-FM   --       Philadelphia, PA
(wvoc) 01/23/1930* 12/31/1986  --       WIS      Columbia, SC
WJR    08/20/1925*             --       --       Detroit, MI
(wknr) 05/09/1929* 06/11/1985  --       WJW      Cleveland, OH
WJZ    11/03/2008*             WJZ-FM   WJZ-TV   Baltimore, MD
WKY    03/16/1922              --       --       Oklahoma City, OK
WLS    04/11/1924              WLS-FM   WLS-TV   Chicago, IL
WLW    03/02/1922              --       --       Cincinnati, OH
WMC    01/19/1923              --       WMC-TV   Memphis, TN
WMT    11/11/1928*             --       --       Cedar Rapids, IA
WOC    02/18/1922              --       --       Davenport, IA
WOI    04/28/1922              WOI-FM   WOI-DT   Ames, IA
WOL    11/11/1928*             --       --       Washington, DC
WOR    02/20/1922              --       --       New York, NY
(wtem) 06/28/1923  02/27/1984  --       WRC-TV   Washington, DC
(ktck) 03/13/1922  04/14/1978  WRR      --       Dallas, TX
WSB    03/15/1922              WSB-FM   WSB-TV   Atlanta, GA
WSM    10/05/1925              WSM-FM   --       Nashville, TN
WWJ    03/03/1922*             --       WWJ-TV   Detroit, MI
WWL    03/30/1922              WWL-FM   WWL-TV   New Orleans, LA
=====                          ======   ======   ================
52 AM (23 K's, 29 W's)         28 FM    21 TV    101 total three-
                                                 letter stations
=================================================================
Three-letter call assignments:
25 AM-only
 8 FM-only
 7 TV-only
13 AM/FM
 7 AM/TV
 7 AM/FM/TV
== =====================
67 Unique Calls (32 K's, 35 W's)


Historical Recap: April 11, 1929 - January 1, 2025

Following is an overview of three-letter calls in use since April 11, 1929, a date when the industry had somewhat stabilized after the chaotic earlier part of the decade.

Since April 1929, 29 calls have completely disappeared from the airwaves--the map below shows the former location of these call signs. Six calls are gone due to station deletions--WRK (1930), KZM (1931), WNJ (1933), WOQ (1934), WOS (1936) and KID (2023), listed in red in the map--while the other 23, listed in black, have disappeared due to call changes and station consolidations: WCX (1929), WFI (1935), KTM (1935), KVL (1936), WPG (1940), WLB (1945), KLS (1945), KPO (1947), KQW (1949), KLX (1959), WOV (1959), KTW (1975), KOL (1975), KMO (1983), KXA (1986), KRE (1986), WHN (1987), KWK (1988), KSO (1989), KOH (1994), KYA (1994), WOW (2000) and KGY (2014).

GONE THREE-LETTER SINCE APRIL 1929
29 Three-letter Calls Which Have Completely Disappeared Since April 1929

Major AM Three-letter Call Actions: April 11, 1929 - January 1, 2025

The list below recaps the significant AM three-letter call actions from April 11, 1929 through January 1, 2025. [NOTE: For a fuller review, of all the actions starting in 1921, see: Three-Letter Roll Call] As of that date there were 94 three-letter calls, all on the AM band (FM and TV stations didn't exist yet). Since then the number of three-letter calls on the AM band has declined by 41, to 53. However, 14 of the calls which have disappeared from the AM band still are used by FM or TV stations, so reviewing all stations, the number of surviving unique three-letter calls is currently 67.

"Total on AM" is the number of three-letter calls on the AM band after the action took place. "Not on AM" is the number of "independent" three-letter calls, i.e. held only by an FM or TV station after being given up by the original AM station. "All Bands" is the total number of unique three-letter calls in use on AM, FM and TV, i.e. "Total on AM" plus "Not on AM". 

                                                                   Total
                                                                   on AM
                                                                   =====
04/11/1929 KLO OGDEN, UT. Call changed from KFUR (see 11/03/2020)     94
04/22/1929 WCX PONTIAC, MI. Call sign deleted [WJR-WCX became WJR]    93
05/09/1929 WJW MANSFIELD, OH. Call changed from WLBV (see 6/11/1985)  94
12/16/1929 KUT AUSTIN, TX. Station became KTRH-Houston, KUT call      94
               call given to x-KDGR, which moved from San Antonio
               to Austin (see 1/26/1932)
01/23/1930 WIS COLUMBIA, SC. Call changed from WGTB (see 12/31/1986)  95
09/29/1930 WRK HAMILTON, OH. Station deleted.                         94
06/23/1931 KZM HAYWARD, CA. Station deleted.                          93
01/26/1932 KUT AUSTIN, TX became KNOW (now KJFK -- see 8/21/1958)     92
05/09/1932 WOC DAVENPORT, IA consolidated with WHO Des Moines         92
               as WHO-WOC (see 11/11/1934)
06/02/1933 WNJ NEWARK, NJ. Station deleted.                           91
06/14/1934 WOQ KANSAS CITY, MO.  Station deleted.                     90
11/11/1934 WOC DAVENPORT, IA. Call split-off from WHO-WOC             90
               Des Moines, moved to x-KICK Davenport (see 5/9/1932)
12/03/1934 KYW CHICAGO, IL station moved to Philadelphia, PA          90
               (see 2/13/1956)
01/21/1935 WFI PHILADELPHIA, PA. Station consolidated with WLIT       89
               as WFIL
03/17/1935 KSO DES MOINES, IA. Called transferred to x-KWCR,          89
               old KSO became KRNT (see 9/11/1989)
05/06/1935 KTM LOS ANGELES, CA became KEHE (now KABC)                 88
03/27/1936 WOS JEFFERSON CITY, MO. Station deleted.                   87
12/15/1936 KVL SEATTLE, WA became KEEN (now KPTR)                     86
01/03/1940 WPG ATLANTIC CITY, NJ consolidated with WBIL and WOV       85
               as "new" WOV (see 11/12/1941)
01/28/1941 WOR NEWARK, NJ. Station moved to New York, NY              85
11/12/1941 WOV NEW YORK, NY swapped calls with WNEW                   85
               (now WBBR--see 11/1/1959)
05/06/1944 KJR SEATTLE, WA swapped calls with KOMO                    85
06/01/1945 WLB MINNEAPOLIS, MN became KUOM                            84
09/10/1945 KLS OAKLAND, CA became KWBR (now KMKY)                     83
11/12/1947 KPO SAN FRANCISCO, CA became KNBC (now KNBR)               82
09/15/1948 WHN NEW YORK, NY became WMGM (see 2/28/1962)               81
04/03/1949 KQW SAN FRANCISCO, CA became KCBS                          80
02/20/1950 WOL WASHINGTON, DC swapped calls with WWDC (now WQOF)      80
03/01/1953 WJZ NEW YORK, NY became WABC (see 8/5/1957)                79
02/13/1956 KYW PHILADELPHIA, PA. Call moved to x-WTAM Cleveland, OH   79
               (x-KYW in Philadelphia became WRCV -- see 6/19/1965)


                                                                          Not 
                                                                   Total   on  All
                                                                   on AM   AM Bands
                                                                   ===== ==== =====
08/05/1957 WJZ BALTIMORE, MD. Call reactivated for TV station         79    1   80
               (see 3/1/1953, 11/3/2008)
08/21/1958 KUT AUSTIN, TX. Call reactivated for FM station            79    2   81
               (see 1/26/1932)
06/07/1959 KLX OAKLAND, CA became KEWB (now KKSF)                     78    2   80
11/01/1959 WOV NEW YORK, NY became WADO (see 11/12/1941)              77    2   79
06/29/1960 KYA SAN FRANCISCO, CA became KDBQ (see next)               76    2   78
07/13/1960 KYA SAN FRANCISCO, CA returns from KDBQ (prev.)            77    2   79
02/28/1962 WHN NEW YORK, NY returns from WMGM (see 9/15/1948 and      78    2   80
               7/1/1987)
04/29/1963 KRE BERKELEY, CA became KPAT (see 6/11/1972)               77    2   79
06/19/1965 KYW CLEVELAND, OH. Call returned to Philadelphia           77    2   79
               (x-KYW became WKYC, now WTAM--see 2/13/1956)
10/12/1969 KDB SANTA BARBARA, CA became KAPN (FM retains three-       76    3   79
               letter call -- see next)
10/22/1969 KDB SANTA BARBARA, CA returns from KAPN (see 9/8/1990)     77    2   79
06/11/1972 KRE BERKELEY, CA returns from KPAT (see 4/29/1963,         78    2   80
               8/13/1986)
08/30/1975 KTW SEATTLE, WA became KYAC (now KKDZ)                     77    2   79
09/01/1975 KOL SEATTLE, WA became KMPS (now KKOL)                     76    2   78
04/14/1978 WRR DALLAS, TX became KAAM (now KTCK -- FM retains call)   75    3   78
03/15/1982 KGB SAN DIEGO, CA became KCNN (now KLSD -- FM retains call)74    4   78
04/18/1983 KMO TACOMA, WA became KAMT (now KKMO)                      73    4   77
09/01/1983 WGH NEWPORT NEWS, VA became WNSY -- see 12/10/1984         72    4   76
12/13/1983 KYA SAN FRANCISCO, CA became KOIT (now KSFB) (FM retains   71    5   76
               -- see 3/27/1994)
02/27/1984 WRC WASHINGTON, DC became WWRC (now WTEM -- TV retains)    70    6   76
03/19/1984 KSD SAINT LOUIS, MO became KUSA (FM retains call --        69    7   76
               see 10/4/1993)
06/01/1984 KWK SAINT LOUIS, MO became KGLD (now KXFN -- FM retains    68    8   76
               call -- see 2/29/1988)
12/10/1984 WGH NEWPORT NEWS, VA returns from WNSY (see 9/1/1983)      69    8   77
01/07/1985 KHQ SPOKANE, WA became KLSN (now KQNT -- TV retains call)  68    9   77
06/11/1985 WJW CLEVELAND, OH became WRMR (now WKNR -- TV retains call)67   10   77
02/01/1986 KHJ LOS ANGELES, CA became KRTH (TV retains call -- see    66   11   77
               12/2/1989, 3/15/2000)
04/11/1986 KXA SEATTLE, WA became KRPM (now KTTH)                     65   11   76
08/13/1986 KRE BERKELEY, CA became KBLX (now KVTO -- see 4/29/1963,   64   11   75
               6/11/1972)
10/28/1986 KOB ALBUQUERQUE, NM became KKOB (TV retains call)          63   12   75
12/31/1986 WIS COLUMBIA, SC became WVOC (TV retains call)             62   13   75
07/01/1987 WHN NEW YORK, NY became WFAN (now WEPN)                    61   13   74
02/29/1988 KWK SAINT LOUIS, MO. KWK-FM drops 3-letter call            61   12   73
09/11/1989 KSO DES MOINES, IA became KGGO (now KXNO)                  60   12   72
12/02/1989 KHJ LOS ANGELES, CA. KHJ-TV drops 3-letter call (see       60   11   71
               2/1/1986, 3/15/2000)
09/08/1990 KDB SANTA BARBARA, CA became KSPE (now KOSJ)(FM retains)   59   12   71
12/04/1990 WIL SAINT LOUIS, MO became WRTH (FM retains call -- see    58   13   71
               6/29/2005) 
03/01/1993 KGW PORTLAND, OR became KINK (now KPOJ -- TV retains call) 57   14   71
10/04/1993 KSD SAINT LOUIS, MO returns from KUSA (see 3/19/1984,      58   13   71
               3/10/1997)
03/10/1994 KOH RENO, NV became KRCV (now KPLY)                        57   13   70
03/27/1994 KYA SAN FRANCISCO, CA. KYA-FM drops call                   57   12   69
03/10/1997 KSD SAINT LOUIS, MO became KTRS (FM retains call -- see    56   13   69  
               10/4/1993)                                 
10/17/1997 WHB KANSAS CITY, MO swapped calls with KCMO                56   13   69
05/07/1999 KOY PHOENIX, AZ. Call transferred to x-KISO, x-KOY became  56   13   69
               KGME (now KFYI)
11/22/1999 WOW OMAHA, NE became KOMJ (now KXSP) (FM retains call --   55   14   69 
               see 10/9/2000)
03/15/2000 KHJ LOS ANGELES, CA returns from KKHJ (see 12/2/1989)      56   14   70 
10/09/2000 WOW OMAHA, NE. WOW-FM drops call (see 11/22/1999)          56   13   69
02/26/2001 WHK PARMA, OH. Call transferred to x-WCCD, x-WHK became    56   13   69  
               WHKK (now WHK). (see next) 
08/03/2001 WHK CLEVELAND, OH. Call transferred to x-WHKC (now WHKW),  56   13   69
               x-WHK Parma returns to WCCD(see previous, 4/5/2005)
08/30/2004 KFH WICHITA, KS. Swapped calls with KNSS                   56   13   69
12/06/2004 WGH NEWPORT NEWS, VA became WCMS (FM retains--see 7/1/2005)55   14   69
04/05/2005 WHK CLEVELAND, OH call transferred to x-WRMR, x-WHK became 55   14   69
               WHKZ (now WHKW). (see 8/3/2001)
06/29/2005 WIL SAINT LOUIS, MO returns from WRTH (see 12/4/1990,      56   13   69 
               3/5/2008)
07/01/2005 WGH NEWPORT NEWS, VA returns from WCMS (see 12/6/2004)     57   12   69
03/05/2008 WIL SAINT LOUIS, MO became KZQZ (deleted 3/20/2020)        56   13   69
               (FM retains call-see 6/29/2005)    
11/03/2008 WJZ BALTIMORE, MD changed call from WJFK (see 8/5/1957)    57   12   69
06/01/2011 KXL PORTLAND, OR became KXTG (FM retains call)             56   13   69
11/06/2014 KGY OLYMPIA, WA became KBUP                                55   13   68
12/01/2014 WIP PHILADELPHIA, PA became WTEL (FM retains)              54   14   68
07/04/2020 KGB SAN DIEGO, CA changed call from KFMB                   55   13   68
11/03/2020 KLO OGDEN, UT changed call to KMES (FM retains -- see      54   14   68  
               04/11/1929)
12/21/2021 KNX LOS ANGELES, CA. KNUS (FM) became KNX-FM               54   14   68
03/03/2023 KID IDAHO FALLS, ID. Station deleted                       53   14   67
01/01/2025 KGO SAN FRANCISCO, CA. Became KSFO (TV retains)            52   15   67